Lp 60

Question 1

Regulation of Glomerular filtration ensure

Answer 1

Adequate BF through glomerulus: vasodilation of afferent arterioles & vasoconstriction of efferent vessels slow passage of blood through glomerulus & increase local BF

Question 2

-kidney maintains GFR & controls diameter of afferent arterioles
-myogenic mechanism
•increase systemic BP causes afferent arterioles to construct
-decrease systemic BP causes dilation of afferent arterioles

Answer 2

Intrinsic- renal auto regulation

Question 3

-tubuloglomerular feedback mechanism
•controlled by macula densa cells of juxtaglomerular apparatus
-macula densa cells respond to filtrate
-increase GFR= increase filtrate
-macula densa cells release vasoconstrictor to afferent arterioles
•decrease NFP & GFR
-low filtrate= macula densa cell secretion inhibited

Answer 3

Intrinsic- renal auto regulation

Question 4

-help maintain systemic BP
-sympathetic NS overrides local regulatory mechanisms in an emergency
-afferent arterioles vasoconstriction= decrease filtration
-renin-angiotensin regulates systemic BP

Answer 4

Extrinsic- neural & hormonal mechanisms

Question 5

-low systemic BP
•juxtaglomerular cells secrete hormone renin
-renin converts plasma protein angiotensinogen to angiotensin I
-angiotensin I is converted to angiotensin II by enzymes in lungs (ACE)
-angiotensin II increase systemic BP
•vasoconstricts systemic arterioles

Answer 5

Extrinsic- neural & hormonal mechanisms

Question 6

-increase reabsorption of NA
•stimulates renal tubules & triggers release of aldosterone from adrenal glands
-increase release of antidiuretic hormone & activated thrust centre
-increase h2o reabsorption into peritubular capillaries
-decrease GFR

Answer 6

Extrinsic- neural & hormonal mechanisms

Question 7

-liquids= 1.5L
-foods= 0.75L
-metabolic h2o= 0.25L

Answer 7

Daily h20 intake

Question 8

-urine= 1.5L
-insensible sweating & expiration= 0.7L
-other= 0.3L

Answer 8

Daily h2o output

Question 9

Mechanism to ensure h2o intake is adequate

Answer 9

Thrust

Question 10

Thrust centre is in

Answer 10

Hypothalamus

Question 11

Thrust centre is stimulated by

Answer 11

Decrease h20 volume or increase Na+

Question 12

Thrust centre is inhibited when

Answer 12

-h2o is ingested
-blood plasma volume increase
-osmolarity of ECF decrease
-increase Na in diet increase thirst & h2o intake
•puts extra stress on kidneys

Question 13

H2o output > h2o intake

Answer 13

Dehydration

Question 14

H2o intake> h2o output

Answer 14

Hypotonic hydration (h2o intoxication)

Question 15

Increase fluid in IS

Answer 15

Edema

Question 16

-Na+ balance is regulated by reabsorption in kidney tubules
-Na+ is lost from body urine, sweat, feces
-hypernatremia
-hyponatremia

Answer 16

Sodium imbalance

Question 17

-usually d/t dehydration
-results in CNS dysfunction
•confusion
•fatigue
•neuromuscular irritability

Answer 17

Hypernatremia

Question 18

-can be d/t:
•renal dysfunction
•water retention
•burns
•sweating
•GI dysfunction
-neurologic dysfunction d/t cerebral edema

Answer 18

Hyponatremia