Urinary system Flashcards
urinary system
kidneys, ureters, urinary bladder, urethra remove metabolic wastes from blood out of the body
kidney location
high on posterior abdominal wall left is higher than the right retroperitoneal
renal capsule
TOUGH fibrous shell around kidney
pain receptors are here
renal cortex
outer portion of kidney
(Next layer inside kidney from the renal capsule)
renal medulla
inner portion of kidney
renal pyramids
cone shaped masses of tissue in renal medulla
renal pelvis
superior end of ureter, expanded to form funnel shape
major calyx (calyces)
divisions of renal pelvis (2-3)
minor calyx (calyces)
divisions of major calyx (4-6)
papilla
tip of renal pyramid
renal maintenance of blood
RBC formation (erythropoietin) blood pressure (renin) blood volume (ADH) blood composition (osmolarity) blood pH (bicarb) vitamin D
nephron
functional unit of kidney; 85% are cortical, 15% are juxtamedullary; composed of renal corpuscle and renal tubule
renal corpuscle
glomerulus within Bowman’s capsule (Filtration unit)
renal tubule (Know for Lab Final!)
- proximal convoluted tubule (PCT) 2. descending loop of Henle 3. ascending loop of Henle 4. distal convoluted tubule (DCT) 5. Collecting Duct (empties into minor calyx)
blood flow (heart -> kidney)
aorta renal artery interlobar artery arcuate artery interlobular artery afferent arteriole glomerular capillaries efferent arteriole peritubular capillaries / vesa recta InterlobULAR veins Arcuate veins InterlobAR veins Renal vein
juxtaglomerular apparatus
point of contact between the afferent arteriole and the distal convoluted tubule (DCT);
Cells: very important in regulation of glomerular filtration
macula densa
“Dense spot”
cells in DCT in contact with afferent arteriole
juxtaglomerular cells
smooth muscle cells in afferent arteriole
urine formation
glomerular filtration tubular reabsorption tubular secretion
glomerular filtration
fenestrated glomerular capillaries filter water and dissolved materials from blood, leaving filtrate in Bowman’s capsule
pressures that promote filtration
capillary hydrostatic pressure: 60mmHg
Bowman’s osmotic pressure: 0 mmHg
amount of production
filter 125ml per minute; most reabsorbed
glomerular filtration (step 1 of urine)
filtration ois due to a force called hydrostatic pressue
Inside glomerular capillaries –> 60mmHg
–>Bowmans capsu: 15mmHg
tubular reabsorption (step 2 of urine)
- process by which substances are transported from the glomerular filtrate to blood in peritubular capillaries
****2. most occurs in PCT through active transport/osmosis
- reabsorbed substances include: glucose (only in PCT), amino acids, water, ions, etc.
tubular secretion (step 3 of urine phase)
- process by which substances are transported from the blood in peritubular capillaries into the DCT.
- maintains ion concentrations in blood
- as you absorb more sodium (Na) = more potassium (K+) gets passed on. (They are inversly related)
regulation blood concentration and volume
ADH promotes reabsorption of water through the DCT ——This negative feedback prevents DEHYDRATION
stimulus of ADH is depended on osmolarity of ICF of supraoptic nuclei in hypothalamus
excretion of wastes (Urea and Uric Acid)
by products of metabolism (
- urea from amino acid metabolism
- uric acid from nucleotide metabolism
*wastes are RE-absorbed by tubules, then SECRETED back INTO urine and excreted
urine composition
95% water
5% urea: (uric acid, amino acids, electrolytes)
ureters are:
Small tubes that carry urine from kidneys to bladder through peristaltic movements
a. 25-29cm
b. retroperitoneal
c. 3 layers:
inner mucosa (transitional epithelium)
middle muscularis (smooth muscle)
outer serosa (fibrous CT)
bladder
Location: within pelvic cavity, behind symphysis pubis
Structure: hollow, distensible, muscular organ.
Lined with transitional epithelium
It’s a detrusor muscle =3 layers of smooth muscle
Function: storage of urine
urethra
female: 4cm
male: 20cm
micturition
process by which urine is expelled from the body
trigone
triangle formation within the bladder composed of the passageways to the ureters and urethra
urine process
Bowman’s capsule-> PCT –> loop of Henle–> DCT–>. collecting duct (urine)–>. minor calyx –>major calyx –>. renal pelvis–> ureter –>(peristalsis) urinary bladder –>urethra (micturition)
proteins are NOT filtered because
they are large and negatively charged and have low permeability
Cannot filter easily
Osmosis
reabsorption of water
Kidney releases what to help regulate BP?
Renin
(not rennin)
this is part of Renin-Angiotensin System
