BIO - Urinary System

Question 1

Urinary System Fxns (3)

Answer 1

Adjusts water content
Adjusts blood plasma ions (sodium & potassium)
Adjusts blood pH
“Balancer”of blood plasma

Question 2

Kidney

Answer 2

Process blood and form urine as waste (empties into ureters)
L-Kidney: larger
R-Kidney: inferior

Question 3

Urinary bladder

Answer 3

reservoir for urine, expels urine (with urethra)

- contains detrusor muscle

Question 4

Urethra

Answer 4

Small mucous membrane–lined tube extending from the trigone (part of the bladder) to the exterior of the body

Question 5

Micturition

Answer 5

Process of urination:
Bladder volume incr > involuntary micturition contractions (from detrusor m) incr > internal urethral sphincter m relaxes (voluntarily)

Question 6

Nephrons

Answer 6

functional units of kidneys

consist of: renal corpuscle (filter blood) & renal tubule (balance- reabsorption)

Question 7

Renal Corpuscle

Answer 7

Filters fluid out of blood
Consist of Bowman capsule (glomerular capsule) that collect filtrate from glomerules (capillary network
-fenestration: pores

Question 8

Renal Tubule (3-parts)

Answer 8

Primary function is reabsorption
Either returns filtrate to blood or passes it > secreted as urine
Receives filtrate from Bowman’s capsule to transport (some filtrate is reabsorbed) > collecting duct
1st part: proximal convoluted tube (closest to Bowman capsule) - winding
2nd part: Henle loop
- thin descending limb > sharp turn > thin to thick ascending limb
3rd part: distal convoluted tubule - joins common collecting duct

Question 9

Nephron blood supply

Answer 9

Afferent arteriole (enters glomerular capillary network)
Efferent arteriole: leaves glomerulus > peritubular blood supply (along renal tubule)
  -Vasae Rectae: vessels along nephron (allows transferring of substances to/from blood)

Question 10

Kidney Fxn (3)

Answer 10

Filtration
Tubular reabsorption
Tubular secretion

Question 11

Urine formation (3 parts)

Answer 11

Filtration: substances to bowman’s capsule
Tubular Reabsorption: passive/active transport from all renal tubules (greater at proximal convoluted tubules)
Tubular Secretion: movement of substances out of blood > tubular fluid (part of urine)

Question 12

PROXIMAL CONVOLUTED TUBULE

Answer 12

drains Bowman’s capsule
almost complete absorption of nutritionally important substances takes place here
- reabsorption of water/solutes recovered by blood

Question 13

Na Reabsorption

Answer 13

Requires active transport (from hormones)

• Aldosterone: incr Na/K pumps,incr Na blood, incr H2O reabsorption
• ADH: influences reabsorption of H2O

Question 14

Na Loss

Answer 14

Atrial natriuretic hormone: promotes loss of Na & H2O = incr urine output

Question 15

Urine Composition

Answer 15

Nitrogenous wastes
Electrolytes: Na, K, ammonium, chloride, bicarbonate, phosphate, and sulfate
Toxins
Hormones

Question 16

Urinary secretion

Answer 16

movement of substances from the bloodstream to the tubule of the nephron

Question 17

Medullary region of Kidneys (structures)

Answer 17

nephrons
interlobular arteries
renal pyramids