urinary system (anatomy)

Question 1

structures of the urinary system?

Answer 1

kidneys, bladder, ureters, urethra

Question 2

functions of the urinary system?

Answer 2

• filter blood (to produce urine)
• excretion of metabolic waste products and water soluble toxins
• maintains fluid balance (regulates BP and blood volume)
• maintains blood pH

Question 3

what are the kidneys?

Answer 3

paired and about the size of a soap bar, retroperitoneal (T12-L3 on dorsal surface)

Question 4

kidneys are surrounded by? (3 layers)

Answer 4

• fibrous capsule (collagen on surface)
• adipose capsule (cushions surface)
• renal fascia (dense c.t, anchors kidney to muscle and dorsal wall of abdominopelvic cavity)

Question 5

3 regions of the kidney?

Answer 5

cortex, medulla, sinus

Question 6

urine drainage flow?

Answer 6

collecting ducts, minor calyx, major calyx, renal pelvis, ureter, urinary bladder, urethra

Question 7

microscopic anatomy of the kidney?

Answer 7

functional unit= nephrons

• around 1.25 million in the kidneys
• glomerulus (capillaries) and capsule

Question 8

functions of the nephron (3)

Answer 8

1. filtration (filtrate of blood pushed across glomerulus to glomerular capsule)
2. reabsorption (movement of useful molecules from tubules back- so not lost in urine)
   3 secretion (transport of undesirable molecules-so they can be excreted in urine, from blood into tubules)

Question 9

materials are exchanged between nephron loops/tubules and a system of?

Answer 9

capillaries- peritubular capillaries (around PCT and DCT) and vasa recta (around loops of nephron)

Question 10

what are the ureters?

Answer 10

convey urine from kidneys to the bladder

-lined in transitional epithelium and layer of smooth muscle

Question 11

urinary bladder function?

Answer 11

store urine (500mL)

Question 12

3 layers of the urinary bladder?

Answer 12

1. mucosa= transitional epithelium forms rugae and stretches
2. submucosa (connective c.t)
3. muscularis (circular and longitudinal layers of smooth muscle form powerful detrusor muscle- expels urine)

Question 13

urethra function?

Answer 13

drains bladder (shorter in females than males)
-controls micturation (urination)

Question 14

2 urethral sphincters?

Answer 14

1. internal (smooth muscle prevents leakage)

2. external (skeletal muscle voluntary control)

Question 15

micturition reflex.. explain

Answer 15

bladder fills, stretch receptors, sacral nerves— reflexive contraction of detrusor muscle— relaxation of internal urethral sphincter

Question 16

cycles of contraction become more frequent as?

Answer 16

bladder reaches its capacity

Question 17

centers in the ____ can promote micturition or storage?

Answer 17

PONS

Question 18

voiding or urine occurs with conscious relaxation of?

Answer 18

the external urethral sphincter