Benha University Faculty of Veterinary Medicine Histology and Cytology Department 9 June 2018 HISTOLOGY 1st year 2nd Semester Time Allowed:

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1 A- Total (15 Marks) (1) Choose the correct answer and write it ONLY down in your answering papers: (½ Mark each) a- ) Both of them) b- Seven. c- Six. d- Epineurum. e- Two. (2) Define ONLY the following from histological view:- (1.5 Mark each) a- Purkinje Neurons. - It composed of single layer of large, ovoid, spherical cell body known as purkinjie cell. - It project tree like dendrites with the molecular layer with flatten disk like pattern with the branches oriented transverse to the long axis of the cerebellar folia. - Axon of purkinjie cell provides only efferent of cerebral cortex. - All cortical must be impressed on the purkinjie cell so neuronal information can be transmitted from cerebellar cortex to the other portion of the brain. b- Purkinje fibers. Located in the deep layer of endocardium. Special cardiac Ms & wider than that of the cardiac muscle. Centrally located nucleus and few myofibrils peripherally. Stored glycogen in the cytoplasm and mitochondria. More prominent in sheep heart. Sarcoplasmic reticulum not developed as in cardiac Ms. c- Metachromsia. Detected by H&E. By Toluidine blue reddish purple granule d- Sarcomere. Sarcomeres are the smallest unit structure and functional of the skeletal muscle. It extend from two successful Z line ( dark line that determine the end of each sarcomere) It consists of :- A band (anisotropic), which appear dark in color due to overlapping of thick (myosin) and thin (actin) filaments. I band (isotropic), which appear light in color and it only contain thin filament. H band is the lighter area of the A band. It formed of thick filament alone. M line is the center of H band which is consists of lateral connection between thick filaments. It mostly consists of creatine kinase ( sulphated protein) Intermediate filaments are present, primarily desmin which provide support and attachment for the myofibrils. e- Hassall's corpuscles. Are composed of flattened epithelial reticular cells that have. Degenerated. May show some keratinization. They are arranged in a concentric formation. It can vary in size. Have no known function (3) Enumerate ONLY the following:- ( 2.5 Marks each) a- Surface Epithelium. A- Simple epithelium 1-Simple squamous 2-Simple cuboidal 3-Simple columnar Simple columnar non ciliated epithelium A- Absorptive type 4-Pseudo stratified columnar epithelium B-Stratified epithelium:-

2 (1) Stratified squamous epithelium. (A) Mucous type non keratinized. (B) Cutaneous type keratinized. (2) Stratified cuboidal epithelium. (3) Stratified columnar epithelium. (4)Transitional epithelium. b- Connective tissue cells. Mother cells. Adipose cell Chromospheres Fibroblast eukocyte Blood Fibrocyte macrophage Mast cell. Plasma cells. B- Total (18 Marks) (1) In, Table Differentiate between the histological structure of the following with drawing:- a-- Cartilage types. (4 Marks) HYALINE CARTILAGE ELASTIC CARTILAGE FIBRO CARTILAGE Matrix Site: -Auricle of ear epiglottis External auditory canal cuneiform cartilage of larynx Eustachian tube Structure Appear yellowish coloration. Mainly appositional growth. Matrix has collagen type II, elastic fiber. Perichondrium, chondroblast, chondrocyte. More great opacity & elasticity. This Type between Dense C.T & hyaline cartilage. No Perichondrium observed in this type of cartilage. - Matrix is acidophilic because it contain numerous coarse collagen type I Chondrocyte as single or isogenous group & also arranged in column. Amorphous matrix is not abundant Contain equal amount of chondratin sulphate and dermatin sulphate. * Site Inter vertebral disk.

3 40% collagen fiber II (not as bundle but thin meshwork) in amorphous intra cellular substance & it can t be visible due to. It present in form of fibrils which had microscopic appearance. Its refractive index like that of the amorphous substance. Perichondrium:- All hyaline covered with dense layer of C.T except articular cartilage It responsible for growth & maintenance of cartilage. It contains collagen fiber & cell similar to fibroblast in inner surface cells differentiated to chondroblast. Chondrocyte It present in the periphery of the cartilage. Round in adult, flat in young. It may arranged in group of 8 cells from mitotic division of one chondrocyte isogenous group Chondrocyte:- E.M Round or oval nucleus contains several nucleoli. Juxtanuclear cell center with pair of centriole & well develop GA. Elongated mitochondria, lipid droplets and glycogen. Ground substance is obscured by net work of the elastic fibers. Growth by appositional growth Symphsis pubica. At attachment of certain ligament to bone. b-- Clock face cells and Signet cells. (4 Marks)

4 Large ovoid cell. Basophilic, cytoplasm due to richness with R.E.R. Few numbers in C.T Spherical nucleus, eccentrically located contain compact coarse heterochromatin of equal size resemble wheel with spokes giving the nucleus clock face appearance. Juxtanuclear Golgi apparatus with centriole occupy region of the cytoplasm which appear pale Before storage of the lipid in the cell, it s shape look like fibroblast. Fat droplet present in the cytoplasm, then collected together forming one large fat droplet. The cytoplasm appears as rim and the nucleus bulged in the section. This give fat cell signet Ring It scattered in the loose CT as single or in group & around blood vessels (2) Draw ONLY with complete data the following:- a- Spleen. (2.5 Marks)

5 b- C.S and L.S of Striated and involuntary muscle. (2.5 Marks) c- Spinal Cords. (2.5 Marks) d- 3 types of mode of secretion for glandular epithelium. (2.5 Marks) C- Total (17 Marks) a- Classify the blood vessels and differentiate between large artery and large vein. (5 Marks) 1- Large artery 2- Medium sized artery 3- Small sized artery 4- Metarterioles 5- Large vein 6- Medium sized vein 7- Small sized vein I- Tunica Intima: It represents large proportion of the total thickness &it increase with age advanced or in case of any disorder of the blood vessels. a- Endothelial cells. b- Subendothelial pale amorphous substance contains smooth muscle cells, elastic, collagen C.T macrophage and fibroblast. c- Internal elastic lamina present but is difficult to distinguish because large amount of concentric elastic lamina. II- Tunica Media: - It form bulk of the artery & consists of concentric fenestrate elastic lamina. - Collagen fine fiber & SM cells to secrete elastin & collagen & proteoglycans of the lamina. - Elastic lamina change to collagen fiber & thickened with adult age. - External Elastic lamina present but indistinct. III- T. adventitia:- It is thin and characterized by presence of:- 1- (Collagen & Elastic fiber), fibroblast and few Ms Cells. Collagen present in large amount to prevent over dilatation during systol. 2- Vasa vasorum (blood supply of the artery) & T. intima:- Endothelium layer. Subendothelial CT: - loose connective tissue. T.media:- Few layers of smooth muscle fibers with collagen and elastic fiber. T.adventitia:- It is the most prominent layer. Contain longitudinal or spiral arranged bundles of smooth muscle fibers that challenge the pressure over the vein especially in abdomen & extremities. It also contain collagen and elastic fibers

6 lymphatic vessels Vasa vasorum that supply the vessels wall and may extend to the tunica media in the large artery. N.B some arteries begin as elastic then gradually or abruptly change to muscular artery e.g. Femoral, vertebral and brachial b- Sketch Only the main component of the cerebellum. (4 Marks) s c- The heart wall has great structure, which keep it bombing forever, what are the main histological structure for that with drawing. (4 Marks) Pump with 4 chambers separated by an interatrial and interventricular septi Contains valves that maintain a one-way flow of blood Heart wall contains: Cardiac muscle for contraction Fibrous skeleton for attachment of valves Internal conduction system Heart Wall:- Epicardium Layer of mesothelial cells on outer surface of heart. Visceral pericardium overlies thin layer of CT. Subepicardium which consists of loose CT & white fat, blood vessels and nerves. Myocardium Cardiac muscle which surrounded by thin layers of CT. Contains

7 a dense capillary network. Thickest in left ventricle. It comprise the cardiac skeleton and the purkinjie fibers. Endocardium * This layer completely lines the atria and ventricles and forms the cardiac valves. It consists of * Inner layer consists of endothelium resting on a basal lamina * Middle layer consists of subendothelial, CT and smooth muscle * Outer layer (Subendocardial layer) which contains impulse-conducting system, it consists of loose CT, collagen and elastic fibers. d- Mention the sites of smooth muscle and its structure. (4 Marks) Site of smooth muscle Dispersed in C.T of some organs ( prostate and seminal vesicle ) Small muscle bundle erector pill muscle of skin Constitute large bulk in the myometrium of the uterus present in capsule of some gland in the tunica media of the blood vessels * The smooth muscle has involuntary action except in the muscle of urinary bladder and ciliary muscle of eye. Long spindle like cell ( u ) Centrally located nucleus & elongated. At side pole of elongated nucleus there numerous mitochondria, R.E.R & large Golgi body The cytoplasm appear unstructured under E.M, it consists of arrays & myofilaments. Acidophilic, homogenous cytoplasm. The fine structure of the smooth muscle consists of actin, myosin and desmin filaments. It also contains caveolae, (pockets) in its cell membrane but no T tubules. It has autonomic innervation. Mesenchymal in origin. ********************************************************************* GOOD LUCK. Prof. Dr/ Ehab Elzoghby