Topic 1 - Transport In Humans

Question 1

What is the function of Plasma?

Answer 1

To transport CO2, digested food, urea, and hormones, as well as spreading heat around the body.

Question 2

What is the job of white blood cells? How do they do this?

Answer 2

To protect you against illness and disease by ingesting pathogens and producing antibodies.

Question 3

What is the function of platelets?

Answer 3

To form blood clots in order to prevent or stop bleeding, as well as preventing the entry of infection causing pathogens into the blood stream.

Question 4

What is the function of red blood cells? How do they do this?

Answer 4

To transport oxygen around the body by binding to haemoglobin.

Question 5

What are 4 adaptations of red blood cells?

Answer 5

1. Small and flexible -Can fit through narrow blood vessels
2. Bio-concave shape (Flattened disc), which maximises surface area for oxygen absorption.
3. They contain/bind to haemoglobin, a red protein that combines with oxygen]
4. They have no nucleus (and other organelles) in order to maximise space for haemoglobin.

Question 6

What is a pathogen?

Answer 6

A disease causing organism.

Question 7

What are the two types of white blood cell, what do they do?

Answer 7

Phagocyte - Engulfs pathogens
Lymphocyte - Produces antibodies which bind onto antigens on a pathogen.

Question 8

How do antibodies destroy pathogens?

Answer 8

They bind onto the antigens (Which the lymphocyte recognises the pathogen with), and then they clump the pathogens together.

Question 9

What do lymphocytes produce to remember a pathogen?

Answer 9

Memory cells.

Question 10

How do phagocytes destroy pathogens?

Answer 10

They engulf pathogens, and then destroy them by breaking them down/ digesting them with enzymes.

Question 11

What do phagocytes do after breaking down a pathogen?

Answer 11

It will absorb the pathogen. This process is called phagocytosis.

Question 12

What do vaccines result in? How does this work?

Answer 12

Vaccines result in the production of memory cells. These remember the antigens on a pathogen and remember the specific type of antibody required to bind to the pathogen.

Question 13

What will happen if someone is infected again after a vaccination?

Answer 13

Antibodies will be produced sooner, faster and in greater quantity as the memory cells will already know what antibodies to make.

Question 14

In what direction do arteries carry blood? What type of blood do they carry, and which artery is the exception to this rule?

Answer 14

Arteries carry blood away from the heart. They always carry oxygenated blood, except for the pulmonary artery (Heart to lungs, so goes away but carries de-oxygenated blood).

Question 15

What are the structural features of an artery, why does it need these?

Answer 15

1. Arteries have narrow lumen for blood to flow through.
2. Arteries carry blood with a high pressure as it is oxygenated, and so have a thick layer of muscle and tissue fibre around the lumen (This allows the walls to stretch and recoil to maintain a high pressure).

Question 16

In what direction do veins carry blood? What type of blood do they carry, and which vein is the exception to this rule?

Answer 16

Veins carry blood towards the heart. They always carry de-oxygenated blood, except for the pulmonary vein (Lungs to heart, so goes towards but carries oxygenated blood).

Question 17

What are the structural features of a vein, why does it need these?

Answer 17

1. Veins have thin elastic walls because they carry lower pressure blood as it is de-oxygenated.
2. Veins have valves to stop the back flow of blood.
3. Veins have large lumen for blood to flow.

Question 18

What is the role of capillaries?

Answer 18

To bring blood through organs, and very close to every cell.

Question 19

What are the structural features of a capillary?

Answer 19

1. A one cell thick walls, allowing for quick exchange of substances between blood and cells. This allows for a shorter diffusion distance for oxygen/other substances, it also allows for red blood cells to be in close connection to the capillary wall.

Question 20

What type of circulatory system do humans have (How many loops)?

Answer 20

Humans have a double circulatory system. (2 loops. Heart to organs and back - to spread oxygen. Heart to lungs and back - to get oxygen)

Question 21

What are the two loops humans have?

Answer 21

1. Pulmonary circulation (Heart (de-oxy) -> Lungs (become oxygenated) -> Heart (oxy).
2. Systemic circulation (Heart (oxy) -> Cells (become deoxygenated) -> Heart (de-oxy)

Question 22

Why is having a double circulatory system efficient?

Answer 22

Because higher pressures can be maintained and blood can travels more quickly to organs.

Question 23

1. What is the name of the main and largest artery in the body?
2. What is the name of the main and largest vein in the body?

Answer 23

1. The Aorta
2. The Vena Cava

Question 24

1. What is the word relating to the liver (e.g. ___ artery/vein)
2. What is the word relating to the kidneys (e.g. ___ artery/vein)
3. What is the word relating to the lungs (e.g. ___ artery/vein)

Answer 24

1. Hepatic is the word relating to the liver (e.g. Hepatic artery/vein - The blood vessels that transport oxygen to/from the liver)
2. Renal is the word relating to the kidneys (e.g. Renal artery/vein - The blood vessels that transport oxygen to/from the kidneys)
3. Pulmonary is the word relating to lungs (e.g. Pulmonary artery/vein - The blood vessels that transport oxygen to/from the lungs)

Question 25

How is blood moved through the heart?

Answer 25

By a series of contractions and relaxations of the muscle in the walls of the 4 chambers.

Question 26

What are the 4 steps of the cardiac cycle?

Answer 26

1. Veins carry blood towards the heart, and the two atria fill up simultaneously.
2. The atria contract, and blood moves through the valves towards the ventricles.
3. The ventricles fill up with blood and then contract to push blood through semi-lunar valves.
4. Once all the blood have been pushed through, the ventricles relax and the semi-lunar valves close, stopping any backflow of blood.

Question 27

Why are the chambers/sides of the heart opposite/flipped on a diagram?

Answer 27

Because it is as it is in the (/your) body to the person, not as from the outside.

Question 28

What are the 4 chambers of the heart? where are they located on a diagram?

Answer 28

1. Left atrium (Top right)
2. Right atrium (Top left)
3. Left ventricle (Bottom right)
4. Right ventricle (Bottom left).

Question 29

1. What is the valve in between the left atrium and left ventricle called?
2. What is the valve in between the right atrium and right ventricle called?

Answer 29

1. Tri-cuspid valve
2. Bi-cuspid valve.

Question 30

What side of the heart does oxygenated and deoxygenated blood flow on.

Answer 30

De-oxy - Right side on a diagram
Oxy - Left side on a diagram.

Question 31

Why does the left side of the heart have a thicker wall?

Answer 31

It carries oxygenated (higher pressure) blood and so needs a more muscular wall (similar to an artery).

Question 32

What is the fight or flight response triggered by?

Answer 32

The hormone adrenaline from the adrenal glands.

Question 33

Why does our heart rate increase when we get scared?

Answer 33

1. Our body needs to be prepared to run away in a scary scenario
2. This requires muscle contraction, which need energy to be released from cells
3. To produce this extra energy, our cells must increase the rate at which we respire
4. To do this we need more oxygen to reach our cells
5. By increasing our heart rate, more oxygen will be pumped around the body.

Question 34

What is a heart attack caused by?

Answer 34

The coronary arteries being blocked through the buildup of plaque. This means the blood can’t reach the heart.

Question 35

What causes the buildup of plaque?

Answer 35

Alcohol, smoking, unhealthy food, stress, lack of exercise, obesity , high cholesterol, high blood pressure and even genetics.

Question 36

What is the disease when there is a buildup of fatty deposits, which form plaques. What does this lead to?

Answer 36

Coronary Heart Disease (CHD), can lead to reduced blood flow.

Question 37

What can happen if there is a buildup of plaque?

Answer 37

It can cause a tear in a coronary artery, and a clot will form over the tear, blocking the blood getting to the heart. This can starve the heart of oxygen, at which point a person will experience a heart attack.