Anatomy and physiology Flashcards
What divides the heart into 2?
Septum
What are the chambers called?
Atrium and ventricle
Atria
Pushes blood into ventricles so thin walls- high pressure unnecessary.
Ventricles
Push blood out of the heart- they have thicker walls for a higher pressure
Vena cava
deoxygenated blood back to right atrium
Aorta
takes oxygenated blood around the body
Tricuspid valve
Between right atrium and ventricle
Bicuspid valve
Between left atrium and ventricle
Bicuspid valve
Between left atrium and ventricle
Myogenic
The capacity of the heart to generate it’s own impulses
SA Node
Pacemaker
Neural control mechanisms
Proprioceptors, baroreceptors, chemoreceptors
Central Nervous Systems
Brain and spinal cord
Sympathetic nervous system
Causes heart to beat faster
Parasympathetic nervous system
Causes heart to slow down
Cardiac control centre
In the medulla oblongata
Chemoreceptors
Senses chemical changes- increased co2 in the blood.
Stimulates the sympathetic nervous system
Baroreceptors
Senses change in BP due to increased stretch of arterial wall.
Increased stretch leads to decrease in HR.
Proprioceptors
detect increase in muscle movement.
Adrenaline
stimulates SA node, increases speed and force of contraction and increases cardiac output.
Stroke volume depends on
Elasticity of cardiac fibres and venous return
venous return
volume of blood returning to the heart via the veins
average resting stroke volume
70ml
stroke volume
volume of blood pumped out by ventricles per contraction
Starlings Law
Increased VR- Greater diastolic filling of the heart- cardiac muscle stretched- increased force of contraction- increased SV and ejection fraction
Starlings Law
Increased VR- Greater diastolic filling of the heart- cardiac muscle stretched- increased force of contraction- increased SV and ejection fraction
What can SV increase up to?
40-60% of maximum
Average resting HR
72bpm
ATP
Adenosine triphosphate
Aerobic system
Low intensity, high duration
When is aerobic system used?
When oxygen is present.
3 stages of aerobic system
Glycolysis, Krebs cycle and electron transport chain.
Glycolysis
Takes place in sarcoplasm
break down of glucose to pyruvic acid.
for every molecule of glucose, 2 ATP are produced
Best way to illustrate OBLA
multi-stage fitness test
factors affecting rate of lactate accumulation
fitness of performer, exercise intensity, muscle fibre type, respiratory exchange ratio, rate of blood lactate removal.
buffering
a process which aids the removal of lactate and maintains blood and muscle acidity levels.
indirect calorimetry
measures how much co2 is produced and o2 is consumed at rest and during aerobic.
what does indirect calorimetry show?
find out if carbs or fat are being used as main energy source
lactate sampling
take a small blood sample to show how much lactate is present
why do lactate sampling?
show fitness levels, choose relevant training zones, compare for improvement.
