Transport in Animals

Question 1

Why do animals need a transport system?

Answer 1

The need to supply cells with oxygen

Remove waste products

They are too large to perform these actions by simple diffusion (SA : V)

Question 2

What are the 3 factors that influence the need for a transport system?

Answer 2

Size

Surface area to volume ratio

Level of metabolic activity

Question 3

How does size affect the need for a transport system?

Answer 3

If an organism is large the pathway for diffusion to their cells becomes too large

Therefore a transport system is required to supply cells with oxygen and to remove waste

Question 4

How does surface area to volume ratio affect the need for a transport system?

Answer 4

When an organism has a low surface area to volume ratio the rate of diffusion is slow

Therefore it would take too long for oxygen to diffuse into the cells and so a transport system is required

Question 5

How does the level of metabolic activity affect the need for a transport system?

Answer 5

Metabolic activity requires energy

Energy is produced in respiration

Aerobic respiration requires a lot of oxygen

Highly active organisms require lots of oxygen and thus need a transport system to provide it

Question 6

What is a single circulatory system?

Answer 6

Where the blood flows through the hear once per circuit of the body

Question 7

Give an example of a type of animal with a single circulatory system

Answer 7

Fish

Heart -> Gills -> Body -> Heart

Question 8

What is a double circulatory system?

Answer 8

Where there are two different circuits performing different roles

One takes blood to the lungs to pick up oxygen

The other takes this oxygenated blood the working muscles

Question 9

Describe the route of blood in a double circulatory system

Answer 9

Heart -> Lungs -> Heart -> Body -> Heart

Question 10

What are the names of the two circuits in humans?

Answer 10

Pulmonary circuit

Systemic circuit

Question 11

What are the advantages of a double circulatory system?

Answer 11

Can deliver the nutrients more quickly

The heart is able to increase the pressure of the blood after it has passed through the lungs so damage isn’t caused to delicate capillaries

Can remove waste products more efficiently

Question 12

What is an open circulatory system?

Answer 12

Where the blood is not always held in blood vessels

Instead the blood can flow freely through the body cavity

Question 13

What are the disadvantages of open circulatory systems?

Answer 13

Blood pressure is low and blood flow is slow

Circulation of blood may be affected by movement or lack of movement

Question 14

What is a closed circulatory system?

Answer 14

Where blood flows in specialised blood vessels

Question 15

What are the advantages of a closed circulatory system?

Answer 15

High pressure so blood moves quickly

More rapid delivery of oxygen and nutrients

More rapid removal of CO2 and waste

Transport is unaffected by body movements

Question 16

What is the name of the thin single cell layer on the inside of blood blood vessels?

Answer 16

Endothelium

Question 17

Describe and explain the differences in structure between veins and arteries

Answer 17

Arteries have thick layer of smooth muscle and thick layers of collagen whereas veins have thinner layers of smooth muscle and collagen

Arteries have a narrow lumen to maintain high blood pressure whereas veins have a wider lumen to allow ease of flow

Veins have valves to prevent back flow of blood because the blood is maintained at a lower pressure. Arteries don’t need this as the blood is much higher in pressure

Question 18

What are the names of the 3 layers of an artery?

Answer 18

Tunica intima - a thin layer of elastic tissue

Tunica media - thick layer of smooth muscle

Tunica adventitia - Thick layer of collagen and elastic tissue

Question 19

Describe the structure of capillaries?

Answer 19

Very narrow lumen - helps oxygen transfer as it reduces the diffusion distance

Very thin walls - consist of 1 layer of flattened endothelium, reduces diffusion distance

Walls are leaky - allows blood plasma and dissolved substances to leave the blood

Question 20

What does blood plasma contain?

Answer 20

Oxygen
Carbon dioxide
Mineral ions
Glucose
Amino acids
Hormones
Clotting Factors

RBC’s
WBC’s (leucocytes)

Question 21

What is tissue fluid made of and how is it formed?

Answer 21

Similar to plasma but without any blood cells in it

Formed by plasma leaking out of the capillaries

Question 22

What is hydrostatic pressure?

Answer 22

The pressure pushing out on the walls of a blood vessel from the blood inside

Question 23

What is oncotic pressure?

Answer 23

The pressure from water trying to move into the blood vessel due to solute concentrations inside

Oncotic pressure opposes hydrostatic pressure

Question 24

What’s the function of the lymphatic system?

Answer 24

To drain excess tissue fluid out of the tissues and return it to the blood

Question 25

How does the composition of lymph fluid differ to tissue fluid?

Answer 25

Lymph fluid contains more lymphocytes

Question 26

Where are the lymphocytes in lymph fluid produced?

Answer 26

In the lymph nodes

Question 27

At the arterial end of a capillary bed what is higher; hydrostatic pressure or oncotic pressure?

Answer 27

Hydrostatic pressure

Question 28

At the venous end of a capillary bed what is higher; hydrostatic pressure or oncotic pressure?

Answer 28

Oncotic pressure

Question 29

What is the role of the coronary arteries?

Answer 29

To supply oxygenated blood to the cardiac muscle

Question 30

Which vessel delivers deoxygenated blood from the body to the hear?

Answer 30

Vena Cava

Question 31

Which vessel delivers Oxygenated blood from the lungs to the heart?

Answer 31

Pulmonary vein

Question 32

Which vessel delivers oxygenated blood from the heart to the rest of the body?

Answer 32

Aorta

Question 33

Which vessel delivers deoxygenated blood from the heart to the lungs?

Answer 33

Pulmonary artery

Question 34

Which chamber does blood from the vena cava flow into?

Answer 34

Right atrium

Question 35

Which chamber does blood from the pulmonary vein flow into?

Answer 35

Left atrium

Question 36

What are there names of the valves which separate the atria and the ventricles

Answer 36

Atrio-ventricular valves

Question 37

What chamber does the pulmonary artery take blood from?

Answer 37

Right Ventricle

Question 38

What chamber does the Aorta take blood from?

Answer 38

Left Ventricle

Question 39

What valves are found at the base of the arteries leaving the heart?

Answer 39

Semilunar valves

Question 40

What is systole?

Answer 40

When the ventricles contract and force blood out of the heart

Question 41

What is diastole?

Answer 41

After systole the ventricles and atria relax and the heart fill back up with blood

Question 42

Where is the Sino-atrial node located?

Answer 42

In the right atrium

Question 43

What is the role of Sino-atrial node (SAN)?

Answer 43

To act as the pacemaker by initiating a wave of excitation in the heart

Question 44

Why does the bottom wall of the atria not conduct the wave of excitation but the side walls do?

Answer 44

To prevent the wave of excitation spreading to the ventricular walls too quickly which would cause an unsynchronised contraction

Question 45

What is the name of the area by which the wave of excitation is able to pass from the atria to the ventricles?

Answer 45

The atrio-ventricular node (AVN)

Question 46

Why does the atrio-ventricular node delay the wave of excitation?

Answer 46

To ensure that the ventricles don't contract too soon This would cause an unsynchronised heartbeat leading to back-flow

Question 47

What is the name of the tissue in the septum which carries the wave of excitation?

Answer 47

Purkyne tissue

Question 48

What is the name of the graph showing electrical activity in the heart?

Answer 48

Electrocardiogram (ECG)

Question 49

In an ECG, what does the P wave represent?

Answer 49

Excitation of the atria (atrial systole)

Question 50

In an ECG, what does the QRS complex represent?

Answer 50

Ventricular systole

Question 51

In an ECG, what does the T wave represent?

Answer 51

Diastole

Question 52

What is the name of the condition where someones heart rate is slower than normal?

Answer 52

Bradycardia

Question 53

What is the name of the condition where someones heart rate is faster than normal?

Answer 53

Tachycardia

Question 54

What is the name of the condition where someones heart rate is beating at irregular intervals?

Answer 54

Ectopic heartbeat

Question 55

What would an ECG of a patient with atrial fibrillation look like?

Answer 55

No clear P wave (atrial systole)

Question 56

What protein carry oxygen?

Answer 56

Haemoglobin

Question 57

What gives haemoglobin its affinity for oxygen?

Answer 57

Fe2+ Prosthetic group

Question 58

How many molecules of oxygen can be carried per molecule of Haemoglobin?

Answer 58

4

Question 59

Describe the shape of the line on a graph showing saturation at different partial pressures of oxygen

Answer 59

Starts low and rises steeply as oxygen enters haemoglobin easily As saturations reaches 100% the curve flattens off as it becomes harder to add oxygen against a concentration gradient

Question 60

Compare the haemoglobin dissociation curves of adult and feral haemoglobin

Answer 60

Fetal haemoglobin has a higher affinity than adult haemoglobin so fetal haemoglobin increases slightly quicker than adult haemoglobin Still has the same S-shape

Question 61

How is a majority of carbon dioxide transported in the body?

Answer 61

Hydrogencarbonate ions (HCO3^-)

Question 62

Describe the formation of hydrogencarbonate ions

Answer 62

CO2 combine with water to form Carbonic acid (H2CO3) Carbonic acid dissociates into HCO3- and H+

Question 63

What is the name of the enzyme which catalyses the reaction between water and CO2 to form carbonic acid?

Answer 63

Carbonic anhydrase

Question 64

What is the Chloride shift?

Answer 64

The movement of Cl- ions into the red blood cell as HCO3- ions move out Aims to maintain a constant charge inside the cell

Question 65

What is formed inside the red blood cell to prevent a build of of H+ ions (which could cause pH change)?

Answer 65

Haemoglobinic acid

Question 66

What is the Bohr effect?

Answer 66

Describes the effect of CO2 concentration on the ability of haemoglobin to take up oxygen At higher CO2 concentrations uptake is less effective

Question 67

Why does the Bohr effect occur?

Answer 67

When CO2 combines with water in RBC's it forms carbonic acid Carbonic acid dissociates to form H+ ions which lowers pH this causes change in the shape of haemoglobin so it is less effective at holding oxygen