mass transport animals

what is haemoglobin

quaternary protein found in red blood cells

what ion is found in haemoglobin

4 x Fe2+ ions

haemoglobin equation

haemoglobin + oxygen →

what is haemoglobins job

transport oxygen around the body

what does haemoglobin do at the lungs

loads oxygen - readily associate with oxygen

what does haemoglobin do at respiring tissues

unloads oxygen - readily dissociate from oxygen

how does haemoglobin manage to do 2 contradicting jobs

tertiary structure of polypeptides changes allowing the molecule to change shape

haemoglobin with a high affinity for oxygen

loads oxygen more easily but unloads it less easily

haemoglobin with a low affinity for oxygen

loads oxygen less easily but unloads it easily (shape makes it difficult for oxygen to bind)

what is the shape of haemoglobin dependant on

oxygen partial pressure

carbon dioxide partial pressure

pH

temperature

what does partial pressure mean

what proportion of gas is oxygen

as the partial pressure of oxygen increases

changes shape to make it easier for oxygen to bind

what does cooperative binding mean

binding of the first oxygen changes tertiary/quaternary structure of haemoglobin which uncovers/ leads to a second binding site (uncovers another Fe for O2 to bind to)

why do different organisms have different haemoglobin structures

dependent of structure there are different affinity’s for oxygen

what does % affinity mean

how well iron and oxygen binds

why is the haemoglobin oxygen dissociation curve ‘s’ shape

first oxygen binds causing a change in tertiary shape which allows more O2 to bind more easily (cooperative binding)

when CO2 partial pressure increases (Bohr shift)

haemoglobin affinity for oxygen decreases as pH decreases (becomes more acidic) and it unloads more oxygen

what happens to the dissociation curve when CO2 partial pressure increases

shifts to the right

how is the Bohr shift advantageous for exercise

increases dissociation for oxygen (low affinity) for aerobic respiration at cells/tissues (more O2 for respiration)

the timing of the contraction of the different chambers and the opening/closing of the valves is

controlled by changes in blood pressure

process of the cardiac cycle

heart is relaxed, blood passively flows into atria increasing pressure

when the pressure is greater than the ventricle, AV valve opens and blood passively flows into ventricle

atria contracts (atrial systoles)

ventricles contract (ventricular systole) increasing ventricle pressure causing AV valve shuts

when pressure in ventricles exceeds pressure in artery, semilunar valve opens

ventricles relax, when pressure falls below artery, semi-lunar valve shuts

what does diastole mean

relaxed

what does systole mean

contracted

what’s happening with A B C and D

A = AV valve shuts

B= Semi Lunar valve opens

C= semi lunar valve closes

D = AV valve opens

what is an artery

carry blood away from the heart into the atrieoles

what is an arterioles

smaller artery that controls blood flow from artery to capillary

what is a vein

carry blood from capillaries back to the heart

what is a capillirary

tiny blood vessels that link arterioles and veins

what are the different layers of veins, arteries and capilliraries

tough fibrous outer layer- resists pressure changes outside and in

muscle layer - contract and control blood flow

elastic layer - maintain blood pressure by stretching and springing back

endothelium (thin inner layer) - smooth reduces friction and thin allows for simpler diffusion

lumen - cavity that of blood vessel where blood flows

why do arteries have thicker muscle walls then veins

smaller arteries can be constricted and dilatated in order to control volume of blood passing through them

why is the artery elastic layer relatively thicker than the veins

important blood pressure in artery is kept high. Elastic wall is stretched during diastole and relaxed during systole

why is the overall thickness of the artery great

resists blood vessel bursting under pressure

why are their no valves in arteries

blood is under constant high pressure, tend to not flow backwards

why is the muscle wall of arterioles thicker than arteries

contraction of the muscle allows constriction of lumen, restricting blood flow therefore controlling blood flow in capillaries

why is the elastic layer in arterioles thinner than artery

blood pressure is lower

why is the muscle wall of the vein relatively thin

veins carry bloodflow away from tissue and therefore constriction and dilation doesn’t control blood flow to tissues

why is the elastic layer relatively thin in the veins

low pressure of blood in the veins

why are vein wall overall thin

overall pressure in veins is too low to cause any bursting, allows them to flatten easily

why do veins have valves

ensure valves don’t flow backwards which it might do as pressure is low

when body muscles contracts, veins flatten compressing blood, valves ensure this pressure is in one direction only

what are the functions of the capillaries

exchange metabolic materials (O2, CO2 and glucose) between blood and cells in the body (blood flow is slow)

why are capillary walls mainly lining layer

extremely thin = diffusion distance is short = quicker diffusion

why are there lots of branched capillaries

large surface area for exchange

why do capillaries narrowly diameter

no cell is far from a capillary for exchange so short diffusion pathway

why do capillaries have a very narrow lumen

red blood cells are squeezed flat against side of capillary, closer to oxygen cells (reduces diffusion distance)

why are their spaces between epithelial cells in capillaries

spaces for wbc to escape to fight infections

capillaries are ‘leaky’

allows molecules such as water glucose and oxygen to move in and out but doesn’t NOT allow whole cells + plasma proteins to leave

what is tissue fluid

substance that moves in and out of blood capillaries (blood plasma)

what are the 2 factors that affect tissue fluid

hydrostatic pressure (heart creates high hydrostatic pressure when ventricles contracts)

water potential

what are the 2 ends of the capillarys called

arteriole end

venous end

process of tissue fluid

blood enters the capillary with relatively high pressure

high pressure causes some tissue fluid to move out

as blood travels along capillary, pressure decreases. when pressure in = pressure out fluid stops leaving

water potential of capillary decreases because the blood is more conc. as plasma proteins are stuck in (creates a water potential gradient)

water moves back into capillary via osmosis

some tissue fluid returns to the blood via the lymphatic system

an effective transport system

reduces diffusion distance

what does double circulatory system mean

blood passes through the heart twice in a complete circuit of the human body - this maintains blood vessel

blood vessel that brings oxygenated blood into the heart

pulmonary vein

blood vessel that brings oxygenated blood out of the heart

aorta

blood vessel that brings deoxygenated blood into the heart

vena cava

blood vessel that brings deoxygenated blood out of the heart

pulmonary artery

valve between atrium and ventricle

atrioventricular valve

valve between ventricle and blood vessel

semilunar valve

what type of muscle is the heart made of

cardiac

why does the left side of the heart have thicker muscle

creates more pressure