transport in animals

Question 1

explain four ways in which the structure of the aorta is related to its function

Answer 1

thick muscular wall which can contract forcing blood through
lots of elastic tissue that can stretch under high pressure , aorta has to carry blood under high pressure
can recoil under low pressure to prevent the artery from bursting
smooth endothelium reduced friction

Question 2

some people produce a much higher ventricular blood pressure that normal. this can cause tissue fluid to build up explain why

Answer 2

more fluid forced out of capillary
less returns to the blood
lymphatic system can’t drain it all

Question 3

explain the role of the heart in the formation of tissue fluid

Answer 3

contraction of the ventricle produces high hydrostatic pressure which forces molecules out of the capillary

Question 4

name the blood vessels that carry blood to the heart muscle

Answer 4

coronary artery

Question 5

explain how the arteriole can reduce the blood flow to capillaries

Answer 5

muscle contracts
narrows lumen

Question 6

What does the blood consist of

Answer 6

liquid blood plasma (90% water) with suspended blood cells and dissolved substances. The blood capillaries supply cells with oxygen glucose and amino acid and waste products

Question 7

Describe the formation of tissue fluid

Answer 7

1. There is high pressure at the end of the arteriole which causes filtration of blood plasma, smaller molecules such as water pass through the wall reducing the pressure
2. Large plasma proteins remain in the blood and the filtered plasma forms tissue fluid surrounding the cells.
3. The plasma proteins reduce the WP causing water to move in via osmosis
4. The osmotic potential is higher than the blood pressure some of the water is reabsorbed by osmosis
5. Some tissue fluid enters lymph capillaries known as lymph

Question 8

what is haemoglobin

Answer 8

an iron containing pigment which combined with oxygen to form oxyhemoglobin.
It consists of 4 haem units and 4 polypeptide chains
Each haem unit combines with an oxygen molecule so haemoglobin can transport 4 o2 molecules

Question 9

Describe the oxygen haemoglobin curve

Answer 9

The shape of the haemoglobin makes it difficult for the first oxygen to bind however this changes the shape of the quaternary structure this makes it easier for other molecules of o2 to bind ( it only takes a small increase in partial pressure)
However it’s difficult for the 4th to bind as the majority of the binding sites are occupied so it’s less likely to find one to bind to