5 - Mass Transport Flashcards
Define haemoglobin
Protein in a RBC that transports oxygen
Haemoglobin has …. polypeptide chains
4
What does haemoglobin form with oxygen?
Oxyhaemoglobin
Describe the structure of haemoglobin (5)
Made of 4 subunits Each subunit has a haem group Each haem group has Fe2+ The shape changes when O2 bonds The shape changes when the pH is lowered
Why is haemoglobin made of 4 subunits?
4 O2 molecules can be transported
Why is blood red?
The haem group contains Fe2+
Why does haemoglobin have an affinity for oxygen?
Contains Fe2+ (bond)
Why does the shape of haemoglobin change when O2 is bonded to it?
Other oxygen molecules can load easily
When does the shape of haemoglobin change? (2)
O2 bonded to it
pH is lowered
Why does the shape of haemoglobin change when the pH is lowered?
Oxygen molecules unload in respiring tissue
Process of transporting oxygen by haemoglobin (3)
1 - Readily associate with O2 at surface where gas exchange happens
2 - Readily dissociate from O2 at respiring tissues
3- Does this by forming oxyhaemoglobin
O2 concentration where gas exchange happens
Low
O2 concentration where respiring tissues are
High
CO2 concentration where gas exchange happens
High
CO2 concentration where gas respiring tissues are
Low
Affinity where gas exchange happens
High
Affinity where gas respiring tissues are
Low
Result where gas exchange happens
Oxygen attached
Result where respiring tissues are
Oxygen released
Define affinity
Ability of haemoglobin to bind to oxygen
Equation about haemoglobin
Loading
Hb + 4O2 -> HbO8
Shape of the oxygen dissociated curve
S
Describe the oxygen dissociated curve
1 - Near tissues. Hard to load as low O2 concentration
2 - Changes shape so happens easier
3 - Near lungs - hard to load but high affinity
Does the curve go left or right in foetal haemoglobin?
Left
Does the curve go left or right in the Bohr Shift? Why?
Right - lower CO2 concentration so give sup extra oxygen
Shift where the curve moves right
Bohr Shift
Describe the process of the Chloride Shift
- Carbon dioxide diffuses into the RBCs and combines with water to form carbonic acid
- Carbonic acid dissociates into protons (H+) and bicarbonate ions (HCO3-)
- The protons are buffered on the surface while the bicarbonate ions are actively exchanged across the surface
- Cl- enters the RBC when HCO3- leaves (Hamburger effect)
- This raises the inter-erythrocyte of chlorine
Effect where HCO3- and Cl- are transported
Hamburger effect
Equations for the Chloride Shift
CO2 + H20 ↔ H2CO3 ↔ H+ + HCO3-
H+ + Hb- ↔ HHb
Why do we need a circularity system? (3)
We are big - blood vessels needed
Diffusion is only effective with a short pathway
Need t transport products of digestion to other cells
Define mass transport
Transporting materials around the body
Why do organisms have a transport system? (3)
SA:V decreases as size increases
Exchange surfaces needed for nutrient exchange and removal of products
Exchange surfaces in specific locations
6 features of a transport system
Suitable medium Move in bulk Closed system Move the medium Flow in one direction Control the flow
Colour of arteries
Red
Where do arteries go?
Heart to body cells
Colour of vein
Blue
Where do veins go?
From body to heart
What does pulmonary relate to?
Lungs
What does renal relate to?
Kidney
What does cardiac relate to?
Heart
Why is the circularity system double?
Heart -> Lungs -> Heart -> Tissues -> Heart
What is the pressure in the lungs? Why?
Low - no damage and long diffusion
Where does the aorta go from and to?
Left ventrical to body
Where does the vena cava go from and to?
Body to heart
Where does the pulmonary vein go from and to?
Lungs to left atrium
Where does the pulmonary artery go from and to?
Right ventricle to lungs
Define the cardiac cycle
Sequence of events undertaken by the heart at around 70 times per minute to ensure blood flows fully around the body
Another word for contraction
Systole
What is systole?
Contraction
Another word for relaxation
Diastole
What is diastole?
Relaxation
What are AV valves? (2)
Atrioventricular - between atrium and ventricle
What are SL valves? (2)
Semi lunar - between ventricles are arteries
What causes increased pressure in the heart? (2)
Contraction and blood entering the chambers
Describe the points if the cardiac cycle (4) Why?
- AV close - V pressure higher than A
- SL open - V pressure higher so force through
- SL close - A pressure higher than V
- AV open - A pressure higher than V
What makes up blood ? %
55% - Plasma
40% - RBC
5% - WBC
What is the role of tissue fluid?
Exchange and transport oxygen and nutrients form the blood to cell for exchange of CO2 and other waste products
Tissue fluid formation (6)
- Blood flows into the capillary network
- High hydrostatic pressure at arterioles
- Push blood into surrounding cells
- Fluid has plasma, O2 and nutrients
- RBC, WBC + plasma stay in blood too big (low WP)
- Fluid in tissue stop new fluid from moving out
Type of pressure in tissue fluid
Hydrostatic
Define hydrostatic pressure
Pressure created by a fluid pushing against it’s container
Pressure at the capillary end
4.3KPA
Units for pressure
KPA
What does the pressure do when going from arteriole to venule? Why?
Decreases - small molecules forced out so less blood (volume)
Equation for pressure in tissue fluid
Change in hydrostatic + change in water potential
How does fluid return to the blood? (5)
- Tissue fluid also has some hydrostatic pressure
- Push fluid back into capillaries
- Blood and tissue contain solutes so negative WP
- WP of tissue fluid less negative than WP of blood
- Osmosis happens
Lymph formation (4)
- Not all fluid returns to the capillaries
- Excess fluid drains into system
- Similar to fluid but have less O2 and nutrients
- Contains lymphocytes and is part of the immune system
What are lymphocytes
WBC - filter bacteria from tissue fluid
Type of vena cava at the top of the heart
Superior vena cava
Type of vena cava at the bottom of the heart
Inferior vena cava
Vessel that enters the right atrium
Vena cava
Vessel that enters the left atrium
Pulmonary artery
Vessel that leaves through the right atrium
Pulmonary artery
Vessel that leaves through the left atrium
Aorta
Artery function
Transport blood away from heart to respiring tissues
Exceptions for the artery carrying oxygenated blood (2)
Pulmonary artery (Heart to lungs) Umbilical artery
Adaptations for the artery (3)
Thick outer wall - withstand high pressure
Narrow lumen - create a high pressure
Elastic walls - stretch and recoil
Capillary function
Minute vessels that are fed into be arterioles
Adaptations for the capillary (3)
1 cell thick - short pathway
Contains O2 - diffuses across wall
Narrow - limit blood flow so travel slowly and more time for diffusion
Vein function
Transport flood into the heart
Exceptions for vein carrying deoxygenated blood (2)
Pulmonary vein - O2 blood form lungs to heart
Umbilical vein
Vein adaptations (2)
Large lumen - holds more blood
Pocket valves - prevent backflow (Semi lunar)
How to calculate cardiac output
Stroke volume x heart rate