Cardio Phys Homework Quiz Q's

Changes in _____ pressure provides a mechanical interaction whereby ______ system function can modulate cardiac function

intrathoracic; respiratory

For a given workload, _____ ventilatory work and ____ respiratory muscles VO2 are observed in trained versus untrained

decreased; decreased

Respiratory fatigue _____ diaphragm contribution to ventilation and _____ respiratory frequency, resulting in _____ ventilatory efficiency

reduces; increases; decreased

Carotid chemoreceptors increase ventilation in response to ?

Decreased PaO2

True or False: Exercise training offers substantial improvements in respiratory muscle function, but offers limited positive effects for lung volume

True

True or False: Inspiratory flow is limited by the ability to generate a negative intra-thoracic pressure, while expiratory flow is limited by difference in transmural pressure

False

Which of the following is true of breathing mechanics during exercise?

elastic energy of the diaphragm is increased

During progressive exercise, lung blood flow increases primarily due to ?

increased Ppa-Pcap difference

Locomotor-respiratory coupling is due to ____ ____ and ____ ____ , but not mechanical consequences

central command; peripheral

feedback

During repetitive muscle contraction, locomotor feedback induces hypernea via ?

Type II and Type IV nerves

Which of the following does not contribute to increased A-aDO2?

Increased VA relative to cardiac output

True or False: Due to redundancy of control, breathing rhythm is maintained if either the pre-Botzinger or the rostral area of the pons is disrupted

True

Coordination of inspiratory and expiratory premotor neurons depends on?

reciprocal inhibition

True or False: Hyperventilation during heavy exercise is due solely to metabolic acidosis stimulation of carotid chemoreceptors

false

The mechanisms underlying the autonomic and cardiovascular response to exercise include the following systems, EXCEPT?

Hypothalamus-pituitary signaling axis (HPA)

Which of the following is an incorrect statement about baroreceptors?

During exercise, the strength of the baroreflex remains unchanged. The reflex is reset to a higher

pressure, a new target arterial pressure. Thus, the baroreflex reinforces the increase in

arterial pressure at the start of exercise.

What is functional sympatholysis?

Reduced SNS-induced vasoconstriction in contracting skeletal muscle

True or False: Standing up abruptly from a lying-down position unloads cardiopulmonary baroreceptors, causing an increase in muscle sympathetic tone.

True

True or False: Initial tachycardia observed at the onset of exercise is due to an increase in central command modulated sympathetic activity.

False

What is the afterload in the ventricle?

The pressure in the aorta, which the pressure in the left ventricle must exceed in order for the aortic valve to open

What is the most correct statement regarding HR?

Under conditions of extremely high heart rates or chronic heart failure, where stroke volume is decreased, an increase in HR will not lead to increased CO

Which of the following is true concerning the effects of static and dynamic exercise?

SV increases at high dynamic exercise intensities but remains unchanged, or only mildly increases, during static exercise

True or False: Exercise training increases SNS activity at rest

False

True or False: Blood flow resistance is inversely proportional to the radius of the blood vessel to the fourth power.

True

True or False: Metaboreflex results when an accumulation of metabolites (e.g., lactate, H+, phosphate, bradykinin, and prostaglandin) activates metaboreceptors to increase blood pressure due to insufficient blood flow required to remove the accumulated metabolites. This reflex is not activated until very high exercise intensities.

False

True or False: The heart is chronotropically regulated via the atrioventricular node.

False

True or False: Studies show that exercise training can lead to bradycardia by down-regulating beta-adrenergic receptor expression in the right atria.

True

True or False: ADP and Pi are said to "pull" electrons down the respiratory chain, and ATP is said to "push" electrons down the respiratory chain.

False

Which of the following is NOT true about a nonpathogenic, healthy heart after exercise training?

As myocardial mass increases with exercise, there is an equal or greater increase in coronary vasculature.

Left ventricular stroke volume is the amount of blood pumped from the left ventricle during one cardiac cycle. At rest, what is the average stroke volume in a healthy adult?

70ml

True or False: Eccentric hypertrophy involves the development of sarcomeres & "in series"; Thus, increasing myocyte length due to volume overload in the heart. Concentric hypertrophy is when sarcomeres develop &"in parallel"; thus, increasing cross-sectional area due to pressure overload in the heart.

True

Which of the following is not true regarding SERCA-2?

SERCA-2 activity increases the Ca2+ concentration in sarcoplasm, causing the membrane potential to approach threshold

True or False: Net Ca2+ efflux from the cardiac sarcoplasm increases via the NCX when HR is increased.

False

Training-induced improvements in cardiac function include all of the following EXCEPT:

increase submaximal exercise HR

True or False: As muscle sarcomere length increases, there is a leftward shift in the {Ca2+}- tension relationship

True

True or False: As the myocardium works closer towards its maximal work load, oxygen consumption exponentially increases

False

With greater vagal input, there is greater membrane hyperpolarization, leading to a slower HR. Which of the following is NOT responsible for this hyperpolarization?

Phosphorylation of L-type Ca2+ channels

Which of the following is NOT one of the downstream targets of PKA

phosphorylation in cardiac myocytes?

SERCA-2 activity affects HR and the ventricular

contractility

Venous pressure is _________ during relaxation between muscle contractions, which _______ the effective gradient for capillary perfusion

Reduced; increases

Contraction of smooth muscle cells casus _____, thereby ____ vessel diameter and ____ resistance to blood flow.

vasoconstriction; reducing; increasing

The flow of blood exerts shear stress on the endothelium which provides a stimulus for the endothelial production of _____, an autacoid that induces vasodilation.

nitric oxide

True or False: Blood flow during exercise is higher in muscles and muscle regions that are composed primarily of oxidative fibers rather than glycolytic fibers

True

Which of the following is NOT a training adaptation that will enhance maximal oxygen consumption?

increasing blood flow velocity through capillaries

True or False: Endothelial cells have a greater thickness than length

False

Increase in blood flow is?

hyperemia

True or False: Smooth muscle cell depolarization results in vasodilation

False

True or False: During blood flow restriction, the extraction of oxygen by an active motor unit is enhanced

True

True or False: As metabolic demand increases, vasodilation is initiated in the feed arteries and descends to large arterioles and then to distal arterioles.

False

True or False: The perfusion of capillaries with red blood cells is controlled at the level of the individual capillaries.

False

Which of the following is the most direct consequence of norepinephrine acting on smooth muscle cells

Opening of L-type Ca2+ channels

The process of sprouting and proliferation of capillary endothelial cells is referred to as?

Angiogenesis

Which of the following events within smooth muscle cells results in vasodilation:

efflux of K+

True or False: Red blood cells can release oxygen as they travel along arterioles before reaching the capillaries

True