Transport Systems in animals

Question 1

Why are specialised transport systems needed ?

Answer 1

High metabolic demands
Small surface area to volume ratio
Molecules may be made in one area but needed in another
Food digested in one organ system needs ti be transported to every cell
Waste products need to be removed from cells and transported to excretory organs

Question 2

What are the features of a circulatory system ?

Answer 2

A liquid transport medium
Vessels that carry the transport medium
A pumping mechanism to move fluid around the body

Question 3

What happens in an open circulatory system ?

Answer 3

There are few vessels to contain the transport medium as it is pumped straight from the heart into the body cavity

Question 4

What is the open body cavity called ?

Answer 4

Haemocoel

Question 5

What is the pressure like the in the haemocoel ?

Answer 5

The transport medium is under low pressure

Question 6

Hows does exchange take place in an open circulatory system ?

Answer 6

Transport medium comes into direct contact withe the cells where exchange takes place, it then returns to the heart through an open ended vessel

Question 7

What animals are open circulatory systems found in ?

Answer 7

Invertebrate animals like most insects and molluscs

Question 8

What is insects blood called ?

Answer 8

Haemolymph

Question 9

What happens in a closed circulatory system ?

Answer 9

Blood is enclosed in blood vessels and does not come into direct contact with the cells of the body. Substances enter and leave the blood by diffusion through the walls of the blood vessels

Question 10

What does the heart do in closed circulatory systems and what is the pressure like ?

Answer 10

The heart pumps the blood around the body under high pressure and the blood returns to the heart

Question 11

What animals have closed circulatory systems ?

Answer 11

All vertabrates,phyla including echinoderms , cephalopod molluscs and annelid worms

Question 12

What is a single closed circulatory system ?

Answer 12

Found in animals such as fish and annelid worms, the blood flows through the heart and is pumped to travel to the body the back to the heart

Question 13

What happens in the 2 sets of capillaries the blood in a single closed circulatory system pass through before returning to the heart ?

Answer 13

In the first it exchanges oxygen and carbon dioxide

In the second in the organ systems substances are exchanged

Question 14

What pressure is the blood in a single closed circulatory system under and why ?

Answer 14

Low pressure due to passing through two sets of narrow vessels, so blood returns to the heart quite slowly

Question 15

What is the activity levels of animals with single closed circulatory systems like ?

Answer 15

Low as the exchange process is not very efficient due to being slow

Question 16

What is the exception to low activity levels in single closed circulatory systems ?

Answer 16

Fish, as they have a countercurrent gaseous exchange system they can take in a lot of oxygen from the water
Body weight is supported by water and they do not have to maintain their own body temperature
Low metabolic demands

Question 17

What animals have double closed circulatory systems ?

Answer 17

Birds and most mammals

Question 18

What are the two circulations in a double closed circulatory system ?

Answer 18

Blood is pumped from the heart to the lungs to pick up oxygen and unload carbon dioxide and then returns to the heart
Blood flows through the heart and is pumped out to travel all around the body before returning to the heart

Question 19

What is the pressure in a double closed circulatory system like ?

Answer 19

High pressure due to the blood only going through one capillary network in each circuit

Question 20

What does blood plasma contain ?

Answer 20

Dissolved glucose and amino acids 
Mineral ions
Hormones
Large plasma proteins
Red blood cells 
White blood cells 
Platelets

Question 21

What is included under large plasma proteins and what are their functions ?

Answer 21

Albumin - maintaining osmotic pressure
Fibrinogen - blood clotting
Globulins - transport and the immune system

Question 22

What is another name for red blood cells ?

Answer 22

Erythrocytes

Question 23

What is another name for white blood cells ?

Answer 23

Leucocytes

Question 24

What are the 7 functions of the blood ?

Answer 24

Transporting …
Oxygen to and carbon dioxide away from the respiring cells
Digested food from the small intestine
Nitrogenous waste products from cells to excretory organs
Chemical messages
Food molecules from storage compounds to cells that need them
Platelets to damaged areas
Cells and antibodies involved in immune response

Question 25

What is the exceptions to arteries carrying oxygenated blood ?

Answer 25

The pulmonary artery that carries deoxygenated blood from the heart to the lungs
The umbilical artery that carries deoxygenated blood from the foetus to the placenta

Question 26

What do artery walls contain ?

Answer 26

Elastin fibres, smooth muscle and collagen

Question 27

What do elastin fibres in the artery do ?

Answer 27

Helps to even out the surges of blood by recoiling during the hearts contraction and stretch during the blood passing through from the heart

Question 28

How are arterioles different to arteries ?

Answer 28

More smooth muscle and less elastin due to little pulse surge

Question 29

What three ways are capillaries adapted for their role ?

Answer 29

Large surface area for diffusion
Thin diffusion distance - one endothelial cell thick
Greater cross sectional area than the arteriole which slows down blood flow to give more time for exchange

Question 30

The blood in veins has to go against gravity at low pressure, list three adaptations that the veins have to enable the body to overcome this

Answer 30

One way valves so that if the blood starts to flow backwards it forces the valves shut
Bigger veins run between active muscles so that when the
Breathing movements of chest act as a pump

Question 31

What is oncotic pressure ?

Answer 31

The tendency of water to move into the blood by osmosis

Question 32

What is hydrostatic pressure ?

Answer 32

Pressure created by the surge of blood every time the heart contracts

Question 33

What is the pressure like at the arterial end of the capillary ?

Answer 33

The hydrostatic pressure is higher than the oncotic pressure, so fluid moves out of the capillaries

Question 34

What is tissue fluid ?

Answer 34

The same as blood plasma without the res blood cells and plasma proteins

Question 35

What is the pressure like at the venous end of the capillaries ?

Answer 35

Hydrostatic pressure falls to lower than the oncotic was so water moves back into the capillaries by osmosis

Question 36

How much of the tissue fluid returns to the blood for the veins ?

Answer 36

90%

Question 37

What is the 10% of tissue fluid called that does not return to the capillaries ?

Answer 37

Lymph

Question 38

What does lymph contain ?

Answer 38

Similar composition to plasma but less oxygen and nutrients

Also contains fatty acids absorbed from the villi of the small intestine

Question 39

How does lymph return to the blood ?

Answer 39

Lymph capillaries join to form larger vessels that the squeezing of the body muscles move the lymph
One way valves prevent backflow
Lymph returns to the blood by the right and left subclavian veins (clavicle)

Question 40

In the lymph vessels there are lymph nodes, what do they do ?

Answer 40

Lymphocytes build up in them and produce antibodies to go into the blood
Can intercept bacteria and other debris in the lymph by phagocytes in them digesting it

Question 41

What is the reaction forming oxyhemoglobin ?

Answer 41

Haemoglobin + oxygen = oxygaemoglobin

Question 42

What is positive cooperativity ?

Answer 42

As soon as one oxygen binds to a haem group the molecule changes shape and makes it easier for the next oxygen to bind