Reproductive Histology/Development Flashcards
(141 cards)
function of testis
produce androgens (testosterone) and gametes (spermatozoa)
function of excurrent ducts (epididymis, ductus/vas deferens)
maturation of sperm and transport to prostatic urethra
layers of testis
- albuginea = outer
- vasculosa = inner
- septa = separate seminiferous tubules
what enters/exits the mediastinum of testis?
- blood vessels
- lymphatics
- rete testis
pathway of sperm
seminiferous tubules –> tubuli recti (straight) –> rete testis –> efferent ductules/epididymis –> vas deferens
Leydig cells
- found in testicular interstitium
- produce testosterone (male development)
- euchromatic cells - active, pale
function of testosterone
- male development
- development of sperm in seminiferous tubules
- regulated by LH (receptors on leydig cells)
layers of seminiferous tubules
- lamina propria (fibroblasts, collagen)
- seminiferous epithelium (sertoli, spermatogenic)
Sertoli cells
- irregular euchromatic nucleus
- junctional complexes and cell junctions
- nourish and help move germ cells
- structural support via cytoskeleton - divides epithelium into basal (immature) and adluminal (mature) compartments
- ABP, inhibin, phagocytose ability
tight (occluding junctions in Sertoli cells)
- no fluid passage
- disassemble and reassemble to maintain structure but allow movement
- blood-testis barrier –> immune privileged site
what happens with damage to tight junctions?
immune cells enter –> mount a response against the sperm
role of antigen binding protein
- produced by Sertoli cells
- binds testosterone in seminiferous tubules for spermatogenic cells
- FSH dependent
- maintains or increases levels of testosterone if needed
role of inhibin
-inhibits FSH release when having excess testosterone
spermatogonia
immature germ cells
-heterochromatin
spermatogenesis
spermatogonia –> 1,2 spermatocytes –> spermatids –> spermatozoa
what cells divide by mitosis?
spermatogonia
what cells divide by meiosis?
primary and secondary spermatocytes
type A dark spermatogonia
- mitosis
- dark, ovoid nucleus
- precursors - produce clones
type B pale spermatogonia
- mitosis
- pale, euchromatic ovoid nucleus
- produce type B cells
- cytoplasmic bridges for synchronous development when differentiating
type B spermatogonia
- formed from type A pale
- round nucleus
- most mature
- differentiate into spermatocytes
primary spermatocytes
- meiosis I (22 days), large cells
- why there are most abundant in histo slide
secondary spermatocytes
-meiosis II (fast), small cells
spermiogenesis
spermatids –> spermatazoa
- Golgi phase
- cap phase
- acrosome phase
- maturation phase
hydrolytic enzymes
- formed from proacrosomal granules
- allows sperm to penetrate ovum