The Heart

Question 1

Know how to label a diagram of the heart

Answer 1

Yes I can!

Question 2

Describe how the blood gets pumped round the body

Answer 2

-The RIGHT TRIUM receives deoxygenated blood from the body through the VENA CAVA
-the deoxygenated blood moves through the RIGHT VENTRICLE which pumps it to the lungs via the PULMONARY ARTERY
-The LEFT ATRIUM receives OXYGENATED blood then moves to the RIGHT VENTRICLE which pumps it to the whole body via the AORTA.
-The LEFT VENTRICLE has a much THICKER WALL than the RIGHT ventricle. It needs more muscle to pump the blood round the whole body whereas the left ventricle has only to pump the blood to the lungs.
The left ventricle is also under higher pressure than the right ventricle
The valves in the heart prevent backflow of blood.

Question 3

Why does your heart rate increase when you are exercising?

Answer 3

• When you exercise your muscles need more ENERGY so you RESPIRE more
• You need more OXYGEN to your cells and to remove more CARBON DIOXIDE

Question 4

How does your heart rate increase?

Answer 4

• exercise increases the amount of CARBON DIOXIDE in the blood
• high levels of blood CO2 are detected by receptors in the AORTA and CAROTIC ARTERY
• these receptors SEND SIGNALS to the brain
• the brain sends signals to the HEART causing it to contract more frequently and with MORE FORCE

Question 5

How does the HORMONAL SYSTEM help control Heart Rate?

Answer 5

• When an organism is threatened, the ADRERNAL GLAND release ADRENALINE
• adrenaline binds to SPECIFIC RECEPTORS in the heart. This causes the cardiac muscle to CONTRACT MORE FREQUENTLY and with MORE FORCE, so the heart rate increases and the heart pumps more blood
• This INCREASES OXYGEN SUPPLY to the TISSUE, getting the body ready for ACTION