Blood pressure Flashcards
to get pass
What is the blood pressure equation
Blood pressure = CO * TPR
cardiac output
total peripheral resistance
What is stroke volume
end diastolic volume - end systolic volume
What is preload
the tension in the cardiac myocytes before they contract
What is preload dependent on
Venous Return
What is contractility
contraction force of the myocardium
What affects stroke volume
Preload
contractility
afterload
What can heart rate be increased by
Higher temperature
Thyroid hormone
Caffeine
epinephrine and norepinephrine
What can heart rate be decreased by
acetylcholine
reduced temperature
intense visceral pain
What nervous system affects vessel radius
sympathetic nervous system
What happens if the SNS activity increases on vessel radius
Vasoconstriction
Where do afferent nerve fibres enter
the brain
where do efferent nerve fibres leave
the brain
Where are the baro receptors
Carotid sinus and aortic arch
What afferent cranial nerves are used by the carotid and aortic sinus
carotid - glossopharyngeal
aortic - vagus
What are the 3 cardiovascular centres
Vasomotor center (vessles)
cardiac inhibitor
cardiac accelerator
What does vagal activity do on heart rate
slow it down
What happens if blood pressure increases (baroreceptors) aortic and carotid
increased firing rate to cardiac and vasomotor centers
stimulates cardioinhibitory centre which increases Parasympathetic activity to SA node thus heart rate lowers
Also inhibits cardioacceleratory and vasomotor centres
what happens if the baroreceptors aren’t stretched as much
firing rate decreases
What is the valsalva manoeuvre
you compress your vena cava (shitting with glottis closed)
What is the humeral control
catecholamines (epinephrine and norepinephrine)
Renin angiotensin aldosterone system (RAAS)
Atrial natriuretic peptide (ANP)
Antidiuretic hormone (ADH)
Arginine vasopressin (AVP)
What are Beta 1 receptors responsible for
SA node and cardiac muscle so increases HR and contraction force
What are Beta 2 receptors for
vascular smooth muscle in heart and skeletal muscles , vasodilator , airway smooth muscle bronchodilator
What are Beta 3 receptors for
adipocytes and lipolysis
What are alpha one receptors for
vascular smooth muscle and vasoconstrictor
