The Structure and Function of the Heart

Question 1

Heart

Answer 1

Pumps blood around the body

Question 2

Cardiac Muscle

Answer 2

Makes up the heart

Question 3

Heart Chambers

Answer 3

Right and left Atrium and right and left Ventricle

Question 4

Left Ventricle

Answer 4

Is thicker than the wall of right ventricle, this is because the left ventricle has to pump blood to the WHOLE body, whereas the right ventricle only has to pump blood to the LUNGS

Question 5

AV Valves

Answer 5

Prevent the back flow of blood from the ventricles to the atria

Question 6

SL Valves

Answer 6

Prevent the back flow of blood into the ventricles from the pulmonary and aorta arteries. These valves open during ventricular contraction, allowing blood flow to the arteries, and close when arterial pressure exceeds ventricular pressure

Question 7

Volume of Blood During Contractions

Answer 7

At each contraction of the heart, the right ventricle pumps the same volume of blood through the pulmonary artery as the left ventricle pumps through the aorta

Question 8

Heart Rate

Answer 8

The number of heartbeats that occurs per minute

Question 9

Stroke Volume

Answer 9

Is the volume of blood expelled by each ventricle per contraction. The stronger the contraction, the greater the stroke volume

Question 10

Cardiac Output

Answer 10

This is the volume of blood pumped out of each ventricle per minute, and is determined by the heart rate and stroke volume

Question 11

Cardiac Output Formula

Answer 11

CO - HR x SV

Question 12

Cardiac Cycle

Answer 12

Refers to the pattern of contraction (systole) and relaxation (diastole) shown by the heart during one complete heartbeat.

Question 13

Average Cardiac Cycle

Answer 13

0,8 seconds - 75bpm

Question 14

Diastole

Answer 14

During diastole blood returning to the atria from the vena cava and pulmonary veins causes the volume of blood in the atria to increase and the blood flows into the ventricles

Question 15

Atrial Systole

Answer 15

Transfers the remainder of the blood through the atrio-ventricular valves to the ventricles

Question 16

Ventricular Systole

Answer 16

This closes the AV valves and pumps the blood out through the SL valves to the aorta and pulmonary artery

Question 17

Atrial and Ventricular Diastole

Answer 17

In diastole, the higher the pressure in the arteries closes the SL valves, and the next cardiac cycle begins

Question 18

Heart Sounds

Answer 18

The opening and closing of the AV and SL valves are responsible for the heart sounds heard with a stethoscope

Question 19

SAN (pacemaker)

Answer 19

Heart beat originates in the heart, the auto-rythmic cells of the SAN are located in the wall of the right atrium and set the rate at which cardiac muscle cells contract

Question 20

Impulses from SAN

Answer 20

Controls the timing of cardiac muscle contraction

Question 21

ECG

Answer 21

Electrocardiogram picks up currents from the heart

Question 22

Heart Regulation

Answer 22

Controlled by nervous and hormonal control

Question 23

Medulla

Answer 23

Part of the brain that regulates the rate of SAN through an antagonistic action of the ANS

Question 24

Cardio-accelerator centre of Medulla

Answer 24

Sends its nerve impulses via sympathetic nerves to the SAN - to increase HR and noradrenaline is released

Question 25

Cardio-inhibitor Center

Answer 25

Sends its information via a parasympathetic nerve to the SAN to decrease HR and acetylchlorine is released

Question 26

Blood Pressure

Answer 26

The force exerted by blood against the walls of the blood vessels and is measured in millimetres of mercury (mmHg)

Question 27

BP Generation

Answer 27

By the conduction of the ventricles and is highest in the aorta and pulmonary artery

Question 28

BP Cycle

Answer 28

As the heart goes through systole and diastole during each cardiac cycle, the arterial pressure rises and falls.

Question 29

What do you use to measure BP

Answer 29

Sphygmomanometer

Question 30

Hypertension

Answer 30

The prolonged elevation of blood pressure when at rest

Question 31

Hypertension Risks

Answer 31

Coronary Heart Disease and Strokes