Which factor best explains why shoveling snow may be associated with an increased risk for a cardiovascular event?     myocardial oxygen demand     cold weather     arterial oxygen content     lower-body force generatio

someone has profusely bled and her blood pressure dropped what mechanisms in her body will help compensate? select all that apply vasoconstriction increased adh increased heart rate  vasodilation

Blood pressure depends on: Group of answer choices the height and weight of an individual. atrial volume and stroke rate. blood flow and resistance of blood against the vessel walls. total blood volume. heart rate.

pulmonary oxygenated systemic deoxygenated left right The circulatory system is divided into two circuits. The circuit transports blood through the lungs and returns the blood to the side of the heart. The circuit transports blood through the body, returning the blood to the side of the heart.

When exercising, the American Heart Association recommends the intensity of your exercise regimen to be determined by your heart rate during exercise. This is known as a target heart rate zone and it is dependent on your current resting rate, age and fitness level. To calculate your target heart rate zone, complete the following: 1. Determine your maximum heart rate: • Subtract your age from 220. (Example, if you are 25 years old 220-25 = 195. 195 is your maximum heart rate). Record your maximum heart rate in box 1. 2. Determine your resting heart rate: • While sitting at your desk or sitting down, take 3 deep breaths. After taking the third breath, lightly rest your pointer and middle finger on your neck over your artery until you can feel your heartbeat. Count the number of times your heart beats in 15 seconds. Multiply that number by 4. This is your resting heart rate. Record your resting heart rate in text box 2. Activate Windows Go to Settings to activate

In order for VO2 to increase which of the following changes must occur: Group of answer choices A decrease in RER A decrease in heart rate An increase in cardiac output A decrease in extraction of oxygen from the blood none of the above all of the above

Caffeine lowers the heart rate by increasing rates of depolarization at the SA node   True False   Nicotine raises the heart rate because it stimulates the activity of the sympathetic neurons in medulla oblongata   True False   The Frank-Starling Law of the Heart states that the force of heart contraction is directly proportional to the initial length of the muscle fiber, within optimal limits of length   True False If the sarcomeres stretched beyond the optimal length, the force of contraction would go down, but that can potentially happen only during open heart surgery when the heart is not constrained by the pericardium, lungs, ribs and diaphragm.   True False It is the Na+ channel-driven spontaneous depolarization that is affected by sympathetic and parasympathetic inputs to speed up or slow down the firing rate of the SA node and other conductive cells.   True False

Blood doping has benefits for performance, but it has some consequences on the heart, short term and long term. Learning that blood doping adds red blood cells to the blood, what variable in the blood does this change and how does that affect blood flow? viscosity; increase blood flow resistance; decrease blood flow viscosity; decrease blood flow O resistance; increase blood flow

Why may low cardiorespiratory fitness contribute to more deaths than other primary risk factors for cardiovascular disease?     increased risk associated with risk factor     increased prevalence of the risk factor     reduced risk associated with risk factor     reduced prevalence of the risk factor

Regulation of the heart ( or any organ or tissue ) by neural input , circulating hormones , or any other factor originating from outside the organ is referred to as control . neurogenic myogenic Ointrinsic extrinsic voluntary