Male Repro System Flashcards
(30 cards)
Where do the testes lie and what suspends them? Why are they located where they’re located?
In the scrotum, suspended by the spermatic cords; kept at temperature of 2 degrees C less than abdo temp
What is the tunica vaginalis? What does it touch?
Serous sac (simple squamous epi) with outer parietal and inner visceral layers; tunica albuginea (via visceral layer)
What is the tunica albuginea?
Capsule of DICT covering the testis
Where do you find the mediastinum testis; what goes through here? What does its projections give rise to?
On the posterior surface of the testis (thickened tunica albuginea); vessels and ducts; incomplete septa to divide testis into 250 lobules
What are the two major components of the testicular lobule?
- 1-4 seminiferous tubules per lobule
2. LCT stroma (interstitial tissue) with bv’s, lymphatics, nerves, and Leydig cells (testosterone)
What sort of epi do the seminiferous tubules have? What are the tubules surrounded by? What helps move spermatozoa through the seminiferous tubules? What types of cells are in the seminiferous epithelium?
Complex stratified germinal epi;
Tunica propria (tunica lamina, peritubular tissue; has fibroblasts and myoid cells)
Myoid cells (contractile properties)
Spermatogenic cells and Sertoli cells
What is a function of the seminiferous tubules? How does this process proceed directionally? What is formed from what? What does this process require?
Spermatogenesis; proceeds from basal lamina to the lumen; spermatozoa (N) are formed from spermatogonia (2N); this process requires testosterone from Leydig cells
What structures are found between spermatogonia daughter cells? What do spermatogonia appear as?
Cytoplasmic bridges (coordinate spermatogenic events); round cells sitting on basal lamina, with heterochromatic (dark) nuclei
What phase will most primary spermatocytes be found in? How are they in terms of size and what are their nuclei like?
Prophase;
largest germ cells; large nucleus with thick strands of condensed chromatin
Do secondary spermatocytes undergo DNA synthesis prior to division?
No
What N state are spermatids in? What are they converted to? Where are these numerous? How do the nuclei differ between early and late spermatids?
Haploid; spermatozoa through spermiogenesis; most numerous near the lumen of the seminiferous tubules; early spermatids have small condensed nuclei and late spermatids have TINY highly condensed nuclei
When does spermiogenesis occur and what are the changes that occur during this process (5)?
When the spermatids are attached to Sertoli cell plasma membrane; 1. acrosome formation 2. flagellum formation (one centriole helps initiate assembly of microtubules; mito collect around prox part of flagellum and form middle piece) 3. nucleus condense and moves anteriorly 4. change in orientation (head towards basal lamina, tail towards lumen) 5. Excess cytoplasm released and Sertoli cells phagocytose; spermiation (release of spermatids into lumen to become spermatozoa)
What three parts make up the spermatozoa?
- Head (mostly a condensed nucleus with acrosomal cap having the enzymes) 2. Midpiece (mito mostly) 3. Tail (fibrous sheath wrapped around flagellar axoneme)
What cell types make up Sertoli cells? Where can it be found? What is the nucleus type? What halpes make basal and luminal epithelial compartments? Where do you find the developing germ cells?
Tall columnar non-replicating epi cells; adheres to basal lamina, extending to tubule lumen; euchromatic nucleus with a prominent nucleolus; occluding junctions at basolateral part of cell; spermatogonia and early primary spermatocytes at basal compartment, mature spermatocytes and spermatids found in luminal compartment
What are the four functions of the Sertoli cells?
- Support, protection, nutrition for developing spermatozoa
- Phagocytosis of residual bodies of spermatids and degenerating spermatogenic cells
- Secretion of testicular fluid into tubule lumen; ABP secretion and inhibin
- Blood-testis barrier made by Sertoli cell tight junctions
What does the interstitial tissue contain cell-wise? What are some characteristics of these cells? What is the major product of these cells?
Connective tissue with Leydig cells primarily;
Central nucleus, eosinophilic cytoplasm with SER, lipid droplet-rich; 95% testosterone made here; LH will stimulate Leydig cell testosterone production;
Testosterone
What factors affect spermatogenesis?
- Dietary deficiencies 2. General/local infections 3. Systemic diseases 4. Steroid hormones and related meds 5. Toxic chems 6. Ionizing radiation 7. Elevated testicular temp (e.g. testes might not descend into scrotum, leading to sterility and increased risk of testicular cancer)
What carries spermatozoa and fluid from the seminiferous tubules to the epididymis? What is the order of these ducts?
Intratesticular ducts;
ST’s, tubuli recti (straight tubules), rete testis, ductuli efferentes, epididymis
What is the rete testis? What does the ductuli efferentes contain that can only be found here for the male repro system? How does the ductuli efferentes epi appear? Why?
Anastomotic network of channels; only true cilia;
scalloped shape due to the presence of alternating cells like non-ciliated cuboidal (low columnar) cells and ciliated tall columnar cells
What is the epithelium of the ductus epididymis? What cells makes this up? What surrounds the epididymis?
Pseudostratified columnar epi; basal cells (stem cells on BL) and principal cells (tall columnar with stereocilia and basal nuclei); smooth muscle cells (more layers in tail than in head/body)
What do the sperm acquire once they go through the epididymis? What four functions does the ductus epididymis also have?
Motility and ability to fertilize oocyte with decapacitation factor;
- reabsorption of testicular fluid (head and body)
- phagocytosis of residual bodies and degen sperm (head and body)
- Principal reservoir for mature sperm (tail)
- Expulsion of sperm during ejaculation (symp)
Where does the ductus deferens empty into? What does its distal end become? What are the key histological features in terms of epi and smooth muscle?
Prostatic urethra; ampulla;
pseudostratified columnar epi (rounded basal cells), lamina propria with CT, mucosa makes folds near ampulla, thick layer of smooth muscle with inner and outer long layers separated by middle circular layer
Where are the seminal vesicles located? What are they parallel to? What does it form when joining with the ampulla? What does it secrete?
Between posterior surface of bladder and rectum; ductus deferens; ejaculatory duct
Fructose-rich substance that is pale yellow, alkaline; contributes about 70% of volume of ejaculate
Where is the prostate found? What is it composed of in terms of glands? What are the three zones and what is characteristic of each?
Inferior to urinary bladder and surrounds prostatic portion of urethra; tubuloalveolar glands; transition zone (BPH originates here, 20% prostate cancers) central zone (around ejaculatory ducts; 1-5% prostate cancers) peripheral zone (main prostatic glands, origin of >70% prostate cancers, palpable for rectal exam)
