Exercise Physiology Test 3 (Cardiac and Pulmonary)

1. Circulatory and cardiorespiratory system work together to...:

transport O2 and nutrients to tissues remove CO2 waste and regulate body temperature

Two ways that adjust blood flow during exercise:

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

Hepatosplanchnic shunting:

shunting blood away from liver kidneys and intestines (inactive organs) towards active muscles during exercise

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

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

Why is the pressure in the systemic circuit much higher than the pulmonary circuit?:

the blood has to travel a much greater distance in the body

Right and left ventricles:

pressure generation

Aorta and larger arteries:

pressure storage (myocardium = thickness varies)

Small arteries and arterioles:

resistance vessels (less elastin more circular smooth muscle)

Veins:

volume storage (little elastin/elasticity/smooth muscle and thin walls)

Capillaries:

exchange vessels (thinnest walls allow diffusion of O2 CO2 nutrients)

Diastolic pressure:

'relaxation' pressure

Systolic pressure:

pressure associated with ejection/contraction

Pulse pressure:

difference between systolic and diastolic pressure

Mean arterial pressure (MAP):

average pressure in the arteries

Normal systolic:

diastolic blood pressure: 120/80 mmHg

3 layers of the heart:

epicardium myocardium endocardium

Myocardium:

heart muscle that receives blood supply via right and left coronary arteries (myocytes/cardiac muscle cells)

Myocardial infarction:

blockage in coronary blood flow results in cell damage (heart attack; exercise training protects against heart damage during MI)

Regular/endurance exercise is cardio______:

protective (reduce incidence of heart attacks; improves survival/prevents damage from heart attack)

Systole:

contraction phase ejection of blood (~2/3 blood is ejected from ventricles per beat; highest pressure)

Diastole:

relaxation phase filling with blood (lowest pressure)

Heart beat consists of systolic ______ and diastolic ______:

contraction;filling

Both decrease in duration during exercise but does systole or diastole experience a greater change?:

diastole

Pousille formula:

F = (”P*rÀ^4)/8LN

What is a determining factor of peripheral resistance?:

vessel radius

Constriction of arterioles results in increased __________:

peripheral resistance

Short term regulation of blood pressure:

sympathetic nervous system

Long term regulation of blood pressure:

kidneys via control of blood volume (RAAS)

Subthalamic locomotor region regulates...:

HR arterial BP left ventricular contractility motor unit recruitment ventilatory control cardiac rate and strength

Cardiovascular control center:

the area of the medulla that regulates the cardiovascular system

Metabolic auto-regulation:

automatic changes in the blood flow through an organ directly related to changes in the organ's metabolism; blood flow increased to meet metabolic demands of tissue

Metabolic auto-regulation is not a biological control system it is _______- :

self governance; centrally controlled

Capillary recruitment:

the process by which the increase in pulmonary blood flow during exercise opens up some pulmonary capillaries that are not used during rest

2 types of muscle afferents that cause a change in circulation:

type III and type IV

Type III muscle afferent:

ergoreceptors (stretch sensitive)

Type IV muscle afferent:

chemo & thermo sensitive

Muscle afferents ___ blood flow to metabolically active tissues:

reduce

Muscle afferents oppose ___ & ___-receptors; ___:

chemo & baroreceptors; autoregulation

Osmoreceptors:

afferents for RAAS system

Osmoreceptor location:

hypothalamus and macula densa (in kidney)

EKG records:

electrical activity of the heart

P wave:

atrial depolarization

QRS complex:

ventricular depolarization and atrial repolarization

T wave:

ventricular repolarization

ST segment depression indicates myocardial ___ while ST segment elevation indicates myocardial ___:

ischemia (low perfusion/oxygenation); infarction (heart attack)

Myocardial cell vs pacemaker cell RMP:

all myocardial cells have a RMP while pacemaker cells do not

Cardiac output:

the amount of blood pumped by the heart each minute

End Diastolic Volume (EDV):

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

Average aortic blood pressure:

pressure the heart must pump against to eject blood ("afterload")

Frank-Starling Law of the Heart:

relationship between preload and stroke volume (venoconstriction SKM contraction pulmonary siphon)

Females have __ blood volume hemoglobin and hematocrit than males- :

less

Blood flow is ____ ____ to the pressure difference between the two ends of the system and ____ ____ to resistance:

directly proportional; inversely proportional

Fick equation:

VO2 = Q * a-vO2 difference

Metabolic autoregulation:

changes in blood flow from less to more metabolically active (due to changes in O2 and CO2 tension nitric oxide potassium adenosine and pH)

T or F? Training decreases recovery time of HR and blood pressure after exercise:

true

Cardiovascular drift:

an increase in heart rate during exercise to compensate for a decrease in stroke volume (helps maintain cardiac output)

Gradual increase in HR cardiovascular drift is ______________ mediated:

catecholamine

T or F? Sudden cardiac death during exercise is very uncommon:

true

Ventilation:

movement of air in and out of the lungs; bulk air transport

Pulmonary respiration:

the exchange of oxygen and carbon dioxide between the alveoli and circulating blood in the pulmonary capillaries (lungs); "external" respiration

Cellular respiration:

O2 utilization and CO2 production by the tissues; "internal" respiration

Organs of the respiratory system:

nose and nasal cavities pharynx and larynx trachea and bronchial tree lungs (alveoli)

Diaphragm:

major muscle of inspiration

Diaphragm moves __ when you breathe in

__ pressure in the thorax to allow air to come in:

Diaphragm moves __ when you breathe out

__ pressure to push air

out:

up; increases

Lungs are enclosed by membranes called:

pleura

Visceral pleura:

covers the lungs; outer surface of lung

Parietal pleura:

lines the thoracic wall

Intrapleural space:

intrapleural pressure is lower than atmospheric (prevents collapse of alveoli bc of the very thin alveoli walls)

Inspiration is active therefore requires...:

ATP

Inspiration:

diaphragm pushes down lung volume increases intrapulmonary pressure decreases

Expiration:

diaphragm relaxes and moves upward lung volume decreases intrapulmonary pressure increases

Do respiratory muscles adapt to training?:

Yes; increased oxidative capacity improves respiratory muscle endurance reduced work of breathin

Asthma:

narrowing of airways (increased work of breathing shortness of breath)

Pulmonary ventilation:

the total air volume moved in or out of the lungs per minute (VE)

Alveolar ventilation:

the volume of fresh air that reaches the respiratory zone with each breath

Dead space ventilation:

the volume of air that remains in conducting airways with each breath

Dalton's law:

the total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently

Fick's law of diffusion:

the rate of gas transfer (V gas) is proportional to the tissue area

When standing most of the blood flow is at _____ due to gravity; during exercise there is more _____ to _____:

the bottom of the lungs; blood flow/apex

Ventilation-perfusion ratio:

indicates matching of blood flow to ventilation (VE/Q)

Ventilation-perfusion ratio is _____ during light exercise and _____ during heavy exercise:

improved; worsened

Oxyhemoglobin dissociation curve:

relationship between available oxygen and amount of oxygen carried by hemoglobin; high PO2 at lungs and low PO2 at tissues

Myoglobin:

shuttles O2 from the cell membrane to the mitochondria

Myoglobin has a ___ affinity for O2 than hemoglobin:

higher (allows myoglobin to store O2 for muscle)

What is the primary buffer of acidity in the blood stream?:

bicarbonate

Carbiminohemoglobin:

CO2 bound to hemoglobin

Acid-base balance:

pulmonary ventilation removes H+ from the blood by the HCO3- reaction

At onset of constant load submaximal exercise ventilation...:

initially increases rapidly then a slower rise toward steady state

Ventilatory threshold:

maximal efficiency of ventilation or breathing response

EIAH:

exercise-induced arterial hypoxemia

Hypoxemia in elite athletes:

low PO2; PO2 can decrease 30-40 mmHg at near-maximal work

EIAH occurs in ______% of elite highly-trained male and female endurance athletes:

40-50%

Control of ventilation at rest: inspiration and expiration:

produced by contraction and relaxation of diaphragm

Stimulus for inspiration comes from four respiratory rhythm centers:

(in medulla) prebotzinger complex and retrotrapezoidal nucleus (in pons) pneumotaxic center and caudal pons

Group pacemaker hypothesis (briefly mentioned):

suggests that regulation of breathing is under redundant control

Hyperventilation is caused by _____:

higher CO2 not lower O2

Do lungs adapt to training?:

no effect on lung structure