Heart & Circulation

Question 1

Cardiovascular System Purpose

Answer 1

Transport blood between the heart, organs & peripheral tissues

Question 2

Pulmonary Circuit

Answer 2

Gas exchange

Question 3

Systemic Circuit

Answer 3

Rest of the body

Question 4

Blood Functions

Answer 4

Trasports gases (O2 & CO2), nutrients (e.g. glucose), & hormones (chemical messages)
Regulates normal pH (keep it 7.3/7.4)
Prevent fluid loss (blood clotting)
Defence (white blood cells)
Maintain body temperature (absorb/release heat)

Question 5

Heart Location

Answer 5

Just behind chest wall (ant. in thorax)

In the mediastinum, in the pericardial cavity

Question 6

Pericardium

Answer 6

Sac surrounding the heart
Fibrous (outside) & serous (inside) layers
Contains [pericardial] fluid
Ensures no irritation or inflammation on the heart as it beats

Question 7

4 Muscular Chambers (pumps)

Answer 7

Atria x2

Ventricles x2

Question 8

The left side of the heart has muscle 3 times thicker…

Answer 8

than the right side because it has to pump blood to most of the body’s organs

Question 9

Right Atrium

Answer 9

Receives blood from systemic circuit and empties into the right ventricle

Question 10

Left Atrium

Answer 10

Receives blood form the pulmonary circuit and empties into the left ventricle

Question 11

Atria

Answer 11

Receiving chambers
Expandable
Connects to:
- Superior vena cava
- Inferior vena cava
- Cardiac veins
- 4 pulmonary veins (2L & 2R)

Question 12

Ventricles

Answer 12

Heart pumps
Blood pumps from ventricle through pulmonary valve to pulmonary trunk
Blood pumped form ventricle through aortic valve to aorta

Question 13

4 Valves Control Directional Blood Flow

Answer 13

Atria -> Ventricles
2x Atrioventricular valves (AV valves)
2x Semilunar valves

Question 14

Atrioventricular Valves (AV valves)

Answer 14

Located between the atria & ventricle
Fibrous tissue
Cusps (leaflets) at atrioventricular border:
- Right AV has 3
- Left Av has 2
Chordae tendinae (tedious cords attached to the leaflets)
Papillary muscles (anchor the chordae tendinae)

Question 15

Semilunar Valves

Answer 15

Located between the ventricles and blood vessels
Aortic SL valve (ventricle -> aorta)
Pulmonary SL valve (ventricle -> pulmonary trunk)

Question 16

Heart Wall

Answer 16

Endocardium
Myocardium
Epicardium

Question 17

Endocardium

Answer 17

Endo - inside
Lines inner surfaces of the heart
Endothelial cells - squamous, thin & compressed

Question 18

Myocardium

Answer 18

Middle
Cardiac muscle
Muscular walls of the heart
Atria & ventricles

Question 19

Cardiac Muscle Cells (Myocardium)

Answer 19

‘Cardiomyocytes’

Connect at attachment points (intercalated discs) so they don’t rip apart when the heart is beating

Question 20

Epicardium

Answer 20

Epi - outside
Outer surface of the heart
Visceral pericaridum
Blood vessels travel through

Question 21

Conduction System of the Heart

Answer 21

Coordinates contractions of the heart

Maintains blood flow to organs & tissues

Question 22

Cardiac Cycle

Answer 22

Diastole & Systole phases
Blood moves through the heart
Valves open & close

Question 23

Diastole Phase

Answer 23

Relaxation of ventricles
AV valves open
1. Sinoatrial node
2. Internal pathways
3. AV node
4. AV bundle (bundle branches)
5. Purkinje Fibers

Question 24

Systole System

Answer 24

Contraction of the ventricles

AV valves close