Exercise Physiology final notes (CARDIOO)

What is the circulatory systme and what doe it do? how does it adjust blood flow

works with the pulmanory sutem]

1. purpose: transport o2 and nutreints to tissues

2. remove co2 from tissues

3. regulates body temrpeature

two major adjustments of bloodflow

1. increased cardiac ouptut

2. redistribution of bloodflow

What is the normal cardiac output

1. 5L per munte

   1. we want the systems in th e hart to be MAP.

      1. discoordination in the heart leads to ehart faileure

What is the systme pathway of a pump of blood

1. pressure gradients in the body helps move blood

What are the different leves of the cardiovasuclar system and how do they differ

1. heart

   1. creates and pumps blood

2. arteries and arterioles

   1. carreis blooed away from the heart

3. caplilaries

   1. excahge of gasses and nurteints iwth the tissues

4. veins and veules

   1. carry blodo toward the heart

What are teh different leves of the heart

Aorta

1. can accomidate a large chunk of bloodflow to reduce pressuers

2. very stretcy (gets stiffere as you age htough)

ARteries

1. have some smooth msucels (kidna like plumbing)

2. decently sized pipes)

areteriooles

1. brances from thea artiers

   1. has alot more smooth ucles relative to size (promotes vasoconstriction and dialation

   2. this mechanism is triggured by pressures, hormoens (by the sympathetic nervous system)

capillaries (used for gas and nutriosue exchange

Venules

Veins

Vena canva (the rest kinda help with return of blood to be oxygenated

Q? what are the differnecs between the pulmoary circute and the systematic circuit

the pulonary circut

1. the right sized of the heart (pumps deoxigenated blood to the lungs via pulmiary ariters

2. returns oxygenated blood to the left side via pulmonary veins

systematic circuit

1. the left side of the heart

2. pumps oxygenated blood to the whole body via arterers

3. returns dexogenated blood to teh right side of the ehart veia veins

   

Qwhat is the makeup of the wall fo the heart

1. epicaridum

   1. serves as lubricative outer coating (membran)

2. myocardium

   1. muscle cells that allows for contractions

3. endocardium

   1. serves as an inner lining changer of the valvles (endothel

What are teh difference between myocardial ischemia and myocardial infractiosn

1. myocardial isechemisa re buildup of plaque in the heartmuscles

   1. they can sometimes rupture and can lead roto a stop in bloodflw

2. infarctions are cell deaths aresulting from myocardial ischemia

describe the relationship between exercise fitness and heart health

1. REgual exercise is cardioprotective

   1. reduces risks of heart attacks and incresase sruvial reates

REduces the rates of myocardial damage from heartattaches

1. impves antioxitnt capacity

   1. enduracen exercise protects against ijury during a heart attach

what are the myocardium cells and how do they funciton

1. they are only made up of one fiber type

   1. have high capillary density

   2. high number of mitochondria

   3. stirated

2. they are connected by interclasted disks

3. held together by desosomes

4. gap junctions allow for more sencorized communications

Q? what are some of the differencs between skeletal mucel cells an dheart cells

1. skeletal muslcesceslls have satelite cells (can repair while heart muscles cells cannot)

2. action potentials in heart muscls uses calsium isntead of sodium to signla

What are the two major phases of the cardiac cycle and what are their functions

Systoly

1. contractionary period

2. ejectino of blood

3. 2/3 of blood is ejected form ventricals per beat

Diastole

1. relaxion phase

2. filling of blood

note: at rest diastole is longer than sistole

during exercise sytloe and diastole are shorter

what is the order of thing sneed ed for a peroper contraction

1. electrical activity

2. mechanical activity

3. generatio of pressures (pressure gradients)

4. volume changes for flow

Describe the cardiac cycel (mechanical events) (descrive in phase of events) (and relate it to pressure differnces in the wiggers diagram

1.Starting in diastole

1. ventricles fill with blood

   1. phase 1( AV valves open and the aortic and pulmonary vavles are closed

2. atrial contraction allows for a bit more blood to come through (atrial kcik)

systole

1. isovollumetric contraction phase

2. leads to ventricular ejection phase from contractions

   1. period 2b = av valves are closed and aortic pulmonary vavles re open

reentry into diastole

1. muscls relax and the heart fills

   1. av valves are open and the aorti pulmorary vavles are clsoed (back to phase 1)

      

describe the wiggers diagram and pathways to pressures in the ehart? what are some of the pressure diffferecnces

1. Diastole (end)

   1. Av valves open (atrial pressure is higher than ventricular pressure

   2. Atrial kick = pushes the ventricle pressure higher than the atrial pressure (AV valve closes

2. Start of systole

   1. Isovlumentric period = heart is contracting until ventricular pressure is higher than aortic pressure

   2. Valve opens and blood rushes out of the heart\

   3. Left ventricular pressure decreases 

      1. Aortic pressure is heri than ventricular pressure (recloses)

Describe some of the pressure chagnes during the carida ccycle

1. Diastole

   1. Pressure in ventricles are low

   2. Fillign of blood from the atria

      1. AV valves open when ventricular pressure is less than atrial pressure

2. Systole

   1. Pressure in ventricles rises

      1. Blooode enjected into the body and lungs

         1. Semiluminar vavlues open when ventricular presusre is greater than aortic preessue

3. Heart sounds

   1. First clsoign is of the av valves

   2. Second is closing of the aortic and pulmonary valves

4. q

wiggers diagram further (what are some of the abrivations and try to find relationships btween all of the componetns

1. MC= atria closed

2. MO = atria open

3. AC = aortic close

4. AO = aortic open 

5. EDF = early diastolic filling

Use the wright table to describe the heart cycle? whata re teh different stePs? what are some of the pressur relationships? which direction does blood flow? which part of the cycle are thes

1. Steps: electirca, mechanical, pressures, volumes, 

   1. Steps:

      1. Slow ventricular filling (diastole to diestole) (atria and ventricles)

         1. Blood is flowing = blood is flowing from the pulminary veins to the left atrium to the left ventrile (high pressure to low pressure)

         2. D\P wave = atrial depolarization 

         3. Leads to mechanical reaction leading to the second phase (ative ventricle filling)

      2. Active ventricular fillign (S/D) (P)

         1. Pressure in the veins are consistent, pressure in the left atrium increases to further push bloodflow to the left ventricle and some backflow into the veins 

      3. QRS compled (VEntircular depolarization)(ventricular emptying (D/S))

         1. Eleccal signal for ventricals to depolarize

            1. After isoolumentic contraction phase = left ventricular pressure is higher than aortic pressure = flow of blood out of the aorta (roughly 120)

               1. Capilariy muscles keep the blood from goign back into the left atrium (no regurgitiaton) 

      4. Rapid ventricular filling (DD) look at chart(

What is map? what is the pulse pressure? Systolic pressure? diastolic pressure

1. Expressed as systolic/diastolic

   1. Normal is 120.80

2. Systolic preussure

   1. Pressure genrated during ventricular contraction

3. Diastolic pressure

   1. Puressure in the arteres during cardiac  relaxation

4. Pulse pressure

   1. Difference beteen systolic and diastolic

5. MAP

   1. Average pressure in the artierses

      1. Map = DBP + 0.22(SBP-DBP)*** (memorize?)

         

describe how arteriol blood pressure cuffs work/

WHAT is MAP and what is the stuff that falls into it> what dare some of the things that impact map

1. It is cardiac output x totoal vascular resistance

   1. Change in pressure = flow x resistance

   2. MAP = CO x VR

      1. Cardiac output x vascular resistance

   3. CO = HR x SV (stroke volume)

Q? What are some of the factos that influence ARterial lood pressure

1. Determinants of MAP 

2. Short term regulation (during exercises BP increases)

   1. Sympathetic nervous system

   2. Baroreceptors in aorta and carotid arteries

      1. Increase in BP = decreased SNS activity

         1. To correct increases in blood pressure by shuttinf off system and responses 

      2. Decrease in BP = increased SNS activity

3. Longterm regulation

   1. Kidneys

      1. Via control of blood volume 

What is the conducting systme of the heart? describe what they are and their functions

1. pacemaers depolarize the msucl cells

   1. AV node and SA node

1. SA nodes (pace makers)

   1. Starts the system and sends it to the av node

      1. Sends wave of electricity throughout the tissue of the atria (contraction)

2. AVnode

   1. Action potentials pass through the AV node which extends into the muscle cells itself

   2. Divides into left and right bundle branches allowing action potneitals to enter the ventricular muscle cells

3. Purkinje fuibers

   1. Action potentials are carried by this to the ventricular walls

Describe some of the electrical events for heart functioning? what does it look like on an ekg (draw it out)

Descibe some fo the different sections in the EKG> what causes them

1.  Steps

   1. 1. Atrial depolarizitation from the SAnode cuases a p wave

   2. 2. Atrial depolarizaiton = impulse is delayed at the AV node

   3. 3, ventricular depolarization begins at apex = QRS complex 

      1. Atrail reopolarization occurs

   4. 4. Ventricular depolarization is complete 

   5. 5. Ventricular repolization begins at apex = twave 

   6. 5. Ventricula repolariaation is ocmplee 

      

Which interval is related to heart attachks? what are some of the intervals for the electical portion of the cardiac cycle

1. How logn does ieach portion of the wave last

   1. Look at the graph chart for itnervals

      1. PR interval

      2. ST interval 

         1. Related to heart attacks

         2. STEM i

            1. ST elevation myocardial infrarcion 

            2. If its elevated = potential heart attack… its suupsed to be flat

            3. If it is chressed = ischemia 

      3. And the QT interval

         

Describe the Eithnoven’s triangle? waht is its use? what are the different leads

 Describe the einthoven’s triangle 

1. If you take the average of all the vecotrs, they should all be facing downwards. (electricity) on average the vector … Heart depolarizes from top right to bottom left (how ekgs work(

Q? Describe the 3 lead views of the heart

1. Put one on the right arm left arm, and left leg 

2. Electricity is typically working from right to left (on thee diagram not for yourself)

   1. For a healthy heart (causes a postive pwave) -positive difflection

3. If electricity is traveling in the opposite direction it would be inverse (not healthy)

   1. Causes negative p wave (negative is not goo dor healthY

4. Lead 3

   1. You have a negative reference point at LA and positive resting point at the Left Leg 

      1. Lead 3 should show an upright p wave since its going from negative to positive 

5. Lead 2 from RA to LL

   1. Goes from negative to positive = QRS slope

      1. Largest voltage

      2. Lead 3 and lead one will add up to lead 2 

         

What happens if the ethovens triangle is reversetd (the signals and the humps)

1. All of the peaks would be in reverse and become negative. The slopes and electric changes will go in the opposite direction

Look at the chart and describe wthat is wrong with the EKGs in relation to the ehtovins trialge and electrical signaling

1. Atrial flutter

   1. Too many p waves

2. Atrial fibrillation

   1. Irregular p waves/ no clear p waves in the cycle 

      1. Random myosies depolarizing in the atria

3. First degree AV block

   1. Look at the pr interval )it is a little bit too long)

4. Second degree av block

   1. The pr interval is sm longer

   2. Misi

   3. P wave doesnt translate to sign of qr complex

   4. Do not see atrial polarization (not alot of electrical 

5. Thrid degree AV vlock

   1. P wave doesnt translate to anything 

6. Premature ventricular complex

   1. PVC = P wave is going in opposite direction. Electricity is travling in the opposite direction. Its affecting the ventricles 

      1. Qrs complex is notgood. R complex is going in the opposite direction

7. Ventricla tachycardia

   1. A bunch of stuff is going at once. No normal QR

   2. S

8. Fiburlation

   1. Myocites are going off randomly

What are some of the diagnostic uses of the ECG during exercise? how would you go about stimulating stress? and what do depressions in the st complex mean

1. Graded exercise tests to evaluate cardiac function

   1. Observe ECG during exercise

   2. Observe changes in blood pressure

2. Atherosclerosis

   1. Fatty plaque that narrow coronary arteries

   2. Reduces blood flwo to myocardium

      1. Myocardial ischemia

3. ST segment depression

   1. Suggests myocardial ischemia 

Q? How can you stress the heart (increase demand)  what happens

1. Increased dimand = increases 

   1. Heart rate

   2. Preload 

   3. Afterload 

   4. Contractility

2. Decreases

   1. Perfusion pressure

   2. Arterial oxygen content

Depression demonstrates ischemia (can show decrease in function of the heart due to plaque uildup and

• St segment falls down (depressed)

how is heartrate rgulated by the nervous systems

1. Parasympathetic 

   1. Via vagus nerve

   2. Slows Hr by inhibiting SA and AV node

2. Sympathetic 

   1. Via cardiac accelerator nerves

   2. Increases HR by stimulating SA and AV node

3. Low resting hr due to parasympathetic tone

4. Increased in HR at onset of exercise

   1. Initial increase due to parsympathetic withdrawal

      1. Up to 100 bpm

      2. Later increases due to increase SNS stimulation

What is the regulation of stroke volume in the body? what components make it up

1. end - diastolic volume (EDV)

   1. Volume of blood in the ventricles at the end of diastole (preload)

2. Average aortic blood pressure

   1. Pressure the heart must pump against to eject blood (afterload)

      1. MAP

3. Stength of the ventricular contraction (contracility)

   1. Enhansed by c

      1. Circulatnig eneprhine and norepinephrine

      2. Drect sympathetic stimulation of heart

4. Heart rate 

preload vs aferload in the hart? what is the preload

preload: contracility

1. the degree a stretch of cardiac muscle cells before they contrac (frank starling mechanism)

   1. Cardiac muscle exhibits a length tension relationship

   2. At rest, cardiac muscle cells are shorter than at optimal length

   3. Slow heart beat and exercise increase venous return

afterload: pressure that must be overcome for the ventricles to eject blood (high rates reduce stroke volume)

1. Hypertension increases acterload = increased ESV and reduced SV

what are some of the factors that impact venous return (the strenght fo ventricular contraction) (how effecient is it in pumpin the blood

1. Contractility (inotropu): contractile strength at a given muscle elnge independent of muscle stretch and EDV***

2. Positive ionotropi agents increase contractility

   1. Increases CA++ influx due to sympathetic stimulation

   2. Hormones (thyroxine, glucagon, and epinephrine)

3. Negative ionotropic agents decrease contractility

   1. Acidosis

   2. Increased extracellular K+

   3. Calcium channel blockers

4. Heart rate

   1. The lower the heart rate, the higher the stroke volume 

   2. And vice versa

   3. 

       

How does LVEDV (left ventricular end diasttolic volume relate to stroke volume

1. The higher the stroke volume the higher the LVEDV

   1. Impacted by heart rate

   2. Contractility (venous return)

   3. And sympathetic activity 

   4. And reduced afterload 

      1. Know how to make a starling curve 

 What are some of the factors ath impact cardiac output

1. Cardiac rate (sympathetic and parasympathetic nerves)

2. Stroke volume (contractility, stretch (frank starling mechanism), EDV, and MAP)

Q? What is the relationship between pressure, resistance, and flow

1. Blood flow

   1. Directly proportional to the pressure difference between the two ends of the system

   2. Inversely proportional to resistance

      1. As resistance increase, blwo flow decreases

         1. Blood flow= pressure/ resistance

2. Pressure

   1. Proprotional to the difference beteen MAP and right atrial pressure 

How do changes in muscle and Splanchnic blood flow during exercise

1. AS mustle blood flow increases from rest, splanchitic blood flow decreases 

   1. Splanchnic bloodflow = bloodflwo in the organs 

   2. Describe trends in bloodflow and how it changes during exercise 

      1. Organ bloodflwo decreases during heavy exercises

      2. Heart bloodflwo remains the same

      3. Kidney bloodflwo reduces 

      4. Bloodflow increases into the muscles during heavy exercises

      5. Bloodflow to the brain decreases during heavy exercises 

      6. Bloodflwo to the brain decreases during exercises 

 What are some of the methods to intrinsically control boloodflow

1. The ability of local tissues to constrict or dilate arteorls 

2. Alters in regional flow deependant on needs

   1. Three types of intrinsic control

      1. Metabolic

         1. Functional (sympatholysis 

         2. Local control 

         3. Buildup of local metabolic byproducts 

            1. Decreases o2

            2. Increase in CO2, k+ and H+ and lactate 

      2. Endothelial

         1. Substances secreted by vascular endothelihilium

            1. No, prostaglandisn, EDHF

      3. Myogenic 

         1. Local pressure changes can cause VC, VD

         2. 

            Increases in pressru, venous control,

 How is MAP controlled by neural control

1. Central command

   1. Initial drive signal to cardiovascular syste comes from higher brain centers

   2. Due to centrally generated motor signals

2. fine -tuned by feedback from

   1. Heart mechanoreceptors

   2. Muscle chemoreceptors (EPR =exercise pressure reflex)

      1. Sensitive to muscle metabolites (K+, lactic acid)

   3. Muscle mechanoreceptors (EPR = exercise pressure reflexors

      1. Sensitive to force and speed of muscular movement

   4. Baroreceptors

      1. Sensitive to changes in aterial blood pressur e

? WHAT ARE EXERCISE PRESSURE RECEPTORS (epr)

Bloodpressure changes whether or not you are exercising or not (prepares you for high intensity exercise activites0

 What do you think increases as you exercise (or is impacted)

1. Central command

   1. Increased venous return 

      1. By respiratory pump

      2. SNS

      3. Skeletal muscel pump

2. Increased heartrate

   1. Increased SNS

3. Increased contractility

   1. By SNS and Contractility (preload)

4. Increased afterlaod

5. Functional sympatholysis (vasodialation)

6. Increased resistance 

7. Increased exercise pressure reflex 

Q? Soem fo the cardiovascular adjustments to exercise (primary mechanisms)

1. Central command

   1. Brain increases the set point = allows you to have higher blood pressure

2. Mechanical

   1. Proprioceptors finre (icnrease set point), skeletal sucle pump (msucel contracts on veins to increase vR)

3. Metabolic 

   1. Metabolites (functional symptolyss of EPR, increased breathing respiratory pump 

4. Autonomic 

   1. Decreases parasympathetic activity (decreases heart rate), increasing sympathetic nerve activity (increases contracility, increase VR, increase hr

5. Homoral

Q? How does map increase during exercise

 the cardiac output increases more than the total resistance decreases, so the mean arterial pressure usually increases by a small amount. Pulse pressure, in contrast, markedly increases because of an increase in both stroke volume and the speed at which the stroke volume is ejected.

MAP = CO x SVR

CO = HR SV