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
renal cortex
outer portion of kidney
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
renal tubule
proximal convoluted tubule (PCT)
descending loop of Henle
ascending loop of Henle
distal convoluted tubule (DCT)
blood flow (heart -> kidney)
aorta renal artery interlobar artery arcuate artery interlobular artery afferent arteriole glomerular capillaries efferent arteriole peritubular capillaries / vesa recta
vesa recta
long-hairpin shaped vessels that run parallel to the loops of Henle; slow rate of blood flow which helps maintain the osmotic gradient required for water reabsorption
juxtaglomerular apparatus
point of contact between the afferent arteriole and the distal convoluted tubule; regulates glomerular filtration; macula densa, juxtaglomerular cells
macula densa
cells in DCT in contact with afferent arteriole; dense spot
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; proteins are NOT filtered
hydrostatic pressure (renal)
glomerular capillaries 60mmHg
Bowman’s capsule 15mmHg
oncotic pressure (renal)
glomerular 25mmHg
Bowman’s capsule 0mmHg
amount of production
filter 125ml per minute; most reabsorbed
glomerular filtration rate
juxtaglomerular apparatus
blood pressure/volume
tubular reabsorption
- process by which substances are transported from the glomerular filtrate to blood in peritubular capillaries
- most occurs in PCT through active transport/osmosis
- reabsorbed substances include: glucose (only in PCT), amino acids, water, ions, etc.
tubular secretion
- process by which substances are transported from the blood in peritubular capillaries into the DCT.
- maintains ion concentrations (Na+ and K+ are inversely related)
regulation blood concentration/volume
ADH promotes reabsorption of water through the collecting ducts (negative feedback); stimulus is based on osmolarity of ICE of superoptic nuclei in hypothalamus
excretion of wastes
by products from amino acid metabolism (urea) and nucleotide metabolism (uric acid); reabsorbed by tubules, but secreted back into urine
urine composition
95% water
5% urea, uric acid, amino acids, electrolytes
ureters
- small tubes that carry urine from kidneys to bladder through peristaltic movements
- 25-29cm; retroperitoneal
- 3 layers: inner mucosa (transitional epithelium), middle muscular (smooth muscle), outer serosa (fibrous CT)
bladder
- within pelvic cavity, behind symphysis pubis
- hollow, distensible, muscular (detrusor) with transitional epithelium covered with fibrous CT
- function: storage of urine
urethra
- tube that carries urine from bladder to outside
- length: 4cm (F), 20cm (M)
- internal (smooth m.) and external (skeletal m.) sphincters
micturition
process by which urine is expelled from he 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 ducts minor calyx major calyx renal pelvis ureter urinary bladder urethra POTTY! :D
3 common diseases of urinary system
- cystitis/ureteritis: bacterial infection; pain, frequency, urgency, possible fever
- kidney stones: 75% calcium oxalate; can be seen on X-ray; pain management, lithotripsy, or surgery
- pyelonephritis: kidney infection often resulting from bladder infection; same symptoms plus sharp flank pain