Physiology 208 Cardiovascular part 1

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Lecture 1

Question Answer
Transport in the circulatory system can be divided into three typesMaterials: entering, moved and leaving
The heart's two serial circuitsPumpmonary vs. Systematic
Is the atrium above or below the ventricles?Above
Carrying blood back to the heart are ___ (veins/arteries)veins
Carrying blood away from heart are ___ (veins/arteries)arteries
Smallest vessels where transport takes place are the?Capillaries
Notable circulations within systemic circuitCoronary circuit - Digestive tract/liver portal system - Kidney portal system
Does the right or left side of the heart contain blood with low oxygen content?Right
Does the right or left side of the heart contain well-oxygenated blood?Left
Where does the right atrium recieve blood from and send blood to?venae cavea - Right ventricle
Where does the right ventricle recieve blood from and send blood to?Right atrium - Lungs
Where does the left atrium recieve blood from and send blood to?Pulmonary veins - Left ventricle
Where does the left ventricle recieve blood from and send blood to?Left atrium - body except lungs
Where does the left ventricle recieve blood from and send blood to?Systemic veins - Right atrium
Where does the artery recieve blood from and send blood to?Right ventricle - Lungs
Where does the pulmonary vein recieve blood from and send blood to?Lung veins - Left atrium
Where does the aorta recieve blood from and send blood to?Left ventricle - Systemic arteries
How does blood flow though the cardiovascular systemΔP high pressure to low
The initial region of high pressure in the cardiovascular system is created by?contraction of the heart
As blood flows through the vessels pressure is lost due to?friction created between the blood and vessel walls
The pressure exerted by a fluid in a container that is not moving is equal to theHydrostatic pressure
Is the low pressure or the high pressure created in the ventricles considered the driving pressure?High
Equation: Fluid flows only if there is a ____ ΔPPositive: = P1 - P2
Fluid flows only if there is a ____ ΔPPositive
Flow is ____ proportional R to resistanceinversely
Flow is ____ proportional pressure gradientdirectly
Poiseuille’s equationpredict the resistance to flow from the properties of the vessel and fluid
Flow is ____ proportional to the fourth power of the vessel radiusdirectly
As tube radious decreases, resistance to flow ____ (increase/decreases)Increases
Flow is ____ proportional to both the length of the vessel and viscosity of the liquidinversely
Resistance is _____ proportional to viscosity of liquid and length of tubedirectly
A ____ radius tube will have less resistance and more flowlarger
A ____ length tube will have less resistance and more flowshorter
What are the units of flow?Amount per minute ex. (ml/min)
What is the velocity of flow equation?v=Q(^3)/A(^2)
What is the RESISTANCE of flow equation?R = 1/r^4
What is the flow equation?F = 1/resistance
In one minute the heart performs the equivalent work of lifting a ___ pound weight up ___ foot5 and 1
In a 70 year life span your heart will contract how many times?>2.2 billion times
The heart is encased in a tough membranous sac known as?pericardium
The heart is on the ___ side of the thoracic cavity, between lungsVentral
What allows flow from the atria into the ventricles?Atrioventricular valves (AV)
RA -> RV uses which valve?tricuspid valve
LA -> LV uses which valve?Mitral valve
The AV valves are attached to?papillary muscle in each ventricle by chordae tendineae
One way valves that exist between the ventricle and outflow arterySemilunar valves
Which valves have 3 cup-like leaflets?Aortic and pulmonary
During contraction ___ valve remains closed to prevent blood flow back into atriaAV
During contraction ___ valve prevent blood that has entered the aerteries from flowing back into ventricles due to ventricular relxationSemilunar

Lecture 2

Question Answer
Cardiac action potential originates in a group of cells in which node?SA node
The AV node and purkinje fibres have ____ pacemaker activity over ridden by that of the SA nodeslower
Firing rate: SA node60-100/min
Firing rate: AV node40-60/min
Firing rate: AV node15-40/min
Conducts action potentials from the SA pacemaker into the left atrium causing contractionBackman’s bundle
Anterior, middle and posterior internodal pathways conduct the action potential from the ___ node to the ___ nodeSA and AV
Anterior, middle and posterior internodal pathways depolarizing ___ ___ muscle along the wayRight atrial
Atrial conduction rate is, ____ms80-100
Conduction slows down through the AV node to allow?blood from atria to empty in to ventricles
Ventricular conduction depolarization proceeds through the ____ to the ____septum apex
Why do ventricular muscles have a spiral arrangement?Ensures blood is squeezed upwards from heart's apex
Complete conduction blockcomplete dissociation between the atria and ventricles
During complete conduction block, does SA node continue to be pacemaker for atria but as electricity doesn't make it to ventricles, what can be done?Purkinje fibers take over as pacemaker
What does an ECG represent?Summed electrical activity generated by all the cells of the heart
What chemical components allow ECG to work?NaCl based ecf are good conductors
If the electrical activity of the heart is moving towards the positive electrode of the lead then an ____ deflection is recordedupward
electrical activity moving away from a positive electrode is recorded as a ____ deflectiondownward
electrical activity moving perpendicular to the axis of the electrodes causes ___ deflectionno
Direction of ECG indicates relationship between?Vector direction & axis of lead

Lecture 3

Question Answer
ECG: P waveAtrial depolarization
ECG: P-R segmentConduction through AV node and AV bundle
ECG: QRS complexVentricular depolarization
ECG: T waveVentricular repolarization
Premature ventricular contractionspurkinje fibres randomly kick in as pacemaker; O2 loss - Skipped beat
Long QT syndromedelayed repolarization of the ventricles
Two primary phases of cardiac cycleDiastole and Syastole
DiastoleCardiac muscle relaxes (~500ms)
SystoleCardiac muscle contracts (~300ms)
5 phases of cardiac phasesLate diastole - Atrial sytosole - Isovolumetric ventricular contraction - ventricular ejection - Isovolumetric ventricular relaxation
What occurs during late diastole?Atria relaxed and filled with blood from veins
What occurs during atrial systole?last 20% blood enters ventricle when atria contracts
What occurs during isovolumetric ventricular contraction?Ventricle contractions cause AV to shut (s1) - Both valves
What occurs during ventricular ejection?Contract pressure exceeds pressure in outflow arteries causing the semi lunar valves to open flowing blood
What occurs during isovolumetric ventricular relaxation?Ventricle relaxes - Aware of blood flow backwards; semi lunar valves close (s2)
End diastolic volume (EDV)Maximal volume in the ventricle, after ventricular filling
End-systolic volume (ESV)the minimal amount of blood in the ventricles, blood left after ventricle contraction
Stroke volume (SV)amount of blood ejected during ventricular contraction
Equation of SVSV = EDV-ESV
cardiac output (CO)Flow of blood delivered from one ventricle
Equation of (CO)CO=F=HR*SV

Lecture 4

Question Answer
What does stroke volume measure?Amount of blood pumped per ventricle per contraction
2 factors determine the amount of force generated by cardiac musclecontractility - muscle fibre lengh at contraction's beginning
The length of the muscle fibres at the beginning of contraction is determined by?volume of blood in the ventricle at the beginning of contraction
inotropic agent Chemical that effects contractiliy
CatecholamineNorepinephrine and epinephrine
Do catecholamine cause a +ve or -ve intropic effect?+ve
Frank-starling law of the heartstroke volume increases with increasing end-diastolic volume
Skeletal muscle pumpcompresses veins in the extremities pushing blood back to the heart
Respiratory pumpChest expansion and diaphragm moves down; draws blood into vena cava - Veins in abdomen force blood back to heart
Sympathetic constriction of veinsDecreases their volume squeezing blood back towards that heart
ejection fraction equationEF=SV/EDV
All vessels contain an inner layer of which cells?thin endothelial cells
In most vascular smooth muscle there is a state of ____ contraction at all times?Partial
Describe arteries' wallsboth stiff and springy
What do arteries branch into?Arterioles
microcirculation is made up of?arterioles, capillaries and venules
What do metarterioles act as?Capillary bypass vessels and WBC's
Smallest vessels in the cardiovascular systemCapillaries
Capillaries are single thin endothelial layer surrounded by a ___ ___basal lamina
Membrane lined conduits running through them to allow the transportfenestrations
Capillary types (3)Continuous - Fenestrated - Discontinuous
Are continuous capillary thick or thin?Thick
Are fenestrated capillary thick or thin?Thin
Continuous capillary only allow passage of?Water and small ions
Fenestrated capillary allow passage of?small molecule
What do discontinuous capillary lack? lack a basal membrane
Discontinuous capillary have large open ____ as well as ____fenestrations - gaps

Lecture 5

Question Answer
venous circulation the ____ reservoir of the circulatory systemvolume
How are veins better than arteries?Numerous, large volumes, thinner, elasticity
Angiogenesisthe formation of new blood vessels
Development of new blood vesselsAngiogenics activate endothelial receptors - endothelial produce proteases degrading basal laminal & proliferate in matrix making sprouts
Promoter VEGF's inhibitaor is...Endostatin
Promoter FGFs' inhibitaor is...Angiostatin
Promoter ANGPT1's inhibitaor is...ANGPT2
ventricular contraction creates the force necessary to ____ ____ through the cardiovascular systempropel blood
Ventricual contractionContraction pushes blood into arteries causing stretch
Ventricual relaxationElastic recoil in arteries maintain dirving pressure during ventricular diastole
systolic pressure is ___ mm Hg120
diastolic pressure ___ mm Hg80
Equation: Pulse pressure = ?systolic pressure-diastolic pressure
Pulse pressure normally only exists on the _________ side of circuitarterial/arteriole
Hypotensionblood pressure falls too low; pressure can't overcome gravity
HypertensionBlood pressure is chronically elevated - Vessel walls can break
Hypertension in the brain is known as?cerebral hemorrhage
Sphygmomanometer cuff pressure > 120 mmHgNo sound heard over branchial artery as arterial blood flow is stopped
Sphygmomanometer cuff pressure 80 - 120 mmHgKorotkoff sounds created by pulsatile blood flow through compressed artery
Sphygmomanometer cuff pressure < 80 mmHgBlood flow is silent when artery is not compressed

Lecture 6

Question Answer
mean arterial pressure ∝cardiac output x peripheral resistance
Increased volume in arteries = _____ arterial blood pressure (Increased/Decreased)Increased
Most cases of hypertension believed to be due to increased ____ resistance without changes in cardiac outputperipheral
veins are high volume vessel and hold ~_____% of the circulating blood volume at any one time60
Arteries are low-volume vessels that contain ~______% of the total blood volume at any one time11
Normal blood volume ~_____L5
Veins act as volume reservoir but can constrict if?If blood needs to shift to arterial side
Small changes in blood volume occur from ingestion of food and liquids is primarily resolved by?Kidneys
Blood pressure control includes ____ responses from cadiovascular system and ____ response by kidnerysrapid - slower
Resistance in the arterioles contributes ____% of total resistance to flow in cardiovascular system>60
changing the radius of vesselsarteriolar resistance - sympathetic reflex - hormones
What happens when a blood pressure increase causes vascular smooth muscle in wall of the arteriole to stretch?causes the vascular smooth muscle to contract, leading to vasoconstriction
What leads to VSMC contraction (5)?Intraluminal pressure - Vessel tension & stretch - Mechano-dependent event - depolrization - L-type Ca2+ activation/entry
myogenic response will be lead to when?TRPV2, TRPC6, and TRPM4 mechano-depolarization
Paracrines alter _____ smooth musclevascular
Metabolism related↓O2, ↑CO2, NO, H+, lactate, adenosine
Non-metabolismkinins and histamine (inflammation), serotonin
How can tissue metabolism be increased?↑ Metabolic vasodialators into ECF - Arteroles dialate - ↑blood flow
↑ Neurophine release onto a receptorsvessels constrict
↓ Neurophine release onto α receptorsvessels dialate
↓ Epinephrine release onto b receptorsvessels dialate
↑ Epinephrine release onto b receptorsvessels constrict

Lecture 7

Question Answer
What does CVCC ensure?Blood flow to the braina nd heart maintaining pressures
The primary reflex pathway for homeostatic control of mean arterial blood pressure is?baroreceptor reflex
baroreceptors are ____ active stretch sensitive mechanoreceptorstonically
Baroreceptors are situated on the ____ and on the ____ arteryaorta - carotid
When there is an increase in blood pressure, what do the baroreceptors do?Sense stretch and increase firing
Orthostatic ________ triggers baroreceptor reflexhypotension
Cardiac output falls from ___ L/min5-3
Within two heart beats, activation of the baroreceptors increases ____ and peripheral resistance to increase ____: CO - MAP
Question Answer
Peripheral chemoreceptors are located on the?Aortic arch and cartotic artery
What do peripheral chemoreceptors do ? Returns blood gas levels to normal values
For an unknown reason some individuals faint in response to sudden emotional distress, sight of blood, phlebotomy (needle insertion), acute pain: Vasovagal syncope