the heart

Question 1

what are coronary arteries

Answer 1

they cover the surface of heart supplying heart with oxygenated blood

Question 2

what does the septum do

Answer 2

muscle which separates ventricles and oxygenated and deoxygenated blood

Question 3

why does the left ventricle have a thicker muscle

Answer 3

as blood is travelling to the body so a higher pressure must be created

Question 4

what is the initiation of a heart beat

Answer 4

-wave of excitation is released from the SA node
-the wave spreads across the atria
-atrial walls contract
-waves of excitation reaches AV node
-Wave spreads down the septum along the bundle of His to the purkinje fibres
-ventricles contract pushing blood up and out of the heart

Question 5

what are atrio-ventricular valves

Answer 5

valves between the atrium and ventricles
tricuspid and bicuspid

Question 6

what side of the heart pumps deoxygenated blood to the lungs

Answer 6

right side

Question 7

what side of the heart pumps oxygenated blood to the body

Answer 7

left side

Question 8

what do tendinous cords do

Answer 8

attached to the valves and prevents them from turning inside out when the ventricle walls contract

Question 9

what is systole

Answer 9

contraction of the heart muscle

Question 10

what is diastole

Answer 10

relaxation of the heart muscle

Question 11

what is an ECG trace

Answer 11

monitors the electrical activity of the heart

Question 12

what is bradycardia

Answer 12

slow heart rhythm

Question 13

what is ectopic heartbeat

Answer 13

an extra beat or an early beat of the ventricles

Question 14

what is fibrillation

Answer 14

uncoordinated contraction of atria and ventricles

Question 15

what is trachycardia

Answer 15

rapid heart rhythm

Question 16

why is it important for the atria and ventricles to be in coordination

Answer 16

causes fibrillation which causes an inefficient pumping

Question 17

what does the P wave show on an ECG

Answer 17

shows the excitation of the atria

Question 18

what does the QRS waves show on a ECG

Answer 18

indicates the excitation of ventricles

Question 19

what does the T wave show on an ECG

Answer 19

shows diastole

Question 20

properties of the atria

Answer 20

-thin walls as does not need to contract
-elastic walls to stretch when blood enters

Question 21

properties of left ventricles

Answer 21

-thick walls to enable contraction
-this creates higher blood pressure to enable blood to flow longer distances (to lungs and the rest of the body)

Question 22

properties of the right ventricle

Answer 22

-pumps blood to the lungs
-blood needs to be at lower pressure to prevent damage to capillaries in the lungs and to allow time for gas exchange to happen

Question 23

what are the two veins in the heart

Answer 23

pulmonary vein and the vena cava

Question 24

what does the vena cava do

Answer 24

transports deoxygenated blood from the body to the right atrium

Question 25

what does the pulmonary vein do

Answer 25

carries oxygenated blood from the lungs to the left atrium

Question 26

what are the two arteries in the heart

Answer 26

pulmonary artery and aorta

Question 27

what does the pulmonary artery do

Answer 27

carries deoxygenated blood from the right ventricle to the lungs

Question 28

what does the aorta do

Answer 28

carries oxygenated blood from the left ventricle to the body

Question 29

when do valves open and close

Answer 29

opens when pressure is higher behind the valve closes when the pressure is higher in front of the valve

Question 30

what happens in diastole

Answer 30

-ventricles and atria are both relaxed -The pressure in the ventricles drops below the aorta and pulmonary artery, forcing the SL valves to close -The atria continues to fill with blood -Blood returns to the heart via the vena cava and pulmonary vein -Pressure in the atria rises above that in the ventricles, forcing the AV valves open -Blood flows passively into the ventricles without need of atrial systole

Question 31

when are the atrioventricular valves open and closed

Answer 31

open- atrial systole and diastole closed- ventricular systole

Question 32

when are the semi-lunar valves open and closed

Answer 32

open- ventricular systole closed- atrial systole and diastole

Question 33

what is the pressure like in the aorta

Answer 33

high

Question 34

what is the pressure like in the tissue fluid

Answer 34

low

Question 35

what is the pressure like in the lymph

Answer 35

low

Question 36

what is the pressure like in the blood in vena cava

Answer 36

low