Pulse, BP, Cholesterol Flashcards
Effect of sympathetic nervous system on whole cardiovascular system
increases rate/strength of contraction
constricts BVs
effect of parasympathetic nervous system on whole CV systen
decreases rate/strength of contraction
little influence on BVs
Other factors affecting rate/strength of cardio contraction
hormones age gender body position exercise stress temperature
hearts electrical system known as
cardiac conduction system
2 nodes in cardiac conduction system
Sinoatrial (SA)
Atrioventricular (AV)
Role of SINOATRIAL NODE
INITIATES contraction - creates electrical impulse - speeds through atria walls = contract PACE MAKER of heart sets RATE & RYTHM impulse travels to AV node
Role of ATRIOVENTRICULAR node
RELAY STATION
impulses relayed to
ATRIOVENTRICULAR BUNDLE
(Bundle of his)
bottom of heart called
apex
Impulse travels from Atrioventricular bundle to
R & L bundle branches (RBB & LBB) to APEX
After apex impulse travels -
up PURKINJE FIBRES in ventricles = contract
back to SA node - cycle repeats
ECG stands for
Electrocardiography
waves of ECG
P
QRS
T
how ECG works
study size/shape waves
time between waves
rate/regularity beating abnormalities
P waves record
electrical activity hearts atria
QRS waves record
electrical activity hearts Ventricles
T waves record
hearts return to resting state
describe pulse
blood pressure wave originating from heart
4 pulse points
radial - wrist
carotid - neck
dorsalis pedis - medial to big toe
posterior tibial - superior to medial malleolus
how pulse differs new born - adult
slows
newborn 130
ave adult 70-90
What is venous return
rate of blood flow back to heart
Venous return relies on 4 things -
body position (gravity, feet up etc)
skeletal muscle pump/muscular contraction (GN esp)
respiratory pump
valves
What is systolic blood pressure
or systole
measure of BP while heart CONTRACTS
force that drives blood out of heart
what is diastolic BP
or diastole
measure of BP while heart RELAXES
normal rhythmically occurring relaxation/dilation of heart
why is BP lower in veins than arteries
velocity decreased as get further away from heart,
lumen in vein larger than artery
top/bottom numbers BP
top systolic
bottom diastolic
describe skeletal muscle pump
muscle action squeezes veins
forces blood back up to heart
Why is a ‘cool down’ important after exercise rather than stopping
as gives muscles a chance to squeeze veins = blood back up to heart for reoxygenation
what is respiratory pump
breathing movements that force blood to flow to heart
describe muscular movements of respiratory pump which aid venous return
INSPIRATION - intercostals>up - diaphragm>down
EXPIRATION - intercostals/diaphagm relax
What do valves prevent
backflow of blood
define tachycardia
rapid heart rate >100/min
define bradycardia
slow heart rate <60-50/min
define cardiac output
volume of blood being pumped out by heart per minute
equation for cardiac output
stroke volume x heart rate
define cardiac stroke volume
amount of blood pumped at each beat
average cardiac output
5 litres per minute
5 L/min
What is the push
a force that drives blood out of the heart
Systole
What is the relax
a normal rhythmically occurring relaxation and dilation of the heart
Diastole
What is blood pressure
Pressure exerted by circulating blood on the blood vessels walls
What happens to BP as blood moves around body
Progressively decreases as it moves away from heart through arteries then back through veins
Normal Uk BP
135/85
What happens when blood is usher into the Aorta in Systole
it expands with force
What happens to the aorta in Diastole
valve closes, walls retract like elastic bans
forces blood forward/keeps blood moving
difference between pulse and BP
Pulse is the surge you feel
cannot feel BP
Where are receptors for low BP feedback system
BARORECEPTORS in arch of aorta/carotid sinus are stretched less
where are the control centres for Low BP
CV centre in
medulla oblongata,
adrenal medula
What is the input from the receceptoes to the control centre in the low blood pressure feedback system
decreased rate of nerve impulses
what are the effectors in the feedback system for low BP
heart - increased stroke volume/rate = more cardiac output
BVs - constriction increases SYSTEMIC VASCULAR RESISTANCE
What is CO
Cardiac OUtput
What is SVR
Systemic vascular resistance
What is the output of the control centre during feedback system low BP
Increased sympathetic NS stimulation
Increased secretion of adrenalin & noradrenalin
another term for adrenalin & noradrenalin
epinephrine
norepinephrine
two types cholesterol
LDL “bad”
HDL “good”
Describe LDL A
big & Buoyant
made from fat
harmless
Describe LDL B
small & dense
made from carbs
harmful
which tools do you use to check BP
stethoscope
sphygmomanometer
where do you find cholesterol
in every cell of the body
what is cholesterol essential for the health of
all cells,
many hormones
Vit D
where do we get cholesterol from
some from diet
much made in liver
Cholesterol is vital but what may happen if you have too much
develop fatty deposits in your blood vessels
increases risk of heart disease
name condition where you have fatty deposits in your BVs
Atheroma/atherosclerosis
Why does cholesterol need to be transported around the body
it’s a LIPID
hydrophobic
how is cholesterol transported around the body
via lipoproteins
where are lipoproteins made
synthesised by the liver
what happens if cholesterol too low
hormone problems
Vit D probs - affects immune system/bone health
LDL stands for
Low density Lipoproteins
HDL stands for
High density lipoproteins
job of LDL in body
carry cholesterol from liver to cells of body
job of HDL in body
collects cholesterol from cells to liver
Recommended readings for total cholesterol,
non-hdl cholesterol
Triglycerides
total chol - less than 9.0 mmol/litre
non hdle chol - less than 7.5 mmil/litre
triglycerides - less than 4.5 mmil/litre
