the circulatory system

Question 1

active transport

Answer 1

the movement of molecules form low to high concentration against a concentration gradient

Question 2

pulmonary circuit

Answer 2

transports blood from the right side of the heart to the lungs

Question 3

what happens in the lungs during the process of the circulatory system

Answer 3

• oxygen diffuses to the blood from the alveoli (the blood becomes oxygenated)
• carbon dioxide diffuses from the blood into the lungs

Question 4

systemic circuit

Answer 4

transports blood from the left side of the heart to all other parts of the body
- also carries oxygen and nutrients to the body
- carbon dioxide and other wastes away from cells

Question 5

why must blood must flow through the circulatory system in one direciton

Answer 5

• it makes sure that oxygenated blood and deoxygenated blood are kept separate
• it also ensures that there is always a concentration for diffusion

Question 6

what is used to ensure blood flows through the circulatory system in one direction

Answer 6

valves in the heart and veins ensure backflow is prevented

Question 7

what does a double circulatory system ensure?

Answer 7

• ensures a concentration gradient for diffusion of oxygen into the blood at the lungs is maintained
• blood pressure is maintained by returning oxygenated blood to the heart
• oxygen is supplied to all tissues efficiently, as blood travels though small capillaries which provide a large surface area for diffusion

Question 8

how to calculate surface area to volume ratio

Answer 8

surface area / volume

Question 9

alveoli

Answer 9

Where gas exchange occurs; comprised of tiny air sacs with a capillary network

Question 10

two common waste substances that the human body needs to remove

Answer 10

uera, carbon dioxide

Question 11

how does alveoli increase SA:V ratio of the lungs

Answer 11

one cell thick wall for high rates of diffusion

Question 12

vein

Answer 12

• carries blood back to the heart
• wide tube
• thin flexible walls

Question 13

arteries

Answer 13

• take blood away from the heart
• narrow tube
• thick layer of elastic and muscle fibres

Question 14

capillaries

Answer 14

• one cell thick to allow faster diffusion of substances
• narrow tube

Question 15

erythrocytes

Answer 15

• red blood cells
• carry oxygen
• carries haemoglobin (type of protein)

Question 16

lymphocytes

Answer 16

• immune response to invading bacteria and viruses
• contains antibodies

Question 17

phagocytes

Answer 17

• immune response to invading bacteria and viruses
• engulfs foreign materials

Question 18

equation for cardiac output

Answer 18

cardiac output = stroke volume x heart rate

Question 19

direction of blood through the heart

Answer 19

vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta

Question 20

why must temperature be kept the same during a respiration experiment

Answer 20

• increases rate of respiration for the soda lime
• causes enzymes to work faster
• gas expands at warmer temperatures

Question 21

explain the role of soda lime during a respiration experiment

Answer 21

• absorbs carbon dioxide
• carbon dioxide produced by the small organisms would take up some of the volume lost by the removal of oxygen

Question 22

why is the heart described as a ‘double pump’

Answer 22

• the heart carries deoxygenated blood from the body to the lungs
• carries oxygenated blood from the lungs to the body

Question 23

similarities and differences between aerobic and anaerobic respiration

Answer 23

• both are exothermic
• both release energy
• both require glucose
• aerobic = glucose + oxygen > carbon dioxide + water
• anaerobic = glucose > lactic acid
• lactic acid causes muscles to tire
  anaerobic gives less energy