Animal transport Flashcards
What does myogenic mean?
The heart’s contraction is initiated within the muscle itself, rather than by nerve impulses
Where’s the bicuspid valve found?
Between left atrium and ventricle
Where’s the tricuspid valve found?
Between right atrium and ventricle
What does AVN do to the impulse?
Receives it from SAN, delays it & conveys it to Purkinje fibres
What’s an ectopic heartbeat?
Having early or extra heartbeats
What’s a fibrillation heartbeat?
Irregular, fast heartbeats
What’s meant by affinity for oxygen?
The degree to which oxygen tends to combine with haemoglobin
What way does dissociation curve shift with fetal haemoglobin?
To the left
What way does dissociation curve shift with Bohr effect?
To the right
What’s tissue fluid made from?
Substances that leave the blood plasma e.g., oxygen, water and nutrients
What doesn’t tissue fluid contain?
Large proteins of RBC
What’s hydrostatic pressure?
The pressure exerted by a liquid
What’s water potential?
The likelihood of water molecules diffusing in/out of a solution
What’s the composition of blood?
RBC, WBC, Platelets, Proteins, Water, Dissolved solutes
What’s the composition of tissue fluid?
Few WBC (only enter when there’s an infection), Very few proteins, Water, Dissolved solutes
What’s the composition of Lymph?
WBC, Only antibody proteins, Water dissolved solutes
What does opening/ closing of valves depend on?
Relative pressure of heart chambers
What’s the first ‘lub’ of the ‘lub-dub’ heartbeat caused by?
The atrioventricular valves closing
What’s the second ‘dub’ of the ‘lub-dub’ heartbeat caused by?
The semi-lunar valves closing
What’s the cardiac cycle?
The ongoing sequence of the contraction and relaxation of the atria and ventricles that keeps blood continuously circulating around the body
What is cardiac musle?
Myogenic
What is the SAN?
Pacemaker (sets rhythm of heartbeat)
What prevents waves of electrical activity from being passed from atria to venticles?
Non-conducting tissue
Why is there a delay before AVN reacts?
Makes sure atria are fully empty before ventricles contract
What are waves of electrical activity initiated by the SAN also called?
Waves of excitation
What does the height of wave on the electrocardiogram mean?
The amount of electrical charge is passing through the heart
(e.g., bigger wave = more electrical charge = stronger contraction)
Who might a slow heart rate be normal in?
Trained athletes
What’s an ectopic heartbeat?
When there’s an earlier contraction of the atria (or ventricles)
What’s fibrillation?
Irregular heartbeat
What’s the role of the Purkyne tissue?
Carries wave of electrical activity into muscular ventricle walls, causing them to contract from bottom up
What’s partial pressure of oxygen?
A measure of oxygen concentration
What do oxygen dissociation curves show?
How saturated the haemoglobin is with oxygen at any given partial pressure
What’s the partial pressure of carbon dioxide?
A measure of the carbon dioxide concentration in a cell
Why does hydrostatic pressure decrease as blood moves away from the heart?
- Divides into smaller blood vessels
- Larger total lumen/ cross-sectional area
- Fluid moves out of capillary
- Arteries stretch
