week 7 - HEART

Question 1

AV valves

Answer 1

close: ventricles contract AP<VP
open: ventricles relax AP>VP
- anchored by chordae tendinae to papillary muscles

Question 2

SL valves

Answer 2

close: ventricles relax AP>VP
open: ventricles contract AP<VP

Question 3

coronary circulation 1

Answer 3

L and R coronary arteries arise from base of aorta

Question 4

coronary circulation 2

Answer 4

L coronary artery gives rise to the anterior ventricular artery and R coronary artery gives rise to the posterior interventricular artery

Question 5

coronary circulation 3

Answer 5

anterior interventricular artery supplies oxygenated blood to the anterior ventricles and the posterior interventricular artery supplies oxygenated blood to posterior ventricles

Question 6

coronary circulation 4

Answer 6

middle cardiac vein drains blood from the posterior ventricles to the coronary sinus and the great cardiac vein drains venous blood to coronary sinus - returns to the right atrium

Question 7

blood pathway 1

Answer 7

blood enters the right atrium from the superior and inferior vena cava

Question 8

blood pathway 2

Answer 8

blood moves to the right ventricle through the tricuspid valve

Question 9

blood pathway 3

Answer 9

blood leaves the right ventricle via the pulmonary semilunar valve and moves into the pulmonary trunk

Question 10

blood pathway 4

Answer 10

pulmonary trunk divides into left and right pulmonary arteries that take blood to the lungs - carbon dioxide is taken out and oxygen is put into blood

Question 11

blood pathway 5

Answer 11

blood returns to the heart via pulmonary veins to the left atrium

Question 12

blood pathway 6

Answer 12

blood moves from left atrium into left ventricle through aortic valve/mitral valve

Question 13

blood pathway 7

Answer 13

blood leaves the left ventricle via the aortic semilunar valve and moves into the aorta where it is distributed around the body

Question 14

phase one cardiac cycle - ventricular filling

Answer 14

atria: relaxed then contracted
ventricles: relaxed
chamber: atria P>ventricular P
AV valves: Open
VP/AP: ventricular P<arterial P
SL valves: closed
blood movement: atria - ventricles

Question 15

phase 2a cardiac cycle - isovolumetric contraction

Answer 15

atria: relaxed
ventricles: beginning to relax
chamber: VP>AP
AV valves: closed
VP/AP: VP<AP
SL valves: closed
blood movement: none (isovolumetric)

Question 16

phase 2b cardiac cycle - ventricular ejection

Answer 16

atria: relaxed (diastole)
ventricles: contraction
chamber: VP>AP
AV valves: closed
VP/AP: VP>AP
SL valves: Open
blood movement: ventricles - arteries

Question 17

phase 3 cardiac cycle - isometric relaxation

Answer 17

atria: relaxed
ventricles: beginning to relax
chamber: ventricular P>arterial P
AV valves: closed
VP/AP: ventricular P<arterial P
SL valves: closed
blood movement: none

Question 18

intrinsic innervation

Answer 18

parasympathetic activity - myocardium is able to stimulate its own contraction - formed by pacemaker cells

1. sinoatrial node
2. Atrioventricular node
3. Atrioventricular bundle
4. Bundle branches
    5. Purkinje fibres

Question 19

extrinsic innervation

Answer 19

autonomic NS - modifies myocardial activity (otherwise HR is always 100bpm - set by SA node)

• Cardioacceleratory (cardiostimulatory) centre increases BOTH heart rate and force of contraction
• Cardioinhibitory centre decreases heart rate ONLY

Question 20

cardiac output

Answer 20

stroke volume x heart rate - volume of blood pumped by the left or right ventricle in one minute

Question 21

factors that effect cardiac output

Answer 21

• SV: volume of blood ejected from L or R ventricle per peat
• HR
• EDV + ESV + preload (volume of blood after diastole before systole)

Question 22

venous return

Answer 22

amount of blood returning to the heart from systemic or pulmonary circuits

Question 23

contactility

Answer 23

amount of force produced by myocardial contraction

= higher SV (lower ESV) - higher CO

Question 24

bradycardia

Answer 24

heart rate is slower than normal >60bpm

Question 25

tachycardia

Answer 25

heart rate is faster than normal <100bpm