KEY wk 9 lec 1 Flashcards
3 parts of nephric system in embryp
- pronephros (induction)
- mesonephros (temporary filtration system)
- metanephros (primitive proper kidney)
pronephros
what week
from what somites
4-14th somites
disappear at 4th week
mesonephros
what week
devlelop into what
4-8 weeks
develop bowmans capsule and glomerulus
–> mesoneprhic duct
metanephros
forms
ureteral bud forms renal pelvis
outgrowth from renal pelvis form primitive collecting ducts
increase number of tubules as kidney group,
distal and proximal ends of metanephros become what
Distal Ends: Glomerulus & Bowman’s capsule
Proximal Ends: Coalesce with collecting tubules –> Distal & proximal tubules, loop of Henle
glomeruli are developed by what weeek
36
metaneprhos arise at which level and need to move up to which level by birth
what forms and regresses at each level
at L4 (28th somite) and need to go up to T12-L1
-transient lateral splanchnic arteries
2 problems with kidney ascent/ arterial form
get stuck in pelvis (ectopic kidney)
lower poles fuse together (horseshoe kidney)
kidney locations
under ribs, behind peritoneal cavity
innervation of kidney
renal plexus
urine flow
kidney pyramids (medulla) –> papilla –> minor calyx –> major calyx –> renal pelvis –> ureter
kidney pyrmaids divisions
medulla (inner and outer)
outer medulla subdivided into inner and outer stripe
kidney blood flow
renal artery
segmental artery
interlobar artery
arcuate artery
interlobular artery
afferent arteriole
glomerulus
efferent arteriole
peritubular capillaries (associated with convoluted tubules) and vasa recta (associated with loop of henle)
interlobular vein
arcuate vein
interlobar vein
renal vein
functional unit of the kidney
nephron
nephron purpose
modify filtered fluid to form urine
also for hormonal action to regulate blood pressure and urine output
nephron starts at which artery and goes to which structure to deliver urine to for excretion
interlobular artery to renal papilla
renal corpuscle is made of 2 parts (for blood filtration)
where does filtration occur
what collects filtrate
- glomerus (capillaries where filtration occurs)
- bowmans capsule (collects filtrate)
vascular and tubular pole of renal corpuscle
vascular: blood enters and exits glomerulus
tubular: filtrate enters nephron tubules for processing
renal corpuscle structure
Capillaries (glomerulus) covered by epithelial cells (Bowman’s capsule).
arterioles for bowmans capsule at vascular pole
afferent arterioles towards glomerulus
efferent arterioles away from glomerulus
glomberulualr mesangial cells
podocytes
function? found in?
GMC: remove trapped material from basement membrane of capillaries, maintain filtration rate
podocytes: sieving role in filtration
(in renal corpuscle)
bowmans space
for urine collection (after filtered by glomerulus)
nephron- proximal convoluted tubule
start at tubular pole of bowman capsule and drain it
loop of henle- nephron
starts?
cells that mark the end of thick ascending limb and beginning of distal convoluted tubule?
start at border of outer and inner stripe of outer medulla
macula densa
cells of the distal convoluted tubule
macula densa
macula densa
found where?
function?
distal convoluted tubule
salt sensors
-asses kidney function: renal blood flow, glomerular filtration, endocrine functions (renin)
nephron collecting duct
turn into what?
drain into?
connecting tubules from several nephrons merge to form cortical collecting duct which enter medulla to become inner and outer medullary collecting ducts
which merge into papillary collecting ducts
empty into calyx and renal pelvis
renal calyx is continuous with ureter
when does tubular fluid become urine and not get further altered
when enters the calyx
cells of the 2nd 1/2 of distal convoluted tubule
principal cells (respond to aldosterone; increase Na+ resorption, K+ secretion)
intercalated cells (acid base balance)
prinicpal cells
respond to aldosterone; increase Na+ resorption, K+ secretion
intercalated cells
acid base balance
medullary collecting duct is made of which cells and which function
inner medullary collecting-duct cells.
–> Respond to ADH (reabsorption of water)
juxtaglomerular apparatus where
when thick ascending limb meets macula densa
cells in the juxtaglomerular apparatus
granular cells: contain renin (granules)
extraglomerula mesangila clels
macula densa cells: salt sensors
granular cells contain
renin
functions of each part of nephron:
- renal corpuscle (glomerulus and bowmans capsule)
-proximal convoluted tubule
-loop of henle (descending and ascending limb)
-distal convoluted tubule
-collecting duct
- Renal Corpuscle:
§ Glomerulus: Initial filtration of blood.
§ Bowman’s capsule: Collects initial filtrate. - Proximal Convoluted Tubule: Reabsorbs most of the filtered water, glucose, amino acids, and ions from the filtrate back into the bloodstream.
- Loop of Henle:
§ Descending limb: Permeable to only water. As it descends into themedulla, water is reabsorbed, concentrating the fluid.
§ Ascending limb: Only transports ions out of the tubular fluid, contributing to the establishment of a concentration gradient in the medulla. - Distal Convoluted Tubule: Reabsorbs ions (aldosterone).
- Collecting Duct: Water reabsorption (ADH) and ion balance.
proximal convoluted tubule
distal convoluted tubule
collecting duct
what do they resorb?
proximal: resorb water, glucose, amino acids, ions
distal: resorb ions (aldosterone)
collecting: resorb water (ADH)
hormone in distal convulsed tubule and collecting duct to control urine output
distalCT: aldosterone (increase Na+ absorb, K+ secrete)
CD: ADH (concentrates urine)
ureters pathway
(embryo: ureteric bud)
from ureteropelvic junction –> anterior to iliac bifurcation–> anterior to psoas –> bladder via trigone
nerves in ureters
renal, testicular/ovarian and hypogastric plexuses
sensory fibers @ T11-L2
3 constriction sites of ureters
- renal pelvis
-pelvic brim anterior to bifurcation of common iliac artery
-enterance to bladder
male ureters go along
ductus deferens and anterior to seminal vesicle
female ureters go
lateral to cervix, then inferior to uterine artery
“water under the bridge”
–> uterine artery is bridge and ureters is water
parts of urinary bladder
apex
base; openings is trigone where ureters enter
neck
3 muscles/ sphincters of urinary bladder
- detrusor muscle (in wall)
- internal urethral sphincter (at neck)
- external urethral sphincter
SNS vs PNS innervation of muscles of bladder
SNS: relaxation of detrusor and contraction of internal urethral sphincter = store urine
PNS: contraction of detrusor and relaxation of internal urethral sphincter= pee
which sphincter is voluntary in the urinary bladder and whats it innervated by
external urethral sphincter; pudendal nerve (S2-S4)
muscle type in internal and external urethral sphincter; which is voluntary and involuntary
internal: smooth muscle
external: skeletal muscle, voluntary
The external urethral sphincter is a skeletal muscle located around the urethra that provides voluntary control over the release of urine from the bladder. Unlike the internal urethral sphincter (which is smooth muscle and involuntary), the external urethral sphincter allows for conscious control of urination.
PNS and SNS innervation of urinary bladder
PNS: s2-s4 spinal cord
SNS: sacral splanchnic nerves
micturition reflex
- bladder distends when urine fills
- visceral sensory fibers relay stretch to s2-s2 spinal cord via pelvic splanchnic nerves
- pelvic splanchnic nerves enter inferior hypogastric plexus, where they synapse with postganglionic PNS fibers
- detrusor muscle contracts + internal urethral sphincter relaxes
- somatic motor neurosn in pudendal nerve cause relaxation of external urethral sphincter and contraction of bulbospongiosus muscles; expel last drop of urine from urethra
3 parts of male urethra
- prostatic
- membranous
- penile/ bulbous
SLIDE 32 -35… honestly till slide 54,,,, not helpful… dont want to do lol
podocytes form
primary processes –> secondary processes to cover capillary surface
filtration slit pore are between
pedicels
proximal tubules histology of cells
central nuclei and very acidophilic cytoplasm because of the abundant mitochondria.
principal cells are rich in _____ for ____ transport
rich in aquaporins, the specific channel for water molecules,
3 layers of uters which are made of
mucosal, muscular and adventitial layers
via urothelium (transitional epithelium)
cells in bladder
umbrella cells
uretha in males (SLIDE 52)
prostatic urethra (prostate gland)
membranous urethra (through external sphincter)
spongy urethra (in erectile tissue of penise)
