Male reproductive Anatomy Flashcards
What is the pathway of sperm during ejaculation?
SEVEN UP.
Seminferous tubules, epidiymis, vas deferens, ejaculatory ducts (nothing), urethra, penis
Where are the seminal vesicles?
posterior to prostate
Where is the ejaculatory duct?
from seminal vesicle, through prostate, to urethra.
Where is cowper’s (bulbourethral) gland?
Distal to prostate, connects to urethra.
What are the parts of the posterior urethra?
Prostatic, Membranous urethra (distal to prostate), bulbar (distal to membranous)
What is the anterior urethra?
penile urethra
What causes erections?
Parasympathetic innervation, Pelvic nerve:
- NO –> incr cGMP –> smooth muscle relaxation –> vasodilation –> proerectile.
Nor-epi increases Ca2+, causes smooth muscle contraction and vasoconstriction, anti-erectile.
What causes emission?
Sympathetic nervous system - hypogastric nerve
What causes ejaculation?
visceral and somatic nerves - pudendal nerve
How does sildenafil work?
Inhibits cGMP breakdown.
What are the cell types in the seminiferous tubules?
Spermatogonia (germ cells)
Sertoli cells
Leydig Cells
Where are spermatogonia located?
Line the periphery of the seminiferous tubules.
In what order, from outside to in, are sperm at various stages of developent?
Spermatogonium
Spermatocyte
Spermatids
Spermatozoa (spermies). Wiggle in backwards into the lumen.
Where are sertoli cells located and how are they organized?
Line seminiferous tubules as well. Tight junctions between adjacent sertoli cells form blood-testis barrier –> isolate gametes from autoimmune attack.
What do sertoli cells secrete?
In development: MIF
Inhibin: inhibits FSH
Androgen-binding protein: maintain local levels of testosterone
What is the analogous female cell to sertoli cells?
granulosa cells
What endocrine function do sertoli cells have?
Convert testoserone and androstene to estrogens via aromatase
What is the effect of increased temperature on sertoli cells?
Decreased inhibin secretion, decreased sperm production.
Where are leydig cells located?
In the interstitium outside the seminferous tubules.
What is hte function of leydig cells?
To secrete testosterone in the presence of LH.
What is the effect of temperature on Leydig cells?
Unaffected.
What is the homologous female cell to leydig cells?
Theca interna cells.
What does testosterone negatively inhibit?
LH and GnRH
What does inhibin negatively inhibit?
FSH
