Animal Transport

Haemocoel

The space blood is pumped into (open circulatory system)

SAN

Internal pacemaker - Top right atrium

SAN firing (not P.E.)

Initiates wave of excitation

which causes atrial systole

What happens when impulse reaches the AVN

causes a delay allowing atria to complete contraction before ventricles

Bundle of HIS

Causes contraction of ventricles

Purkinje fibres

Ensures contraction is form the bottom up

Diastole

Heart relaxation

Systole

Contraction

P on ECG

SAN firing - atrial systole

QRS wave

Ventricle systole - purkinje fibres

T on ECG

Diastole

erythrocytes

Red blood cells - carry haemoglobin

Haemoglobin association

Oxygen binds in lungs

Haemoglibin dissociation

Oxygen unloads in respiring tissues

What happens at a low ppo2

Harder for oxygen to associate

Why is it difficult for o2 to bind to haemoglobin

Heam groups in the centre

What happens after the first oxygen binds

Changes shape to make it easier for other to bind

Why is it harder for the 4th oxygen to bind

Difficult to collide to final haem group

What does low PPo2 in working muscles cause

Oxygen unbinds form haemoglobin

What causes oxygen to release to respiring tissue

Pressure difference between high haemoglobin and low working tissue

Bohr shift

High concentration of co2 causes oxygen to release more

Which direction is the Bohr shift

Shifts to the right

Where would foetal haemoglobin be on a dissociation curve

Shifted to left

Myoglobin

Proteins that stores oxygen in muscles

Where would myoglobin be on dissociation curve

shifted left

What happens to red blood cells at high altitude

number of red blood cells increases

Functions of tissue fluid

Bathes all cells

Transports o2, nutrients, co2

What percentage of tissue fluid is reabsorbed by veinous end

90% return rate

What happens to the remaining fluid in capillaries

Removed into lymphatic system

Subclavian vein

Where lymph returns to the blood stream

Lymphocytes

Intercept bacteria and viruses

3 ways CO2 is transported to lungs

5% in blood plasma

10% carbamino heamoglobin

85% hydrogen carbonate ions

Co2 transportation (chloride shift) (6)

Balance the loss of negative charge when hydrogen carbonate ions (HCO3-) leave the cell

Co2 diffuses into RBC from tissues

Co2 + H2O = Carbonic acid (H2CO3)

This then dissociates to form hydrogen carbonate ions (HCO3-) + hydrogen ion (H+)

Hydrogen carbonate (HCO3-) out into blood plasma and chloride shift in

Oxyhemoglobin releases oxygen

Haemoglobin binds to H+ to act as a buffer

O2 diffuses back into cell to be respired

Tissue fluid + functions (2)

Area between blood vessels and cells

Bathe all cells

Supply oxygen, glucose, hormones to cells

Plasma without proteins