Circulation

Question 1

What helps the blood to clot?

Answer 1

blood platelets

Question 2

What cells protect against disease?

Answer 2

white blood cells

Question 3

what cells transport oxygen

Answer 3

red blood cells

Question 4

some functions of the blood?

Answer 4

-to supply/remove water
-carry oxyge, CO2, waste and nutrients around the body
-protect the body against infection through white blood cells

Question 5

what does plasma contain?

Answer 5

fibrinogen- blood clotting
serum-(water, marrow,proteins,hormones,antibodies,enzymes)

Question 6

why are red blood cells good at their Jon?

Answer 6

-huge number of them
-tiny to allow them to pass through narrow capillaries
-have a flattened disc shape to increase surface area allowing rapid diffusion of oxygen
-contain haemoglobin which absorbs oxygen in lungs and releases oxygen in the rest of the body

Question 7

why are white blood cells good at their job?

Answer 7

-can engulf bacteria and other pathogens by phagocytosis
-they can change shape easily and produce enzymes that digest the pathogens

Question 8

why are blood plasma good at their job?

Answer 8

-straw-coloured liquid. transport dissolved substances around the body including:
hormones
antibodes
nutrients, such as water, glucose, amino acids, minerals and vitamins
-water substances, such as carbon dioxide and urea

Question 9

what produces red blood cells in mammals?

Answer 9

bone marrow

Question 10

what does birds blood contain

Answer 10

erythrocytes (red blood cells)
leucocytes (white blood cells)
thrombocytes (platelets)

Question 11

what transport function does the heart and blood vessel carry out?

Answer 11

-carry food molecules, water and oxygen to cells and remove waste products such as carbon dioxide. They form the circulatory system

Question 12

steps of the circulatory system

Answer 12

-blood gets pumped from the heart to the lungs and picks up oxygen
-the blood is then taken back to the heart
-the heart pumps the blood to the intestine (where oxygen and glucose is removed)
-and to the rest of the body (where oxygen is removed)
-after the oxygen and glucose have been removed for respiration the blood is sent back to the heart and starts again

Question 13

what is double circulation

Answer 13

circulation system in which blood flows through the heart twice

Question 14

define pulmonary circulation

Answer 14

blood flow between the heart and lungs

Question 15

define systemic circulation

Answer 15

movement of the blood from the heart through the rest of the body (excluding the lungs) then back to the heart

Question 16

Advantages of double circulatory system

Answer 16

-mammals because it increases the pressure and hence the flow rate of blood supplied to the tissues of the body via the systemic circulation.

Question 17

how many cavities does the adult mammalian have ?

Answer 17

4 cavities

Question 18

what are the mammalians heart divided into?

Answer 18

top two- atria (atrium)
bottom two- ventricles

Question 19

function of the right atrium in the avian heart?

Answer 19

receives deoxygenated blood from the body and delivers it to the right ventricle which pumps it to the lungs (pulmonary)

Question 20

function of the left atrium in the avian heart?

Answer 20

receives oxygenated blood from the lungs and delivers it to the left ventricle, which pumps it to the rest of the body (systemic)

Question 21

what are the differences in the avian heart compared to mammalian?

Answer 21

-4 pulmonary veins rather than 2
-they have a right aortic arch- mammals don’t

Question 22

what does the left ventricle do?

Answer 22

pumps blood to all of the boy

Question 23

what does the right ventricle do?

Answer 23

pumps blood to the lungs from where it returns to the left side of the heart

Question 24

steps of the avian heart

Answer 24

-blood fills the atria and the bicuspid and tricuspid valves are closed

-atria gently contract and push their blood into the two ventricles

-ventricles start to contract, this closes the atrioventricular valves and pushes the blood out through the semi-lunar valves into the pulmonary artery and aorta.

Question 25

structure of blood vessels- tunica intima

Answer 25

thin inner lining (endothelium) that is very smooth and enables blood to flow through the vessels without causing friction

Question 26

structure of blood vessels- tunica externa

Answer 26

tougher outer layer that helps to protect the vessel from pressure exerted from external organs rubbing against it

Question 27

structure of blood vessels- tunica media

Answer 27

middle layer containing muscles and elastic fibres

Question 28

adaptations of the arteries

Answer 28

-carry blood from the heart
-muscular walls to withstand pressure
-divide into arterioles
-the aorta is the largest artery in the body

Question 29

adaptations of the veins and venules

Answer 29

-returns blood to the heart
-thin-walled, elastic, acts as blood reservoirs
-non-return valves
-superior and inferior vena cava are both large key veins

Question 30

adaptations of the capillaries

Answer 30

-narrow, single layer of cells
-direct contact with tissues, allows diffusion