Transport in animals Flashcards
What does the plasma consist of
-Oxygen
-CO2
-Minerals
-Glucose
-Amino acids
-Hormones
-Plasma Proteins
-Platelets
What does tissue fluid not contain
Most of the cells found in the blood / Plasma Proteins
Blood vessels order
Artery - Arterioles - Capillaries - Venules - Veins
Pressure at the arterial end of capillary
High hydrostatic - pushes blood fluid out of capillary
-Plasma with dissolved nutrients and O2
Pressure at the venous end of capillary
Smaller
-oncotic pressure exceeds hydrostatic pressure
- Carries CO2/ urea back into capillaries
What happens to the tissue fluid that does not re-enter the blood
- directed to lymph system
- Drains excess tissue fluid and returns to blood system in subclavian vein in the chest
- Contains more lymphocytes
Blood plasma / tissue fluid / lymph
Blood Plasma:
high hydrostatic / more negative / RBC, Neutrophils, lymph /Plasma Proteins / transported in lipoproteins
Tissue fluid:
low H / Less negative / some neutrophils / few P/ Few fats
Lymph:
Low H / Less negative / lymph / few P / More fats - near digestive system
Hydrostatic / Oncotic
Hydro:
- push fluid out into tissues
- push fluid into capillaries
Onco:
- Pull water back into blood
- Pull water into tissue fluid
Hydrostatic pressure definition
The pressure that a fluid exerts when pushing against the sides of a vessel/ container
Hydrostatic pressure definition
Why does tissue fluid form
Exchange of gases and nutrients
-diffusion/facilitated/ active uptake
Myogenic
Muscle can initiate its own contraction
Fibrillation
Uncoordinated contractions of atria and ventricles
SAN
Pacemaker
- Small patch of tissue that send out wave of electrical excitation at regular intervals in order to initiate contractions
AVN
Top of interventricular septum
- delayed so atria can finish contracting
Advantages of double circulatory systems
Can regulate pressure so that lower pressure in pulmonary so does not damage the delicate capillaries, whilst systematic circulation is at a high pressure
How is a steep concentration maintained at the lungs for O2
O2 is taken out of solution
Dissociation
Releasing O2 from the oxyhaemoglobin
Why doesn’t O2 associate at low p02
The haem groups are at the middle of the haemoglobin molecule so does not readily associate
Conformational change
Slight change in the haemoglobin molecule so more O2 can readily associate
Where is pO2 high/low
Arterial / venous
Why does fetal haemoglobin need a higher affinity for O2
Must be able to associate where there is low pO2
How does a fetal haemoglobin get O2 from the mother
Placenta (low pO2) absorbs O2 from surrounding fluid lowering the pO2 further
- means O2 diffuses from mothers blood to placenta lowering pO2 more
- causes to dissociate more
Three ways CO2 is transported
5% plasma
15% carbaminohaemoglobin
85% hydro carbonate
Formation of hydrocarbonate ions
1) CO2 in blood plasma diffuses into RBC
2) Combines with water to form carbonic acid (weak)
- Catalysed by carbonic anhydrase
3) Carbonic acid dissociates into H+ and HCO3-
4)HCO3- out of plasma
5) Chloride shift to maintain charge
6) H+ ions taken out of solution to form haemoglobinic acid to stop RBC becoming too acidic
Bohr shift
When H+ taken out of solution and associates with haemoglobin causes a change in tertiary structure
- more readily dissociate and less saturated with O2
- Ideal where there is lots of respiring tissue
What does haemoglobin act as in CO2 transport
A buffer to stop the RBC becoming to acidic
Diastole
Relax
elastics recoil - increase volume
allows blood to flow in from the vein
Atrial systole
right/ left A contract
thin walls - small amount of pressure pushing blood into ventricles
- SL open / AV close
Ventricular systole
Right/ Left V pump
Contraction at apex
Blood pushed upwards towards the arteries
