UT104 - histology Flashcards
Where are mesangial cells found?
within the renal corpuscle and along its vascular pole; they reside within the basement membrane of the glomerular endothelial cells
what are the roles of mesangial cells?
1) phagocytotic
2) generate and maintain the extracellular matrix
3) regulate capillary flow
4) communicate with endothelial cells and podocytes
5) secrete interleukin-1 and platelet-derived growth factor in response to glomerular injury
what is the purpose of the juxtaglomerular apparatus?
regulates systemic blood pressure by controlling the renin-angiotensin-aldosterone system
what are the components of the juxtaglomerular apparatus?
1) macula densa
2) juxtaglomerular cells
2) extraglomerular mesangial cells (Lacis cells)
why do patients with chronic renal failure suffer from anemia?
Because the kidney’s release erythropoietin (EPO) which is produced by the mesangium cells of the glomerulus and stimulates erythropoiesis in the bone marrow
what are the functions of the male reproductive system?
1) produce spermatozoa
2) produce seminal fluid
3) produce androgens
4) delivery of male gametes into female reproductive tract
what do leydig cells secrete?
testosterone
what stimulates leydig cells to produce testosterone?
LH
what is spermiogenesis?
when round spermatids form elongated spermatozoa
what is bilateral anorchia?
when the testes were presumably present but were absorbed before birth or postnatal. These patients have normal external genitalia
what is leydig cell aplasia?
congenital absence of leydig cells is a cause of male pseudohermaphroditism associated with ambiguity of the external genitalia
trace the flow of spermatozoa from the seminiferous tubules to outside the body.
seminiferous tubules –> retes testis –> ductuli efferentes –> ductus epididymus –> vase deferens
what is the difference between the retes testis and the ductus efferentes?
the rete testis is lined by cuboidal epithelium with surface microvilli and the ductus efferent is lined by a single layer of columnar epithelia. It also has a thin band of smooth muscle around each ductus.
what is the function of the epididymis?
1) accumulation
2) storage
3) maturation
