8 Transport in animals

Question 1

Why are specialised transport systems needed in animals (5)

Answer 1

-metabolic demands are higher
-smaller SA:V ratio
-molecules, hormones, enzymes are made in one place but needed in another
-food digested in one organ is needed all around the body
-waste products is cells need to be removed

Question 2

features of a good transport system (5)

Answer 2

-fluid medium, carry nutrients + oxygen
-pump - create pressure to push fluid around
-exchange surfaces, specialised
-tubes or vessels to carry fluid
-two circuits one to collect oxygen, one to transport it

Question 2

what systems are in place for circulatory (3)

Answer 2

-a liquid transport medium that circulates around the system (blood)
-they have vessels that carry the transport medium
-they have a pumping mechanism to move the fluid around the system

Question 3

layers of the artery + use

Answer 3

-lumen
-endothelium
-elastic fibres (stretch)
-smooth muscle
-collagen fibres (strength)

-(transport) Thin lining of endothelium which is smooth to reduce friction

Question 4

Layers of the vein + use

Answer 4

-lumen
-endothelium
-elastic fibres (stretch)
-smooth muscle
-collagen fibres (strength)

-(transport) have a thin lining of endothelium which is smooth to reduce friction.

Question 5

Layers of the capillary + use

Answer 5

-lumen (small so blood flows slow)
-endothelium

-(exchange) have a thin layer of endothelium which is smooth to reduce friction

Question 6

what sets the temp of the heartbeat + how it works

Answer 6

-SA node (pacemaker)

-generates electrical signals, that spread through both Atria making them contract simultaneously.

Question 7

Where are these signals then delayed + time +what happens

Answer 7

-Au node

-for 0.1 seconds
-during which blood in the atria empties into the ventricles

Question 8

What fibres then conduct the signals to the apex of the heart (2)

Answer 8

-Purkinjean fibres

-bundle branches (bundle of HIS)

Question 9

What do the signals from the Purkinjean fibres (bundle of HIS) trigger

Answer 9

A powerful contraction of both ventricles from the apex towards the atria, driving blood into the large arteries.

Question 10

Other name for Red blood cells

Answer 10

Erythrocytes

Question 11

Other name for white blood cells

Answer 11

Leucocytes

Question 12

Blood composition (4)

Answer 12

-Erythrocytes (RBC)
-Leucocytes (WBC)
-Platelets
-Plasma

Question 13

What does plasma contain (10)

Answer 13

Dissolved:

-Co2,
-O2
-salt
-minerals
-glucose
-fatty acids
-amino acids
-hormones
-plasma proteins
-urea

Question 14

How is tissue fluid formed (2)

Answer 14

-from plasma leaking from capillaries
-its in direct contact with cells + provides nutrients and oxygen

Question 15

Haemoglobin info (3)

Answer 15

-4 subunits, different peptides, 2 alfa, 2 beta
-complex primary, ternary, quaternary structures
-prosthetic group = heme group

Question 16

How does haemoglobin work (5 steps)

Answer 16

-oxygen is absorbed into the blood in the alveoli
-oxygen diffusing into blood plasma enters red blood cells
-oxygen associates with haemoglobin (reversibly binds)
-oxygen is taken out of solution
-removal of dissolved oxygen maintains a diffusion gradient allowing more oxygen to enter the cells

Question 17

What does infinity mean for haemoglobin

Answer 17

When haemoglobin holds on to oxygen

Question 18

Difference in foetal haemoglobin to normal (why)

Answer 18

-less partial pressure for more oxygen to be absorbed

(as when the umbilical cord passes the mothers blood it must have a higher infinity to take blood)

Question 19

what does ODC stand for

Answer 19

oxygen dissociation curve

Question 20

what is ODC (oxygen dissociation curve) (2)

Answer 20

When the percentage saturation haemoglobin in the blood is plotted against the partial pressure of oxygen (PO2)

ODC show the affinity of haemoglobin for oxygen

Question 21

A change in what can make a significant difference to the saturation of oxygen

Answer 21

-a change in the partial pressure of oxygen
- once the first molecule becomes attached the change in the shape of the haemoglobin molecule means other oxygen molecules are added rapidly

Question 22

what is the Bohr effect

Answer 22

As the partial pressure of carbon dioxide rises (at higher partial pressures of CO2) haemoglobin gives up oxygen more easily

Question 23

Why is the Bohr effect so important (2)

Answer 23

-In active tissues with a high partial pressure of carbon dioxide, haemoglobin gives up its oxygen more readily.
-In the lungs the proportion of CO2 is low, it makes oxygen binding to haemoglobin are easily.

Question 24

which 3 ways is CO2 transported + %

Answer 24

5% dissolved in plasma

10% combines with haemoglobin and forms carbonic haemoglobin

85% transported in form of hydrogen carbonate ions (HCO3-)

Question 25

can haemoglobin acid hold oxygen

Answer 25

-no
-it removes it

Question 26

what does chloride do

Answer 26

it balances the cell with the negative charge

Question 27

There are 6 steps in knowing how Co2 is transported via HCO3- and they are (information card)

Answer 27

1
Some of the CO2 enters RBC and combines water forming carbonic acid (H2CO3)

2
Carbonic acid dissociates releasing negatively charged hydrogen carbonate ions and positively charged hydrogen ions

3
The hydrogen ions combine with haemoglobin (Hb) forming haemoglobin acid

4
This distorts the Hb molecule decreasing its affinity for oxygen so more oxygen is released to tissues (Bohr effect)

5
Hydrogen carbonate ions build up inside the RBC causing them to diffuse out into the plasma leaving the membrane positively charged

6
To balance the electrical charge, negatively charged chloride ions diffuse into the RBC from the plasma (Chloride Shift)

Question 28

How does Hb act as a buffer

Answer 28

By removing H+ (acidity) so maintaining the pH of the blood