Neph Exam 1 - Jones Content

what are the organs of the urinary system?

what are the organs of the urinary system?

diaphragm

kidney

ureter

bladder

urethra

what are the fxns of the kidneys?

maintain homeostasis (water balance, ECF ions, plasma volume, acid-base balance)

filter (excrete waste and foreign material)

produce/activate hormones (erythropoietin, renin, vitamin D to active form)

explain how urine travels

first through hilium then afferent arteriole then urine starts at glomerulus (where it is filtered) then it goes thorugh the medulla next through the pyramids then minor calyces then major calyces then to collect in renal pelvis, which is connected to ureter and the urine drains into

what is the cortex of the kidney?

houses filtering units (glomeruli)

what is the capsule of the kidney?

protective layer

what is the medulla of the kidney?

inner layer containing pyramids, calyxes, renal pelvis

what is the hilum of the kidney?

opening in capsule which allows blood supply, ureter and nerves to enter/exit

what does the afferent arteriole do?

send blood to glomerulus (1st capilllary) and 20% of fluid we filter goes into kidney and other fluid goes to efferent arteriole

what happens to the fluid from the efferent artreriole?

it goes to the peritubular cortex (in cortical nephron) or the vasa recta (in juxtamedullary nephron) then the fluid goes and meets into the venus side

where are the peritubular capillaries located?

in cortex, around the fxnal unit of nephron

where is the vasa reta

surrounding the loop of henle

what is the difference between a cortical and juxtamedullary nephron

cortical has a smaller looper and reabsorbs back into blood materia; has peritubular capillaries; higher on the image

juxtamedullary has a long loop with the vasa recta (a capillary network deep into the medulla around the long loops of henly;; lower in image

what is the goal of the kidney?

get back everything we need and remove what we don’t by filtering plasma and forming urine

describe the detailed process of the kidney

enters and filtered through glomerulus

goes to proximal tubule (75% of reabsorption)

then descending loop of henle (helps w/ water reabsorption and creating salt gradient)

then up the ascending loop to the distal convoluted tubule

when you start to have aldosteorne regulation of salt and water

then the cortical collecting duct (CCD) where ADH hormone regulated water reabsorption

then through the collecting duct

then urine starts to pull at the papillary duct

and then drain into minor calyces

what is an interesting feature of the kidney?

the tubules fold up on each other so the distal tubule ends up being right next to the glomerulus

what are the components of the renal corpuscle?

glomerulus and bowman’s capsule

what is bowman’s capsule?

the beginning of the nephron

creates layer engulfing glomerular capillaries

when something enters the afferent arteriole, where does it end up?

20% in proximal

80% out efferent to vasa recta and peritubular capillaries

what are the components of the juxtaglomerular apparatus?

ascending limb/distal tubule macula densa cells

granule cells (juxtaglomerular cells) - secrete renin

macula densa cells - regular renal fxn

mesanglial cells - communicate w/ macula and effferent/afferent to adjust resistance in arterioles

what type of control is predominant?

sympathetic control

• beta 1 stimulates renin (sympathetic nerve fiber on juxtaglomerular cell)

• alpha 1 mediated vasoconstriction - w/in afferent and efferent arterioles

• stimulate Na+ reabsorption in tubule

what connects renal pelvis to bladder?

ureters

what are composed in ureter?

adventitia, muscularis, mucosa (in order of outermost to inner most)

muscularis - smooth muscle

how goes the ureter move urine?

when it starts to feel urine, it starts a wave of contraction (peristaltic wave) helping urine to bladder

stretch contracts the smooth muscle

what is the bladder?

muscular sac composed of smooth muscle which stores and removes urine (micturition)

what composes the bladder?

detrusor muscle - lines all bladder, smooth muscle; relax = fill, contract = get smaller, increase pressure, force urine down and out

trigone - where ureters enter and sphincter begins/where urine leaves

internal and external sphincter

• internal - help hold urine in, smooth muscle, autonomic control

• external - striated, voluntary control