8) Transport in Animals Flashcards
Why does multicellular organisms need transport systems
Low SA:Vol ratio
High metabolic rate
Very active
Large no.of cells are all respiring very quickly
Ensure to have good enough supply.
What is the difference between single and double circulatory system.
single- Pass through heart once
Double - Pass trhough heart twice
Describe Arteries
Blood from heart to the body
Thick walls, muscular and elastic tissue to stretch and recoil maintain HBP
Describe Capillaries
Smallest vessel
one cell thick gas exchange
Describe Veins
Wider lumen , very little elastic or muscle tissue.
Contain veins prevent the backflow of blood.
How is tissue fluid formed
Doesn’t contain red blood cells or big proteins
High hydrostatic pressureis greater in the cappilaries
Force fluid out of capillaries into space around the cell . This is tissue fluid
As fluid leaves , HSP reduces in capillaries,it is lower at the end of the capillary bed. Oncodtic pressure is geater at this point.so water reenters by osmosis.
What is Lymph
Excess tisue fluid that returns to lymphatic system.
What is the cardiac cycle
Contraction and relaxation of atria and ventricle that keeps blood circulating
What happens in atrial systole
Ventricle relax , atria contract
Pressure inc , volume decrease
Push blood into ventricles through atrioventricular valves.
What happens in ventricle systole
Atria relax , ventricles contract
Pressure increases in ventricles that atria so atrioventricular valves shut close.
Opens semi-lunar valves, blood forced out into pulmonary artery and aorta
What happens in diastole
Ventricle and atria relax
Semi-lunar valves close , artia fill up blood .Ventricle pressure falls below atria pressure,
Cause atrioventricular valves to open and restart the cycle
How do the cardiac muscles regulate the heart.
Myogeniv-Contract + relax w/o signals
SAN sends waves of electrical activityto the atrial walls
Atria both contract at same time
Collagen tissue prevents electrical activity passing from atria to ventricle
Waves transfer from SAN to AVN
Pass wave to bundle of his.
Delay to make sure ventricles contract after atria is empties
Bundle of his conduct activity to purkyne fibres
Cause both ventricles to contract
On electrocardiograph.
What to the different parts represents
p wave - Contraction of atria
QRS complex- Ventricle contraction
T wave - Ventricles relax
What are the different heart problems
Tachycardia - Beat too fast
Ectopic Heartbeat - extra heartbeat, early atria contraction
Bradychardia - Beat too slow
Fibrillation - Really irregular heartbeat
Describe haemoglobin
more than 1 polypeptide chain
Iron prosthetic group
High affinity for oxygen , 4
Describe Haemoglobin Saturation
Oxygen loads onto haemoglobin at high pO2
Unloads at lower pO2
When cells respire , this lowers pO2
What does a dissociation curve show? Describe its shape
Hows the affinity of oxygen
when pO2 is hgigh , Hb has high affinity for O2,so has high saturation
When pO2 is low , Hb has low affinity for so release O2 , has low saturation
S shape as when Hb combines with O2 its shape alters where it makes it easier to join too .
As Hb become saturated , harder for more oxygen to join.
Why does fetal Hb have a higher affinity for O2 than Adult Hb
Fetal blood is better absorbing oxygen than mothers.
By time mother’s blood reache placenta , oxygen saturation has decreased,Fetal Hb has to have a higher affinity to take up more oxygen
How does carbon dioxide affect oxygen unloading
CO2 reacts with water => Carbonic acid.
Catalysed by carbonic anhydrase.
Carbonic acid dissociate to give Hydrogen and hydrogencarbonate ions
Inc H ions cause oxyhaemoglobin to unload, form haemoglobinic acid.
HC)3- ions diffuse out of RBC and transport intp plamsa.
What causes Chloride Shift
High levelsof carbon dioxide cause dissociation curve to shift , show that more oxygen is released from blood.
Maintainsa Charge of plasma and RBC
