transport in animals

Question 1

what is the need for a transport chain

Answer 1

organisms that are small diffusion is sufficient for respiration however when there are more than 2 layers of cells.

Question 2

factors that influence the need for a transport system

Answer 2

size
surface area to volume ration
rate of metabolic reactions

Question 3

advantages of a double circulation system

Answer 3

quicker blood flow- higher blood pressure

Question 4

advantages of a single circulatory system

Answer 4

fish do not need a double circulatory system because they aren’t as metabolically active as mammals because they don’t maintain their body temperature.

Question 5

what is the order of size of blood vessels

Answer 5

arteries -arterioles veins-venules capillaries

Question 6

features of arteries

Answer 6

they have thick muscular wall, small lumen, inner layer with elastic tissue to withstand recoil

Question 7

features of veins

Answer 7

large lumen, thinner layers of muscle and elastic tissue. contain valves to prevent backflow

Question 8

features of capillaries

Answer 8

small lumen, one cell thick to allow diffusion, they are leaky allowing exit of blood plasma and dissolved substances.

Question 9

what is the difference between blood plasma and tissue fluid

Answer 9

blood plasma contains hormones plasma proteins amino acids etc tissue fluid only contains oxygen and carbon dioxide nutrients etc

Question 10

what is an eythrocyte

Answer 10

red blood cell

Question 11

what is a leucocyte

Answer 11

a white blood cell

Question 12

what is the formation of tissue fluid

Answer 12

at the arterial end of the capillary blood is at high pressure meaning blood fluid is pushed out through tiny gaps in wall. fluid contains oxygen and dissolved nutrients which surrounds the body cells so exchange of gases and nutrients can occur at the venous end blood pressure is lower so some returns to the capillary. while others gets drained in the lymphatic system and returns to the blood through the subclavian vein in the chest.

Question 13

what is oncotic pressure

Answer 13

the pressure created by osmotic effects of the solutes

Question 14

how does fluid get pushed out of arterial end to venule end

Answer 14

hydrostatic pressure of blood pushes fluid out into tissues
hydrostatic pressure of tissue fluid moves tissue fluid into capillaries
then oncotic pressure of the blood tends to pull water back into the blood
and oncotic of tissue fluid pushes water into the tissue fluid
the net forces creates a pressure to push fluid out of capillary

Question 15

external features of the heat

Answer 15

the heart is made up of 4 chambers, coronary arteries cardiac muscles

Question 16

what is the significance of the heart muscle

Answer 16

cardiac muscle consisting o fibres that branch producing cross bridges. they help spread stimulus around heart and encourage the heart to contract in a squeezing action rather than just a linear contraction lots of mitochondria

Question 17

what are the 3 stages of the cardiac cycle

Answer 17

atrial systole (contraction) ventricular systole and diastole (relax)

Question 18

atrial systole

Answer 18

higher pressure in atria than ventricles. atrioventricular valves open blood to atria to ventricles

Question 19

ventricle systole

Answer 19

higher pressure in ventricles pushes blood to lungs and body.

Question 20

contraction of atria

Answer 20

in the right atria is the SAN which produces electrical activity. the wave of excitation spreads over the walls of both atraia causing the cardiac muscle to contract. tissue at base is not conductive so can’t pass on electric current to ventricles. instead it gets passed to the the AVN.

Question 21

contraction of ventricles

Answer 21

the wave of excitation is carried away to the purkyne tissue which runs down the interventricular septum it spreads upwards from the apex causing it to contract. pushing blood up towards the major arteries at the top of the heart.

Question 22

different waves in electrocardiograms

Answer 22

p- atrial systole
qrs- ventricular systole
t- diastole

Question 23

transport of oygen

Answer 23

oxygen associates with haemoglobin. becoming oxohaemoglobin. each haemoglobin molecule can hold 4 oxygen molecules. it has a high affinity for oxygen.

Question 24

what affects the ability of dissaciation

Answer 24

partial pressure of oxygen ( concentration) in surrounding tissue. when the oxygen tension rises there is more association. once one oxygen molecule has entered the molecule it produces a conformational change which makes it easier for more oxygen molecules to enter.

Question 25

what is the difference with fetal haemoglobin

Answer 25

it has a higher affinity for oxygen

Question 26

transporting co2

Answer 26

5 % is dissolved directly in plasma
10 % is combined with haemoglobin to make carbaminohaemoglobin
about 85 % is transported in the form of hydrogen carbonate ions

Question 27

formation of hydrogencarbonate ions

Answer 27

co2 diffuses into red blood cells and combines with water to make carbonic acid. the reaction is catalysed by the enzyme then it dissasociates to release h+ ions and hydrogen carbonate ions. these ions diffuse out of the red nlood cell into the plasma ( maintained by chloride ions from the plasma.

Question 28

what are the complications of H+ accumalation as a result of of formation of hyrdrogencarbonate ions

Answer 28

could make blood too acidic to counteract this hydrogen ions are taken out of solution by associating with haemoglobin to produce haemoglobinic acid.

Question 29

the Bohr effect

Answer 29

carbon dioxide enters red blood cells forming carbonic acid which dissassociates to form hydrogen ions
these hydrogen ions affect the ph of the cytoplasm,making it more accidic changes the tertiary structure of haemoglobin and reduces its affinity for oxygen.