8 - Transport in animals

Question 1

Why are transport systems needed in a multi-cellular organism?

Answer 1

All living cells need a supply of oxygen and nutrients to survive.
They also need to remove waste products so these don’t build up and become toxic.
Small cells don’t need them because diffusion is sufficient enough to sustain the cell.
Large organisms will have more than 2 layers of cells so diffusion wont be able to supply all the requirements.

Question 2

How does size affect transport systems?

Answer 2

Cells inside the organisms and further from the surface –> the diffusion pathway is increased –> rate of diffusion reduces.
Less supplies will reach the cells in the middle causing them to not perform at them best ability

Question 3

How does SA:V ratio affect transport systems?

Answer 3

The smaller the organism the larger SA:V ratio which means that for every gram of tissue thy have a sufficient area through which exchange can occur

Question 4

How does the level of metabolic activity affect transport systems?

Answer 4

Animals need energy from food, so that they can move around. They release energy form food via respiration which requires oxygen.
The more active a cell is the more oxygen and nutrients are needed.
This all requires energy

Question 5

Single Circulatory System

fish

Answer 5

The blood flows through the heart once for every circuit of transport

Question 6

Double Circulatory System

mammals

Answer 6

The blood flows through the heart twice for every circuit of transport
2 separate circuits.
One carries blood to the lungs to pick up oxygen = Pulmonary Circulation
The other carries oxygen and nutrients around the body to the tissues. = Systematic Circulation

Question 7

Limitation of the single circulatory system

Answer 7

Blood pressure drops as it passes through the tiny capillaries.
Low blood pressure means the blood will not flow quickly
The rate at which oxygen is delivered to tissues is limiting

Question 8

Limitation of the double circulatory system

Answer 8

The blood pressure cannot be too high in the pulmonary circulation as it might damage the capillaries.
Heart can increase pressure of the blood so it can flow quicker.
Systematic circulation can have a higher blood pressure than pulmonary circulation

Question 9

Systematic Circulation

Answer 9

Carries oxygen and nutrients around the body to the tissues

Question 10

Pulmonary Circulation

Answer 10

Carries blood to the lungs to pick up oxygen

Question 11

Open Circulatory Systems

Disadvantages: Open Circulatory Systems

Answer 11

One in which blood is not held in vessels.
The blood fluid circulates which means the tissues and cells are bathed in blood.

Blood pressure is low and blood flow is slow.
Circulation is affected by body movement.

Question 12

Closed Circulatory Systems

Advantages: Closed Circulatory Systems

Answer 12

One in which blood is held in vessels.
The cells and tissue are bathed in tissue fluid.
Higher pressure, blood flows more quickly
More rapid delivery of oxygen and nutrients
More rapid removal of carbon dioxide and other wastes
Transport is independent of body movements

Question 13

Insects and the open circulatory system

Answer 13

They have a muscular organ pumping similar to the heart.

Blood enters the body through ostia pores. Then the blood is pumped by peristalsis

Question 14

Arteries

Answer 14

Vessels that carry blood away from the heart.
Blood is at high pressure so the artery wall must be thick
3 Layers:
Inner (tunica intima) - thin layer of elastin
Middle (tunica media) - thick layer of smooth muscle
Outer (tunica adventita) - thick layer of elastin and collagen

Question 15

Arterioles

Answer 15

Small blood vessels that distribute blood from an artery to the capillaries

Question 16

Capillaries

Answer 16

Very small vessels within the cell wall

Question 17

Veins

Answer 17

Vessels that carry blood back to the heart

Question 18

Venules

Answer 18

Small blood vessels that collect blood from capillaries and lead into veins.

Question 19

Hydrostatic Pressure

Answer 19

The pressure that a fluid exerts from pushing against the sides of a vessel

Question 20

Oncotic Pressure

Answer 20

The pressure created by the osmotic effect of the solute

Question 21

Lymph

Answer 21

The fluid held in the lymphatic system which is a system that returns excess tissue fluid to the blood system

Question 22

Tissue fluid

Answer 22

The fluid surrounding the cells and the tissue

Question 23

How to calculate cardiac output

Answer 23

cardiac output = heart rate x stroke volume

Question 24

Tachycardia

Answer 24

Very rapid heartbeat over 100 bpm

Question 25

Bradycardia

Answer 25

Very slow heart rate below 60 bpm

Question 26

Ecotopic heartbeat

Answer 26

Extra heart beats outside the rhythm

Question 27

Atrial fibrillation

Answer 27

Rapid electrical impulses are generated in the atria

Question 28

Diastole

Answer 28

Heart relaxes atria and ventricles filled with blood pressure is at a minimum

Question 29

Systole

Answer 29

Atria contract followed by ventricles

Pressure increases

Question 30

Tunica

Answer 30

Layers of blood vessels

Question 31

Bohr’s Effect

Answer 31

The shift in the oxygen dissociation curve caused by the change of concentration of carbon dioxide with a pH of the environment

Question 32

Carbonic anhydrase

Answer 32

The enzyme that catalyses the combination of carbon dioxide and water

Question 33

Chloride shift

Answer 33

The movement of chloride ions into erythrocytes to balance the charge as hydrogen carbonate ions leave the cell

Question 34

Haemoglobin acid

Answer 34

The compound formed by the buffering action of haemoglobin as it combines with excess hydrogen ions

Question 35

Cardiac Cycle

Answer 35

The sequence of events in one full heart beat

Question 36

Formation of tissue fluid

Answer 36

When an artery reaches the tissues a branches into smaller arterioles and then into a network of capillaries.
They eventually link up with being used to carry the blood back into the veins therefore blood flowing into an organ is contained in the capillaries
At the arterial end of a capillary the blood has a relatively high pressure.
This pressure pushes the blood through the rules on the fluid leave between the tiny gaps in the walls

Question 37

Oxygenation of blood

Answer 37

The deoxygenated blood enters through the vena cava and passes into the right atrium.
From the right atrium it travels to the right ventricle via the tricuspid valve.
Then from the right ventricle it passes through semi-lunar valve into the pulmonary artery out to the lungs.
From the lungs the oxygenated blood passes through the pulmonary veins, to the left atrium
From the left atrium to blood travels to the left ventricle via the bicuspid valve.
From the left ventricle to the aorta via a semi-lunar valve and outwards to different area of the body from the carotid arteries.

Question 38

Myogenic muscles

Answer 38

Muscle that can initiate its own contraction

Question 39

Purkyne Tissue

Answer 39

Consists of specially adapted muscles fibres that can conduct the wave of excitation from AVN down the septum to the ventricles

Question 40

Sino-atrial node

Answer 40

The hearts pacemaker.
It is a small patch of tissue that sends out waves of electrical excitation at regular intervals in order to initiate contractions.