a&p unit 11: urology

urinary system function

1. removes metabolic wastes from blood and excrete to the outside (urine)

2. maintains balance of water and electrolytes

3. maintains pH of body fluids

urinary system organs

kidneys, ureters, urinary bladder, urethra

kidney renal capsule

tough, fibrous outer shell

kidney renal cortex

outer portion

kidney renal medulla

inner portion; renal pyramids

renal pyramids

cone shaped masses

ureter

tube leaving from kidney

renal pelvis

superior end of ureter which is expanded to form a funnel shape; major and minor calyces

renal capsule

renal pelvis

renal cortex

renal medulla

ureter

renal pyramid

major calyx

glomerulus

bowmans capsule

3 stages of urine formation

1. glomerular filtration

2. tubular reabsorption

3. tubular secretion

glomerular filtration location

renal corpuscle

glomerular filtration

bowmans capsule filters out everything except cells and proteins, fluid is now called filtrate

tubular reabsorption location

PCT, loop of Henle, DCT

tubular reabsorption

90% of water and ions are reabsorbed and put back into the blood (peritubular capillaries)

reabsorption in PCT

nutrients, ions, and water

reabsorption in loop of henle

descending = water, ascending = Na and CI-

reabsorption in DCT

hormonal regulation (ALD, ADH), fine tuning of water/electrolyte balance

tubular secretion location

DCT and collecting duct

tubular secretion

substances from blood are secreted back into DCT and removes what is not needed, maintains ion concentration of blood, helps in acid-base balance and removal of excess ions and toxins

micturition

process of expelling urine

ureters

transport urine from kidney to bladder via peristalsis

urinary bladder

pelvic cavity, behind symphysis pubis, hold 400-600mL of urine

detrusor muscle

smooth muscle layer of the bladder responsible for bladder contraction during urination

urethra

tube that carries urine outside of the body

urination process

1. storage phase

2. voiding phase

storage phase

bladder fills with urine, the detrusor muscles relax, urethral sphincters contract to prevent leakage

voiding phase

bladder fills (~150mL0 stimulates stretch receptors to initiate involuntary reflex arc mediated by the spinal cord, initiates detrusor contraction, internal sphincter relaxes (involuntary), and external sphincter relaxes (voluntary) = urination

calyc-

small cup

cort-

covering

detrus-

to force away

glom-

little ball

mict-

to pass urine

nephr-

pertaining to the kidney

papill-

nipple

trigon-

triangle