Heart And Circulatory System

Question 1

What type of system to mammals have

Answer 1

Closed double cirulatory system
Blood in vessels passes twice through the heart

Question 2

Why do mammals have a doubel circulatory system

Answer 2

To pass blood around the body rapidly
When blood is passed through the lungs, pressure is reduced
If it passed immediately around the body low pressure would make circulation slow

Question 3

What are the two types of systems

Answer 3

Open and closed

Question 4

What is a closed circulatory system

Answer 4

Blood is pumped around the body and is always contained in a network of blood vessels

Question 5

What is an open circulatory system

Answer 5

Blood is not contained within blood vessels but pumped directly into body cavities

Question 6

What type of circulatory system to humans have

Answer 6

Closed
Double
Circulatory system

Question 7

Describe the two circulatory systems in the heart

Answer 7

Right side pumps deoxygenated blood to the lungs = pulmonary circulatory system
Blood returns from left side pumped to the body = systematic circulatory system

Question 8

Function of the heart

Answer 8

Hollow muscular organ located in the chest cavity whivh pumps blood
Cardiac muscle tissue specialised for repeated involuntary contraction without rest

Question 9

Function of arteries

Answer 9

Blodo vessels which carry blood away from the heart
Walls of arterioles contain lots of muscle and elastic tissue and a narrow lumen, to maintain high blood pressure

Question 10

Function of arterioles

Answer 10

Small arteries which branch from larger arteries and connect to capillaries

Question 11

Function of capillaries

Answer 11

Tiny blood vessel that connect arterioles and vanules
Size means they pass directly past cells and tissues and perform gas exchange and exchange of substances such as glucose

Question 12

Function of venules

Answer 12

Small veins which join capillaries to larger veins

Question 13

Function of veins

Answer 13

Blood vessels which carry blood back towards the heart
The walls of veins are thin in comparison to arteries, having less muscle and elastic tissue but a wider lumen
Valves help maintain blood flow back towards the heart

Question 14

How are contractions of heart muscles and volume related

Answer 14

Contraction of heart muscles = decrease in volume of corresponding heart chamber

Volume decreases = pressure increases
Volume increases = pressure decreases

Question 15

How do valves affect the cardiac cycle

Answer 15

Heart valves open and close due to pressure changes in different heart regions
Valves open when pressure of blood behind them is greater than the pressure infront
Close when p in front is greater than behind

Question 16

Name the two typ of systoles

Answer 16

Atrial systole
Ventricular systole

Question 17

What happens when the atria walls contract

Answer 17

Atrial volume decreases
Atrial pressure increases

Question 18

How do atrioventricular valves open

Answer 18

Pressure in the atria rises above that in the ventricles forcing the atrioventricular valves open
Blood is forced through
Ventricular pressure and volume increases as the ventricles receive blood from the atria

Question 19

What happens when the ventricles contract

Answer 19

Ventricular volume decreases
Pressure increases

Question 20

How do atrias close

Answer 20

Pressure in ventricles rises above pressure in atria
Forces atrioventricular valves to close preventing back flow

Question 21

How do semi lunar valves open

Answer 21

Pressure in ventricles > aorta and pulmonary artery
Forces the semilunar valves open so blood is forced into the arteries out fo the heart

Question 22

Name for when venticles and atria is relaxed

Answer 22

Ventricles = ventricular diastole
Atria = atrial diastole

Question 23

Describe the whole cardiac cycle

Answer 23

1) Atrial systole, ventricular diastole = atria contract pushing blood into the ventricles
2) Atrial diastole, ventricular systole = after the atria relax, the ventricles contract pushing blood out of the heart
3) Cardiac diastole = all chambers relaxes and blood flows into hearrt
(Goes back to 1)

Question 24

Describe the valves during atrial systole

Answer 24

Atrioventricular valves open
Semilunar valves closed

Blood flows in ventricle

Question 25

Describe valves duirng ventricular systole

Answer 25

Atrioventriular closed
Semilunar open

Blood flows into aorta or pulmonary artery

Question 26

Describe valves during diastole

Answer 26

Atrioventricular open
Semilunar closed