KINE 433 Cardiovascular and Respiratory Physiology Flashcards

Comprehensive practice questions covering cardiovascular and respiratory responses, muscle physiology, gas transport mechanisms, and training adaptations based on KINE 433 lecture materials.

What are the characteristics of the pulmonary circuit?

It is a low pressure system ($20-30$) where oxygen-poor (blue) blood moves from the right ventricle to the lungs to get reoxygenated.

How does the systemic circuit differ from the pulmonary circuit?

It operates at a higher pressure ($100-140$) and moves oxygen-rich (red) blood from the lungs to the heart and the rest of the body, overcoming the forces of gravity.

What is the primary role of the arterioles in the microcirculation?

They act as stopcocks, regulating blood flow ($BF$) and blood pressure ($BP$) by closing and opening as needed (e.g., during exercise).

What are the three primary cardiovascular adjustments to exercise?

1. Increase in cardiac output ($CO$), 2. Redistribution of $CO$ to active tissue/muscle, and 3. Increase of venous return ($VR$) to the right side of the heart.

What are the functions of the SA node and the AV node?

The SA node acts as the pacemaker, generating action potentials spontaneously; the AV node acts as a delay station to allow the chambers to fill with blood.

How does the autonomic nervous system ($ANS$) regulate heart rate ($HR$)?

The $PNS$ releases acetylcholine ($ACh$) to lower $HR$, while the $SNS$ releases norepinephrine ($NE$) to increase $HR$ and stroke volume ($SV$).

What are the three layers of the functional anatomy of blood vessels?

1. Intima (single layer of endothelial cells), 2. Media (smooth muscle cells), and 3. Adventitia (collagen for anchoring).

How do alpha-adrenergic and beta-adrenergic receptors respond to norepinephrine ($NE$)?

Alpha-adrenergic receptors cause constriction and reduce $BF$, while beta-adrenergic receptors cause dilation to increase $BF$.

How does capillary density differ between glycolytic and oxidative muscles?

Capillary density is low in glycolytic (non-oxidative) muscle like the white gastrocnemius and high in oxidative muscle like the red gastrocnemius to aid in $O_2$ delivery.

What is the Fick equation for oxygen consumption ($VO_2$)?

$$VO_2 = CO \times a-v O_2 \text{ difference}$$

What is the best index of aerobic capacity?

$VO_2 \text{ max}$, which is determined by the ability to deliver and then use $O_2$.

What was the highest recorded $VO_2 \text{ max}$ and who achieved it?

$94 \text{ ml/kg/min}$ recorded by cross-country skier Bjorn Daehlie.

How is a metabolic equivalent (MET) defined clinically?

$$1 \text{ MET} = 3.5 \text{ ml/kg/min}$$

How does Cardiac Output change from rest to max exercise in healthy males?

It increases 4-fold, from a resting value of $5 \text{ L/min}$ to a max of approximately $20 \text{ L/min}$.

What happens to the distribution of Cardiac Output during maximum exercise?

The percentage of $CO$ going to the muscle increases from $25\%$ at rest to $85-90\%$ at maximum intensity.

What is the formula for maximum heart rate?

$$HR \text{ max} = 220 - \text{age}$$

What are the three determinants of Stroke Volume ($SV$)?

1. LV preload (filling and stretching), 2. LV contractility (force of contraction), and 3. LV afterload (pressure to overcome to eject blood).

Why does Stroke Volume ($SV$) eventually level out or plateau during building exercise intensity?

Because of increased afterload (increased $BP$) and less time for the heart to refill due to increased $HR$.

What four mechanisms aid venous return during exercise?

1. Increased pressure gradient between aorta and right atrium, 2. SNS-mediated venoconstriction, 3. Respiratory pump, and 4. Skeletal muscle pump.

What are three vasodilators produced by endothelial cells to local control blood flow?

Nitric oxide, Prostaglandins, and endothelium-derived hyperpolarizing factor ($EDHF$).

What is functional sympatholysis?

A process where local dilators inhibit $NE$ release, make alpha receptors less responsive, and cause relaxation of vascular smooth muscle to increase $BF$ to skeletal muscle despite $SNS$ activity.

What is the difference between Central Command and the Exercise Pressor Reflex ($EPR$)?

Central Command follows a feedforward mechanism originating in the brain, whereas the $EPR$ provides feedback from the active muscles via Group III (mechanical) and Group IV (metabolic) nerves.

How do Systolic and Diastolic Blood Pressure respond to exercise?

$SBP$ increases due to increased $CO$, while $DBP$ typically remains unchanged due to the offset of decreased systemic vascular resistance and increased $HR$.

What are the two functional zones of the pulmonary system?

1. Responding zone (designed for gas flow, no alveoli) and 2. Respiratory zone (designed for gas exchange, containing alveoli).

What is the relationship between alveolar pressure and atmospheric pressure during inspiration?

Alveolar pressure is less than atmospheric pressure ($< 760 \text{ mmHg}$), allowing air to flow into the lungs.

What is the formula for minute ventilation ($V_e$)?

$V_e = V_t \times f_b$ (Tidal volume times frequency of breathing).

What is the ventilatory threshold and when does it occur?

It is the point where there is a sharp/exaggerated increase in ventilation to rid the body of $CO_2$, typically occurring at $65-75\%$ of $VO_2 \text{ max}$.

How much oxygen is typically carried by saturated Hemoglobin ($Hb$)?

$$1.34 \text{ mlO}_2 \text{/g Hb}$$

What factors cause a 'right shift' in the oxygen dissociation curve (Bohr effect)?

A drop in $pH$ (acidity) and an increase in temperature, both of which favor the release of $O_2$ from $Hb$ to the active muscle.

In what three ways is $CO_2$ transported from the muscle to the lungs?

1. Dissolved in plasma ($5\%$), 2. Bound to Hemoglobin ($25\%$), and 3. As bicarbonate ($HCO_3^{-}$) ($70\%$).

What is the primary reason for the increase in maximum Cardiac Output after endurance training?

Increased maximum Stroke Volume ($SV \text{ max}$).

What is the difference between angiogenesis and arteriogenesis in training adaptations?

Angiogenesis is the increase in capillary density, while arteriogenesis is the increase in the size of the arteries (lumen diameter).