The Heart And Circulatory System

Question 1

Why do large organisms need a transport system ?

Answer 1

Small surface area to volume ratio.
Long diffusion pathway therefore requires specialised systems for efficient gas exchange. High metabolic rate requires a lot of oxygen for gas exchange.

Question 2

What are the benefits traveling from the intestine and stomach to the liver via the hepatic portal vein before rejoining the circulatory system.

Answer 2

Liver processes toxins in ingested food.

Question 3

What is pulmonary definition ?

Answer 3

Between heart and gas exchange surface

Question 4

Systemic definition

Answer 4

Between heart and body tissues

Question 5

All gerund Carey deoxygenated blood apart from …..

Answer 5

The pulmonary vein

Question 6

Why is the hepatic Portal vein not a true vein ?

Answer 6

Doesn’t take blood back to the heart

Question 7

Which blood vessel has the thickest walls and why ?

Answer 7

Arteries. To withstand the high blood pressure in the ventricles.

Question 8

In which blood vessels may backflow be an issue

Answer 8

Veins because there is less blood pressure to transport the blood forwards and the the blood may also have to travel against gravity.

Question 9

Which blood vessels join the right ventricle to the lung capillaries

Answer 9

Pulmonary artery

Question 10

Which blood vessel allows oxygenated blood to move away from the heart ?

Answer 10

Aorta

Question 11

Which blood vsessel allows deoxygenated blood to move away from the liver

Answer 11

Hepatic vein

Question 12

Which is the first blood vessel which O2 molecules meet after absorption in the alveoli.

Answer 12

Pulmonary vein

Question 13

Give 2 factors that make it more likely for an organism to have a circulatory system ?

Answer 13

High metabolic rate

Small surface area to volume ratio

Question 14

What is the advantage of a double circulatory system in mammals.

Answer 14

Increases blood pressure so increased blood flow to tissue.

Question 15

Why are fish able to have a single circulatory system ?

Answer 15

Fish are cold blooded so don’t require heat from respiration to heat their body. Therefore the energy demand per cell is lower than in mammals so a single circulatory system provides sufficient energy.

Question 16

Give the main features of transport mediums

Answer 16

Medium to carry materials such as blood plasma.
Closed system of tubular vessels.
Way of moving transport system with vessels.
Way to maintain blood flow in one direction.
Way of controlling flow rate of the transport medium.

Question 17

What are the main features of arteries ?

Answer 17

Arteries are organs.
They have elastic collagen fibres and smooth muscles to allow recoil during changes in blood pressure.
Smooth endothelium allows high pressure as there is no energy used to overcome friction. No valves

Question 18

What are the main features of arterioles ?

Answer 18

Smooth muscle cell rings
Smooth endothelium reduces friction.
Elastic layer enable vasodilation and vasoconstriction to regulate blood flow.
No valves
Thick muscle layer to withstand pressure.

Question 19

Give the main features of veins.

Answer 19

Wide lumen - low pressure
Thin walls - les elastic as pressure is low
Valves- prevent backflow of low pressure in blood
Smooth endothelium - reduces pressure
No pulsating- smooth blood flow

Question 20

What are the main features of capillaries.

Answer 20

Thin layer of endothelium cells - 1 cell thick for a short diffusion pathway.
Numerous and highly branches capillaries give a high surface area for diffusion.
Narrow linen ensure red blood cells are close to the tissue and give a short diffusion pathway.
Spaces between cells allow white blood cells to espace.

Question 21

What is the main function of the left side of the heart ?

Answer 21

Pumps oxygenated blood to body tissue

Question 22

What is the main purpose of the right side of the heart ?

Answer 22

Deoxygenated blood pumped to lungs for gas exchange.

Question 23

Which side of the heart pumps deoxygenated blood to the lungs for gas exchange ?

Answer 23

Right

Question 24

Why does the left side of the heart , especially the left ventricle, have more cardiac muscle than the right ?

Answer 24

Allow an increased pressure for blood going to the whole body.

Question 25

Why are the atria walls elastic

Answer 25

To allow collection of blood from the whole body

Question 26

Give an adaptation if the atria to collect blood from the whole body.

Answer 26

Elastic walls

Question 27

Why do the ventricles have thick muscular walls ?

Answer 27

To contract and pump blood to the heart.

Question 28

What type of muscle is the heart made out of.

Answer 28

Cardiac muscle

Question 29

What are the purpose of heart valves ?

Answer 29

Prevent backflow.

Question 30

How are valves controlled.

Answer 30

By pressure changes in the heart.

Question 31

What is the main purpose of the coronary arteries and cardiac veins ?

Answer 31

Supply the heart muscle with oxygen so that myscles can respite and remove carbon dioxide.

Question 32

What is the medical term for a heart attack ?

Answer 32

Myocardial infarction

Question 33

What happens if the coronary arteries or cardiac veins are blocked ?

Answer 33

Muscle is deprived of oxygen and therefore dries.

Question 34

What causes myocardial infarction ?

Answer 34

Blocked coronary arteries and cardiac veins.

Question 35

Compare the right and left sides of the heart

Answer 35

Right is less muscular while the left side has more muscle to allow high blood pressure transporting blood to whole body.

Right side carries deoxygenated bloody from body. Let side carries oxygenated blood from lungs.

Right side has the tricuspid valve. Left side has bicuspid valve.

Right side pumps blood to lungs. Left side pumps blood to whole body b