The Heart

Question 1

Open circulatory system

Answer 1

Heart pumps blood into vessels that are opened
Blood flows around all the cells of the body
Insects

Question 2

Advantages of closed circulatory system

Answer 2

Blood pumped around the body faster

Blood pumped in different restes in different parts as required

Question 3

Arteries

Answer 3

Away from heart
High pressure
Thick, strong walls
Small lumen
No valves 
Divided into arterioles
Blood in pulses 
Oxygenated

Question 4

Veins

Answer 4

To heart
Low pressure
Thin, weaker walls
Large lumen 
Valves
Divided into veniole
No pulse 
Deoxygenated
Prevents back-flow and stores blood

Question 5

Function of capillaries

Answer 5

One cell thick for Exchange of materials

E.g. gases, foods

Question 6

Blood Pressure

Answer 6

The force the blood exerts on the wall of the blood vessels

Question 7

Advantages of double circulation

Answer 7

Keeps oxygen rich and oxygen poor blood separate

Blood pressure is high enough to reach all parts of the body

Question 8

Diastole

Answer 8

Heart muscle relaxes

Question 9

Systole

Answer 9

Heart is contracted

Question 10

Cardiac Cycle

Answer 10

Blood enters atria by different vessels
The bicuspid and tricuspid valve remain closed
The chambers are relaxed in diastole
Increased volume of blood cause increased pressure in atria
Atria contrast in systole
Valves open and blood flows in ventricles
Atria relaxes and ventricles filled with blood contract
Bicuspid and tricuspid valve close and semi-lunar valves open
Blood is pumped out to the lungs and body
Ventricles relax and semi-lunar valves close
Cycle starts again

Question 11

Pacemaker

Answer 11

• Sino-atrial node
• Wall of the right atrium near the entrance of the vena cava
• Control the rate of heartbeat
• Sends out electrical impulses to cause atria to contract

Question 12

Closed circulatory system

Answer 12

Blood remains in a continuous system of the vessels and exchange materials through the cell of blood vessels
Human

Question 13

Transports blood out of the muscles of the heart

Answer 13

Cardiac vein

Question 14

Carries very little CO2

Answer 14

Pulmonary vein

Doctor

Question 15

Brings blood into the right atrium

Answer 15

Vena cava

Question 16

Hepatic portal vein

Answer 16

Links liver with stomach and intestines

Question 17

Movement of blood through veins

Answer 17

Voluntary muscles contract

Valves prevent backflow

Question 18

Pulse

Answer 18

The alternate contraction and relaxation of an artery as blood passed through it

Question 19

Heart beat

Answer 19

Regular, rhythmic contraction of the heart

Question 20

Blood pressure

Answer 20

The force the blood exerts on the wall of the blood vessels

Question 21

Which structure is carbon dioxide produced

Answer 21

Mitochondrion

Question 22

Why do veins have CO2

Answer 22

Veins has collected carbon dioxide from respiration

Arteries has been cleared of CO2 in lungs

Question 23

Role of carbon dioxide in breathing system

Answer 23

Medulla oblongata registers blood carbon dioxide levels

More CO2 results in faster breathing

Question 24

Name of two circuits

Answer 24

Systematic circuit

Pulmonary circuit

Question 25

Systematic circuit

Answer 25

Carries blood away from heart Delivers it to most of organs and tissues Returns it to heart again

Question 26

Pulmonary circuit

Answer 26

Carries blood between heart and lungs

Question 27

Diet

Answer 27

• High in saturated fats Increases blood pressure and atherosclerosis, causes a build up of cholesterol • High in salt Increases blood pressure, salt levels increase in blood volume without increase in circulatory system volume (water is taken in)

Question 28

Exercise

Answer 28

Stimulates an increase in heart rate and blood pressure Increases strength of heart Long term: stronger heart, lower BP Strengthens cardiac muscle

Question 29

Smoking

Answer 29

Highly addictive Nicotine - addictive drug Causes an increase in heart rate and blood pressure Can lead to heart disease and stroke

Question 30

Atrial-ventricular node

Answer 30

* Near the septum wall between the atria and ventricles | * Receives electrical impulses from SA node to control the heart rate

Question 31

Cardiac Cycle | Stage 1

Answer 31

* Atria receives blood and begins to fill at the same time * Bicuspid and tricuspid valve remain closed * Chambers are in diastole * Increased volume of blood causes increased pressure in atria * Atria contracts (systole)

Question 32

Cardiac Cycle | Stage 2

Answer 32

* Bicuspid and tricuspid valve open and blood flows into the ventricles * Atria relaxes and ventricles now filles with blood contract (systole) * Bicuspid and tricuspid valve close and semi-lunar valve open * Blood is forced to pulmonary artery and aorta * Ventricles relax (diastole) * Semi-lunar valves close * Cycle starts again

Question 33

What are the arteries made from

Answer 33

* Outer layer - collagen (connective tissue) * Inner layers - elastic tissue and smooth muscle * Innermost layer is called endothelium

Question 34

How Pacemaker works

Answer 34

* Pacemaker sends out electrical impulses that cause Atria to contract * Impulses reach AV node and pulse is strengthened and sent to Purkinje fibers * Causes wall of ventricles to contract and heart beats