transport in animals

Question 1

what is the circulatory system

Answer 1

a heart which pumps blood
a system of blood vessels that carry blood
valves that ensure flow in one direction

Question 2

oxygenated blood

Answer 2

comes from the lungs, lots of oxygen

Question 3

de-oxygenated blood

Answer 3

contains little oxygen, needs to go to the lungs to get more oxygen

Question 4

double circulatory system

Answer 4

blood passes through the heart twice in 1 complete circuit in the body
found in all mammals, birds, reptiles
made of 2 parts: pulmonary, systemic system

Question 5

single circulatory system

Answer 5

blood passes through the heart only once in one complete circuit of the body
found in fish

Question 6

benefits of double circulation

Answer 6

when blood flows through tiny vessels at the lungs or gills it loses pressure
in mammals, blood goes back to the heart to increase pressure again
this is more efficient for getting energy to cells quickly for respiration
it enters a different chamber of the heart
in fish the pressure stays low, so blood gets to the organs more slowly than in mammals.

Question 7

the 4 chambers of the heart

Answer 7

atria where blood flows in
ventricles which pump blood out

Question 8

what is a septum

Answer 8

a structure that separates the left and right chambers.

Question 9

how blood enters the heart

Answer 9

left atrium receives oxygenated blood through the pulmonary veins (from the lungs)
right atrium receives de-oxygenated blood from the rest of the body through ha vein called the vena-cava
then blood passes through the ventricles. strong muscles in the walls contract to pump blood out of the heart.

Question 10

how blood leaves the heart

Answer 10

aorta- largest artery, receives oxygenated blood from the left ventricles and pumps it to the rest of the body
pulmonary artery- carries de-oxygenated blood from the right ventricle to the lungs.

Question 11

red blood cells

Answer 11

full circulation takes about 1 min
deliver oxygen to every tissue in the body
live up to 120 days, then are recycled
don’t have a nuclei, making them even more efficient in carrying oxygen
biconcave
no nucleus or mitocondria
cytoplasm contains heamoglobin
large surface area
small

Question 12

valves

Answer 12

atrioventricular valves- valves between atrium and ventricle in the heart. allows blood to flow form the atria to ventricles, not the other way
semilunar valve- close to entrance of aorta and pulmonary artery
prevent backflow of blood from the arteries back into the ventricles

Question 13

thickness of ventricles

Answer 13

because ventricles have to pump blood out of the heart they have much thicker, more muscular walls that the atria.
the left ventricle is thicker as it needs to pump the blood to the rest of the body.

Question 14

coronary arteries

Answer 14

vessels that supply blood to the heart muscles on outside of heart
heart needs oxygen to continue pumping blood.

Question 15

preventing CHD

Answer 15

cannot completely eliminate the risk
not smoking
regular exercise
healthy diet

Question 16

ECG

Answer 16

a graph showing the electrical activity of a heart plotted over time (electrodiogram)

Question 17

arteries

Answer 17

vessels carrying high-pressure blood away from the heart
carry high-pressure blood
have strong walls to withstand high pressure
blood pulses through therefore arteries have elastic tissue in their walls.

Question 18

capillaries

Answer 18

vessels that take blood close to body cells
arteries split again and again and eventually from capillaries
one cell thick
wall made of a single layer of cells
allow diffusion and active transport

Question 19

veins

Answer 19

vessels take low-pressure blood towards heart
blood flows more smoothly, so they do not need to have thick and elastic walls
lumen is much bigger to allow blood to flow a bit faster
have valves to stop blood flowing backwards
capillaries eventually join up again to form veins
large lumen thin layer of muscles and elastic fibres.

Question 20

heamoglobin

Answer 20

red pigment
a protein that contains iron
iron combines with oxygen in the lungs where there is a high conc. of O2

Question 21

oxyheamoglobin

Answer 21

haemoglobin combines with O2 it released O2 when levels are low.

Question 22

white bloods cells

Answer 22

have nucleus that large
move around easily. can squeeze out of capillaries
they fight of pathogens and to clear up dead body cells

Question 23

phagocytes

Answer 23

destroy pathogens by engulfing them and digesting them. this process is called phagocytosis
have a lobed nucleus
white blood cell

Question 24

lymphocytes

Answer 24

produce antibodies which fix onto pathogens and destroy them
lymphocytes usually have a large round nucleus that fills the cell
white blood cell
large nucleus

Question 25

platelets

Answer 25

small fragments of cells with no nucleus
made in red bone marrow
involved in blood clotting
involdved in blood clotting
clotting prevents blood loss and stops pathogens getting in through breaks in the skin

Question 26

how does blood clotting happen

Answer 26

blood plasma contains a soluble protein called fibrogen
when a blood vessel breaks, platelets release a substance that makes the fibrinogen change into insoluble fibrin
fibrin forms fibres that pile up on top of each other to seal the wound
clumps of platelets and red blood cells all come together to form a blood clot

Question 27

plasma

Answer 27

mostly water
many substances dissolves in it
transports hormones like adreniline
transports waste products like CO2 and urea
55% of blood