Physiology 7.2, 7.3, 7.5,7.6

How might a regular program of aerobic exercise influence the resulting blood pressure? Explain your answer.

Regular aerobic exercise should lower the resting blood pressure. Exercise often results in a lowering of the resting cardiac rate and an increase in the resting stroke volume. Athletes have a greater degree of inhibition of the SA node by the vagus nerve and an increased blood volume. Working together these factors increase in cardiac output, improve the delivery of oxygen to the tissues, and result in lowered blood pressure

the scientific term for insufficient blood flow to the heart muscle

myocardial ischemia

Suppose a person's blood pressure is 168/112 What is the systolic? What is the diastolic pressure? What is the pulse pressure? What is the mean arterial pressure?

168 112 56 130

abnormally long P-R wave indicates

AV blockage

The arterial blood pressure is directly proportional to two factors: the ____________________ and the ________________________________

Cardiac output; total peripheral resistance

How do you think the arterial blood pressure, pulse pressure, and mean arterial pressure would change during exercise? Explain

During exercise the increase in heart rate and stroke volume (cardiac output) raises the systolic pressure more than it raises the diastolic pressure. However, both pressure can rise to as high as 200/100 mmHg. The pulse pressure(systolic minus diastolic) in this case would increase to 100mmHG while the mean arterial pressure(1/3 pulse pressure plus diastolic pressure)would rise accordingly. The exercise-induced vasodilation causes the diastolic pressure to rise the least.

What condition does BP 168/112 have

Hypertension

Describe what is meant by "laminar flow" and "turbulent flow". Before you inflate the cuff, which term more closely describes the blood flow in the brachial artery? Explain

Laminar or "layered" flow of blood through the arteries occurs when all parts of the fluid move smoothly in the same direction, parallel to the axis of the vessel. Blood in the central axial stream moves the fastest, and blood closer to the artery wall moves more slowly. By contrast, turbulent flow occurs when some parts of the fluid move in radial and circumferential directions, churning and mixing the blood, which may cause vibrations and sounds. Blood flow in the brachial artery before the cuff is inflated is mostly laminar, and so is smooth and silent

which ECG wave must occur before the ventricles can contract

P

conducting tissue of the heart located in the interventricular septum is the

bundle of his

the ECG wave completed just before the end of the ventricular diastole is the

Q wave

which ECG wave must occur before the ventricles can relax

QRS

the ECG wave that occurs at the beginning of the ventricular systole

R wave

the ECG wave that occurs at the end of systole and beginning of diastole

T wave

Were the blood pressure measurements different when they were taken in the standard sitting position, reclining, and standing up? Explain what might have any differences observed.

The position of the arm directly affects the measurement of diastolic pressure partially due to the effect of gravity. When the arm is below the heart level the diastolic pressure measured by the cuff is raised. When the arm is positioned above the heart level the diastolic pressure measured by the cuff is raised. When the arm is positioned above the heart level, the diastolic pressure is lowered. This helps to explain why the cuff should be placed at the heart level on the arm of the subject during blood pressure measurements. The greatest drop in diastolic pressure should occur immediately upon standing. Theoretically, the highest diastolic pressures should be read when the subject is lying down or immediately upon standing with activation of the baroreceptors reflex response. However, there are many factors that can vary results from the expected-such as anxiety, sympathetic drive, respiratory movements (laughter), and others.

How is the pulse pressure calculated, and how does its value relate to the pulse? Also, described how the mean arterial pressure is calculated, and explain its significance

The pulse pressure is systolic minus diastolic pressure. AS the blood pressure from diastolic to systolic values within an artery, the rise is hydrostatic pressure against the artery wall causes the artery to expand somewhat. This is the "pulse" you feel when you press you fingers against the outside of an artery. In this way, the pulse pressure causes the pulse. The mean arterial pressure represents the combined systolic and diastolic pressure head that drives the blood from the arterial tree into the blood capillaries

How are the Korotkoff sounds produces? When do you hear the first Korotkoff sound? Explain why this is true of the first and last sounds

Vibrations heard through a stethoscope due to the turbulent flow of blood through a partially compressed brachial artery cause Korotkoff sounds. The narrowing of the lumen creates turbulent blood flow and the vibrations produced are characterized as Korotkoff sounds. The first Korotkoff sound is heard when the pressure in the sphygmomanometer cuff is lowered so that the brachial artery is only partially compressed (the cuff pressure is equal to the systolic pressure) thereby permitting the initial turbulent flow out the distal portion of the cuff. The last Korotkoff sound is heard as the flow of blood throught the cuff is no longer compressed by the cuff and laminar flow is restored (diastolic pressure) and no more sounds are detected

scientific term for listening carefully (as with a stethoscope) is

ascultation

P wave

atrial depolarization

abnormally slow heart beat

brachycardia

the second heart sound occurs at the beginning of the

diastole

The last Korotkoff sound occurs when the cuff pressure equals the ________________ pressure

diastolic

the first heart sound is correlated with which ECG wave

end of QRS

the second heart sound is correlated with which ECG wave

end of T

the electrical synapses between adj. myocardial cells are called

gap junction

abnormal heart sounds are called

heart murmurs

the specific nerve that when stimulated causes a decrease in the cardiac rate

parasympathetic fibers

the first heart sounds (lub) is caused by

resulting vibrations of AV vales closing

the pacemaker region of the heart is known as the

right atrium, SA node

The scientific name of the device used to take a blood pressure reading (hint:one word) is the

sphygmomanometer

Leads 1, 2, 3 are collectively called

standard lib leads

the nerve that increases the rate of discharge of the SA node is a

sympathetic fibers nerve

during which phase of the cardiac cycle does the first heart sound occur?

systole

When blood pressure measurements are taken, the first wound of Korotkoff occurs when the cuff pressure equals the _______________________ pressure

systolic

abnormally fast heart beat

tachycardia

The sounds of Korotkoff are produced by

turbulent blood flow

QRS

ventricular depolarization

T

ventricular repolarization

the second heart sounds (dub) is caused by

vibrations of SV valves closing