Chapter 5: Blood & Circulation

Question 1

In mammals, what does blood transport?

Answer 1

1. oxygen from the lungs to all parts of the body 2 co2 from all parts of the body to the lungs 3. nutrients from the gut to all parts of the body 4. urea from the liver to the kidneys also, hormones, antibodies transported…it also distributes heat

Question 2

What’s a single circulatory system?

Answer 2

Blood is pumped from the heart to the gas exchange organ and then directly onto the rest of the body. e.g. fish

Question 3

what’s a double circulatory system?

Answer 3

Blood is pumped from the heart to the gas exchange organ, back to the heart and then directly onto the rest of the body e.g. human

Question 4

what are the two parts to the double circulation?

Answer 4

the pulmonary circulation (carries blood to the lungs to be oxygenated and then back to the heart. )… …the systemic circulation (carries blood around the body to deliver the oxygen and returns de-oxygenated blood to the heart)

Question 5

What does the circulatory system comprise?

Answer 5

the heart, which is the muscular pump that keeps the blood moving the arteries, which carry blood away from the heart the veins, which return blood to the heart the capillaries, which are tiny blood vessels that are close to the body’s cells.

Question 6

How do you calculate the amount of blood that can be pumped:

Answer 6

heart rate x stroke volume = cardiac output

Question 7

Explain how the heart works ? as well as explaining this…go look at page 56 & 57 in the text book…dis is important to know

Answer 7

The heart has four chambers. The two atria collect the blood. The two ventricles pump the blood out of the heart. Valves prevent the blood from flowing backwards. The septum separates the two sides of the heart. The right side of the heart pumps de-oxygenated blood (blood not containing oxygen) to the lungs to pick up oxygen. The left side of the heart pumps the oxygenated blood from the lungs around the rest of the body.

Question 8

What do the arteries do & what are their characteristics?

Answer 8

• Carry blood away from the heart (always oxygenated apart from the pulmonary artery which goes to the lungs) - Have thick muscular walls - Have small passageways for blood (internal lumen) - Contain blood under high pressure

Question 9

What do the veins do & what are their characteristics?

Answer 9

• Carry blood to the heart (always de-oxygenated apart from the pulmonary vein which goes from the lungs to the heart) - Have thin walls - Have larger internal lumen - Contain blood under low pressure - Have valves to prevent blood flowing backwards

Question 10

What do the capillaries do & what are their characteristics?

Answer 10

• Found in the muscles and lungs - Microscopic – one cell thick - Very low blood pressure - Where gas exchange takes place. Oxygen passes through the capillary wall and into the tissues, carbon dioxide passes from the tissues into the blood

Question 11

What are the four components of blood?

Answer 11

1. Plasma - Fluid part of blood - Carries carbon dioxide, hormones and waste 2. Red blood cells - Contain haemoglobin which carries oxygen - Made in the bone marrow. The more you train the more red blood cells are made. 3. White blood cells - An important part of the immune system, they produce antibodies and destroy harmful microorganisms - Made in the bone marrow 4. Platelets - Clump together to form clots - Protect the body by stopping bleeding

Question 12

When exercising what does blood do?

Answer 12

• Transports nutrients and waste - Delivers oxygen to the working muscles - Removes heat (temperature regulation) - Dilutes/carries away lactic acid (acidic balance)

Question 13

Describe the characteristics of red blood cells…

Answer 13

• Highly specialised cells made in the bone marrow - Have a limited life span of 100 days - Only have one function: to transport oxygen - They contain haemoglobin…which combines with oxygen - As red blood passes through lungs, they load oxygen…as they pass through tissues they unload oxygen - They have no nucleus, they are bioconcave, they have a large surface area and thin cell surface membranes…which means they are super fantastico at loading & unloading oxygen…oh yes

Question 14

Describe white blood cells

Answer 14

• There are several types - Main role is to protect the body against bacteria and viruses…. …they do this in two ways: phagocytosis and antibody production

Question 15

Describe phagocytes

Answer 15

= 70% of white blood cells they can ingest the badies….by changing their shape and surrounding them…then secretes enzymes to breakdown dem badies

Question 16

Describe antibodies/lymphocytes

Answer 16

= 25% of white blood cells are lymphocytes their function is to make antibodies Antibodies recognise they ‘markers’ of the surface of bacteria and viruses….and then destroy in 3 ways: - causing bacteria to stick together - causing bacteria cells to burst open…oh yes - neutralising poisons

Question 17

What are memory cells?

Answer 17

Memory cells make us immune to a disease. If the disease tries to reinfect the memory cells quickly reproduce antibodies so the disease can be dealt with quickly

Question 18

What is immunisation?

Answer 18

A person can be given artificial immunity to a disease without contracting the disease…can get vaccines against polio, measles, typhoid, whooping cough, diphtheria, influenza