module 3 Flashcards
vital capacity
the maximum air volume
inhaled/exhaled one breath
how are gills adapted for efficient gas exchange
lots of lamellae
secondary lamella
short distance between blood and water
causing a gradient
countercurrent flow
why does tissue fluid not contain erythrocytes
gaps between endothelium are to small
erythrocytes to big
role of hemoglobin in transporting oxygen
1 haemoglobin has high affinity for oxygen
2 oxygen binds to haemoglobin in,
lungs /alveoli / high pO2
3 oxyhaemoglobin
4 oxygen released, in tissues where pO2 is low / where
respiration is occurring
equation for carbon dioxide to hydrogen carbonate ions
CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-
how are hydrogencarbonate ions produced from carbon dioxide
CO2 diffuses into erythrocytes
and reacts with water
to form carbonic acid
which dissociates into HCO3 ions
what is Bohr shift
high CO2 conc causes reduced affinity for oxygen in hemoglobin
as H+ ions form hemaglobnic aicd
which alters hb shape
causing O2 to be released on areas with high CO2
Pulmonary circuit
Pick up oxygen
what does the Systemic circuit do
Deliver oxygen around the body
Why is a single circulatory system less effective
As blood flows through gill capillaries, overall pressure decreases
Speed of flow decreases
Blood flowing to body will have a lower pressure and flow slower
Rate at which O2 and nutrients are delivered to respiring tissue and waste removed is limited
Tissues in artery
Folded endothelium
Elastic fibres
Smooth muscle
Collagen fibres
Function of arterioles
Link arteries and capillaries
Structure of veins
Larger lumen - allow lower pressure, reduces resistance to flow
Endothelium
Elastic fibres
Smooth muscle
Collagen fibres
Advantages of a closed circulatory system
High pressure so blood flows more rapidly
More rapid delivery of oxygen and nutrients
More rapid removal of carbon dioxide and other waste
Transport is independent of body movement
Role of vascular cambium
Responsible for secondary growth and contains meristematic tissue