Week 4 - Circulatory System

Question 1

Name the two systems in the circulatory system

Answer 1

Cardiovascular system and Lymphatic system

Question 2

Functions of the Cardiovascular system

Answer 2

Transports blood which contains gases, hormones, nutrients and cells around the body.

Also assists with regulation of blood pressure and directs blood flow to tissue

Question 3

Functions of the Lymphatic system

Answer 3

Protects the body against infections

Question 4

3 types of circulations

Answer 4

1. Systemic circulation
2. Pulmonary circulation
3. Coronary circulation

Question 5

Explain the flow starting with the right atrium

Answer 5

Right atrium > Tricuspid valve > Right ventricle > Pulmonary semilunar valves > Pulmonary arteries > Pulmonary capillaries > Pulmonary veins > Left atrium > Bicuspid valve > Left ventricle > Aortic semilunar valves > Aorta > Body tissues (systemic circulation) > Superior and Inferior vena cava > right atrium

Question 6

Which side of the heart receives oxygenated blood?

Answer 6

Left

Question 7

Explain cardiac muscle structure

Answer 7

Striated, branching chains of cells that uni- or binucleate, which fibres are connected mechanically and electrically and form a functional syncytium

Question 8

Explain Functional Syncytium

Answer 8

A syncytium is a mass of cells that have merged together.

Question 9

Cardiac muscle cells are joined end to end by intercalated discs, which contain two types of specialized junctions: what are these?

Answer 9

Desmosomes - mechanically holding the cells together

Gap junctions - permit action potentials to propagate from cell to cell

Question 10

Cardiac cycle

Answer 10

All mechanical and electrical events that occur during one heartbeat

Question 11

Diastole - what occurs during this phase

Answer 11

Relaxation phase: chambers fill with blood, twice as long as systole, ventricle untwists, lengthens, unthickens

Question 12

Systole

Answer 12

Contraction phase: chambers eject blood, high blood pressure, ventricle twists, shortens, thickens

Question 13

What happens to ventricular pressure and volume during Systole?

Answer 13

Venctricular pressure increases as blood is ejected out, ventricular volume drops

Question 14

What happens to ventricular pressure and volume during Diastole?

Answer 14

Ventricular pressure stays relatively the same as ventricular volume slowly increases

Question 15

Name the two nodes in the right atrium

Answer 15

Sinoatrial (SA) node, Atrioventricular (AV) node

Question 16

What type of cells do the SA and AV node have

Answer 16

Autorythmic cells

Question 17

Sinoatrial (SA) node

Answer 17

initiates the electrical impulses to stimulate contraction

Question 18

Atrioventricular (AV) node

Answer 18

delayed impulse ensuring complete atrial systole prior to ventricular systole

Question 19

Journey of an action potential during a heart beat

Answer 19

SA node > internodal and interatrial pathway > AV node > Bundle of His > ventricular septum > Purkinje fibers > left and right ventricles

Question 20

Autonomic nervous system has two branches

Answer 20

Sympathetic and Parasympathetic

Question 21

Sympathetic nervous system

Answer 21

Fight or flight - increase in HR

Question 22

Parasympathetic nervous system

Answer 22

Rest and digest - decrease in HR

Question 23

Name the different events in an Electrocardiogram (ECG)

Answer 23

P wave, QRS Complex, and T wave

Question 24

P wave

Answer 24

Atrial depolarization (atrial contraction)

Question 25

QRS complex

Answer 25

Ventricular depolarization (ventricular systole commences)

Question 26

T wave

Answer 26

Ventricular repolarization