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heart

III Result

A Heart Sound: The two of my first sounds seemed a bit stronger and louder that two of the second sounds.

B Blood Pressure

1. Systolic/Diastolic after 5 minutes rest: 120mmHg / 80mmHg. Pulse rate: 73 beats/min. Pulse pressure: 40mmHg

2. Systolic/Diastolic sitting: 120mmHg / 80mmHg. Pulse rate: 68beats/min. Pulse pressure: 40mmHg

3. Systolic/Diastolic after standing: 130mmHg / 90mmHg. Pulse rate: 75 beats/min Pulse pressure: 40mmHg

4. % change :

a Resting to sitting: systolic=0 diastolic= 0

b Resting to sitting: systolic=8.3% diastolic= 12.5%

Calculation: %change = ------------------------------------X 100

C EKG

IV Summary

1. In the heart sounds experiment, two of my first sounds located at tricuspid area and mitral area seemed a bit stronger and louder that two of my second sounds which located at aortic area and pulmonary area.
2. In the blood pressure experiment, after 5 minutes rest, my systolic pressure is 120mmHg and diastolic pressure80mmHg. Both the systolic and diastolic pressure of the sitting position remains the same after given a 5-minute rest. Blood pressure was increased after I changed position to standing. Percentage change from resting to sitting for both systolic and diastolic pressure is 0. Systolic pressure changed 8.3% from resting to standing. Diastolic pressure changed 12.5%.
3. I have a normal consistent EKG. Each P wave is followed by a QRS. And there is T wave after a QRS.

V Conclusion.

1. The first hear sound is caused by turbulence when the closure of the atrioventricular valves, mitral and tricuspid happened at the beginning of ventricular contraction. The second sound is caused by turbulence when the aortic valves and pulmonic valve close at the end of ventricular systole.
2. Blood is carried from the heart to all parts of your body in vessels called arteries. Blood pressure is the force of the blood pushing against the walls of the arteries. Each time the heart beats (about 60-70 times a minute at rest), it pumps out blood into the arteries. Blood pressure is always given as these two numbers, the systolic and diastolic pressures. Systolic pressure is the highest pressure in the measured artery. It is an indication of force of heart contraction. Diastolic pressure is the lowest pressure in the measured artery. It is an indication of the condition of the artery. Pulse pressure is the difference between systolic and diastolic. (systolic minus diastolic pressure)
3. EKG or ECG – is a test that measures the electrical activity of the heartbeat. With each beat, an electrical impulse (or “wave”) travels through the heart. This wave causes the muscle to squeeze and pump blood from the heart.

VII Food for Thought

1. If you were going to design a medication which would relieve high blood pressure, what are some possible physiological methods of action that you might exploit?

· Beta blockers

· ACE inhibitors

· Angiotensin receptor blockers

· Calcium channel blockers

· Diuretics

· Alpha blockers

2. What changes in pulse rate as determined as the radial artery would occur in there was a sudden occurrence of :

a. ventricular fibrillation becomes quick but weak.

b. partial A-V block becomes slower

c. complete A-V block becomes very slow.

3. What are some of the changes which might occur with exercise in :

a. heart rate: will increase

b. blood pressure: will increase but even out gradually

c. cardiac output: will increase

d. coronary artery diameter: will increase

e. number of cross bridges attaching to actin molecules in the ventricular myocardium: more cross bridges attaches to actin now.

4. Before a physiology exam the student’s heart is beating quickly. Explain the mechanism of the increased rate and what mechanisms are involves when the heart rate returns to normal?

Stress stimulate and epinephrine from the adrenal medulla open the HCN channels of the pacemaker cells, including a faster rate of diastolic depolarization. This causes action potentials to be produced more rapidly, resulting in a faster cardiac rate.

Exercise will help the heart rate to back to normal. Ach released by vagus nerve endings, binds to receptors and caused the opening of separate K+ channels in the membrane. The outward diffusion of K+ partially counters the inward diffusion of Na+ through the HCN channels, producing a slower cardiac heart rate which can bring the faster rate back to normal.

5. Upon placing the stethoscope in the fifth intercostals space as close to the sternum as possible, a rushing sound is heard. Explain this pathology.

This may due to the bruit which is usually occurs in a middle aged or older person. It is the unusual sound that blood makes when it rushes past an obstruction in an artery when the sound is observed with a stethoscope. It associated with stroke and carotid artery disease.

posted by C-T @ 11:33 AM