Respiration during exercise and circulatory response to exercise

The circulatory system works with what

pulmonary system (cardiopulmonary or cardiorespiratory system)

what are the purposes of the cardiorespiratory system

transport O2 and nutrients to tissues, removal of C O2 wastes from tissues, regulation of body temp (because of blood)

what are the 2 major adjustments of blood flow during exercise

increased cardiac output, and redistribution of blood flow from inactive organs to active muscle

Heart

creates pressure to pump blood

arteries and arterioles

carry blood away from the heart

capillaries

exchange of O2, C O2, and nutrients with tissues

veins and venules

carry blood toward the heart

what is the pulmonary circuit

right side of the heart, pumps deoxygenated blood to the lungs via pulmonary arteries, returns oxygenated blood to the left side of the heart via pulmonary veins

what is the systemic circuit

left side of the heart, pumps oxygenated blood to the whole body via arteries, returns deoxygenated blood to the right side of the heart via veins

what is a myocardial infarction (MI)

blockage in coronary blood flow results in cell damage/death (of the myocardium), exercise training protects against heart damage during MI

regular exercise is cardioprotective which reduces and improves what

reduces incidence of heart attacks, improves survival from a heart attack

Exercise reduces the amount of myocardial damage from heart attack and improves

there is improvemnets in hearts antioxidant capacity

hypertension is a

blood pressure above 130/80 mmHg

what is primary (essential) hypertension

the cause is unknown (multifactorial), 90% cases of hypertension

cardiac muscles are

shorter then skeletal muscle fibers and branching, single nuclei, striated, has cellular junctions (intercalated discs), involuntary

Skeletal muscles are

elongated (no branching), multi nucleiated, striated, no junctional complexes, voluntary

What is secondary hypertension

result of some other disease process

hypertension risk factor for

left ventricular hypertrophy (enlarged left ventricule), atherosclerosis and heart attack, kidney damage, stroke

where does the electrical activity of the heart starts

in the right atrium in the SA node

contraction of the heart depends on what

electrical stimulation of the myocardium

what is the sinoatrial node (SA node)

natural pacemaker, initiates depolarization

what is the atrioventricular node (AV node)

goes here after SA node, passes depolarization to ventricles, brief delay to allow for ventricular filling

what are bundle branches

connect atria to left and right ventricle

what are purkinje fibers

spread wave of depolarization throughout ventricles

purkinje fibers and bundle branches do what

contract ventricles

graded exercise test to evaluate cardiac function is used to

observe EKG during exercise, and observe changes in blood pressure

what is atherosclerosis

fatty plaque that narrows coronary ateries, reduces blood flow to myocardium (myocardial ischemia (heart attack))

what does S-T segment depression show

suggests myocardial ischemia

what is parasympathetic nervous system

“breaks” via vagus nerve, slows HR by blocking SA and AV node

what is the sympathetic nervous system (SNS)

“gas,” via cardiac accelerator nerves, increases HR by stimulating SA and AV node

low resting HR due to what

parasympathetic tone

increase in HR at onset of exercise because

initial increase due to parasympathetic withdrawal (up to approximately 100 beats/min) later increase due to incresed SNS outflow

what are Beta-adrenergic blocking drugs (beta-blocker) used for

slow down HR and contractility (lower the myocardial oxygen demand), compete with epinephrine and norepinephrine for beta adrenergic receptors in the heart

beta-blockers are prescribed for patients with

coronary artery disease and hypertension

Beta-blockers will

lower HR during submaximal and maximal exercise (important for exercise prescription)

End-diastolic volume (EDV) is dependent on

venous return

what is venous return increased by

venoconstriction (via SNS), skeletal muscle pump (rhythmic skeletal muscle contractions force blood in the extremities toward the heart, one-way valves in veins prevent backflow of blood), respiratory pump (changes in thoracic pressure pull blood toward heart)

Hemodynamics resistance depends on

length of the vessel, viscosity (thick and sticky) of the blood, radius of the vessel (greatest influence on resistance)

what are the sources of vascular resistance

M A P decreases throughout the systemic circulation, Largest B P drop occurs across the arterioles (arterioles are called “resistance vessels”)

oxygen demand by muscles _____ during exercise

increases (15x to 25x greater at rest)

Increase in O2 delivery is accomplished by

increased cardiac output, redistribution of blood flow (from inactive organs to working skeletal muscles)

Does body position have a major influence on SV

true at rest and during exercise, related to the effect of gravity on venous return (gravity promotes blood pooling in legs, lowering venous return, lower EDV- F. starling effect)

why does upright exercise results in increased SV

due to larger EDV, increased venous return, increased in EDV and SV at high HR

why does supine exercise (swim) results in small increases in SV

due to resting SV being relatively high while supine

At the same oxygen uptake, arm work results in higher what then legs

heart rate (due to higher sympathetic stimulation) and blood pressure (due to vasoconstriction of large inactive muscle mass)

sudden cardiac death during exercise is

uncommon (1/200,000 young athleates)

why does sudden cardiac death during exercise occur

caused by abnormal, lethal heart rhythms

why does sudden cardiac death during exercise occur in children and adolescents

genetic anomalies of coronary arteries, cardiomyopathy, myocarditis

why does sudden cardiac death during exercise occur in adults

coronary artery disease, and cardiomyopathy

alveoli are located where

only in the lungs

capillaries are located where

in both lungs and tissue

what is the main “mover” that moves air into and out of lungs

diaphragm

what does your ribs and diaphragm look like when inhaling

oval shape of ribs, diaphragm flatens and contracts

what does your ribs and diaphragm look like when exhaling

heart shape ribs, diaphragm relaxes and arches/curves

what does COPD stand for

chronic obstructive pulmonary disorder

what diseases is COPD made up of

chronic bronchitis and emphysema

emphysema is seen in

smokers

During resting conditions (standing), most of the blood flow is to the ________

base of the lung (due to gravitational force)

During exercise, blood flow increases in ________

top of lung (apex)

how many lobes does the right lung have

3

how many lobes does the left lung have

2

what is the pH scale from

0-14

a pH of 0 is what

very acidic

a pH of 14 is what

very basic (alkaline)

a pH of 7 is what

neutral (blood)

an increased ventilation results in CO2 exhalation and

pH increases

decreased ventilation results in buildup of CO2 and

pH decreases

when matched for body weight, women have _____ _______ than men

smaller airways

what do smaller airways result in

higher resistance to airflow and limitations to maximal ventilatory capacity during very heavy and severe exercise

increased airway resistance in women results in

greater work of breathing during exercise