Unit 4 Urinary

Question 0

Urinary organs

Answer 0

1. kidneys
2. ureters
3. urinary bladder
4. urethra

Question 1

Fcn of Urinary System

Answer 1

1. plasma ion regulation
2. plasma osmolarity
3. plasma volume and bl. presssure
4. plasma hydrogen ions
5. waste elimination
6. drug excretion
7. hormone production

Question 2

Describe kidney anatomy

Answer 2

3 areas: outer renal cortex, middle renal medulla,, inner renal pelvis

nephrons, collecting ducts

Question 3

Components of nephrons

Answer 3

1. bowman’s capsule ->
2. proximal convoluted tubule ->
3. loop of henle
4. distal convoluted tubule

Question 4

Explain the blood flow through the kidneys

Answer 4

about 20% total cardiac output

various arteries -> afferent arteriole -> glomerulus -> efferent arteriole -> peritubular capillaries -> veins

Question 5

basic renal exchange process

Answer 5

filtration - reabsorption - secretion

the outcome is excretion

Question 6

explain the process of filtration

Answer 6

fluid from bl stream leaves glomerulus and enters lumen of the bowman’s capsule

glomerular capillary hydrostatic pressure ->
bowman’s capsule hydrostatic pressure <-
net filtration into capsule

Question 7

factors which influence filtration (GRF)

Answer 7

1. Myogenic
2. Nerves
3. Osmotic pressure

Question 8

how does myogenic influence GFR?

Answer 8

autorhythmic control over afferent arteriole

Question 9

how do nerves influence GFR?

Answer 9

sympathetic stimulation to afferent arteriole (alpha receptors) (vasoconstriction will decrease GFR)

sympathetic stimulation to efferent arteriole (alpha receptors) (vasoconstriction will increase GFR)

Question 10

how does osmotic pressure influence GFR?

Answer 10

(COP) increase osmotic pressure will decrease GFR

Question 11

List the amount of water filtered, reabsorbed, and percent reabsorbed.

Answer 11

f: 180 l/ day
r: 178.5 l/day
pr: 99%

Question 12

List the amount of sodium filtered, reabsorbed, and percent reabsorbed.

Answer 12

f: 630 g
r: 626 g
pr: 99.5%

Question 13

List the amount of glucose filtered, reabsorbed, and percent reabsorbed.

Answer 13

f: 180 g
r: 180 g
pr: 100%

Question 14

List the amount of urea filtered, reabsorbed, and percent reabsorbed.

Answer 14

f: 54 g
r: 27 g
pf: 50%

Question 15

discuss how glucose and aa are reabsorbed in the kidneys

Answer 15

they are 100% reabsorbed in the PCT where they use co-transport carriers with sodium ions

Question 16

discuss transport maximum and how this relates to glucose levels in normal and diabetic individuals

Answer 16

• normal bl glucose= 70-110 mmg%
• amount of glucose filtered is below the transport max, thus all glucose is reabsorbed
• a diabetic may have level of 500 mmg%
• the amount of glucose filtered is above the transport max, thus the excess amount of glucose is excreted

Question 17

dehydration occurs because

Answer 17

water follows glucose

Question 18

discuss how sodium is reabsorbed in the kidneys. include regional differences an hormonal influences

Answer 18

• active transport of sodium occurs in the proximal convoluted tubule, the ascending loops of Hnle, distal convoluted tubule, and collecting duct
• sodium reabsorption is influenced by aldosterone in the DCT and collecting ducts

Question 19

discuss how water is passively reabsorbed

Answer 19

• passive reabsorption follow sodium by osmotic difference

- ADH influences water reabsorption in the distal convoluted tubule and the collecting ducts

Question 20

discuss how urea is passively reabsorbed

Answer 20

follows the osmotic gradient created by water reabsorption (50% reabsorbed)

Question 21

discuss the process of secretion

Answer 21

some substances enter the renal tubules by secretion from the peri tubular capillaries into the tubular lumen. can involve either active or passive transport mechanisms.
-hydrogen ions, potassium ions, an penicillin are secreted in this manner

Question 22

discuss micturition

Answer 22

• capacity btn 60-800 ml
• wall contains sm muscle (detrusal muscle) inverted by autonomic nerves. at base of blasser is the internal sphincter of sm musle
• detruor muscle is relaxed, and the internal sphincter is closed when bladder is filling with urine
• around the urethra is a band of skeletal muscle called external squincter -> closed when muscle is contracted

Question 23

discuss the basic spinal reflex of micturition and how the brain can postpone or initiate voiding

Answer 23

• 300 ml of urine in the bladder cause stretch receptors to fire impulses to the spinal cord
• the effect of neurons stimulate parasympathetic nerves to contract the urinary bladder muscl
• sympathetic inhibition opens the internal sphincter while somatic inhibition relaxes and open the external sphincter
• urine will follow from the bladder
• brain stem and cerebral cortex can override the spinal reflex by inducing voiding or postponing it