Histology Flashcards
3 functions of kidney and urinary tract?
maintain water and electrolyte homeostasis, body fluid osmolality and acid-base balance
excrete toxic metabolic waste products (urea and creatinine)
acts as an endocrine gland producing renin and erythropoietin
what is erythropoietin
related to RBC production and maintainance
what are the papillae?
apices of medullary pyramids which point towards the hilum, ending on the minor calyces
at what point does urine drip off from the kidney/
papillae
what are the renal columns?
acts as conduit for renal blood supply
give structure
blood supply to the kidneys?
arteries enter and travel up through renal columns to supply the renal capsule
the medulla receives its supply from the capsule
basic functional unit of the kidney?
nephron
what are nephrons composed of and how long are they?
renal corpuscle and renal tubules
each is around 45-65mm long
nephrons empty into what?
collecting system
what does the renal corpuscle do?
production and collection of glomerular filtrate
structure of the renal corpuscle?
formed of a tuft of capillaries called the glomerulus and the cup of simple squamous epithelium at the blind end of the nephron which the capillaries invaginate into called bowmans capsule
how does the renal corpuscle develop?
tuft of capillarie envaginate into bowmans capsule (cup of squamous epithelium)
coating the capillaries in the epithelium
what 2 cell layers separate the blood from the glomerular filtrate?
capillary endothelium and a specialised epithelium which lies on top of the glomerular capillaries (made of podocytes)
the endothelium is fenestrated with pores and the podocytes have interdigiting cell processes forming filtration slits
how much glomerular filtrate is produced per minute? how does this compare to urine production?
100-125ml/min
only 1ml/min of urine
afferent vs efferent arteriole?
afferent is larger as some volume is lost from capillaries at bowmans capsule
vascular vs urinary pole of glomerulus?
the beginning of the proximal renal tubule is opposite where the afferent and efferent arterioles enter and leave bowmans capsule
= vascular end and urinary pole