Unit 2 - Blood and Circulation

Question 1

Plasma

Answer 1

Carries blood cells, dissolved nutrients, hormones, Carbon Dioxide and urea. Distributes heat around the body.

Question 2

Red blood cells (erythrocytes)

Answer 2

Transport of oxygen. Contains mainly haemoglobin.

Question 3

White blood cells (lymphocytes)

Answer 3

Produce antibodies to destroy microorganisms. Some lymphocytes persist in our blood after infection and give us immunity to specific diseases.

Question 4

White blood cells (phagocytes)

Answer 4

Digest and destroy bacteria and other microorganisms that have infected or bodies.

Question 5

Platelets

Answer 5

Release chemicals to make to make blood clot when we cut ourselves. Are really fragments of other cells.

Question 6

Single circulatory system

Answer 6

Where the blood is pumped from the heart to the gas exchange organ and then directly to the rest of the body.

Question 7

Double circulatory system

Answer 7

System where the blood is pumped from the heart to the gas exchange organ, back to the heart and then to the rest of the body.

Question 8

Pulmonary circulation

Answer 8

Deoxygenated blood leaves the heart through the pulmonary arteries, and is circulated through the lungs where it becomes oxygenated. The oxygenated blood returns to the heart through the pulmonary veins.

Question 9

Systemic circulation

Answer 9

Oxygenated blood leaves the heart through the aorta and is circulated through all other parts of the body, where it unloads its oxygen. Deoxygenated blood returns to the heart through the vena cava.

Question 10

Which two organs are connected by the hepatic portal vein?

Answer 10

The digestive system (intestines) and the liver. Blood from the digestive system travels through the liver after it has absorbed nutrients from digestion.

Question 11

To which organ do the hepatic vessels carry blood?

Answer 11

The liver

Question 12

To which organ do the renal vessel carry blood?

Answer 12

The kidneys

Question 13

On which side if the heart can you find the tricuspid valve?

Answer 13

The right side (left side from our POV looking at a picture of the heart)

Question 14

On which side or the heart can you find the bicuspid (mitral) valve?

Answer 14

The left side (right side from our POV looking at a picture of the heart)

Question 15

Coronary heart disease

Answer 15

Occurs when the coronary arteries are blocked up by a build-up of fatty substances (including cholesterol) in their walls. This can cut off the blood supply to an area of cardiac muscle, often leading to a heart attack.

Question 16

What factors affect the likeliness of contracting Coronary Heart Disease?

Answer 16

• hereditary
• high blood pressure
• bad diet
• smoking
• stress
• lack of exercise

Question 17

How is heart rate controlled?

Answer 17

The medulla in the cardiac centre of the brain gets nerve impulses from the heart according to the level of Carbon dioxide in the blood. As a result, it can secrete the hormone adrenaline into the blood, which make the heart beat faster.

Question 18

What are the main structures of arteries and veins?

Answer 18

Walls of muse fibre and elastic tissue, a lining (endothelium) and a lumen as the central cavity.

Question 19

How do arteries vary from veins and capillaries?

Answer 19

Artieries have very thick walls and muscle fibres to overcome the high blood pressure unlike the vein which has a thin wall. The lumens in arteries are also often smaller, and veins can have semi-lunar valves. A capillary is extremely small and has a wall of only one cell in thickness.

Question 20

Antibodies

Answer 20

Soluble proteins (created by lymphocytes) that pass into the plasma. They recognize “markers” on pathogen surfaces called antigens, to which they stick. Through this they destroy the pathogen by either causing bacteria to stick together, acting as a label that is easily recognized by phagocytes, causing bacteria cells to burst open, and by neutralising toxins produced by the pathogens.

Question 21

What are memory cells?

Answer 21

Lymphocytes that remain in the blood for many years and remember specific pathogens. If someone gets re-infected by the same pathogen, the memory cells can quickly produce a lot of antibodies that wipe out the pathogens before you get sick. This is the secondary immune response of your body.

Question 22

Homeostasis

Answer 22

Keeping your internal environment relatively constant.