IGSCE Biology - Transport in Humans

What is the name of the part of the heart labelled as 1?

Pulmonary artery

What is the name of the part of the heart labelled as 2?

Vena cava.

What is the name of the part of the heart labelled as 3?

Right atrium.

What is the name of the part of the heart labelled as 4?

Right ventricle.

What is the name of the part of the heart labelled as 5?

Left ventricle.

What is the name of the part of the heart labelled as 6?

Left atrium.

What is the name of the part of the heart labelled as 7?

Pulmonary vein

What is the name of the part of the heart labelled as 8?

Aorta.

Blood is made from:

red blood cells, white blood cells, platelets, and plasma. 55% of blood is plasma.

White blood cells contain:

Lymphocytes and phagocytes.

What is the role of platelets?

To help blood clotting and prevent bleeding.

What per cent of plasma is water?

About 90%

The plasma transports the following things:

• glucose

• Amino acids

• Antibodies

• Chlosterol

• CO2

• Urea

• Lactic acid

• Hormones

• The plasma also distributes heat around the body.

What is the function of red blood cells?

To transport oxygen from the lungs to body tissues and carry carbon dioxide back to the lungs.

How are red blood cells adapted for their role?

They have a biconcave shape to increase surface area for gas exchange, lack a nucleus to maximize haemoglobin content, and contain haemoglobin to bind oxygen to form oxyhaemoglobin.

The innate immune system:

• first line of defence (immediate)

• Non-specific

• No immunological memory

• It doesn’t respond differently the second time you come into contact with a pathogen

• It includes physical barriers like skin and mucous membranes, as well as immune cells such as phagocytes that respond quickly to pathogens.

How does a phagocyte remove bacteria?

A phagocyte removes bacteria by engulfing them through a process called phagocytosis, where the bacteria are enclosed in a vessel and then destroyed by enzymes.

Example of a physical defence:

Ear wax = has acidic environment that kills bacteria. It traps dirt, dust and small object from damaging your ear.

Adaptive immune system

• second line of defence (5-7 days)

• Has immunological memory - your immmune system responds better the second time.

• Just cellular defence - T and B cells (lymphocytes)

• B cells produce antibodies

• T cells kill virally infected cells.

Antigens

Fact 1: they are found on the surface of all cells

Fact 2: there are hundreds of thousands of different antigens

Lymphocytes recognise antigens and when they do they:

1. Make more of themselves

2. Cause inflammation

3. The B cells will produce antibodies.

What is the role of antibodies?

Antibodies lock onto invading pathogens and mark them out for destruction by other white cells.

1. They stick to antigens

2. They can clump bacteria together and this makes them difficult to reproduce

3. They stick to viruses and this makes them difficult to get inside cells.

What is a vaccine?

Typically, either alive microbe, mild or weakened, or a dead microbe

Therefore, the antigens are present but the ability to cause the disease is not.

• the antigens are present

• Therefore, the lymphocytes multiply

• Some become memory cells.

• If theses memory cells meet the actual pathogens (antigens), they multiply quickly, produce more antibodies and fight the pathogens before you even feel the effects.

Active immunity

You make an immune response either following a real infection or following a vaccine

Passive immunity

You are given antibodies either naturally (in utero) or artificially.

Order of the cardiac cycle.

1. Atrial systole

2. Ventricular systole

3. Diastole

Atrial systole

Atria contract

Ventricular systole

Ventricles contact

Bicuspid/tricuspid open

Blood → ventricles

Bicuspid/tricuspid will close

Blood leaves the heart

Semi-lunar valves open

Diastole

Both relay

Semi-lunar valves close

Blood enters atria

How does the heart rate change during exercise?

1. More energy so there is more respiration

2. More carbon dioxide in your blood stream and your brain detects this

3. The brain sends a signal to your heart so it beats faster and more forcefully.

4. More blood is sent out from the heart (stroke volume) in each heart beat the blood arrives at the lungs and muscles quickeR

5. More oxygen arrives at the muscles and more CO2 is removed

6. Therefore, the muscles contract more.

How does the heart rate change under the influence of adrenaline?

• adrenaline is released from the adrenal glands

• It increases the heart rate (more oxygen and glucose arrive at the muscles)

• The muscles can therefore contract more

Risk factors for coronary heart disease:

Smoking is a risk factor as blood is more likely to clot

Lack of exercise can be a risk factor

stress can affect the heart

Bad diet is a risk factor

• saturate fats increase the risk.

What are the three types of blood vessels?

Arteries, veins and capillaries

Arteries

• carry blood away from the heart to the organs

• The blood is under high pressure so the walls must be able to stretch and recoil

• Generally carry oxygenated blood

Veins

• carry blood from the organs back towards the heart

• Under low pressure

• Must allow blood to pass through easily and prevent it flowing backwards

• Veins generally carry deoxygenated blood

• They have ‘watch-pocket’ valves to prevent back flow

Capillaries

• carry blood through organs, bringing the blood close to the cells in the organ

• They are permeable so that substances are transferred between the blood and the cells

• Their walls are only one cell thick

What does 1 represent?

Pulmonary artery

What does 2 represent?

Hepatic vein

What does 3 represent?

Mesentric vein

What does 4 represent?

Infenar vena cava

What does 5 represent?

Mesentric artery

What does 6 represent?

Hepatic artery

What does 7 represent?

Aorta

What does 8 represent?

Pulmonary veins