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Special histology
Central and peripheral nervous system
Cardiovascular system
Blood and the bone marrow
The immune system and lymphoid organs
The digestive system
Organs associated with the digestive system
The respiratory system
The skin and its derivates
The urinary system
The endocrine system
The male reproductive system
The female reproductive system
Organs of special sense
The central and peripheral nervous system
The central nervous system
The specimen is the spinal cord, medulla spinalis (HE). On a cross-section of the spinal cord, the central canal can be seen. The central canal is lined by a single layer of cubic ependymal cells - specialized glial cells. Surrounding this canal an area of gray matter can be seen, while the white matter is located peripherally. In the gray matter, there are perikaryons of multipolar nerve cells, with a clearly visible nucleus and basophilic cytoplasm filled with Nissl bodies or tigroid (clusters of granular endoplasmic reticulum). Around the perikaryon is the neuropil, which consists of a network of nerve fibers, glial cells (microglia, astrocytes, oligodendrocytes) and blood capillaries. In the white matter area, we find myelinated nerve fibers, some glial cells and capillaries. Since myelin is dissolved during the preparation of the preparation, the fibers are surrounded by white (empty) space.
The specimen is the spinal cord, medulla spinalis (silver impregnation). On a cross-section of the spinal cord, the central canal of the spinal cord can be seen, surrounded by an area of gray matter, while the white matter is located peripherally. In the gray matter, there are darkly stained perikaryons of multipolar nerve cells with a light-colored nuclear area. Around the perikaryon is the neuropil, which consists of a network of black-stained nerve fibers, the nuclei of glial cells (microglia, astrocytes, oligodendrocytes) and blood capillaries. In the white matter area, we find myelinated nerve fibers, some glial cells and capillaries.
The specimen is a cross-section through the small brain or cerebellum (HE). At low magnification, the folds (sulci and gyri) of the cerebellum can be seen, as well as the arrangement of gray and white matter within them. These resemble a branched tree crown and is therefore also called the tree of life or arbor vitae. The surface of the cerebellum is covered with a soft meningeal membrane - the pia mater. At its surface is the cortex or gray matter, made up of three well-defined layers (going from the surface inwards): the molecular layer (stratum moleculare) the Purkinje cell layer (stratum gangliosum) and the granular layer (stratum granulosum). In the molecular layer, the nuclei of basket and stellate cells and the neuropil - a dense network of fibers of the cells of the molecular layer as well as the fibers of the cells located in the granular layer and the dendrites of the Purkinje cells are visible. The stratum gangliosum is made up of one layer of large Purkinje cells whose dendrites branch in the molecular layer, and the axon goes into the granular layer. The granular layer is made up of numerous granular and Golgi cells as well as nerve fibers. In some places between the perikaryons of the cells there are areas without cells called parenchymatous islands or glomerula cerebellaria. They represent the sites of synapses of the cells of the cerebellar cortex with fibers coming from the white matter. Throughout the gray matter we find numerous blood capillaries. In the white matter area we find myelinated nerve fibers, some glial cells and capillaries. As the myelin is dissolved during the preparation of the specimen, the fibers are surrounded by white space..
The preparation is a cross-section through the small brain or cerebellum (silver impregnation). At low magnification, the furrows and convolutions, sulci and gyri of the cerebellum can be seen, as well as a certain arrangement of gray and white matter within them, which resembles a branched tree crown and is called the tree of life or arbor vitae. The surface of the cerebellum is covered with a soft meningeal membrane - the pia mater. O At its surface is the cortex or gray matter, made up of three well-defined layers (going from the surface inwards): the molecular layer (stratum moleculare) the Purkinje cell layer (stratum gangliosum) and the granular layer (stratum granulosum). In the molecular layer, the nuclei of basket and stellate cells and the neuropil - a dense network of fibers of the molecular layer cells as well as the fibers of the cells located in the granular layer and the dendrites of the Purkinje cells are visible. The stratum gangliosum consists of one layer of large Purkinje cells whose dendrites branch in the molecular layer and the axon goes into the granular layer. At high magnification, you can see the "baskets" surrounding the Purkinje cells. These are collateral shoots of the axons of the basket cells that form networks around the perikaryon of the Purkinje cells. The fibers are easily visible because they are colored black with this staining method. The granular layer is made up of numerous granular and Golgi cells as well as nerve fibers. Numerous blood capillaries are found throughout the gray matter. Myelinated nerve fibers are found in the white matter, which is stained dark brown to black with this method, so that the entire white matter area appears dark.
The preparation is a part of the large brain, the cerebrum (HE). The greater part of the preparation is made up of the cerebral cortex, made up of gray matter with numerous perikaryons of nerve cells. There are pyramidal and non-pyramidal neurons (granular, stellate, horizontal cells) arranged in six layers that cannot be differentiated well on the preparation. These are, from the surface to the inside: lamina molecularis, lamina granularis externa, lamina pyramidalis externa, lamina granularis interna, lamina pyramidalis interna and lamina multiformis. At high magnification, the triangular appearance of pyramidal neurons can be seen, from the base of which the axon emerges, and from the sides the dendrites. On part of the preparation, white matter or medulla made up of myelinated nerve fibers can be seen. Since myelin is dissolved during preparation of the preparation, the fibers are surrounded by white (empty) space. Throughout the specimen, we find a large number of blood capillaries.
The cardiovascular system
The heart
The specimen is the inner part of the heart wall, the endocardium (HE). The endocardium consists of the endothelium with its supporting connective tissue, a middle myoelastic layer of smooth muscle cells and elastic connective tissue and a subendocardial layer of connective tissue. The endocardium is connected to the heart muscle, the myocardium, by the subendocardial connective tissue in which large, bright Purkinje cells belonging to the cardiac conduction musculature can be seen. The myocardium is the layer of the heart made up of the working musculature of the heart (cross-sectioned cardiac muscle fibers). In this specimen, a purkinje fiber can be seen to deeply enter the myocardium. The myocardium is highly nutrient and oxygen-intensive and the endomysium therefore contains a large number of blood capillaries.
The specimen is the outer part of the heart wall, the epicardium (HE). The epicardium covers the outer surface of the heart and forms the visceral layer of the pericardium. It is covered by mesothelium, under which connective tissue with numerous blood vessels, nerves and ganglia can be seen. Under the epicardium is adipose tissue, the so-called subepicardial fat tissue. The connective tissue enters the middle, muscular layer of the heart, the myocardium, alongside the larger blood vessels.
Blood vessels
The specimen is a cross-section of an artery, vein and (small) nerve (HE). The wall of an artery is made up of 1. the tunica intima: a layer of endothelium, a subendothelial layer of loose connective tissue of the lamina propria and a wavy, red-stained elastic membrane (membrana elastica interna; difficulat to discern on this specimen, but it can be clearly seen in Blood vessel II). 2. tunica media; a collection of thick bundles of smooth muscle cells. 3. tunica externa/adventicia; a layer of loose connective tissue via which the artery is connected with its surrounding tissues. In addition, a large vein can be seen. Its wall is made up of the same layers as the arteries. However, veins do not have the thick elastic layer in the tunica intima. Also, typically the tunica media is much thinner, whereas the adventicia is thicker. Veins also usually have a larger lumen. Vains also have valves to prevent blood from flowing back, but this cannot be seen on this specimen. A small nerve surrounded by connective tissue is also visible in cross-section on the preparation.
The specimen is a cross-section of an artery, vein, and nerve (HE). This slide shows similar histological structures as the previous one, but with a much larger nerve, allowing the distinction between the perineurium surrounding nerve bundles and the epineurium surrounding the entire nerve. At the top of the specimen, in the vein bordering the nerve, we can see a valve. Finally, we can clearly see the thick meandering elastic layer in the tunica intima of the artery.
The specimen is a cross-section of an elastic artery (orcein). The wall of the artery is made up of the tunica intima: a layer of endothelium, loose connective tissue of the lamina propria, and a wavy, darker brown colored elastic membrane (membrana elastica interna); tunica media: thick bundles of weakly stained smooth muscle cells separated from the next layer by a dark, wavy membrane (membrana elastica externa). Elastic arteries are characterized by a large number of elastic fibers, which arise from smooth muscle cells in this layer; tunica externa: a layer of loose connective tissue with which the artery has grown to the environment. Small veins can also be seen at the bottom of the specimen. Clearly, the tunica intima of these structures contain much less elastic fibers.
Blood and the bone marrow
Blood
The specimen is a blood smear (May-Grunwald-Giemsa). In addition to a large number of red blood cells - erythrocytes, white blood cells - leukocytes can be seen on the preparation, which can be segregated in granulocytes (neutrophils, basophils, eosinophils) and agranulocytes (monocytes, lymphocytes). Individual clusters of blood platelets - thrombocytes can also be seen on the preparation as small purple spots. Erythrocytes are biconcave discs without a nucleus. Neutrophils are cells with a segmented nucleus of which the granules do not stain. Therefore, their cytoplasm is clear or light basophilic. Basophils are rare cells with a segmented nucleus, eosinophilic cytoplasm, and blue-stained granules. Eosinophils are rare cells with a segmented nucleus, eosinophilic cytoplasm, and red-stained granules. Monocytes are large cells with a kidney-shaped nucleus and basophilic cytoplasm. Lymphocytes are small cells with a large round nucleus surrounded by a small rim of basophilic cytoplasm.
The bone marrow
The specimen is red bone marrow, medulla ossium rubra (decalcified, HE). In the specimen, red bone marrow can be seen between the pink-stained bone beds. The marrow is made of stroma (reticular cells and fibers), which in the preparation is covered with hematopoietic threads from different developmental stages of erythrocytes and leukocytes. At higher magnification, large birght pink multinuclear cells can be seen. These are megakaryocytes, which do not enter the bloodstream, but release platelets into the sinusoids. A greater number of sinusoidal capillaries and adipocytes can be seen in the specimen.
The specimen is a cross-section of the epiphyseal plate of a long bone (HE). Hematopoiesis takes place between the trabecular bone on both sides of the epiphyseal plate. However, the bone marrow on the left side of the preparation mainly contains adipocytes with rare hematopoietic islands. The tissue on the right side contains adipocytes, but also numerous cells from the hematopoietic lineage. This specimen also clearly shows some wide blood vessels, the sinusoidal capillaries, which allow the emigration of mature blood cells from the bone marrow.
The immune system and the lymphoid organs
Primary lymphoid organs
The specimen is red bone marrow, medulla ossium rubra (decalcified, HE). In the specimen, red bone marrow can be seen between the pink-stained bone beds. The marrow is made of stroma (reticular cells and fibers), which in the preparation is covered with hematopoietic threads from different developmental stages of erythrocytes and leukocytes. At higher magnification, large birght pink multinuclear cells can be seen. These are megakaryocytes, which do not enter the bloodstream, but release platelets into the sinusoids. A greater number of sinusoidal capillaries and adipocytes can be seen in the specimen. In the bone marrow, all cells from the immune system are formed, except mature T cells. Therefore the bone marrow is a primary lymphoid organ.
The specimen shows the thymus, thymus (HE). In the preparation, the thymic lobes can be seen separated by dense connective tissue. At low magnification one can see that each lobe consists of a peripheral darker part (the cortex), and a central lighter part (the medulla). Both areas contain a dense stroma of epithelial reticular cells. These cells are stellate in shape and have light, oval nuclei. The majority of cells are immature T cells, or thymocytes. These are significantly more numerous in the cortex, which is why it stains more darkly. In the medulla we find red-stained Hassall corpuscles of flattened reticular epithelial cells filled with keratohyaline granules. The thymus is the only organ in the body that generates mature T cells. Therefore, the thymus is a primary lymphoid organ.
Secondary lymphoid organs
The specimen is a lymph node, nodus lymphaticus (HE). The lymph node is surrounded by a connective tissue capsule from which trabeculae extend inwards. The parenchyma is divided into a cortex and a medulla. The capsule is separated from the cortex by a lighter area of subcapsular sinuses. These are areas where lymph from afferent lymphatic vessels collects before it enters the lymph nodes. Afferent lymphatic vessels are usually lost during isolation of the organ. The subcapsular sinuses continue into the intermediate sinuses, which follow the course of the trabeculae consisting of dense connective tissue and drain into the medulla. The cortex consists of two parts: the outer and inner cortex. The outer cortex contains B cells, whereas the inner cortex contains B cells. Only the B cells can form secondary lympoid follicles, visible as ball-like structures with a lighter and a darker area, which are temporary structures in which B cells of high antigen affinity are selected. Both the inner and outer cortex contain a network of reticular cells and fibers. The medulla is made up of medullary strands of lymphatic tissue and medullary sinuses, both of which contain many lymphocytes, plasma cells and myeloid cells. Lymph is finally collected in the hilus, which drains into the efferent lymphatic vessel.
The specimen is the spleen, lien (HE). The spleen is covered by a thick outer capsule of dense connective tissue. A number of trabeculae, also consisting of dense connective tissue, enter the parenchyma or pulp of the spleen from capsule. The parenchyma consists of a red and white pulp. The white pulp consists of a central artery with a sheath of lymphatic tissue (periarterial lymphatic sheath, PALS). The inner sheath consists of T cells, whereas the outer sheath is made up of B cells. Surrounding the PALS is a thin margnial zone containing large blood vessels, or sinuses, from which specialized antigen-presenting cells capture blood-borne antigens. If there is a secondary lymph node within the white pulp, this structure is called a Malpighian corpuscle. Between the white pulp we can find the red pulp, consisting of Billroth's tracks. The red pulp also contain numerous venous sinuses, which are involved in the capture and elimination of old (effete) red blood cells. In this specimen, the red pulp is much more pronounced than the white pulp.
The specimen is a lingual tonsil, tonsilla lingualis (HE). At the surface of the specimen, towards the lumen, a multilayered squamous epithelium is visible, which invaginates into the lamina propria, forming crypts. The lamina propria is almost completely made up of lymphocytes. Whereas they can be segregated into B and T cell zones using immuno-histochemistry, they do not form an inner and outer cortex as in the lymph node. Various secondary lymph nodes can be seen in the B cell zones. At the bottom of the crypts, lymphocytes can be found to infiltrate the the epithelium.The lower part of the tonsil is defined by a thick capsule of dense irregular connective tissue, which reaches all around the tonsil up to the squamous stratified epithelium of the oral cavity.
Tonsil II - Longitudinal section
This slide also shows the lingual tonsils (HE). However, this slide is cut longitudinally, which shows the crypts as cavities in the middle of the tissue. We can also see some skeletal muscle tissue and a mucous salivary gland in this specimen.
The specimen is a cross-section of the appendix, appendix vermiformis (HE). This structure is part of the colon, but is considered an immunological organ. It has a narrow and irregular lumen. The mucosa is made up of simple columnar epithelium that invaginates into the lamina propria, forming simple tubular glands, or crypts oif Lieberkühn, which are highly numerous in the rest of the large intestine. The lamina propria is filled with a large amount of lymphocytes that extend into the submucosa. The submucosa, tella submucosa, is made up of well-developed connective tissue. The tunica muscularis, the muscle layer, is made up of bundles of smooth muscle fibers in two layers (inner circular and outer longitudinal). The surface of the appendix is made up by a tunica serosa.
The digestive system
The oral cavity
The specimen is the lip, labium (HE). The outer surface of the lip is covered with stratified squamous keratinized epithelium, or thin skin. There are also longitudinally cut hairs, pili, which grow from follicles in the dermis. Attached to the hear sheath, we can see several small sebaceous glands, gll. sebaceae, which release sebum in this canal. The inner surface of the lip is covered with stratified squamous pseudo-keratinized or non-keratinized epithelium. Mucous glands, gll. labiales, are located in the connective tissue of the lamina propria. The border between the keratinized and non-keratinized epithelium is a sharp line on the red edge of the lip. In this place, the connective tissue papillae are extremely deep, and the blood vessels are located close to the surface of the epithelium, giving the lips their characteristic red color.
The specimen is the lip, labium (HE). This preparation is darker in color then Lip-I, which allows for better observation of the musculature.
The specimen is the upper surface of the tongue, dorsum linguae (HE). It is covered with squamous, keratinized epithelium lying on a lamina propria. The protrusions of the lamina propria are the lingual papillae - papillae linguales. The tongue contains four types of papillae (i.e. Filiform, fungiform, foliate and vallate). This specimen shows densely arranged filamentous papillae - papillae filiformes, which are heavily keratinized, especially at their tips. During preparation of the specimen, much of the dead keratinized layer is lost, which is why we see it only at the tips of the papillae as bright pink coverings. The papillae filiform provide a rough surface that facilitates
movement of food during chewing. For this reason, the epithlium and underlying lamina propria are heavily folded in ridges and papillae to provide stronger adhesion between the layers. Beneath the mucosa, mostly in the submucosa, we find both serous and mucous glands. Underneath, we observe a very thick layer bundles of skeletal muscle arranged in multiple directions, which allows extensive manipulation of food entering the oral cavity.
The specimen is the upper surface of the tongue, dorsum linguae (HE). It shows the dorsal end of the tongue, where we find much fewer filliform papillae and instead, we observe pseudostratified epithelium. This speciment shows the 'walled' papilla - papilla vallata. The papilla is mushroom-shaped, and is surrounded by a fold, or wall, which gives the papilla its name. This wall raises the papilla above the level of the surrounding mucous membrane and is covered with pseudostratified squamous epithelium. Between the papilla and its wall is a depression, or trench. In this trench, the serous von Ebner glands open, which start in the connective tissue directly under the papilla and reach deep between the bundles of muscle cells. In the epithelium of the trench, on the side of the papilla, we can see the taste buds - caliculi gustatorii. The taste buds are made up of spindle-shaped sensory and supporting cells arranged like "barrels" with a depression in the middle into which the cilia of the sensory cells protrude.
Teeth
The specimen is dental pulp, pulpa dentis (HE), which is the inner tissue mass insode of a tooth. Under low magnification, unformed loose connective tissue with numerous arterioles and blood capillaries, some of which are filled with blood, are visible. Under high magnification, the nuclei of endothelial cells protruding into the lumen are visible in the walls of the blood capillaries.
The preparation is part of the tooth crown (ground tissue). The base of the tooth crown is made up of dentin, substantia eburnea covered by enamel, substantia adamantina. Due to the method of preparation, only the inorganic part of the tissue is visible in the specimen. In the dentin area, longitudinally arranged dentinal tubules can be seen, which are covered by darker enamel. Within the dentin, areas of interglobular dentin are visible - areas in the preparation that are darker due to the smaller amount of minerals that remain between the calcospherite spheres during dentin mineralization (shaped like a lowercase letter m). At the dentin-enamel border, enamel defects are visible at high magnification: enamel bushes, spindles and lamellae. Enamel is made up of enamel prisms that gently curve and extend from the enamel-dentin junction to the free enamel surface. Obliquely arranged Retzius stripes are visible in the enamel (corresponding to the increase in mineralization during enamel growth and development). By examining the preparation under a microscope without light (one can do this by covering the light source on the microscope with your hand), it is possible to see white-silver areas in the enamel: Hunter-Schreger stripes, which occur as an optical phenomenon due to the different refraction of light passing through differently placed enamel prisms.
The specimen is a part of the tooth root (ground tissue). The base of the tooth root is made up of dentin, substantia eburnea covered with cementum. Due to the method of preparation, only the inorganic part of the tissue is visible. The specimen shows longitudinally arranged dentinal tubules covered with cellular cementum. At the border of dentin and cementum is Toms' granular layer - a darker colored granular area of irregularly mineralized dentin. Peripherally, we see a homogeneous layer which is made up of hyaline dentin. Cementum continues to this layer and contains cementocyte lacunae. The tubules that emerge from the lacunae, which in vivo contain cementocyte outgrowths, are oriented towards the outer surface of the tooth. Between the lacunae in the cementum, parallel-laid tubules are visible, which are filled with Sharpey's periodontal fibers during life.
Gingiva I
The specimen is a tooth in the dental alveolus (decalcification + HE). Next to the part of the tooth crown (which lacks enamel due to the decalcification process during preparation) the oral mucosa protrudes from the dental alveolus and forms the gums, or gingiva. The gingiva are made up of 1. the multilayered squamous epithelium of the oral cavity that has a thin layer of keratin on its surface, 2. the connective tissue of the lamina propria with deep connective tissue papillae, and 3. thick collagen fibers that attach the mucosa to the alveolar bone and to the tooth (periodontal ligaments). The part of the gingiva that adheres to the tooth enamel forms the gingival pocket and is made up of a thin multilayered squamous epithelium without connective tissue papillae. This tissue has a cuticle on the free surface that is structured like a basal lamina - Gottlieb's epithelial junction, with which it is firmly attached to the tooth.
The specimen is a tooth in the dental alveolus (decalcification + HE).
The specimen is a tooth in the dental alveolus (decalcification + HE). The specimen shows a tooth attached to the jawbone by periodontal ligaments. The bundles are formed by collagen fibers. Note that the ligaments pull the tooth upward, thereby reducing the pressure of the tooth on the bone during chewing.
The specimen is a tooth in the dental alveolus (decalcification + HE).
The specimen is a tooth in the dental alveolus (decalcification + HE).
The specimen is a tooth in the dental alveolus (decalcification + HE).
The gastroinstestinal tract
The specimen is a cross-section of the first 1/3 of the oesophagus, esophagus (HE). The slide shows that the wall of the esophagus is made up of the following layers (from the luman outwards): 1. mucosa (tunica mucosa); this layer can be subdivided in a. the lamina epithelialis (in the submucose maden up of a multilayered squamous non-keratinized epithelium), b. the lamina propria (loose connective tissue) and c. lamina muscularis mucosae (bundles of smooth muscle fibers); 2. submucosa (tella submucosa): loose connective tissue Here we also find clusters of seromucous glands, gll. oesophageae; 3. muscularis externa (tunica muscularis) made up of bundles of skeletal muscle cells that form an inner circular and outer longitudinal layer separated by connective tissue; 4. outer layer (tunica adventitia) of light connective tissue. Note that in the middle of the oesophagus, the muscularis externa transits from skeletal to smooth muscle. The lower 1/3 of the oesophagus ois therefore exclusively made up of smooth muscle.
The specimen is a part of the wall of the body of the stomach, corpus ventriculi (HE). We can see that the gastric mucosa is covered by a single-layered cylindrical epithelium that folds deep into the lamina propria, forming gastric pits. Several branched tubular gastric glands, gll. gastricae propriae, open into each of these pits, which fill the entire width of the lamina propria. The reticular connective tissue that makes up the lamina propria is therefore only visible as thin lines underneath the epithelial folds. The glands extend to the lamina muscularis mucosae, which can be seen as a layer of smooth muscle of 5-10 cells thick directly underneath the gastric pits. Below the muscularis mucosae is a thin layer of submucosa (tella submucosa) made of loose connective tissue. Next follow three layers of the muscularis externa (tunica muscularis) made of bundles of smooth muscle cells separated by connective tissue. At high magnification, the individual types of cells that make up the gastric glands can be seen: Facing the lumen and reaching down into the pits until the neck region we find mucous cells that produce an alkaloid mucuous that protects the inner cell wall of the stomach from gastric juices. In the neck region and at the upper part of the glands we find parietal cells, large round cells with and of eosinophilic cytoplasm and a round, centrally located nucleus, which produce hydrochloric acid and intrinsic factor. In the basal part of the glands we find some lining cells, and chief or zymogenic cells of basophilic cytoplasm with secretory granules. In the basal area there are also enteroendocrine cells that cannot be distinguished using a regular HE staining.
Small intestine I - longitudinal section
The specimen is a cross-section of the wall of the small intestine, intestinum tenue (HE), in the jejunum. On the slide, it is possible to see Kerckring's circular folds of the submucosa, the plicae circulares, which can also be seen macroscopically. At higher magnification, we can see that the mucosa of the small intestine folds outwards in branches called intestinal villi, or villi intestinales. Intestinal villi are built by the epithelium and the lamina propria. The lamina muscularis mucosae does not participate in the structure of the villi, but can be seen in the plicae circulares. Villi are covered with a single layer of cylindrical epithelium. The epithelial cells in this layer, the enterocytes, have a finger-like extensions of their cytoplasma called microvilli into the lumen, which greatly increases the contact surface with the contents of the lumen. Mucous-filled goblet cells, single exocrine cells, are located between the enterocytes and can be seen as lighter-stained bubbles in the epithelial lining. Simple tubular glands called Lieberkühn's crypts, can be found at the basis of the villi and extend through the entire thickness of the lamina propria to the lamina muscularis mucosae. Enterocytes in the glands do not have microvilli yet. At the bottom of these glands are Paneth cells with large eosinophilic granules filled with antimicrobial peptides called defensins. Here, we also find stem cells, which differentiate into enterocytes, paneth cells or goblet cells. Underneath the plicae circulares we see the well-vascularised submucosa. Underneath that, we find two layers of smooth muscle, the tunica muscularis esterna. The outer surface of the small intestine is made up of the tunica serosa, a layer of connective tissue on which we find mesothelium, a single-layered squamous epithelium.
Small intestine II - cross section
This slide shows a transverse section of the small intestine, specifically the jejunum. Note the extreme flexure of the tissue that maximizes the contact surface area.
The specimen is a cross-section through the wall of the large intestine, intestinum crassum or colon (HE). The lamina propria of the colon is filled with a large number of simple tubular glands - Lieberkühn's crypts (on longitudinal and transverse sections) that extend to the laminae muscularis mucosae. The surface of these glands is made up of a single layer of cylindrical epithelium, containing colonocytes, which resemble the enterocytes from the small intestine, but have much fewer microvilli. Between the colonocytes, in the eithelium, we find a large number of goblet cells, which are much more frequent in number than in the small intestine, thus giving the glands a flower-like appearance. The lamina propria also contains many lymphocytes. Surrounding the epithelium and lamina propria we find a thin layer of the muscularis mucosa, made up of smooth muscle cells. The submucosa is made up of dense connective tissue and contains many individual lymphocytes as well as some larger nodes of lymphocytes which form lymph node-like structures, which in the ilium are called Peyer's patches. Peripherally from the submucosa is the muscularis externa, made up of bundles of smooth muscle cells. Three longitudinally oriented bundles pf muscle cells that only cover part of the outer layer called taenia coli are also part of the colon, but cannot be seen on this specimen. The outer layer of the colon is made up of a serosa or adventitia, dependent on the part of the colon.
Organs associated with the digestive system
The salivary glands
The specimen is a parotid gland, gl. parotid (HE). At low magnification, the lobes of the salivary gland can be seen, separated by connective tissue within which are larger blood vessels, nerves and interlobular drainage ducts lined with double-layered cubic epithelium. The parenchyma of the gland is made up of serous acini with a very narrow lumen, lined with pyramidal epithelial cells. The cells have eosinophilic cytoplasm and large, round nuclei. Around the terminal parts of the acini are basket-shaped myoepithelial cells with thin, flattened nuclei. Between the terminal parts of the glands are intralobular drainage ducts - striated ducts or secretory tubes lined with single-layered cubic epithelium with a pale eosinophilic cytoplasm. Adipocytes can also found within the parenchyma. The parotid gland differs from the other salivary glands in that it is exclusively serous, with no mucous glands.
The submandibular salivary gland
The specimen is a submandibular salivary gland, gl. submandibularis (HE). At low magnification, the salivary gland lobes can be seen separated by connective tissue, within which are located larger blood vessels, nerves and interlobular drainage ducts lined with double-row cuboidal epithelium. The parenchyma of the gland is mixed, even though it is made up mostly of serous acini with somewhat fewer tubule-shaped mucous tglands. Serous acini with a very narrow lumen are lined with pyramidal epithelial cells. The cells have an eosinophilic cytoplasm and large, round nuclei. Mucous tubules are lined with cuboidal cells, basally located nuclei and a pale basophilic cytoplasm. On the peripheral parts of some mucous tubules there are Gianuzzi's crescents, also called demilune, which are clusters of serous cells. Around the terminal parts of the gland there are basket-shaped myoepithelial cells with thin, flattened nuclei. Between the terminal parts of the glands are intralobular drainage ducts - striated ducts or secretory tubes. Adipocytes are also found within the parenchyma.
The pancreas
The specimen is the pancreas, pancreas (HE). At low magnification, the lobes of the gland can be seen separated by connective tissue, inside which are larger blood vessels and interlobular drainage ducts lined with double-layered cubic epithelium. The parenchyma of the gland is made up of serous terminal parts with a very narrow lumen, lined with pyramidal epithelial cells. The cells have a two-tone cytoplasm (darker at the base, lighter at the apex) due to the presence of zymogenic granules, and a large, round nucleus. In the center of the acinus are centroacinar cells. The pancreas does not contain striated ducts as found in the salivary glands. Between the terminal parts of the glands are intralobular drainage ducts lined with single-layered cubic epithelium. Within the parenchyma are the endocrine parts of the pancreas - the islets of Langerhans, built of small polyhedral endocrine cells and fenestrated blood capillaries. They can be distinguished as small spots of a few hundred cells with a slightly paler staining than the surrounding exocrine pancreas.
The liver
The specimen shows the liver, hepar (HE). The functional unit of the liver is the liver lobule, a polygonal structure made up mostly of hepatocytes and sinusoid capillaries, around a central vein (v. centralis). In humans, the lobules are not sharply delimited because there is little interlobular connective tissue. At the point where three or more lobes meet, there are interlobular or Kiernan's portal spaces, also called the portal triad. These contain three types of canals: 1. venes, arteries and bile ducts, along with connective tissue. The vein has a wide lumen filled with erythrocytes, the artery has a much smaller lumen and thick walls, whereas the bile duct is lined with a single-layer cubic epithelium. The lobule is made up of hepatocytes arranged in plates that flow radially towards the center where the v. centralis is located. Between the hepatocytes are sinusoids that guide mixed arterial blood and venous blood derived from the vena porta towards the v. centralis.
The specimen is a liver, hepar (Mallory trichrome) of a pig. Structurally, the swine liver is similar to the human liver. However, in the swine thin sheets of connective tissue mark the borders of the liver lobules. For educational purposes we therefore include this specimen to clearly understand the structure of the liver lobules.
The respiratory system
The nasal cavity
The specimen is a longitudinal section through the respiratory part of the nose, regio respiratoria nasi (HE). Several nasal turbinates are visible. The surface of the nasal turbinates is covered with respiratory epithelium; a pseudostratified columnar epithelium with the nuclei of cells arranged in 2-3 rows. At their apical side, these cells are ciliated, which can be seen at high maghnification. Between the columnar epithelial cells we can find goblet cells (unicellular endo-epithelial glands), visible as lightly stained ovals in the epithelial layer. The epithelium also contains brush cells, small granule cells and basal cells, but these cannot be distinguished by HE staining. At high magnification, a thick basement membrane can be seen that separates the epithelium from the connective tissue on which it lies. Beneath the epithelium, in the connective tissue of the lamina propria, there are accumulations of lymphatic cells, as well as mixed seromucous gland (gll. nasales). Also, the nasal lamina propria contains a large networks of veins, the spongy body of the nose, allowing regulation of the hydration of the nasal secrete. The lamina propria continues into the perichondrium on those parts of the nasal septum and turbinates whose base is made of hyaline cartilage, or into the periosteum on parts whose base is made of bone tissue. This specimen does not contain cartilage.
Nasal cavity II - Murine (olfactory region)
The slide shows a section through the head of a mouse (H). The anatomy of a mouse is quite different from that of a human. However, this slide shows the curvature of the nasal cavity, which increases the contact surface between air and the respiratory epithelium. Its purpose is to warm and humidify the air before it enters the lower respiratory tract. Above the nasal cavity (left of the slide) we see the ethmoid bone through which bipolar neurons pass to the olfactory bulb. This area of the brain, which is much larger in mice than in humans (relatively), processes input from olfactory cells. The region of the nasal cavity that we see here is therefore the olfactory region. Its epithelium is made up of bipolar neurons, with cilia at the apical side, which contain the receptors for smell. In addition, we find columnar support cells and basal, stem cell-like cells.
The trachea
Trachea - I (Transversal section)
The specimen is a cross-section of the trachea (HE). The inner surface of the trachea is covered with a mucosa. Its top layer consists of respiratory epithelium, a cell layer consisting of pseudostratified cylindrical cells with cilia and goblet cells. The epithelium also contains brush cells, small granule cells and basal cells, but these cannot be distinguished by HE staining. The epithelium rests on a lamina propria in which there are mixed seromucous glands, gll. tracheales. The mucosa continues into a fibromuscular layer consisting of horseshoe-shaped, hyaline cartilage covered with a perichondrium. Facing the oesophagud is no cartilage, but can we see bundles of smooth muscle cells (m. transversus tracheae). The outer surface of the trachea is covered with a layer of loose connective tissue - tunica adventitia.
Trachea - II (Longitudinal section)
The specimen is a longitudinal section of the trachea (HE). This slide shows cross-section of several cartilaginous rings lining the trachea, separated by elastic fibrous tissue.
The lungs
The specimen is taken from the lung, pulmo (HE). In the lung parenchyma, lobes are separated by connective tissue. Within the lobes, we find cross-sectioned bronchi, bronchioles and alveoli. The bronchus is a tube with a stellate-shaped lumen lined with respiratory epithelium (pseudostratified cylindrical epithelium with cilia and goblet cells), lying on a lamina propria. Bronchi also contain glands, gll. bronchiales, which can be mucous, serous and mixed. The mucosa also contains well-developed elastic fibers. Next, we find a fibromuscular layer containing plates of hyaline cartilage and spirally arranged smooth muscle fibers. The bronchi also often contain lymphocytes. The outer layer of the bronchi is made up of the tunica adventitia, which connects it with the surrounding tissue. This specimen contains two bronchi at the left most side of the specimen. The bronchiolus is a tube thinner than 1 mm in diameter, covered with a single-layer cylindrical or cubic epithelium without goblet cells. The connective tissue of the lamina propria, rich in elastic fibers, continues into a layer of circular smooth muscle cells. On the outside, the bronchiole is covered with the loose connective tissue of the tunica adventitia. Bronchioli do not contain cartilage or glands. Alveoli, alveoli pulmonis are air-filled sacs, lined with a single-layer of squamous epithelium, called pneumocytes type I. In some places inside the alveoli, cuboidal cells, called pneumocytes type II can be seen, which produce surfatant. Between the alveoli there is a dense network of blood capillaries with a small amount of connective tissue rich in elastic fibers and macrophages.
Skin and its derivates
Skin
The specimen is skin, integumentum commune (HE). This specimen was taken from the sole of the foot and shows thick skin. The surface of the skin is covered by a stratified squamous epithelium called epidermis. It is made up of five layers: 1. a single layer of cylindrical cells along the basal lamina, the stratum basale. Proliferation takes place in this layer and it also contains the melanocytes which give pigment to the skin. 2. several layers of cuboidal cells called the stratum spinosum. 3. a layer of cuboidal to squamous cells with clearly visible keratohyaline granules, stratum granulosum. 4. an eosinophilic, homogeneous layer which no longer shows nucei and is typically lighter in color than the surrounding tissues, stratum lucidum. And 5. a thick layer of keratinized tissue made up of dead squamous cells called stratum corneum. The boundary between the epithelium and the connective tissue on which it lies is irregular due to the connective tissue papillae that are imprinted into the epithelium. Beneath the epithelium is the connective tissue of the skin, dermis or corium, which is made up of a network of collagen, reticulin and elastic fibers, with a larger amount of ground substance. The part of the dermis that makes up the connective tissue papillae is loose connective tissue rich in blood vessels and is called the stratum papillare or papillary dermis. The deeper layer is made up of dense irregular connective tissue called the stratum reticulare or reticular dermis. Beneath the dermis is the hypodermis or subcutaneous connective tissue rich in fat cells.
The preparation is skin, integumentum commune (HE). This specimen shows thin skin. Thin skin has the same structure as thick skin. However, it is characterized by a much thinner stratum corneum and lacks a stratum lucidum. The epidermis rests on the papillary dermis, which tends to be less convoluted than in thick skin as it is sibject to less abrasion. Beneath the dermis is the hypodermis. At the border of the dermis and hypodermis, and in the hypodermis, are numerous sweat glands, gll. sudoriferae. Sweat glands are simple convoluted tubular glands that secrete according to the merocrine type. The surface of the skin is covered by a multilayered squamous epithelium - epidermis. I Their terminal parts on the cross-section have a circular shape, a visible lumen, and are lined with a single-layer epithelium made of pyramidal-shaped cells. The drainage ducts, which are darker on the preparations, are lined with a double-row cubic epithelium. Sebaceous glands, gll. sebaceae, are holocrine in the type of secretion. They are located next to the hair follicles. Their terminal parts have a sac-like appearance, without a lumen that is filled with secretion and dead cells. This type of gland is holocrine; their terminal parts are lined with several layers of epithelial cells in different stages of decay. In addition, we find several hair follicles. These are locted in the lower part of the dermis and reach all the way up to the epidermis. They are connected with a bundle of smooth muscle cells, the musculus erector pili, which can make the hair stand up.
This slide shows a thin section of skin where dye was applied to the dermis while the tissue was still alive, commonly known as a tattoo. The dye is absorbed by skin macrophages, which generally retain it for life. In this slide, the dye therefore marks the skin macrophages as dark red.
This slide shows a section of thin skin isolated from the axillary region, which is a pyramid-shaped anatomical space located below the shoulder joint (also called arm pit). This site shows the three types of glands found in the skin. The first are the sebaceous glands, holocrine glands that usually deposit their secretions in the hair shaft, as can be seen here. The second type is the eccrine sweat glands. These glands can be found on most parts of the skin and have an unusual type of stratified cuboidal epithelium. The basal layer contains pale-stained transparent cells that produce most of the fluids in sweat. The lumen is lined with dark cells that contain granules with antimicrobial proteins. Surrounding the glands are myoepithelial cells. The third type of gland is the apocrine sweat gland, which can be found mainly in the apocrine and perineal regions. Apocrine glands have much larger lumens than eccrine glands and are composed of simple cuboidal cells with numerous secretory granules that mediate merocrine secretion. Their secretions are often metabolized by bacteria, which causes a characteristic odor.
Mammary glands
Mammary gland inactive phase - deep tissue
The specimen is a breast, mamma (HE) of an adult woman. The mammary gland is in the inactive phase. The specimen shows lobules made of connective tissue with a large amount of fat cells separated by dense connective tissue. The specimen shows glandular lobules consisting of intralobular ducts surrounded by loose connective tissue and dense interlobular connective tissue with occasional drainage ducts. The lactiferous ducts are lined with double-layered cubic epithelium.No secretory cells can be distinguished.
Mammary gland inactive phase - nipple
The preparation is the breast, mamma (HE) of an adult woman. The mammary gland is in the inactive phase. This specimen was isolated from the tissue directly below the nipple. At this site, the milk ducts, usually about 15-25 per mammary gland, converge to form the openings from which milk is produced during lactation. This site also contains much dense connective tissue that can be seen between the ducts.
Mammary gland - active phase (lactation)
The preparation is a breast, mamma (HE) in the active phase (lactation). The specimen shows glandular lobules made of connective tissue with a large number of alveoli in which the secretion is located. The alveoli are lined with a single-layer epithelium of varying height, which depends on the phase of secretion. The method of secretion of the breast is apocrine. The lobules are separated by dense connective tissue in which there are drainage channels, ductuli lactiferi, lined with double-layered cuboidal epithelium.
The urinary system
The urinary system
Preparat je bubreg, ren (HE). Bubreg je izgrađen od tamnije kore i svjetlije srži. U kori možemo uočiti bubrežna tjelešca građena od glomerula (klupko krvnih kapilara) obavijenih visceralnim i parijetalnim listom Bowmanove čahure. Prostor između visceralnog i parijetalnog lista naziva se interkapsularni prostor i u preparatu se mogu uočiti kao prazni polumjeseci koji okružuju glomerule. Između bubrežnih tjelešaca, u vezivnom tkivu, smješten je velik broj različito presječenih proksimalnih i distalnih kanalića koje možemo razlikovati prema izgledu njihovog epitela i širini lumena. Stanice epitela proksimalnih zavijenih kanalića su piramidalnog oblika i izrazito eozinofilno obojene citoplazme te gotovo u potpunosti zatvaraju lumen kanalića. Na apikalnoj površini posjeduju četkastu prevlaku (mikrovile). Lateralne granice im se teško raspoznaju zbog brojnih međustaničnih interdigitacija. Stanice distalnih zavijenih kanalića su niže, pravilnog kubičnog oblika tako da je lumen širi nego kod proksimalnih kanalića. Citoplazma je blijedo obojena, a lateralne granice između susjednih stanica su lako uočljive. Srž bubrega sastoji se od sabirnih cjevčica silaznih i uzlaznih krakova Henleovih petlji i krvnih žila (vasa recta). Tanki segmenti Henleovih petlji su obloženi jednoslojnim pločastim epitelom, pa ih od kapilara razlikujemo po izgledu stanica i obliku jezgre.
Preparat je mokraćovod, ureter (HE). Mokraćovod ima stijenku građenu od sluznice s prijelaznim epitelom i laminom proprijom, mišićnice i tunike adventicije. Mišićnicu izgrađuju spiralni snopovi glatke muskulature.
Preparata je mokraćni mjehur, vesica urinaria (HE). Unutarnja površina stijenke mokraćnog mjehura pokrivena je slunicom koju izgrađuje prijelazni epitel i lamina proprija od rahlog vezivnog tkiva bez vezivno-tkivnih papila. U sluznici nalazimo još i laminu muscularis mucosae od glatkih mišićnih stanica. Mišićnicu u mokraćnom mjehuru izgrađuju različito usmjereni snopovi glatkih mišićnih stanica, bez strogo odijeljenih slojeva.
Preparata je mokraćni mjehur, vesica urinaria (HE). Prijelazni epitel mokraćnog sustava je poseban jer može prelaziti između dva oblika. Kada je prazan, epitel je pseudostratificirani kuboidni epitel koji se pojavljuje kao pet do deset slojeva. Kada je pun, epitel se rasteže i dobiva pločasti oblik od samo dva ili tri sloja. Na ovom preparatu vidimo pločasti oblik, dok prethodni slajd prikazuje kuboidni oblik. Treba napomenuti da je u oba stanja luman okružen pločastim krovnim stanicama koje štite temeljno tkivo od oštećenja urinom.
The endocrine system
The endocrine system
Preparat je hipofiza, gl. pituitaria (HE). Na djelu površine nalazi se vezivna čahura koja u parehim pruža nešto vezivnotkivnih tračaka. Parenhim ima tri djela. Tamniji dio predstavlja adenohipofizu, građenu od tračaka i nakupina žljezdanih stanica uz krvne kapilare. Stanice imaju različiti afinitet prema histološkim bojama te se dijele na kromofobne - blijedo obojene stanice; te kromofilne, koje su bazofilne ili eozinofilne. Srednji dio organa je pars intermedija - građena od tračaka blijedih stanica i većeg broja različito velikih cista (ostaci Rathkeove vreće). Svijetli dio preparata je neurohipofiza građena od aksona jezgara hipotalamusa, pituicita - posebnih glija stanica te brojnih kapilara.
Preparat je epifiza, corpus pineale ili epiphysis cerebri (HE). Sastoji se od nepravilnih režnjića pinealocita (tip glija stanica bazofilne citoplazme), živčanih vlakana (iz neurona dijencefalona) i glija stanica te nježnih vezivnih pregrada koje se na površini spajaju s piom mater. U epifizi se mogu uočiti crveno obojani kalcifikati - moždani pijesak ili acervulus cerebri.
Preparat je štitnjača, gl. thyroidea (HE). Sastoji se od velikog broja nepravilnih folikula između kojih se nalazi nešto vezivnog tkiva s mnogo krvnih kapilara. Folikularne stanice koje oblažu folikule mogu biti niske cilindrične, kubične ili pločaste, što ovisi o njihovom funkcionalnom stanju. Unutar folikula nalazi se crveno obojani koloid. Parafolikularne ili C stanice smještene su uz folikule (unutar bazalne lamine) ili pak formiraju posebne nakupine između njih. Unutar nekih folikula nalaze se pravilne okrugle šupljine - resorptivne vakuole. Vakuole su nastale tijekom pripreme preparata i predstavljaju artefakt (isto kao i raspucani koloid u nekim folikulima).
Preparat je nadbubrežna žlijezda, gl. suprarenalis (HE). Na površini žlijezde nalazi se čahura od gustog vezivnog tkiva koja u parenhim šalje tanke tračke koji s mrežom retikulinskih vlakana izgrađuju stromu. Parehim žlijezde podijeljen je na koru i srž. Kora nadbubrežne žlijezde ima tri zone: zona glomerulosa građena je od okruglastih nakupina žljezdanih stanica i smještena neposredno ispod vezivne ovojnice; zona fasciculata je najdeblja zona u kojoj stanice formiraju stupiće koji teku paralelno i okomiti su na površinu žlijezde. Između stupića stanica nalaze se krvne kapilare. U citoplazmi stanica zone fascikulate nalazi se veliki broj sitnih masnih kapljica koje se tijekom pripreme preparata otapaju te stanice - spongiociti, izgledaju pune malih vakuola; zona reticularis nalazi se na granici sa srži a izgrađuju je sitne stanice koje formiraju nepravilne tračke koji međusobno anastomoziraju. Srž nadbubrežne žlijezde građena je od poligonalnih stanica koje formiraju tračke okružene retikulinskim vlaknima te obilna mreža krvnih kapilara.
The male reproductive system
The male reproductive system
Preparat je, testis i epididymis (HE). U parenhimu testisa nalaze se različito presječeni zavijeni sjemeni kanalići. Unutar kanalića nalaze se stanice spermatogeneze u različitim fazama razvoja te potporne Sertolijeve stanice, stisnte između njih. Kanaliće okružuje lamelarno vezivno tkivo. Između kanalića nalaze se Leidigove intersticijske stanice s velikim jezgrama i crvene citoplazme. Testis okružuje crveno obojana, debela ovojnica od gustog vezivnog tkiva - tunica albuginea. Na jednom je dijelu vezivo isprekidano pukotinastim prostorima obloženim jednoslojnim kubičnim do pločastim epitelom - rete testis. U vezivu oko testisa nalaze se poprečno presječeni kanalići koji pripadaju pasjemeniku. Kanal pasjemenika - ductus epididymidis, pravilnog okruglog ili ovalnog lumena, obložen je s dva sloja stanica: kubične stanice uz bazalnu laminu i cilindrične na površini. Površne stanice na apikalnom polu imaju velike razgranate mikrovile - stereocilije. Kanalići su okruženi vezivnim tkivom bogatim glatkim mišićnim stanicama. Na preparatu su prisutni i višestruko presječeni kanalići glave pasjemenika - ductuli efferentes. Oni imaju nepravilan lumen, jer su obloženi nakupinama kubičnih stanica s trepetljikama (kinocilije) koje se izmjenjuju s onima bez trepetljika, pa je površina valovita.
Preparat je poprečno presječena sjemenska vrpca, funiculus spermaticus (HE). Unutar sjemenske vrpce može se uočiti više struktura. Najveća struktura je poprečno presječen sjemenovod, ductus deferens, uskog lumena prekrivenog višerednim cilindričnim epitelom sa stereocilijama, laminom proprijom bogatom elastičnim vlaknima te okružen debelom mišićnicom od glatkih mišićnih stanica složenim u tri sloja. Uz sjemenovod u vrpci se nalazi m. cremaster, mišić građen od poprečno - prugaste skeletne muskulature, vene plexusa pampiniformisa, arterija i živci testisa.
Preparata je predstojna žlijezda, prostata (HE). Parenhim žlijezde izgrađuju tuboalveolarni žljezdani djelovi prekriveni kubičnim ili višerednim cilindričnim epitelom okruženi obilnom fibromuskularnom stromom. U nekim se žljezdanim djelovima nalaze crveni prostatički kamenci - prostatoliti. U preparatu su vidljiva i dva poprečno presječena odvodna kanala.
The female reproductive system
The female reproductive system
Preparat je jajnik, ovarij (HE). Na površini jajnika nalazi se jedan sloj pločastih do kubičnih stanica - zametni epitel, ispod kojeg se nalazi tunica albuginea, tanki sloj gustog vezivnog tkiva. Parenhim ovarija sastoji se od kore i srži. Kora ovarija (zona parenhimatosa) građena je od vezivnog tkiva s mnogobrojnim jajnim folikulima u različitim stadijima razvitka ili regresije. Najpovršnije se vide primordijalni folikuli koji su sitni i sastoje se od primarne oocite i jednog sloja spljoštenih folikularnih stanica. Primarni folikuli mogu biti jednoslojni – kada je primarna oocita okružena jednim slojem folikularnih stanica ili višeslojni - kada je primarna oocita okružena s više slojeva stanica. Sekundarni (mjehurasti) folikuli sadrže šupljinu (antrum foliculli) ispunjenu tekućinom (liquor foliculli). Granulosa stanice koje okružuju oocitu i prominiraju u lumen šupljine sekundarnog folikula čine cumulus oophorus. Srž ovarija bogata brojnim krvnim i limfnim žilama smještenim u vezivnom tkivu naziva se i zona vasculosa.
Preparat je poprečni presjek kroz ampularni dio jajovoda, ampulla tubae uterinae (HE). Vide se brojni nabori sluznice prekriveni jednoslojnim cilindričnim epitelom s dobro prokrvljenom laminom proprijom. Neke epitelne stanice imaju trepetljike dok druge vrše sekreciju. Mišićnicu izgrađuju snopovi glatkih mišićnih vlakana. Na površini se nalazi vezivno tkivo pokriveno seroznom ovojnicom.
Maternica I - Faza proliferacija
Preparat je maternica, uterus (HE) u kasnoj proliferacijskoj fazi uterinog ciklusa. Sluznica maternice - endometrij prekrivena je jednoslojnim cilindričnim epitelom koji se mjestimično invaginira u laminu propriju čineći žlijezde, gll. uterinae. Neke stanice površnog epitela imaju trepetljike. Lamina proprija sadrži veliki broj stanica (fibroblasta) i obilnu osnovnu tvar. Površni, deblji sloj endometrija naziva se zona functionalis. U dubljim slojevima lamine proprije vidljive su brojne uterine žlijezde. Taj sloj endometrija koji se nalazi neposredno uz miometrij, naziva se zona basalis i čini onaj dio sluznice iz kojeg se površni dio endometrija ponovno obnavlja nakon menstrualnog krvarenja ili nakon poroda. Ispod endometrija nalazi se miometrij, mišićnica građena od snopova glatkih mišićnih stanica odijeljenih vezivom.
Preparat je maternica, uterus (HE) u ranoj sekrecijskoj fazi uterinog ciklusa. Sluznica maternice - endometrij prekrivena je jednoslojnim cilindričnim epitelom koji se invaginira u laminu propriju čineći žlijezde, gll. uterinae. Žlijezde imaju vijugav tok, dok u lumenu sadrže sekret. Lamina proprija sadrži veliki broj stanica (fibroblasta), obilnu osnovnu tvar te brojne krvne žile. Površni sloj endometrija ili zona functionalis u ovoj fazi ciklusa ima dva dijela: površni ili stratum compactum s većim brojem stanica i dublji ili stratum spongiosum koji ima veću količinu osnovne tvari. Sloj endometrija koji se nalazi neposredno uz miometrij, s brojnim žlijezdama i krvnim žilama naziva se zona basalis i čini onaj dio sluznice iz kojeg se površni dio endometrija ponovno obnavlja nakon menstrualnog krvarenja ili nakon poroda. Ispod endometrija nalazi se miometrij, mišićnica građena od snopova glatkih mišićnih stanica odijeljenih vezivom.
Preparat je rodnica, vagina (HE). Rodnica je pokrivena mnogoslojnim pločastim neooroženim epitelom ispod kojeg je lamina proprija bogata elastičnim vlaknima i s mjestimičnim nakupinama limfocita i neutrofila. Mišićnica je građena od snopova glatkih mišićnih stanica. U perimiziju ima dosta krvnih žila.
Organs of special sense
The Ear
Preparat je uška, auricula (HE). U osnovi uške nalazi se izdužena pločica elastične hrskavice okružene rahlim vezivnim tkivom perihondrija. Na površini uške se sa svih strana nalazi koža s brojnim dlakama, uz koje su žlijezde lojnice. U vezivu se nalaze i žlijezde znojnice te dosta masnog tkiva.
Preparat je uška, auricula (orcein). U osnovi uške nalazi se izdužena pločica elastične hrskavice okružene rahlim vezivnim tkivom perihondrija. Na većem povećanju se između pojedinih nakupina hondrocita - izogenih skupina može uočiti mreža smeđe obojanih elastičnih vlakana u međustaničnom matriksu. Na površini uške se sa svih strana nalazi koža s brojnim dlakama, uz koje su žlijezde lojnice. U vezivu se nalaze i žlijezde znojnice te dosta masnog tkiva.
Na preparatu se vidi dio šupljina koštanog labirinta, labyrinthus osseus, te dio membranoznog labirinta, labyrinthus membranaceus, i to poprečno presječn trokutasti prostor pužničkog kanala, ductus cochlearis (HE). Dio koštanog labirinta oko kojeg zavija pužnica je modiolus koji sadrži ganglion spirale. Lateralno se od njega izbočuje koštani greben, lamina spiralis ossea, od kojeg polazi bazilarna membrana. Prostor ispod nje je dio koštanog labirinta - scala tympani, a iznad nje endolimfatični prostor membranoznog labirinta, pužnički kanal. Trokutasti pužnički kanal odvojen je vestibularnom membranom od scale vestibuli (sadrži perilimfu, dio koštanog labirinta). Treću stranicu trokuta čini periferna stria vascularis, posebni tip prokrvljenog epitela koji luči endolimfu. Na bazilarnoj membrani nalazi se Cortijev organ, posebno organiziran organ sluha. Sadrži osjetne i potporne stanice koje s gornje strane prekriva membrana tectoria. Perilimfatični prostor scale vestibuli i scale tympani prekriven je jednoslojnim epitelom, mezotelom.
The eye
Na preparatu se može uočiti histološka građa pojedinih struktura prednjeg segmenta oka (HE). Rožnica, cornea, prozirni je prednji dio je vanjske očne ovojnice. Građena je od 5 slojeva: 1.mnogoslojni pločasti epitel (5 -6 slojeva stanica) čije površne stanice imaju mikrovile; 2. Bowmanova membrana, homogeni sloj bez stanica od kolagenih vlakana i zgusnute osnovne tvari; 3. stroma građena od većeg broja lamela od kolagenih vlakanaca koja se križaju pod pravim kutem, s nešto fibroblasta i amorfne glikoproteinske osnovne tvari; 4. Descemetova membrana, homogena masa s nešto kolagenih vlakanaca; 5. endotel prednje očne sobice, jednoslojni pločasti epitel mezenhimskog porijekla. Cilijarno tijelo, corpus ciliare, dio je srednje očne ovojnice. Izgrađuje ga orbiculus ciliaris - glatki dio koji počinje na nazubljenoj liniji, ori serrati i pruža se prema naprijed te ciliarni nastavci, processus ciliares, koji izgrađuju coronu ciliaris. Osnova cilijarnog tijela je cilijarni mišić trokutastog oblika (na poprečnom presjeku) okružen rahlim vezivnom s mnogo elastičnih vlakana, melanocita i krvnih žila. Površina cilijarnog tijela koja gleda prema staklovini, leći i stražnjoj očnoj sobici prekrivena je slijepim djelom mrežnice. Mrežnica je na tom djelu izgrađena od dva sloja epitelnih stanica: vanjski, pigmentirani, stratum pigmenti corporis ciliaris te unutarnji nepigmentirani, pars ciliaris retinae koji sudjeluju u lučenju očne vodice. Ta dva epitelna sloja dodiruju se svojim apikalnim plohama koje su međusobno spojene dezmosomima. Na bazalnu laminu unutarnjeg sloja nastavljaju se vlakna koja spajaju cilijarne nastavke s ekvatorom leće, fibre zonulares, građene kao ositalanska vlakna veziva. Šarenica, iris, dio je srednje očne ovojnice koji čini blendu u frontalnoj ravnini ispred leće oka sa šupljinom zjenice ili pupile u sredini. Prednja površina je isprekidani i neravni sloj fibroblasta i melanocita ispod kojeg se nalazi vezivna stroma. Prvi je sloj vezivnog tkiva s malo krvnih žila i vlakana a bogat stanicama. Slijedi dobro prokrvljeno rahlo vezivno tkivo u kojem se pri pupilarnom rubu šarenice nalazi m. sphincter pupillae, a na cijeloj dužini stražnje strane sloj m. dilatator pupillae. Boja šarenice ovisi o količini melanocita u stromi. Stražnja površina šarenice prekrivena je slijepim djelom mrežnice. Mrežnica je na tom djelu izgrađena od dva sloja epitelnih stanica oba pigmentirana: vanjski, stratum pigmenti iridis te unutarnji, pars iridica retinae. Ta dva epitelna sloja dodiruju se svojim apikalnim plohama koje su međusobno spojene dezmosomima. Leća, lens cristalina, bikonveksna je tvorba koja je na prednjoj površini prekrivena jednoslojnim kubičnim epitelom i kompletno okružena čahurom. Osnovu leće izgrađuju lećna vlakna.
Na preparatu je vidljiv stražnji segment oka (HE). Na površini se nalazi neprozirni dio vanjske očne ovojnice bjeloočnica, sclera, koju izgrađuje gusto vezivno tkivo bogato kolagenim vlaknima s malo stanica. Ispod se nalazi lamina suprachoroidea, od rahlog vezivnog tkiva bogatog melanocitima koja ju odjeljuje od srednje očne ovojnice - žilnice ili choroidee. Žilnicu činio sloj rahlog veziva bogatog krvnim žilama, elastičnim vlaknima, melanocitima i brojnim drugim stanicama. Tanki homogeni sloj Bruchove membrane odjeljuje je od vidnog djela unutarnje očne ovojnice, mrežnice ili retinae. Vidni dio mrežnice, pars optica retinae, izgrađen je od vanjskog pigmentnog sloja - stratum pigmenti retinae, te unutranjih 9 slojeva kako slijedi: sloj štapića i čunjića, vanjska granična membrana, vanjski zrnati sloj, vanjski mrežasti sloj, unutarnji zrnati sloj, unutarnji mrežasti sloj, sloj stanica vidnog živca, sloj vlakana vidnog živca, unutarnja granična membrana. Između stanica i vlakana unutarnjih 5 slojeva nalaze se i krvne žile.
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Faculty of Medicine
Department of histology & Embryology
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