Transport In Animals

Question 1

Why do multicellular organisms require transport system

Answer 1

Small surface area to volume ratio, high metabolic rates

Demand for oxygen is high

Question 2

Summarise the different types of circulatory system

Answer 2

Open - blood can diffuse out of vessels
Closed-confined to vessels
blood passes through pump once per circuit
Double - blood passes through the heart twice per circuit of body

Question 3

Define structures of arteries

Answer 3

Thick,muscular walls to handle high pressure
Elastic tissue to allow recoil
Narrow lumen

Question 4

Define structure for veins

Answer 4

Thin walls - low pressure

Valves to ensure blood doesn’t flow backwards

Question 5

Define structure of capillaries

Answer 5

One cell thick walls - short diffusion pathway
Very narrow
Numerous and highly branched

Question 6

What is tissue fluid

Answer 6

Liquid substance, supplies to the cells while removing any waste materials

Question 7

What types of pressure influence formation of tissue fluid

Answer 7

Hydrostatic pressure- higher at arterial end of capillaries then venous end
Osmotic - changing water potential of the capillaries as water moves out

Question 8

How is tissue fluid formed

Answer 8

Blood pumped through increasingly small vessels
Hydrostatic pressure >oncotic pressure
So they move out of capillaries

Question 9

What is the structure and function of arterioles

Answer 9

S-branch off arteries, feed blood into capillaries

Question 10

What is the structure and function of Venules

Answer 10

Larger then capillaries but smaller then veins

Question 11

How does tissue fluid differ from blood and lymph

Answer 11

Tissue fluid is formed from blood
No contain - platelets, erythrocytes and other solutes
Tissue fluid bathed - lymph, less oxygen and nutrients with more waste products

Question 12

Describe what happens during cardiac diastole

Answer 12

Heart relaxed
Blood enters atria ,increase pressure, pushes open ATRIOVENTRICULAR valves
Pressure in the heart < arteries
Semi lunar valves remain closed

Question 13

Describe what happens during atrial systole

Answer 13

Atria contract

Pushing any blood into ventricles

Question 14

Describe what happens during ventricular systole

Answer 14

Ventricles contracts
Pressure increases,closing atrioventricular valves to prevent back flow
Open semi lunar valves
Blood flows into arteries

Question 15

How do you calculate cardiac output

Answer 15

Heart rate x stroke volume

Question 16

Explain how the heart contracts

Answer 16

Sally Always Aims Balls Past Vicky 
SAN-initiates 
AVN -delays
Bundle of His
Purkinje fibres 
Ventricular contraction

Question 17

What is an electro diagram

Answer 17

Graph showing the amount of electrical activity in the heart during cardiac cycle

Question 18

Describe abnormal activity that may be seen on an ECG

Answer 18

Tachycardia-fast heart beat
Bradycardia -slow heartbeat
Fibrillation -irregular, fast heartbeat
Ectopic -early or extra heartbeats

Question 19

What is due role of haemoglobin

Answer 19

S-quaternary structure,4 polypeptide chains, 4 haem groups (iron)
Oxygen molecules bind to haem group
Released in respiring tissues

Question 20

How does partial pressure of oxygen affect oxygen-haemoglobin

Answer 20

Partial pressure increases

Affinity of haemoglobin for oxygen also increases

Question 21

What do oxyhemoglobin dissociation curves show

Answer 21

Saturation of haemoglobin with oxygen
Plotted against partial pressure of oxygen
Curves to left to show haemoglobin has a higher affinity for oxygen

Question 22

Describe the Bohr effect

Answer 22

As CO2 increase, conditions became acidic -haemoglobin changes shape
Affinity decreases so o2 is released

Question 23

Explain the role of CARBONIC ANHYDRASE in the Bohr effect

Answer 23

Carbonic anhydrase present in RBC
Converts CO2 -> carbonic acid, which dissociates to produce H+ ions
H+ haemoglobin - haemoglobinic acid
Encourages oxygen to dissociate

Question 24

Explain the role of bicarbonate ions (HC03-) in gas exchange

Answer 24

Produced alongside carbonic acid. 70% of carbon dioxide is carries in this forms
Lungs, bicarbonate ions convert back to carbon dioxide

Question 25

What is the chloride shift

Answer 25

Intake or chloride ions across a red blood cell membrane

Repolarises the cell after bicarbonate ions have diffused out

Question 26

How does foetal haemoglobin differ from adult haemoglobin

Answer 26

Partial pressure of oxygen is low by the team it reaches the foetus
Foetal haemoglobin has a higher affinity for oxygen than adult

Question 27

Explain why it is important that the pressure changes as blood flows from the aorta to the capillaries

Answer 27

• capillaries are one cell thick, burst

- reduces the chance of tissue fluid build up

Question 28

Describe and explain how the wall of an artery is adapted both to withstand and maintain high hydrostatic pressure

Answer 28

Withstand pressure -
Wall is thick, layer of collagen, provides strength 
Maintain pressure
Thick layer of elastic tissue 
Recoil to original 
Smooth muscle and narrow lumen

Question 29

What causes the overall change in pressure as blood flows from the aorta to the arteries

Answer 29

Blood flows into a larger number of vessels

arteries have a greater cross sectional area then aortas

Question 30

Explain why an oxygen disassociation is S shaped

Answer 30

Co operative binding of o2 and haemoglobin, first oxygen can not bind easily as a result changes shape of haemoglobin
First oxygen hard to remove

Question 31

Carbon dioxide plus haemoglobin -?

Answer 31

CarbonMINOhaemoglobin

Question 32

What happens to 10% of tissue fluid after not being absorbed back

Answer 32

Drains into Lymphatic system

Fluid would accumulate