Unit 9 made by myself

Circulatory System

System of blood vessels with a pump and valves to ensure one way flow of blood

Circulatory System of a Fish

2 chambered heart and a single circulation

Every one circuit of the body, the blood passes through the heart once

Circulatory System in mammals

4 chambered heart and a double circulation

Every one circuit of the body the blood passes through the heart twice

The right side of the heart receives de oxygenated blood and pumps it to the lungs (pulmonary circulation)

The left side of the heart receives oxygenated blood from the lungs and pumps it to the body (Systematic Circulation)

Advantages of double circulation

Blood travelling through the small capillaries in the lungs losses a lot of pressure that was given to it by the pumping of the heart, meaning it can not travel as fast

By returning the blood of the heart after going through the lungs its pressure can be raised again before sending it to the body, meaning cells can be supplied with the oxygen and glucose they need for respiration faster and more frequently

How is blood pumped away from the heart?

Arteries

How is blood pumped to the heart

Veins

How may the activity of the heart be monitored?

ECG

Pulse rate

Listening to sounds of valves closing

What is 9?

Left Ventricle

What is 8?

Right Ventricle

What is 7 and 10?

Heart Valve

What is 6?

Left Atrium

What is 5?

Right Atrium

What is 4

Pulmonary Vein

What is 3

Vena Cava

What is 2

Aorta

What is 1?

Pulmonary Artery

What is 1

Semi Lunar Valves

What is 2

Right Atrium

What is 3

Left Atrium

What is 4

Atrioventricular Valves

What is 5?

Atrioventricular Valve

What is 6?

Right Ventricle

What is 7

Left Ventricle

What is 8

Septum

How is heart rate measured?

Beats per minute

How to investigate effects of exercise on heart rate?

Record pulse rate at rest for a minute

Do some exercise

Immediately measure pulse rate every minute until it returns to normal

Coronary Heart Disease

When a coronary artery becomes partially or temporarily blocked by fatty deposits called plaques mainly made from cholesterol, the arteries are no longer as elastic as they should be so can not stretch to accommodate blood being forced through. Heart muscle deprived of oxygen.

Risk factors for coronary heart disease

Diet high in saturated fats increasing blood cholesterol

Stress, increasing blood pressure

Smoking, nicotine causing blood vessels to narrow

Genetic predisposition, people with family history of Coronary Heart Disease are more likely to get it

Age, risk increases with age

Males are more likely to get it

How to reduce risk of coronary heart disease

Improving diet, less animal fats and more fruits and vegetables mean less cholesterol in blood and loss in weight

Quitting smoking, reduce narrowing of blood vessels

Exercising regularly, reduces blood pressure and cholesterol and stress levels and weight loss

Why are the left ventricles muscle walls thicker than the right ventricles

The right side of the heart pumps blood at a lower pressure than the left since its going to the capillaries in the lungs which would burst under higher pressure

Why is the muscle walls on the ventricles thicker than the ones of the atria

The ventricles have thicker muscular walls than the atria because the ventricles must generate enough pressure to push blood out into the arteries and into the body, whereas the atria only need a weak contraction to move blood a short distance into the ventricles below them.

Importance of septum

Separates the two sides of the heart so prevents oxygenated and de oxygenated blood from mixing so only de oxygenated blood can be sent to the lungs to become oxygenated and only oxygenated blood can be sent to the rest of the body to be used

Describe the functioning of the heart

De oxygenated blood coming from the body flows into the right atrium via the Vena Cava

Once the the right atrium is full of blood, it contracts pushing it through the atrioventricular valve into the right ventricle

The walls of the ventricle contract forcing blood past the semi lunar valves into the pulmonary artery, the valve then closes to prevent blood from flowing back into the heart

The blood travels to the lungs and moves through the capillaries through past the alveoli where gas exchange takes place.

The right side of the heart pumps blood at a lower pressure as it is going to capillaries in lungs which would burst under higher pressure

Oxygen rich blood returns through the left atrium from the pulmonary vein

Once atrium is full, it contracts, pushing blood through the atrioventricular valve into the left ventricle

Thicker muscle walls of the ventricle contract strongly to push blood forcefully into the aorta and all the way around the body

The semi-lunar valve prevents blood flowing back into the heart

Effect of physical activity on the heart

Increases heart rate during exercise to increase blood flow to the working muscles

Why is the heart beating faster during exercise important

Provides muscles with enough nutrients and oxygen for increased respiration

Removes waste products at a faster rate

Why does the heart continue to beat faster even after exercise

Ensures all excess waste products are removed from muscle cells

To deliver extra oxygen to the muscle cells to pay of oxygen debt accumulated by breaking down the lactic acid built up in the cells as a result of anaerobic respiration as the oxygen levels were not high enough for aerobic respiration

Arteries thickness

Thick and muscular with oxygenated blood

Arteries diameter of lumen

Narrow

Arteries valves?

No

Capillary thickness

One cell thick with gaps to let fluid out

Capillaries diameter of lumen

Very narrow

Capillary valves?

NO

Veins Thickness

Thin

Veins diameter of lumen?

Very thick

Do veins have valves?

Yes

Function of Capillaries

Carry blood to the cells of the tisues

Transport oxygenated blood from the arteries to the veins and de oxygenated blood from the cells to the veins

What is 1

Pulmonary artery

What is 2

Pulmonary vein

What is 3

Vena Cava

What is 4

Heart

What is 5

Hepatic Vein

What is 6

Aorta

What is 7

Hepatic Portal Vein

What is 8

Hepatic Artery

What is 9

Mesentric Artery

What is 10

Renal Vein

What is 11

Renal Artery

How is the structure of arteries adapted

Thick muscular walls containing elastic fibers to withstand the high pressure of blood and maintain the blood pressure as it recoil after the blood has passed through

Narrow lumen to withstand pressure

How is the structure of Veins adapted?

Large lumen as blood pressure is low

Contain Valves to prevent the backflow of blood as it is low pressure

How is the structure of capillaries adapted?

One cell thick walls so substances can easily diffuse in and out

Leaky walls so blood plasma can leak out and form tissue fluid surrounding cells

Components of blood

Red blood cells, white blood cells, platelets, plasma

Red blood cells function

Transport oxygen from the lungs to cells around the body. Carry oxygen in the form of oxyhaemolglobin with oxygen carried in the haemoglobin

White blood cells function

Defend the body against infections by pathogens by doing phagocytosis and antibody production

Platelets function

Clotting of blood

Plasma Function

Transport of blood cells, ions, nutrients, urea, hormones and carbon dioxide.

Role of blood clotting

Prevents blood loss and entry of Pathogens

Function of lymphocytes

Antibody Production

Function of phagocytes

Engulfing pathogens by phagocytosis

Describe process of clotting

Conversion of fibrinogen to fibrin to form a mesh