ASSIGNMENT

Assignment: Step Up Test and Exercise



Assignment: Step Up Test and Exercise

Introduction

This project is carried out to understand the step up test, it s execution and results based on the experiment of heart repso0nse to the exercise.

Control of Cardiac Output

Cardiac output relies on the volume of stroke and heart rate. The stroke volume depends on the three significant factors namely the preload, after load and contractility. All these factors are linked. Setting the output of the autonomic nervous system of the heart is the opposite physiological action in anatomically distinct parts namely the sympathetic and parasympaattisen. The cardiac output gets controlled by increasing stroke volume and heart rate, cardiac output gets increased. It is important to note, however, if the frequency is too high, thereby reducing the duration of the rest phase, and if not, venous return is to increase cardiac output for focusing the amount of physiological factors (Linappa, Farey, 2000,65-78).

Branches of Autonomic Nervous System

The autonomic nervous system has central and peripheral divisions. They are located at the central section of suprasegmental distinction (top) and segmental (lower) autonomic centers. Suprasegmental autonomic centers are concentrated in the brain - the cerebral cortex (predominantly in the frontal and parietal lobes), hypothalamus, olfactory brain, the sub cortical structures (striatum) in the brain stem (brain stem) (reticular formation), the cerebellum (cerebellum) and others Segmental autonomic centres get located in the brain and spinal cord. Autonomic centres of the brain gets conditionally divided into midbrain and bulbar (vegetative nucleus of the oculomotor, facial, language pharyngeal and vagus nerves) and spinal cord (Linappa, Farey, 2000, 65-78)

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Increasing the Heart Output

Increasing either heart rate or stroke volume increases cardiac output. Increased heart rate stimulated an increase of sympathetic activity in order to maintain the output of the heart. At first, this helps to compensate for heart failure by keeping blood pressure and perfusion, but additional pressure increase coronary perfusion requirements that can lead to aggravation of heart disease cause. Sympathetic activity may cause potentially fatal arrhythmias. Besides, Good electrolyte helps maintaining high performance of the heart, however, if the larger of the calcium, sodium and potassium levels, cardiac output can be increased. Unfortunately, electrolyte imbalance can also cause irregular heartbeats. Increased intake of electrolytes and improves cardiac output may have disadvantages in non-producing a normal heart rhythm (Katz, 2001, 6-11).

Reflexes That Can Increase Cardiac Output

The two reflexes that increase heart output are:

Baroreceptor reflex: Baroreceptor sensitive to distension opposed to abrupt changes in blood pressure, i.e. they are pressure receptors. They are located in great abundance on the walls of the carotid artery and internal aortic arch wall.

Cardiopulmonary reflexes: A special group of atypical cardiac reflexes are those that occur in response to stimulation of arterial chemoreceptors of the change in oxygen tension in the blood. Under the conditions of hypoxemia develops reflex tachycardia, while breathing pure oxygen - bradycardia. These reactions are exceptionally high sensitivity: the human heart rate increase observed with a decrease in oxygen tension by only 3% when no signs of hypoxia in the ...