Cardiovascular System PowerPoint Presentation

Circulatory and Respiratory UnitPSE 4UI

1.Purposes of the Cardiovascular Systema.To provide a constant supply of oxygen and glucose to the bodyb.To maintain homeostasis by transferring heat energyc.To remove wastes and prevent infection by means of clotting

2. Components:a. Heart: The pump which sends the blood to the lungs and the bodyb. Vessels: Arteries, capillaries and veins transport blood to various parts of the bodyc. Blood: Composed of red and white blood cells, platelets and plasma

Systemic CircuitLeft side of heartBlood is sent to inferior/ superior aspects of body under high pressureReturns deoxygenated blood to right heart via veins

Pulmonary CircuitRight side of heartDeoxygenated blood is sent to the lungs under high pressureOxygenated blood returns to left atrium via pulmonary vein

3. Systemic System

4. Cardiac Cycle

SystoleThe contraction of the heart (pumping action)

Electrical and mechanical changesStimulus from sino-atrial nodeE.g. blood volume changes

DiastoleThe relaxation or filling of the heart muscle

Takes twice as long as systolePump needs to be “primed”Systole = 0.3 sLowest blood pressure in body

5. Arterial Blood Pressure Expressed as systolic diastolicNormal – 120 mm HgHigh – 80 mm HgSystolic pressure (top number)-this is the pump phase of the heart or the highest pressure of within the blood vesselsDiastolic pressure-this is the filling stage of the heart or the lowest pressure

6. Blood PressurePulse Pressure (PP)

DifferencePP = Systolic - Diastolic

Mean Arterial Pressure ( MAP )Average MAP = Diastolic + 1/3(Systolic –Diastolic)

AgeMale/Female

Sedintery Lifestyle/Stress

Chemical Influence Stimulants (ie. Caffeine, etc.)

Body PositionPhysical Limitations

(ie. Arteriosclerosis/Atherosclerosis)

7.

8. Causes of High Blood Pressure AgeRaceHeredityDietStressInactivity

9. Electrical Activity of the HeartContraction of heart depends on electrical stimulation of myocardiumThe sino-atrial node (SA node) or the pacemaker will heart to contract 70-80 times per minuteThe atrio ventricular node (AV node) will transfer that initial electrical impulse to the muscular walls of the ventricles

Electrocardiogram (EKG)Records electrical activity of the heartP wave

Atrial depolarizationQRS complex

Ventricular depolarizationT wave

Ventricular repolarization

Bundle of His

Atrial Stimulation Pathway

Internodal Pathways

Atrioventricular Node

Right and Left Bundle Branches

Purkinje fibres

10.

11. Cardiac Output (Q)Q = Cardiac Output or Q = fH x VsWhere:Q = Heart Rate x Stroke VolumefH = Heart RateVs = Stroke Volume

12. Cardiac Output: the amount of blood that is pumped out of the left ventricle in one minute (L/min)Range of normal at rest is 5-6 L/min

During aerobic activity 20 L/minMax. Q is greater than 30 L/min

13. Heart Rate: the number of times that the heart contracts in a minuteRange of normal at rest is 60 – 80 beats/minIncreases in Max. 220 – Age (Submaximal heart rate)Medications or upper body exercise can incrementally increase heart rate

14. Stroke Volume the amount of blood that is ejected from the left atrium in a single beatRange of normal at rest is affected by exerciseDuring exercise, stroke volume increases depending on the intensity of the activityMax. SV is 180 mlIncreased SV during rhythmic aerobic exercise is due to increased aerobic demand

15. Frank Starling Law of the HeartThe heart will pump and stretch at a rate that will allow it to increase the strength of the contraction

16. Components of BloodPlasma (55% of blood)

90 % water7% plasma proteins (3% other (acids and salts)

CellsRed blood cells (RBC) or erythrocytesWhite Blood Cells WBC) or leukocytesPlateletsFibrinogen protein used for clotting purposes

HematocritPart of hemoglobin complex which is used to transport oxygen

17. Oxygen Delivery During ExerciseOxygen demand by muscles during exercise is determined by carbon dioxide

concentration in bloodIncreased oxygen delivery accomplished by:

Increased cardiac outputImproved delivery of oxygen (VO2 max)

18. Circulatory Responses to Exercise, Heart Rate and Blood PressureDepend on:

Intensity of activityDuration of activity

Ability of body to remove fatigue products such as lactic acid

19. Transition from rest> exercise and exercise> recoveryRapid increase in initial respiratory rate

Plateau in aerobic capacity due to training effect. Most athletes use cross training to “fool” muscles

Recovery depends on:Duration and Intensity

Ability to train and flush lactic acid

20. Incremental ExerciseHeart rate and cardiac outputRaises at an exponential rate

Stabilizes at a target heart rateSystolic blood pressure

The heart does not need to pump as hard under submaximal conditions

Double productIncreases linearly with intensity and duration

Indicates the training level of the athleteDouble product = the athlete can train longer while applying higher

levels of intensity

21. Arm vs Leg Workout at the same oxygen uptake arm work results in higher:Heart rate

Heart rate increases due to the effect of gravityBlood pressure will actually lower over time due to the training effect

22. Prolonged ExerciseCardiac output is maintained

Through regular physical activity (minimum 3 times a week/20-30 minute intervals)

Increasing levels of intensity to maximize training effectCardiovascular drift

This is caused due to dehydration and increased blood flow to the skin.