Cardiovascular + Respiratory System - TOPIC 1 Flashcards
What do proprioceptors do?
Detect movement, are located in the muscle
What do baroreceptors do?
Contain nerve endings that detect stretching in arterial walls
(due to blood pressure changing)
What do chemoreceptors do?
Detect increase in blood acidity due to C02
If there is a greater ———– it can increase ejection fraction
force of contraction
What happens during diastole?
The heart relaxes and fills with blood
What 2 factors are starling law dependant on?
Venous return
Elasticity of cardiac fibres ( during diastole, greater stretch = greater force)
Why does HR increase during exercise
Mentioning the two nervous systems
Sympathetic nervous system - speeds up HR and breathing rate
Parasympathetic nervous system - slows down heart rate to resting level
Definition of ejection fraction is?
% of blood pumped out left ventricle per beat
What happens during systole?
The heart contracts and ejects blood
5 stages of starlings law are?
-Increased venous return
-Greater diastolic filling
-Cardiac muscle stretches
-Greater force of contraction
-increased ejection fraction
VDMFE (very dumb mother fkin eggs)
What do the following usually do to HR (inc or dec)
Baro
Chemo
Proprio
(receptors)
Decrease
Increase
Increase
Order of the receptors in the heart beat is?
Proprio—>Chemo—->Baro
What is stroke volume?
volume of blood ejected from the heart per beat
What is cardiovascular drift?
When:
-Body begins to dehydrate
-Blood plasma then falls as the body begins to sweat
- venous return and stroke volume will decrease
-heart rate increases to maintain cardiac output
What does the phrenic nerve do?
Sends a message to diaphragm and the external intercostal muscles to contract
This lasts for 2 seconds, then stops which causes the lungs to expire
What does the intercostal nerve do?
It can increase expiration by activating the abdominals and internal intercostal muscles
Effects of smoking on the body?
-irritation of trachea and bronchi
- cilia is damaged, excess music builds up in lungs ( cause smokers cough)
- alveoli damaged, walls break down and join together forming larger spaces then normal (reducing surface area)
- increase blood pressure
- carbon monoxide binds to haemoglobin
What is an ischaemic stroke caused by
A blood clot
What is an haemorrhagic stroke caused by
Weakened blood vessel burst
Two factors that cause Bohr shift?
CO2 and heat
When blood arrives back to heart after being oxygenated, what happens?
Left atrium, AVN causes systole but with a 0.1 second delay (to allow filling of atria)
Then goes into left ventricle through bicuspid valve
then bundle of his
purkinje fibres
systole then out of the heart to the working muscles or organs
A-V02 difference is what
the difference between oxygen concentration of the blood in the arteries and veins
during exercise is avo2 diff higher or lower
HIGHER
What is average ejection fraction for a normal and elite athlete
60%, 85%
What do high density lipoproteins do?
GOOD
Remove excess cholesterol,
transfer cholesterol into liver where it is broken down
lower the risk of heart disease
What is the role of vascular shunt mechanism?
To ensure:
- more blood goes to the heart, because heart needs o2 to beat faster and stronger
- more blood goes to muscles as they need more oxygen, and blood is needed to remove waste products
- more blood goes to skin, to cool the body down.
What is vascular shunt?
the redirection of blood flow.
(to working muscle/organs/where it is required)
what does low density lipoproteins do?
it is bad cholesterol
transports cholesterol to tissues where it is deposited
What 2 mechanisms are used to aid vascular shunt and redirect blood flow?
vasoconstriction
vasodilation
During rest A-vo2 diff is ?
low
Would a trained performer have a higher or lower a-vo2 diff? WHY?
HIGHER
As the body is more effective at using 02, so lower resting hr
97% of o2 combines with ? to form ?
3% of o2 dissolves into ?
Combines with haemoglobin to from oxyhaemoglobin
blood plasma
cardiac output = ?
stroke volume x hr
during exercise cardiac output ?
increases, as heart rate and stroke volume both increase
definition of cardiac output?
volume of blood ejected from the ventricles per minute
What is the order of the cardiac conduction system?
SAN, AVN, bundle of piss, purkinje fibres
