Heart & Circulation [Ch20]

Question 1

What are the three paths of circulation?

Answer 1

1) Pulmonary [H -> L]
2) Systemic [H -> B -> H]
3) Coronary [H -> H -> H]

Question 2

What are the two main varieties of vessel?

Answer 2

Arteries - Efferent from Heart

Veins - Afferent from Heart

Question 3

What are the main chambers of the Heart?

Answer 3

Atria [L+R, also known as Auricles]

Ventricles [L+R]

Question 4

What are the external features of the Heart?

Answer 4

Base [Top]
Apex [Bottom]
Coronary Sulcus [b/w RA & RV]
Interventricular Sulcus [b/w RV & LV]

Question 5

What are the major vessels of the Heart?

Answer 5

Vena Cava [Superior/Inferior] [B -> H]
Pulmonary Artery [H -> L, dO2]
Pulmonary Vein [L -> H, oO2]
Aorta [H -> B]

Question 6

What are the different layers of the Heart and what order are they in?

Answer 6

1) Pericardium [Outermost]
2) Epicardium
3) Myocardium
4) Endocardium

Question 7

What is the Pericardial Sac?

Answer 7

Double-walled sac containing the Heart and Roots of the Great Vessels

Question 8

What are the heart valves?

Answer 8

Tricuspid [R-Atrioventricular]
Mitral [L-Atrioventricular]
Aortic [L-Semilunar]
Pulmonary [R-Semilunar]

Question 9

What are some internal features of the Heart?

Answer 9

Interatrial Septum [wall b/w Atria]
Interventricular Septum [wall b/w Ventricles]
Chordae Tendineae [fibrous tissue connecting AV valve to Heart & Papillary Muscles]
Papillary Muscles [muscles in heart that attach to chordae tendineae to prevent inversion/prolapse of valve]

Question 10

What is the function of the Chordae Tendineae and Papillary Muscles?

Answer 10

To prevent inversion or prolapse of the Tricuspid/Mitral valve on systole [V. contraction]

Question 11

What are the foetal remnants in/of the Heart?

Answer 11

Foramen Ovale
Fossa Ovalis
Ductus Arteriosis
Ligamentum Arteriosum

Question 12

During Pulmonary Circulation, what are the Capillary Beds?

Answer 12

Anastomosis between Arteriole and Venules

Question 13

What is the Systemic Circulation?

Answer 13

Blood from the Heart around the body

Question 14

What are the main Coronary Arteries?

Answer 14

Left/Right Coronary Artery
Anterior Interventricular Artery [LAD]
Posterior Interventricular Artery [PDA]
Circumflex Artery

Question 15

What are the main Cardiac Veins?

Answer 15

Small Cardiac Vein
Middle Cardiac Vein
Great Cardiac Vein
Coronary Sinus

Question 16

How does Cardiac Muscle compare to Skeletal Muscle?

Answer 16

Smaller, only has one nucleus and contains more Mitochondria

Question 17

What are some features of the Cardiac Muscles?

Answer 17

Small size, single nucleus
Intercalated discs [interconnect cardiac muscle cells, propagate action potentials]
Many Mitochondria; reserves of Myoglobin, Glycogen and Lipids

Question 18

What is the Sarcomere?

Answer 18

Smalles functional unit of Muscle Fibre

End to End in Myofibrils

Question 19

What does the Cardiac Conducting System consist of?

Answer 19

1) Nodal Cells [Sinoatrial and Atrioventricular Nodes, Pacemaker Cells]
2) Conducting Cells [AV Bundle, Bundle Branches, Purkinje Fibres]

Question 20

What is the function of contractile cells in the Heartbeat?

Answer 20

Produce Contractions

Go through Depolarisation, Plateau, and Repolarisation

Question 21

What occurs in a heartbeat?

Answer 21

1) SA Node spontaneously depolarises
2) AP travels through atrium to AV Node [A. Systole]
3) AV node passes AP to AV bundle [Bundle of His]
4) AP Travels along Purkinje fibres from Bundle of His
5) Purkinje fibres and moderator band [V. Systole]