Male Reproductive System Flashcards
Testes func
Spermatozoa production
Secretion of hormones - testosterone
Testes structure:
-Each tested divided into lobules that contain seminiferous tubules (tightly coiled loops)
-Surrounded by Tunica vaginalis - double layer of mesothelium - visceral and parietal - surrounded by serous fluid)
-Visceral layer rests on Tunica albuginea
How many testicular lobules does the collagenous septa divide into and how many seminiferous tubules are there in each lobule?
-Collagenous septa dived into 250 testicular lobules
-Each lobule contains 1-4 seminiferous lobules
What does the rete testis do?
Network of tubules in posterior testis, receives sperm from seminiferous tubules and transports sperm to efferent ductules
What do the efferent ductules do?
Carry sperm from rete testis to epididymis
What is the seminiferous tubule consist of?
-Tunica propria - slender CT layer, thick seminiferous epithelium
-Basal lamina - separates Tunica propria and seminiferous epithelium
What are the 2 cell types in the seminiferous tubules?
- Spermatogenic (sperm forming cells)
- Sustentacular cells (support sperm production)
What is gametogenesis?
The process of spermatogenesis whereby spermatogonia give rise to spermatozoa
-divided into 3 phases, spermatogenesis, meiosis and spermiogenesis
What happens in Spermatogenesis vs spermiogenesisß
Spermatogenesis- the production of male gametes
Spermiogenesis- development of male gamete into motile sperm
Both together take 70 days - occur within testes
Where does final maturation of spermatozoa occur?
In the epididymis
What are undifferentiated germ cells in basal compartment called and what happens these cxells?
-Type A spermatogonia (SA)
-SA cells go through several cycles of mitotic division to produce further SA and type B spermatogonia (SB)
-SB cells undergo further mitotic division - 1 degree spermatocytes (S1)
-S1 cells undergo first meiotic division - daughter cells
-Smaller 2 degree spermatocytes undergo second meiotic division and are rarely seen
-Gametes are spermatids S3.
What then happens s3 spermatids?
-Spermatids proceed thrpugh maturation process e.g spermiogenesis to become spermatozoa (S4)
-Supported by Sertoli cells
What are the 3 segments of the spermatozoa tail?
Middle piece, principle piece, end piece
Structure of middle piece of tail?
-Approx sam elength as head
-Consists of flagellar axoneme surrounded by 9 coarse fibres arranged longitudinally
-external to core, elongated mitochondria arranged in tightly packed helix
What is prevents the mitochondria from slipping into the principle piece?
The annulus
Structure of principle piece?
Axoneme surrounded by fibrous rubs arranged in a circular ,anner
Structure of sertoli cells?
-rest on basement membrane
-Extensive cytoplasm - encloses all cells of spermatogenic series
-Oval nucleus - deep indentation
-Prominent nucleus
-Dense chromatin bodies
Func of Sertoli cells:
-Secretion of factors involved in spermatogenesis and spermiogenesis
-Secretion of factors which regulate Leydig cells and peritubular cells
-Secretion of inhibin which regulates hormone production
-Secretion of tubular fluid
-Phagocytosis of discarded spermatid cytoplasm
What are Leydig cells and what do they do?
-Found between seminiferous tubules in interstitial tissue
-Produce and secrete androgens e.g testosterone into surrounding interstitial fluid
-Occur singly/clumps and embedded in rich plexus of blood and lymph capillaries surrounding seminiferous tubules
What kind of epithelium is there in the epididymis?
Pseudostratified epithelium
-principal cells contain microvilli
Structure of prostrate gland
Consists of 20-30 tubular glands dispersed among smooth muscle and CT enclosed in fibrous capsule
Structure of internal penis
-Three cylindrical erectile bodies (corpora) covered by dense fibrous CT.
-Corpora cavernosa - paired erectile bodies that split to form crura at base of penis
-Solitary corpus spongiosum expands to form bulb of penis at base
What are the 4 zones in the prostrate gland?
-Transitional zone - surrounds proximal prostatic urethra
-Central zone - surrounds ejaculatory ducts
-Peripheral zone - 70% of glandular tissue
-Anterior fibromuscular stroma - contains no glandular tissue
Func of prostrate gland?
-Secretion of seminal fluid rich in citric acid and hydrolytic enzymes
