3.2 transport in animals

Question 1

Define tachycardia

Answer 1

heart beats too fast

Question 2

Define bradycardia

Answer 2

heart beats too slow

Question 3

Define ectopic

Answer 3

heart skips a beat or extra beat is added

Question 4

Define fibrilliation

Answer 4

heart contracts at an irregular way

Question 5

Define systole

Answer 5

ventricles are contracted

Question 6

Define diastole

Answer 6

ventricles are relaxed

Question 7

What is the tunica intima made up of in an artery

Answer 7

endothelial layer, connective tissue layer, elastic fibres

Question 8

Function of the tunica intima in the artery

Answer 8

reduce friction

Question 9

What is the tunica media made out of in the artery

Answer 9

elastic lamellae, connective tissue, smooth muscle

Question 10

Why is the tunica media layer thick in the artery

Answer 10

• withstand high pressures
• contract and narrow lumen for reduced blood flow

Question 11

Function of elastic tissues in the tunica media in the artery

Answer 11

recoil and change blood pressures

Question 12

What is the tunica adventita made out of in the artery

Answer 12

collagen

Question 13

Function of collagen in the tunica adventita in the artery

Answer 13

protects blood vessels from over stretching

Question 14

Function of a larger lumen in a vein

Answer 14

• ensures blood returns to the heart
• reduces friction between the blood and endothelial layer
• more volume of blood carried

Question 15

Why is the tunic media poorly developed

Answer 15

do not need to withstand high pressures

Question 16

Where is the bicuspid valve found

Answer 16

between the left atrium and left ventricle

Question 17

Where is the tricuspid valve found

Answer 17

between the right atrium and right ventricle

Question 18

Where is the aortic valve found

Answer 18

between the left ventricle and aorta

Question 19

Where is the pulmonary valve found

Answer 19

between the right ventricle and pulmonary valve

Question 20

What happens during atrial systole

Answer 20

• the walls of the atria contract
• atrial volume decreases = artial pressure increases
• pressure in the atria rises above the ventricles forcing the AV valve open
• blood moves into the ventricles

Question 21

What happens during ventricular systole

Answer 21

• walls of the ventricles contract
• ventricular volume decreases = ventricular pressure increases
• pressure in the ventricles rises above artia
• AV valves close
• pressure in the ventricles rises above the aorta and pulmonary artery
• SL valves open so blood is forced out

Question 22

What happens during diastole

Answer 22

• both the atria and ventricles are relaxed
• pressure in the ventricles drop below aorta and pulmonary artery so SL valves close
• atria fills with blood
• pressure rises in the atria and the AV valves open
• cycle is repeated

Question 23

Cardiac output

Answer 23

heart rate x stroke volume

Question 24

Define myogenic

Answer 24

heart beats without any help of an external stimulus

Question 25

What does the SAN do

Answer 25

initiates a wave of depolarisation that causes the atria to contract

Question 26

What does the AVN do

Answer 26

causes a delay so the ventricles contract after the atria

Question 27

What do the purkyne fibres do

Answer 27

initiate depolarisation of the ventricles from the apex (bottom)

Question 28

What is the P wave on an electrocardiogram

Answer 28

causes by the depolarisation of the atria, resulting in atrial systole

Question 29

What is the QRS complex on an electrocardiogram

Answer 29

causes by the depolarisation of the ventricles, resulting in ventricular systole

Question 30

What is the T wave on an electrocardiogram

Answer 30

causes by the repolarisation of the ventricles, resulting in ventricular diastole

Question 31

What happens when oxygen binds to haemoglobin

Answer 31

forms oxyhaemoglobin

Question 32

What is cooperative binding

Answer 32

when an oxygen molecule can bind more easily to the iron in the haem group

Question 33

How are hydrogen carbonate ions formed

Answer 33

* carbon dioxide diffuses into the erythrocyte to combine with water * red blood cells contain carbonic anhydrase - catalyses a reaction between carbon dioxide and water to form carbonic acid * this readily disassociates into hydrogen (H+) and biocarbonate ions (HCO3-) * biocarbonate ions are pumped out of the cell in exchnage with chlorine ions

Question 34

What is the purpose of haemoglobin in the carriage of carbon dioxide

Answer 34

act as a buffer

Question 35

What do H+ ions do in the carriage of carbon dioxide

Answer 35

* bind to haemolgobin to form haemoglobinc acid (prevents H+ ions changing the pH of the erythrocyte)

Question 36

What happens in the chloride shift

Answer 36

* hydrogen carbonate ions are moved out from the red blood cell via a transport protein in the membrane * negatively charged chloride ions are transported into the red blood cells (prevent electrical inbalance)

Question 37

What does a shift to the left on a carriage of oxygen graph mean

Answer 37

increased affinity of oxygen

Question 38

What does a shift to the right mean on a carriage of oxygen graph

Answer 38

decreased affinity of oxygen

Question 39

Define affinity

Answer 39

strength of which two molecules bind to each other

Question 40

When is haemoglobin considered saturated

Answer 40

when all four of its binding sites are taken up with oxygen

Question 41

Process of oxygen association to haemoglobin

Answer 41

* due to the shape of the haemoglobin molecule it is difficult for the first molecule to bind therefore it takes longer * the first oxygen changes the shape so it is easier for the next oxygen to bind * as it approaches saturation it takes longer as there is a shortage of binding sites

Question 42

Why does foetal haemoglobin have a higher affinity

Answer 42

* the placenta has a low pO2 so the mothers haemoglobin dissociates quicker * higher affinity means the foetus can pick up the oxygen at lower pO2

Question 43

Define hydrostatic pressure

Answer 43

pressure exerted by a fluid

Question 44

Define oncotic pressure

Answer 44

osmotic pressure exerted by plasma proteins within a blood vessel

Question 45

What happens at the ateriole end of the capillary

Answer 45

* hydrostatic pressure is greater than the oncotic pressure so fluid is forced out

Question 46

What happens at the venule end of a capillary

Answer 46

* hydrostatic pressure is lower than the oncotic pressure so fluid is forced into the blood

Question 47

Define odema

Answer 47

when too much fluid is pushed outside so it accumlates around the capillary

Question 48

What does the lymphatic system do

Answer 48

maintains correct pressure gradient for the movement of tissue fluid