Cardiovascular 1

Question 1

Blood Flow at Rest and Exercise.
how is it regulated

How much blood is circulated at rest
in exercise

redistribute bloodflow to…

Answer 1

Arterioles
Pre-capillary sphincters

5L per minute
40L per minute

redistribute blood flow to the muscles and less to the liver and kidneys(10%)

Question 2

Pericardium
functions
between the parietal and visceral serous

Pericarditis
increased what…
and accumulation of…
Caused by…
can constrict hearts…. and results in

Answer 2

Tough inelastic sheath covering heart
- Anchors heart
- Acts as a constraint to enable ventricular interaction
- Pericardial fluid for lubrication

Pericarditis
- Inflammation of the pericardium
- Increased capillary permeability
- Fluid accumulation in pericardial cavity
- Caused by viruses, bacteria, or fungi

May restrict heart’s movement and filling
⬧ Results in cardiac tamponade, heart unable to pump

Question 3

Coronary arteries on surface

Answer 3

Prevent compression during contraction
RCA, right marginal, anterior interventricular artery, LCA, Left marginal artery

Question 4

most blood goes straight into ventricles not in diastole

Pulmonary/Aortic valves
prevents… //// open when

Atrio-ventricular (AV) valves
Prevent…. ///// open when

TEST: If you are in ejection, aorta is…. and bicuspid is….

Answer 4

Pulmonary/Aortic valves
- prevent backflow from aorta and pulmonary artery back into ventricles
- Open in systole (contraction), when pressure increases in ventricle greater than in aorta and pulmonary trunk

Atrio-ventricular (AV) valves
- Prevent back-flow from ventricles back to atria
- Open in Diastolic filling, closed in systole

aorta open and bicuspid is closed, never all 4 open at the same time

Question 5

Atrio-ventricular Valves
Chordae Tendinae…
Prevents….
As heart contracts, what muscle contracts…
Papillary muscles control tension on….

Answer 5

Atrioventricular Valves
- Chordae Tendinae anchor AV valves to papillary muscle
- Prevents eversion of valve (back-flow)
As heart contracts, papillary muscle contracts
- Control tension on chordae tendinae

Question 6

AV valves

Aortic and Pulmonary Valves

Answer 6

• Open in filling (diastole)
• Closed during contraction (systole)
• Open during systole (contraction)
• Closed during diastole (relaxation

Question 7

Valve Problems - Murmurs
Stenosis

TEST: hear a murmur for a stenosis when it SHOULD be opening (jetting/whistling sound)

Insufficiency or Regurgitation
due to….
can develop over…. after a….

TEST: hear a murmur for a regurge when it SHOULD be closed (swishing/whirring sound)

Answer 7

aortic valve not opening properly and not shooting out enough blood
Stenosis
- Narrowing of heart valve (eg. Fibrosis)
- Faulty opening
- Decreased ejection

Faulty closure
* backflow
* Decreased forward ejection and stroke volume

• Due to Rheumatic Heart disease
• Auto-immune disease
• Can develop over months or years after a Strep infection (if antibiotics are not finished)

Question 8

Valve Problems and treatment

Orientation of muscle fibres

less twist?

Answer 8

Valve replacement

Ventricular Torsion
Allows for more efficient ejection
Produces diastolic suction
More efficient filling

can be an early indicator of heart attack

Question 9

Cardiac muscle

intercalated disc

Answer 9

A short muscle fibre

Desmosomes - Withstand stress

Gap junctions - Movement of ions, Electrical impulses