Reproductive System Histology Lecture PDF

College of Applied Medical sciences Department of Medical Laboratory technology Histology of reproductive system  Female reproductive system Components: I-Primary sex II-Genital III-External organs tract:...

College of Applied Medical sciences Department of Medical Laboratory technology Histology of reproductive system  Female reproductive system Components: I-Primary sex II-Genital III-External organs tract: genitalia: IV-Accessory (gonads) organs: Two ovaries: Uterine tubes, Uterus, Vagina Clitoris , have an labia minora , labia majora Placenta & mammary endocrine function glands (secretion of female hormones), an exocrine function (production of ova)  The Ovary Paired, almond shaped organ lying in the pelvic cavity. Covered with germinal epithelium ,simple cuboidal Under the epithelium lies tunica albuginea (dense C.T coat)  Ovary (cont.) Ovary is formed of : Small central Wide outer cortex: medulla: stroma containing ovarian follicles in loose highly vascular different stages of CT development.  Ovarian Follicles Site: present in the ovarian cortex under tunica albuginea Types: 1. Primordial follicle 2. Unilaminar primary follicle 3. Multilaminar primary follicle 4. Secondary (antral) follicle 5. Mature graafian follicle - At puberty, FSH stimulates primordial follicles to grow and ovarian cycles begin  1- Primordial follicle 2- Unilaminar primary follicle - - consists of a primary - oocyte (immature ovum) 25 μm in - Oocyte enlarge in size. diameter with large eccentric pale nucleus - Surrounded by a single layer - The Surrounding of flat epithelial follicular cells. follicular cells become cuboidal Multilaminar primary follicle. - Oocyte increase in size. - Surrounding follicular cells become columnar& proliferate to several layers called granulosa cells. - Zona pellucida is formed: an eosinophilic glycoprotein membrane is formed between granulosa cells & oocyte. -Theca folliculi: Stromal cells forms concentric layers around the enlarging follicle forming a capsule-like structure called (separated from granulosa cells by a BM)  Mature Secondary follicle graafian follicle - Primary oocyte increase more in - The primary oocyte reaches its maximum size. size (150 μm). - Granulosa cells divide forming 8 –12 layers around it. - The ovum is pushed to one side -Granulosa cells secrete follicular surrounded by a clear zona pellucida and a fluid which is collected into layer of columnar cells called corona multiple cavities, then cavities radiata attached to granulose cells by coalesce to form a single large follicular cells termed cumulus oophorus. cavity (follicular antrum). -Theca folliculi differentiate into 2 -Primordial follicle after 14 days becomes layers (inner theca interna & outer mature follicle theca externa) Ovulation ❖Definition: Involves the rupture of mature Graafian follicle and release of 2ry oocyte with its corona radiata& cumulus oophorus to be picked up by the fallopian tube ❖ Occurs in the middle of menestrual cycle (14thday) ❖Induced by LH surge of the anterior pituitary The Corpus Luteum. Definition: Yellow body formed in the cortex of ovary as a remnant of mature follicle after ovulation. It collapses & becomes deeply infolded. ❖It is a temporary endocrine gland Functions: 1-Secrete progesterone & estrogen 2-Prevent more development of follicles Atretic follicle Definition: ovarian follicles undergo atresia Atresia occurs at any stage of the developing follicle Atresia is characterized by: death of the oocyte & degeneration of the surrounding cells A scar of fibrous tissue is left in the ovary (only following atresia of large follicles) The Uterus The Uterus A pear-shaped muscular organ that receives fallopian. tubes in its upper part & its lower part opens into the vagina Anatomical parts : 1-Fundus 2-Body 3-Cervix Structure of body & fundus: 1-Endometrium (mucosa) 2-Myometrium (musculosa) 3-Perimetrium ( serosa)  Epithelium: Simple columnar partially ciliated & 1- partially secretary columnar epithelium Endometrium Lamina propria: contains uterine glands (Simple tubular glands) Thickest layer Composed of three poorly-defined layers of SM Stratum submucosum: longitudinal layer of 2- muscle Myometrium Stratum vasculare: circular & oblique muscles arranged in 8-shaped figures enclosing large blood vessels Stratum supravasculare: longitudinal layer Loose CT covered by S. Sq. 3-Perimetrium mesothelium NDuring pregnancy : myometrium grows by hypertrophy & hyperplasia of smooth muscles Cervix of the uterus. Definition: The lower cylindrical part that protrudes into the vagina Internal os: The junction between cervix & uterine body External os: the Cervical lumen opens into the vaginal cavity. The external aspect of the cervix that bulges into the vagina is covered by non-keratinizing stratified squamous epithelium Formed of: Mucosa: contains mucous secreting cervical glands Stroma: dense CT with few SM fibers Male genital system  Male Reproductive System I-Primary sex II-System of III-Accessory IV-External organs excretory genital glands: genitalia: (gonads): ducts: Include Penis & scrotum 2 testes 1- 2-Excretory Intratesticular ducts: ducts: tubuli -ductuli Exoocrine Recti and rete efferents 1-Seminalvesicles part testis (Vasa (seminefrous 2-Prostate tubules)&an efferentia), 3-Bulbourethralgands(of - epididymis Cowper) endocrine - vas 4-Glands of Littré part(interstitial deferens, cells of Lyedig) - ejaculatory ducts, -urethra The Testis ❖Ovoid organ 4–5cm long. Mixed gland, formed of stroma & parenchyma ❖Stroma: testis is covered by 3 coats, from outside inwards they are: Stroma: testis is covered by 3 coats, from outside inwards they are: Double layered peritoneal pouch brought down by the testis during its 1)Tunica descent from abdomen vaginalis: (Inner visceral & outer parietal layers of simple squamous mesothelium) 2)Tunica Dense fibrous C.T. capsule (thickened posteriorly to form albuginea: mediastinum testis) 3)Tunica vasculosa: loose vascular C.T.. ❖From mediastinum testis , thin fibrous septa radiate to the capsule.dividing each. testis into about 250pyramidal compartments (lobules). ❖Each lobule contains 1–4 convoluted semineferous tubules embedded in a C.T. stroma: containing interstitial cells of Leydig (endocrine part). Parenchyma: is formed of Exocrine part: semineferous tubules Endocrine part: interstitial cells of Leydig  Parenchyma: is formed of Exocrine part: Endocrine part: semineferous tubules interstitial cells of Leydig ST is lined by 2 types of cells: stratified germinal epithelium (Spermatogenic cells) Sertoli cells  I- The semineferous tubule ❖Highly convoluted tubule ❖about 0.2 mm in diameter ❖ average 50 cm long ❖Has well-defined basement membrane. ❖ surrounded by C.T. rich in SM-like cells called myoid cells. Myoid cells rhythmically contract to aid sperm movement along the length of the tubule ❖ST is lined by 2 types of cells: 1- stratified germinal epithelium (Spermatogenic cells) 2- Sertoli cells 1- Spermatogenic cells ❖These are the germ cells lining the ST in stratified layers (4–8cells). ❖They differentiate from basal region of ST to its lumen in a sequence of events called ‘’Spermatogenesis’’ (the process of formation of spermatozoa from spermatogonia). Spermatogenic cells are: 1-Spermatogonia 2-1ry spermatocytes 3-2ry spermatocytes 4-Spermatids 5-Spermatozoa Spermatogenesis ❖Begins at puberty under the. control of FSH of the pituitary gland ❖Lasts about 64-70 days & includes 2 stages: 1-Spermatocytogenesis: (spermatogia to spermatids): involves cell division and differentiation 2-Spermiogenesis: (spermatids to spermatozoa):by metamorphosis (no cell division)  (1)Spermatogonia 2)1ryspermatocytes - The largest cell (18μm)of - Basally situated adjacent Spermatogenic series with the to basement membrane. largest nucleus. - Their nuclei have diploid - have the diploid number of number of chromosomes chromosomes which appear - Give rise to primary prominent & thick giving the spermatocytes( cell a characteristic appearance -They enter the 1st meiotic division to give rise to 2ry spermatocytes 3) 2rySpermatocytes (4) Spermatids 5) Spermatozoa - Contain haploid About 55 μm in number of - Very small cells length chromosomes - close to the Composed of a - Not seen in lumen head and a tail sections, regions. The tail - No further region includes - (as they rapidly division middle piece, divide by 2nd meiotic -Change into principal piece division to give rise to spermatozoa and the end spermatids) piece 2- Sertoli cells LM: ❖Pyramidal cells with large pale nucleus & acidophilic.cytoplasm ❖Extend from BM of ST to its lumen ❖Their lateral borders contain pockets for proliferating Spermatogenic cells ❖Lateral borders are bound by tight junctions forming the blood testis barrier  Functions of Sertoli cells: (1) Secretion :of testicular fluid , androgen-binding protein(ABP)& Inhibin hormone (2)Active translocation of differentiated spermatogenic cells &active release of mature sperms into the lumen of ST. (3)Support & nutrition of Spermatogenic cells (4) Phagocytosis of residual bodies (shed during spermiogenesis)& degenerating Spermatogenic cells (5)Formation of blood-testis barrier Blood Testis Barrier ❖Description: A belt-shaped zone formed by tight junctions between lateral borders.of Sertoli cells It divides the semineferous tubule into: ❖Basal compartment: contains spermatogonia ❖Adluminal compartment Contain so the types of spermatogenic cells ❖ Functions: ❖ Selection of nutrients. ,hormones &proper fluid needed for growth & differentiation of cells ❖ Protection of spermatocytes from harmful substances in blood and autoimmune response II- Interstitial cells of Leydig (the endocrine part of the testis). Site: present in groups in the C.T. between ST LM: ❖Polygonal in shape & ❖Pale acidophilic vacuolated cytoplasm (lipid droplets)with central large nucleus Function: ❖Secretion of testosterone  References Basic histology Functional histology High- yield histology