Animal Transport 1 (Circulatory Systems and the Heart)

Question 1

Define an open transport system

Answer 1

Blood is not enclosed in vessels but bathes the cells directly (eg an insect)

Question 2

Define a closed transport system

Answer 2

Blood is enclosed in blood vessels and is never in direct contact with cells

Question 3

Define a single transport system

Answer 3

Blood passes through the heart once for each circuit of the body (eg a fish)

Question 4

Define a double transport system

Answer 4

Blood passes through the heart twice for each circuit of the body (eg a human)

Question 5

What is the disadvantage of a single circulatory system compared to a double?

Answer 5

Pressure is lost when blood passes through the capillaries of the gills. There is a lower pressure then going to the rest of the body

Question 6

Describe the circulatory system of an earthworm

Answer 6

A closed circulatory system with haemoglobin

Question 7

Describe the circulatory system of an insect

Answer 7

An open circulatory system with a fluid-filled body cavity (haemocoele). No oxygen is transported in the blood, this is instead done by the tracheal system

Question 8

Which vein returns blood to the heart from the body?

Answer 8

The vena cava

Question 9

Which vein returns blood to the heart from the lungs?

Answer 9

The pulmonary vein

Question 10

Which artery takes blood from the heart to the body?

Answer 10

The aorta

Question 11

Which artery takes blood from the heart to the lungs?

Answer 11

The pulmonary artery

Question 12

Name the wall down the middle of the heart

Answer 12

The septum

Question 13

Name the valves between the atria and the ventricles

Answer 13

Atrioventricular/bicuspid and tricuspid

Question 14

Name the valves between the ventricles and the arteries

Answer 14

Semilunar/pulmonary and aortic

Question 15

What does it mean that the heart muscle is myogenic?

Answer 15

It initiates its own contractions

Question 16

Name the hearts’ pacemaker

Answer 16

Sino Atrial Node

Question 17

What is the purpose of the AVN?

Answer 17

The atrioventricular node delays the wave of excitation, allowing the atria to finish contracting and the ventricles to fully fill before the ventricles contract

Question 18

What stops the electrical signal in the heart going straight from atria to ventricles?

Answer 18

A layer of non conductive connective tissue

Question 19

Name the tissue that conducts electricity in the septum and ventricles of the heart

Answer 19

Bundle of His in septum/ purkyne/purkinje fibres

Question 20

What does ECG stand for?

Answer 20

Electrocardiogram

Question 21

Which blood vessels supply the heart muscle itself with oxygen and glucose?

Answer 21

Coronary arteries

Question 22

What does the P wave of an ECG correspond to?

Answer 22

Depolarisation of the atria during atrial systole

Question 23

What does the QRS complex of an ECG correspond to?

Answer 23

Spread of depolarisation through the ventricles resulting in ventricular systole

Question 24

What does the T wave of an ECG correspond to?

Answer 24

The repolarisation of the ventricles during ventricular diastole

Question 25

When do the atrioventricular valves open?

Answer 25

When the pressure in the atria is higher than in the ventricles (during ventricular diastole)

Question 26

When do the atrioventricular valves close?

Answer 26

When the pressure in the ventricles is higher than the atria (during ventricular systole)

Question 27

When do the semilunar valves open?

Answer 27

When the pressure in the ventricles is higher than in the arteries (during ventricular systole)

Question 28

When do the semilunar valves close?

Answer 28

When the pressure in the arteries is higher than in the ventricles (during ventricular diastole)

Question 29

Why does pressure in the aorta never drop to zero?

Answer 29

Elastic recoil of the aorta, which decreases the volume and increases the pressure. Also the fact the semi lunar valve closes, preventing backflow.

Question 30

Why does the left ventricle have a thicker wall than the right?

Answer 30

It needs to pump blood at a higher pressure for the systemic circulation