The Heart

Question 1

With its massive infrastructure within the body, the cardiovascular system is our very own _______________

Answer 1

transportation system

Question 2

4 main fuctions of the circulatory system

Answer 2

transport oxygen and carbon dioxide
distribute nutrients
regulate body temp
circulate hormones

Question 3

what are arteries

Answer 3

thick-walled blood vessels that ALWAYS carry blood AWAY from the heart.

Question 4

what are veins

Answer 4

thin-walled blood vessels that ALWAYS carry blood TOWARD the heart.

Question 5

order in how the blood travels

Answer 5

Arteries 🡪 Arterioles 🡪 Capillaries 🡪 Venules 🡪 Veins

Question 6

what are capillaries

Answer 6

Narrowest of all blood vessels.
RBCs travel in single file.
Branching of the capillaries increases the surface area available for diffusion.
Connects the arterial & venous systems.

Question 7

how many chambers make up the heart

Answer 7

4

Question 8

what are the top 2 chambers of the heart called

Answer 8

atria

Question 9

what are the bottom 2 chambers of the heart called

Answer 9

ventricles

Question 10

function of ventricles

Answer 10

Ventricle walls are much thicker because they have to pump over longer distances. The muscles twist to “wring” the blood out of the ventricles

Question 11

what is pulmonary circulation

Answer 11

Right atrium – right ventricle- pulmonary arteries- arterioles- lung capillaries- venules- pulmonary veins- left atrium.

Question 12

what is systemic circulation

Answer 12

Left atrium- left ventricle- aorta- arteries- arterioles- capillaries of body cells- venules- veins- superior/inferior vena cava- right atrium.

Question 13

what does the cardiac cycle refer to

Answer 13

Refers to a complete heartbeat- one contraction and a relaxation of each chamber of the heart. takes 0.8 seconds

Question 14

what are the 2 phases of the cardiac cycle

Answer 14

systole and diastole

Question 15

what is systole

Answer 15

contraction and emptying of the heart

Question 16

what is diastole

Answer 16

Diastole is when the relaxed atria fill with blood. This blood puts pressure on the AV valves which open and the blood fills the relaxed ventricles. When the ventricle is fill it contracts and this begins systole.

Question 17

how the heart work step 1

Answer 17

The heart beat begins when the heart muscles relax and blood flows into the atria.

Question 18

how the heart work step 2

Answer 18

The atria then contract and
the valves open to allow blood into the ventricles.

Question 19

how the heart work step 3

Answer 19

• The valves close to stop blood flowing backwards.
• The ventricles contract forcing the blood to leave the heart.
• At the same time, the atria are relaxing and once again filling with blood.

Question 20

what is a myogenic muscle

Answer 20

it is a safety mechanism to ensure the heart will beat even if the nervous system is damaged.

Question 21

what initiates the heartbeat

Answer 21

cluster of cells in the right atrium sinoatrial (SA) node.

Question 22

3 parts of electrical activity

Answer 22

S.A. Node
AV Node
Purkinje Fibers

Question 23

what is a sinoatriaol Node (S.A. Node)

Answer 23

Pacemaker of the heart
Beats are regulated at about 72 beats/minute
The electrical signal first passes over the atria in a wave causing the muscles to contract.

Question 24

what is an av node

Answer 24

The signals then reach a second mass of cells called the atrioventricular (AV) node. It is located in the wall of the heart between the right atrium and right ventricle.

Question 25

what are purkinje fibres

Answer 25

Special conducting fibres , Purkinje fibres, then run down the septum and throughout the muscles of the ventricles.