Week 8 & 9 - Cardiovascular system Flashcards
CV functions-Transport
- O2 delivery
- CO2 removal
- Hormones
CVS Regulates (3)
- Temp
- pH
- Glucose
CVS Prevents
-Infection (immune function)
CV components
- Heart
- Blood vessels
- Blood
Pulmonary circuit (Location, function)
- Right side of the heart
2. Pumps deoxygenated blood to the lungs via pulmonary arteries.
Systemic circuit (Location, function)
- Left side of the heart
- Pumps oxygenated blood to the whole body via arteries
- Returns deoxygenated blood to the right heart via veins
Right ventricle
- Amount of Q and where
- Regulated by..
- Total Q goes through lungs
- Pulmonary blood flow is regualted by alveolar PO2 and PCO2
Left ventricle
-Total Q (L/min)
- Total Q at rest approx. 5-6 L/min
Left ventricle
-Arterial pressure/volume
- High pressure
- Contains 15-20% of total blood volume
Left ventricle
-Venous circulation pressure/volume %
- Low
- 60% total blood volume
Right ventricle
-Blood volume in resting lung
15% of total
Right ventricle
-Regulated by
Alveolar PO2 and PCO2
Cardiac muscle types
Epicardium, Myocardium, Endocardium
Heart muscle receives blood supply via____
coronary arteries
Myocardium characteristics
- Thickness varies directly with stress placed on chamber walls
- Left ventricle chamber = most powerful/largest
- Intercalated disks allow rapid contraction
SA node known as________ and initiates_____
pacemaker
depolarization
AV node function
- Passes depolarization to ventricles
- Brief delay to allow for vetricular filling
Bundle branches located
- To left and right ventricles
Purkinje fibres located
-Throughout ventricles
SA node innervated by_____ and______branches of the_____ ______ ______.
-the parasympathetic, sympathetic, autonomic nervous system.
AV node built in delay time
-Reason for the delay
- 0.13
- delay allows atrial contraction to precede ventricular contraction (ventricular filling)
AV bundle/Purkinje fibres function
- Conduction to inferior region of each ventricle
- Allows all ventricular parts to contract at approx. same time.
PNS
- Acts through
- Function
- vagus nerve
- Decrease HR/ force of contraction (vagal tone)
SNS function
-Stimulated by stress to increase HR and force of contraction
Catecholamines
- what are they
- why are they released
- function
- Hormones
- Released due to sympathetic stimulation
- Increase HR
Cardiac Arrhythmia-Bradycardia
-RHR below 60bpm
Cardiac Arrhythmia-Tachycardia
-RHR above 100bpm
Cardiac Arrhythmia-Premature ventricular conctraction (PVCs)
-Feel like skipped or extra beats
Cardiac Arrhythmia-Ventricular tachycardia
-3 or more consecutive Pulmonary valve stenosis (PVS) that can lead to ventricular fibrillation in which contraction of the ventricular tissue is uncoordinated
ECG definition
Records electrical activity of the heart
P-wave definition
Atrial depolarization
QRS complex definition
Ventricular depolarization and atrial repolarization
T-wave definition
ventricular repolarization
ECG abnormalities are caused by
ST segment depression=myocardial ischemia
Systole
- definition
- time lapse during rest/exercise
- contraction phase (ejection)
- 0.3s at rest
- 0.2s during exercise
Diastole
- definition
- time lapse during rest/exercise
- relaxation phase (filling)
- 0.5s at rest
- 0.13s during exercise
- Longer than systole at rest
- Shorter during exercise
Cardiac output (Q)
definition
equation
What things affects amount
-Amount of blood pumped by the heart/min
Q=HR x SV
-Amount can depend on training state/gender
Stroke volume (SV) definition equation
-Blood pumped per contraction
SV=EDV-ESV
Ejection faction
Definition
equation
Amount %
-Proportion of blood pumped out of the left ventricle each beat
EF=SV/EDV
-Averages 60% at rest
EDV
Definition
Volume of blood in ventricles at the end of diastole (preload)
The average aortic blood pressure the heart must pump against to eject blood, lso known as____
after load
Strength of the ventricular contraction enhanced by: (2)
- Circulating epinephrine and norepinephrine
- Direct sympathetic stimulation of heart
Frank-Starling mechanism
Definition?
Why?
- Greater EDV results in a more forceful contraction
- -Due to strech of ventricles
Venous return increased by (3)
Venoconstriction
Skeletal muscle pump
Respiratory pump
Vascular system is made up of: (5)
Arteries-aorta, most flexible Arterioles-resistance vessels Capillaries-blood & tissue exchange Venules- Reservoir Veins-vena cava, most stiff
Venous return function/mechanisms (3)
- against gravity
1. Breathing
2. Muscle pump
3. Valves
Autoregulation definition
-Arterioles dilate/constrict in response to local chemical environment
Extrinsic neural control definition:
sympathetic nerves within walls of vessels are stimulated causing vessels to constrict
Blood distribution
Balance between mean arterial pressure and total peripheral resistance
Mean arterial pressure (MAP)
Definition
Equation
Average pressure exerted by the blood as it travels through arteries
MAP=TPR (total peripheral resistance) x Q
Haemodynamics
Meaning
Reason
- Bloodflow
- Directly proportional to the pressure difference between the two ends of the system
Blood flow = difference in pressure/ resistance
Haemodynamics pressure is proportional to the difference between____ and ____ ____ _____
Mean arterial pressure, right atrial pressure
Haemodynamics
Resistance depends on (3)
-equation
Length of the vessel
viscosity of the blood
Radius of the vessel
Resistance = Length x viscosity/radius^4
The Fick Principle equation
VO2 = Q x (a - v) O2
Sinus rhythm definition
Any cardiac rhythm where depolarization of the cardiac muscle begins at the sinus node
SA node alternative name
-Pace maker (60-80 bpm, intrinsic HR)
