fluid electrolyte and acid-base balance

Question 1

intracellular and extracellular fluid occupied

Answer 1

ICF; 2/3 ECF; 1/3 (interstitial and plasma)

Question 2

fluid balance means

Answer 2

water intake 2.5= water output 2.5L

Question 3

water intake consists of

Answer 3

metabolism, food, drinks

Question 4

water output consists of

Answer 4

faeces, sweat, insensible, urine

Question 5

osmolarity of body fluid=

Answer 5

285 osmol.

Question 6

inhibitory feedback mechanisms of drinking water include:

Answer 6

-dry mouth relief
- activation of stomach and
- intestinal stretch receptors

Question 6

thirst mechanism reflex

Answer 6

1. Osmolarity > 285, dry mouth, decrease in blood volume= decrease in blood pressure =
   
   2. osmoreceptors lose water by osmosis to the hypertonic ECF=
   3. Cells crenate/shrink
   4. stimulation of hypothalamic thirst centre=
   5. Thirst sensation created
   6. Water intake
   7. Osmolarity drops
   8. Release of ADH

Question 7

ADH regulates

Answer 7

changes in blood osmolarity

Question 8

Hormonal control is undertaken by ADH steps

Answer 8

1. Excessive sweating, dehydration or inadequate fluid intake = INCREASE in osmolarity= osmoreceptors to SHIRNK .
   
   2. Osmoreceptors in the hypothalamus detect the extracellular fluid solute concentration = OSMORECPTORS SHRINK
   3. Hypothalamus will trigger ADH release from posterior pituitary gland
   4. Thus ADH is TRIGGERED
   5. ADH then targets collecting ducts of kidneys and reabsorb water from the filtrate BACK into the blood stream via aquaporins.
   6. Water reabsorption increases= decrease in water osmolarity
   7. Feedback to hypothalamus= inhibiting more release of ADH

Question 9

HIGH LEVELS will lead to the insertion of ____ into the nephron.

Answer 9

aquaporins

Question 10

an increase in ECF osmolarity=

Answer 10

stimulates ADH release= water reabsorption (aquaporins)= concentrated urine release

Question 11

decrease in ECF osmolarity=

Answer 11

inhibits ADH release=more water lost in urine (water pass through collecting ducts)= dilute large volumes of urine produced

Question 12

long term response for blood pressure and volume regulation hormone regulated:

Answer 12

-ADH
-Angiotensin II
-aldosterone

Question 12

short term response for blood pressure and volume regulation

Answer 12

baroreceptors in sympathetic response

Question 13

where does the most water and sodium reabsorption occur in the kidney?

Answer 13

PCT

Question 14

sodium-water balance is linked tightly to…

Answer 14

blood pressure and volume

Question 15

the amount of sodium in the body determines the volume of the…

Answer 15

EFC

Question 16

plasma volume is an important determinant of…

Answer 16

blood pressure

Question 17

aldosterone controls

Answer 17

sodium ion concentration and reabsorption of sodium back into the blood stream

Question 19

RAS PATHWAY stimulated by decreased stretch (due to decreased blood volume)

Answer 19

1. Renin in the bloodstream CONVERTS angiotensinogen (plasma protein made by liver) into angiotensin I.
   
   2. Angiotensin I enters blood vessels and is CONVERTED INTO angiotensin II as it passes by the lungs.
   3. Angiotensin II causes blood vessels to CONSTRICT, increasing blood pressure.
   4. Angiotensin II stimulates aldosterone SECRETION by the adrenal gland.
   5. Aldosterone acts to diminish urinary output and INCREASE blood volume
   6. Aldosterone works through renal regulation of sodium ions in ECF.
   7. Aldosterone REDUCES excretion of sodium from the body primarily at the DCT and conducting zone.
   8. HIGH LEVELS of aldosterone= promotion of sodium reabsorption into blood. Water follows sodium through osmosis, the extracellular fluid volume INCREASES.

Question 20

Ras system explain

Answer 20

RAS system is stimulated by a
1. DECREASE IN BLOOD PRESSURE OR VOLUME.
2. Detected by DECREASE IN STRETCH of afferent arterioles or DECREASED filtrate of sodium chloride ions in the nephron.
3. Granular kidney cells SECRETE RENIN
4. In the bloodstream renin CONVERTS angiotensinogen to angiotensin I.
5. angiotensin I enters blood vessels and is CONVERTED to angiotensin II via angiotensin converting enzyme.
6. angiotensin II causes blood vessels to CONSTRICT= INCREASE VASOCONTRICTION
7. INCREASE in peripheral resistance= INCREASE in blood pressure.
8. angiotensin II targets adrenal cortex which SECRETES aldosterone.
9. Aldosterone targets DCT causing an INCREASE in sodium reabsorption and DECREASE in potassium reabsorption. Osmotic difference triggers movement of water into blood stream.
10. Blood volume INCREASES

Question 21

granular cells monitor

Answer 21

stretch within the arterioles

Question 22

macula dense cells monitor

Answer 22

sodium chloride concentration

Question 23

what is a potent vasoconstrictor of arterioles

Answer 23

angiotensin II

Question 24

the juxtaglomerular apparatus secretes____ in a response to a decrease in ____ blood pressure

Answer 24

renin decrease in blood pressure

Question 25

aldosterone…

Answer 25

regulates water reabsorption of sodium ions and secretion of potassium ions.

Question 26

if there blood volume is low aldosterone

Answer 26

increases sodium reabsorption in the DCT and decreases potassium reabsorption.