Physiology

Question 1

Which nerve supplies parasympathetic supply to the heart?

Answer 1

Vagus nerve

Question 2

Which nerve supplies sympathetic supply to the heart?

Answer 2

Thoracic spinal nerve

Question 3

Which skeletal muscle has the lowest membrane potential?

Answer 3

Autorhythmic Myocardium - 60mV

Question 4

P-R indicates atrial _________

Answer 4

Activation

Question 5

Do Juxataglomerular nephrons or Cortical nephrons have longer loops?

Answer 5

Juxtaglomerular nephrons ! they have Vasa Recta

Cortical nephrons have shorter loops.

Question 6

Movement of particles between the the glomerular membrane is due to _____and _____ pressures

Answer 6

Hydrostatic and Osmolar pressures.

Question 7

Does afferent or efferent tubules in the kidney have greater effect in controlling Pressure Natreusis?

Answer 7

Afferent - because if efferent is too constricted than it can actually act to increase the colloid pressure even more and hence decrease NFP.

Question 8

Proximal tubule absorbs how much sodium and water?

Answer 8

65% sodium + 65% water

Question 9

____________ is impermeable to H20 and hence only absorbs 25% of sodium. This in turn makes the urine more dilute and allows water to be absorbed in the next part.

Answer 9

Ascending loop of Henle

The descending loop absorbs 10% water.

Question 10

Aldosterone and ADH act at which part of Renal tubes?

Answer 10

Distal convulated

Question 11

Macula densa is found where?

What ion does it look at to regulate increase Renin and Angiotensin release?

Answer 11

Macula densa is found in the JGA
It looks at Sodium concentration. if low sodium it releases more Renin and hence Aldosterone to increase sodium and water absorption.

Question 12

Osmoceptors are very respondent to ________ and slightly respondent to _____. They are found in paraventricular nucleus and transfer ____ to the pituitary.

Answer 12

very respondent to Osmolality and slightly respondent to BP (Big change needed)

Release ADH (vasopressin)

Question 13

Aldosterone is released by the adrenal cortical glomreulosa cells. It is released in response to:
1.
2.

Answer 13

1. Increased k+ ion

2. Angiotensin II

Question 14

Where are Baroceptors found?

Answer 14

Aortic arch and Carotid artery

Question 15

Where are Stretch receptors found?

Answer 15

Atrium, Ventricle and Pulmonary vesicle

Question 16

________is produced by the Liver. Renin acts to convert it to ________. ACE in the _____ converts it then to Angiotensin II which acts on various sites.

Answer 16

Angiotensinogen is produced by the Liver. Renin acts to convert it to Angiotensin I. ACE in the lungs converts it then to Angiotensin II which acts on various sites.

Question 17

Angiotensin acts on Efferent arterioles or Afferent arterioles?

Answer 17

Efferent - leads to their vasoconstriction. Hence increase urine

Question 18

Renin is released in response to three things. Which of the following three out of four?

1. Renal Baroceptors - low BP –> more Renin
2. Potassium concentations –> more postassium –> more renin
3. Increased sympathetic nerves
4. Macula Densa Cells

Answer 18

1. Renal Baroceptors - low BP –> more Renin
2. Increased sympathetic nerves –> leads to decreased Renin
3. Macula Densa Cells

Question 19

What acts to increase permeability of aquopores on the luminal surface?

Answer 19

ADH

Question 20

Alpha intercalated cells secrete acid or base into urine?

Answer 20

Acid! A for A

Question 21

Na+- H+ exhanger are found where? (3)

Answer 21

PCT, Ascending loop and DCT

Question 22

Volume depletion leads to acidosis or alkalosis?

Answer 22

Alakalosis - body tries to retain Na+ and hence H+ is lost and HCO3- is also retained.

Question 23

Increased PCO2 leads to alkalosis or acidosis?

Answer 23

Acidosis in acute - due to buffering system making H+.

Question 24

Increased Aldosterone production leads to acidosis or alkalosis?

Answer 24

Metabolic alkalosis. HCO3- is reabsorbed with Na+

Question 25

Hypokalaemia leads to acidosis or alkalosis?

Answer 25

Alkalosis. To increase K+ reabsorption , HCO3- is also reabsorbed.

Question 26

Osmotic diuretics like mannitol act where?

Answer 26

Descending loop of henle

Question 27

Loop diuretics like Frusemide act where?

Answer 27

Ascending limb of henle. Prevent Sodium absorption?

Question 28

Thiazides and potassium sparing diuretics act where?

Answer 28

DCT

Question 29

ADH acts where?

Answer 29

Collecting tubules?

Question 30

Thiazide act on which channel?

Answer 30

Na+- Cl- Channels at the DCT

Question 31

Frusemide acts on which channel?

Answer 31

Na+,K+, 2Cl- Channel at Ascending loop. hence prevents reabsorption of Na+ and K+

Question 32

Myocardial cells have a longer action potential due to ___ entry

Answer 32

Ca2+ entry - it creates the plateau

Question 33

Stroke volume =

Answer 33

End diastolic volume - end systolic volume

Question 34

Frank Starling Mechanism (law of the heart):

Answer 34

When more blood flows through the heart, the ventricular walls stretch and the force of cardiac contraction increases

Question 35

MAP =

Answer 35

CO x TPR

Question 36

The __________ are the ain mechanism that maintains mean arterial pressure in response to orthostatic stress and the mild haemorrhage

Answer 36

Baroreceptors