Mass transport in animals

Question 1

need for circulatory system

Answer 1

body needs a constant supply of rectants from metabolism

single celled organisms can gain oxygen and glucose directly from surroindings - the molecules can diffuse to all parts of the cell quickly.

we have many layers of cells.
far too long

Question 2

what does mass transport mean?

Answer 2

bulk movement of gases or liquids in one direction
helps maintain diffusion gradients

Question 3

Haemoglobin

Answer 3

globular protien
oxygen-carrying pigment found in vast quantities in red blood cells.
carries up to 4 O2 at once.

Question 4

Haemoglobin function

Answer 4

transporting the oxygen to the tissue
oxygen is not very soluble in water and haemoglobin is more efficient
existence of the iron II ion in the haem group allows oxygen to reversibly bind

Question 5

what is another name for red blood cells?

Answer 5

erythrocytes

Question 6

what is cooperative bonding?

Answer 6

the binding of the first O2 molecule results in a conformational change in the structure of the haemoglobin molecule making it easier for each successive O2 molecule to bind.

Question 7

what are the two stages of the cardiac cycle?

tell me the state of teh Atrioventricular valves and the semilunar valves.

Answer 7

diastole AV - open SV - closed
systole AV - closed SV - open

Question 8

coordination of Heart

Answer 8

sinoatrial node - pacemaker of the heart
generates a wave of electrical stimulation (depolarisation)

Depolarisation spreads through the atria where they contract
Can not go directly to ventricles because of nonconductive tissue region.

atrioventricular nodes stimulated by electrical wave.
Depolarisation passed into bundle of His.

ventricles contract, bundle of His splits into two branches (PURKINJE FIBRES). which carry the wave up to the ventricles. this delay enables the ventricles to fill with sufficient blood before contracting.

Question 9

equation for cardiac output

Answer 9

Cardiac output = Heart rate x Stroke volume
CO = HRSV

Question 10

3 stages to the cardiac cycle.

Answer 10

cardiac diastole (relaxation)
both the atria and ventricles relax
blood enters the atria, pressure builds behind the atrioventricular valve pushing them open, blood enters the ventricles.
SL valves are closed

Atrial systole
atria contract and ventricles remain relaxed.
any remaining blood is pushed up into the ventricles.
SL valved are closed

Ventricular systole
the atria relax and the ventricles contract
this is after a certain volume of blood has filled, increasing the pressure, closing the atrioventricular valves.
SL valves open where blood flows out of the heart. when pressure decreases, semilunar valves close.

Question 11

what are the 2 types of receptor

Answer 11

chemoreceptors
pressure receptors

Question 12

chemoreceptors

Answer 12

detect chemical changes
e.g. change in O2 conc, CO2 levels and pH of the blood, found in the medulla.

Question 13

pressure receptors

Answer 13

detect changes in blood pressure.
found in the carotid arteries (neck) and aorta

Question 14

Sympathetic neuron

Answer 14

secretes noradrenaline - type of neurotransmitter, increases heart rate

Question 15

parasympathetic neuron

Answer 15

secretes acetylchlorine - type of neurotransmitter.