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(updated 10/15/05)

Heart, anterior view of surface with pericardium layers labeled.

Anterior view of coronal section of heart with all associated blood vessels, structures and valves labeled.

Tricuspid valve (right ventricle).

Photo of superior view of valves.

Superior view of valves.

Blood flow schematic between systemic and pulmonary circulation. Note color of vessels associated with oxygen content (red - oxygenated, blue - deoxygenated blood). Blood Vessel Lab

Heart and main vessels - anterior view.

Although the heart is not considered an endocrine organ, in response to blood pressure increase within the heart, the right atrium produces Atrial Natriuretic Hormone (ANH), which lowers blood pressure by decreasing Na+ concentration and antagonizing aldosterone.

Be able to explain each of the events in the diagram below.

Events of the cardiac cycle, including diagrams of the heart, showing contractions and closing of heart valves associated with the first and second heart sounds.

Connection of the glossopharyngeal nerves (red), vagus nerve (green), and sympathetic nerves (from T1 & T2 of spinal cord: preganglionic neuron green, and postganglionic neuron, blue).

The cardiac conduction system. The S-A (sinoatrial) note is derived from the sinus venosus, an embryonic structure in mammals, which can be seen in an adult shark. It forms the first portion of the pacemaker of the heart, and normally initiates the heartbeat. The green lines represent the conductive fibers that carry the impulse over the atria and to the A-V (atrioventricular) node, which carries the impulse into the walls of the ventricles and papillary muscles.

Correlation of the ECG and conduction of electrical activity (depolarization - yellow; repolarization - green) within the myocardium. Note labeling of P wave, QRS wave, and T wave, and the time in milliseconds on the electrocardiogram.

Be able to identify the following ECG patterns, and calculate the heart rates of each. Be able to use three methods to calculate heart rate: 1) heart beats in 6 seconds X 10 = HR; 2) 1500 divided by number of small squares between QRS peaks ( example below: 1500/15 = 100 HR); and 3) number of dark vertical bars between QRS peaks: 1 = 300, 2 = 150, 3 = 100, 4 = 75, 5 = 60, 6 = 50. Remember that 1 dark bar = 0.2 sec, 2 = 0.4 sec, 3 = 0.6 sec, 4 = 0.8 sec, 5 = 1 sec.

Heart rate?

Individual heart cells beat independently in ventricular fibrillation, which will lead to heart failure.

Heart rate?

Heart rate?

Heart rate?

Be able to explain the roles of the brain, hormones, glossopharyngeal nerve, vagus nerve, and sympathetic nerves in the control of heart rate and blood pressure. What roles do the baroreceptors and chemoreceptors play?

Relationships between cardiovascular system and other systems of the body.

Pulse pressure
From Wikipedia, the free encyclopedia Pulse Pressure is most easily defined as being the amount of pressure required to create the feeling of a pulse. Measured in millimeters of mercury (mmHg), the pressure difference between the systolic and diastolic pressures give you the amount of pressure change to create the pulse, which is the pulse pressure. If your resting blood pressure is (systolic/diastolic) 120/80 millimeters of mercury (mmHg), your pulse pressure is 40 which is considered a normal and healthy pulse pressure.

Values and variation

Low (Narrow) Pulse Pressure A pulse pressure is considered abnormally low if it is less than 25% of the systolic value. The most common cause of a low (narrow) pulse pressure is a drop in left ventricular stroke volume. In trauma a low or narrow pulse pressure suggests significant blood loss (insufficient preload leading to reduced cardiac output).[4] If the pulse pressure is extremely low, i.e. 25 mmHg or less, the cause may be low stroke volume, as in Congestive Heart Failure and/or shock.

A narrow pulse pressure is also caused by aortic stenosis and cardiac tamponade. [edit] High (Wide) Pulse Pressure [edit] High values during or shortly after exercise Usually, the resting pulse pressure in healthy adults, sitting position, is about 40 mmHg. The pulse pressure increases with exercise due to increased stroke volume,[5] healthy values being up to pulse pressures of about 100 mmHg, simultaneously as total peripheral resistance drops during exercise. In healthy individuals the pulse pressure will typically return to normal within about 10 minutes. For most individuals, during aerobic exercise, the systolic pressure progressively increases while the diastolic remains about the same. In some very aerobically athletic individuals, for example distance runners, the diastolic will progressively fall as the systolic increases. This behavior facilitates a much greater increase in stroke volume and cardiac output at a lower mean arterial pressure and enables much greater aerobic capacity and physical performance. The diastolic drop reflects a much greater fall in total peripheral resistance of the muscle arterioles in response to the exercise (a greater proportion of red versus white muscle tissue). Individuals with larger BMI's due to increased muscle mass (body builders) have also been shown to have lower diastolic pressures and larger pulse pressures.[6] [edit] Consistently high values If the usual resting pulse pressure is consistently greater than 40 mmHg, e.g. 60 or 80 mmHg, the most likely basis is stiffness of the major arteries, aortic regurgitation (a leak in the aortic valve), arteriovenous malformation (an extra path for blood to travel from a high pressure artery to a low pressure vein without the gradient of a capillary bed), hyperthyroidism or some combination. (A chronically increased stroke volume is also a technical possibility, but very rare in practice.) While some drugs for hypertension have the side effect of increasing resting pulse pressure irreversibly, other hypertension drugs, such as ACE Inhibitors, have been shown to lower pulse pressure. A high resting pulse pressure is harmful and tends to accelerate the normal aging of body organs, particularly the heart, the brain and kidneys. A high pulse pressure combined with bradycardia and an irregular breathing pattern is associated with increased intracranial pressure and should be reported to a physician immediately. This is known as the Cushing reflex and can be seen in patients after head trauma related to intracranial hemorrhage or edema. Examples: (these are examples of WIDENING pulse pressure causes)

Atherosclerosis Arteriovenous fistula Chronic aortic regurgitation Thyrotoxicosis Fever Anaemia Pregnancy Anxiety Heart block Aortic dissection Endocarditis Raised intracranial pressure