Questions set 1

Question 1

Cardiac cycle:

a) aortic blood flow is lowest at end/early of diastole
b) aortic pressure is highest at _mid/late__ systole
c) atrial contraction can account for 20/30/40/50% of ventricular filling
d) QRS complex happens when?
e) aortic valve opens when?

Answer 1

Cardiac cycle:

a) aortic blood flow is lowest at early diastole
b) aortic pressure is highest at mid systole
c) atrial contraction can account for 40% of ventricular filling (at rest nearer 20% but increases with tachycardia
d) QRS complex happens before isovolumetric contraction
e) aortic valve opens when LV pressure exceeds aortic pressure. initial phase of ventricular contraction is isovolumetirc with aortic valve closed.

Question 2

Acute haemorrhage responses include:

a. ADH secretion ↓/↑
b. sympathetic output ↓/↑
c. baroR discharge↓/↑
d. glucagon release↓/↑
e. intersitital fluid formation↓/↑

Answer 2

Acute haemorrhage responses include:

a. ADH secretion ↑
b. sympathetic output ↑ (when blood vol critically deplete periph symp drive drops)
c. baroR discharge ↑ - increase efferent output in response to stretch
d. glucagon release ↑
e. intersitital fluid formation↓ - fluid enters capillaries form interstitium as result of reduced hydrostatic capillary pressure

Question 3

Fetal circ at birth:

a. pulmonary vasc resistance ↓/↑
b. systemic vasc resistance ↓/↑
c. LA pr ↓/↑
d. DA closes within __hrs
e. FO closes when?

Answer 3

Fetal circ at birth:

a. pulmonary vasc resistance ↓ 80%
b. systemic vasc resistance ↑ - intense vasocontriction of umbilical vessels
c. LA pr ↑ - increased pulmonary blood flow
d. DA closes within 48hrs - high PaO2 initiates closure. Prostaglandins maintain patency
e. FO closes when LA pressure rises, fuses at 48hrs

Question 4

Factors that increase movement of fluid out of capillaries:

Answer 4

Factors that increase movement of fluid out of capillaries:

• Increased capillary hydrostatic pressure
• increased interstitial colloid osmotic pressure
• reduced interstital hydrostatic pressure or reduced colloid oncotic pressure
• venous hypertension

in sepsis permeability coeffecient is altered

(Reduced movement out of capillaries: arteriolar vasoconstriction, hypotension)

Question 5

JVP:

a wave is elevated in __

Answer 5

JVP:

a wave is elevated in Tricuspid stensosis

Question 6

JVP a wave absent in __

Answer 6

atrial fibrillation (lack of atrail contraction)

Question 7

JVP a wave enlarged are called

Answer 7

cannon a waves = atrial contraction against a closed tricuspid valve seen in complete heart block or junctional arrhythmias

Question 8

JVP v wave is caused by __

Answer 8

JVP v wave is caused by atrial filling during ventricular systole

Question 9

JVP v wave is elevated in __

Answer 9

tricuspid regurgiation

Question 10

Automaticity is ?

Answer 10

exhibited by pacemaker cells, allows spontaneous depolarisation. if apparatus is disrupted an escape rhythm can originate from in/below the AVN in a junctional escape rhythm or in the Purkinje fibres in a ventricular escape rhythm

Question 11

Cardiac ventricular muscle:

cell membranes are largely impermeable to +/- ions?

Answer 11

impermeable to - ions

includes proteins, sulphates, phosphates which remain intracellularly and contribute to negative RMP

Question 12

Cardic ventricular muscle:

depolorisation followed by plateau potential lasts about ___ms, due to __

Answer 12

Cardic ventricular muscle:

depolorisation followed by plateau potential lasts about 200 ms , due to calcium influx via slow L-type calcium channels