urinary system

major exretory organs of body

temporary storage reservoir for urine

transport urine from the kidneys to the bladder

transports urine out of the body

• urea
• creatine
• (both come from protien metabolism)

• kidneys
• ureters

• renal artery (supplies blood to kid)
• renal vein (drains blood from kid)

T12-L3

• removal of toxins, metabolic wastes, excess ions from blood
• regulation of blood volume, chemical composition(electrolytes), and ph
• gluconeogenesis (new glucose production) during prolonged fasting
• endocrine functions : renin - regluation of bp and kidney function
• erythropoietin- regulation of RBC produciton
• activation of vitamin D

• layers of supportive tissue
• fibrous capsule (kidney is encased in a fibrous capsule)
• -protects kidney
• -has pain receptors (nociceptors)

• renal cortex
• renal medulla
• lobe (medullary pyramid)
• papilla (tip of renal pyramid)
• minor calyx's drain into major calyx's
• renal pelvis
• ureter

• is a branch off of the abdominal aorta
• delivers oxygenated blood to the kidneys through the renal hilum

• RSI ACA
• Renal artery
• segmental artery
• interlobal artery
• arcuate artery
• cortical radiate artery
• afferent arteriole

• structural and functional units that from urine
• about 1 million per kidney

• renal corpuscle
• bowmans capsule

• -glomerulus
• -bowmans capsule
• * visceral layer of bowmans capsule is represented by the cell podocyte
• *parietal layer of bowmans capsule

space between parietal and visceral layer of bowman's capsule

plasma leaks out of the glomerulus into bowman's space

filtrate

• in order for plasma to leave glomerulus and become filtrate it must first go through fenestrations which are in the endothelium of the glomerulus
• -basement membrane
• -podoyctes
• -podocytes make filtration slits

fenestrations plus basement membrane plus filtration slits

• enters tubular system
• after, whatever is left becomes urine

in teh cortex and medulla

glomerulus plus it's glomerular capsule

is too big to pass through the glomerulus into bowmans capsule

• -proximal convoluted tubule (PCT)
• -Loof of Henle
• -distal convoluted tubule (DCT)
• -collecting duct

• tubular reabsorption
• tubular secretion

afferent arteriole gives rise to glomerulus

• efferent arterioles
• efferent arterioles give rise to peritubular capillaries
• peritubular capillaries give rise to peritubular veins

most nephrons are cortical

• 15% of nephrons
• contain loop of henle
• contain second set of capillaries called the vasa recta in addition to peritubular capillaires
• plays critical role in concentrating and diluting the urine

moves from the filtrate to peritubular capillaries. Most reabsorption occurs in PCT (proximal convoluted tubule)

• -ADH (anti diuretic hormone)
• a. mostly in collecting duct
• b. causes increased water reabsorption
• -aldosterone
• a. principal cells

goes from blood into the filtrate

• cells where the loop of henle is becoming the DCT
• -manula densa cells
• they are chemoreceptors, sense content of filtrate
• constrict or dilate depending on sodium chloride content

• found in teh afferent arteriole
• sense blood pressure
• contain granules of renin
• If they sense BP is too low, they will secrete renin which causes aldosterone to be released from the adrenal cortex

smooth muscle which propels urine from the kidney to the bladder

the trigone

autononomic nervous system cause detrusor muscle to contract which causes urination (micturition)

• internal sphincter
• -smooth muscle
• external sphincter
• -in pelvic floor

• urination or voiding
• 3 simultaneous events
• -contration of detrusor muscles by ANS
• -opening of internal urethral sphincter by ANS
• -opening of external urethral sphincter by somatic nervous system