The Cardiovascular System
Polycythemia
Heart Structure
The human heart has four cavities that fill with blood. The chambers in the heart include the right atria, left atria, right ventricle, and left ventricle. The septum separates the right and lefts sides of the heart. A valve prevents blood vessels from going the wrong way, and connects each atrium to the ventricle below it. The mitral valve connects the left atrium with the left ventricle, and the tricuspid valve connects the right atrium with the right ventricle.
Pericardium
This cavity is filled with pericardial fluid which serves as a shock absorber by reducing friction between the pericardial membranes.
1) Keeps the heart contained in the chest cavity
2)Prevents heart from over expanding when blood volume increases
3)Limits heart motion
Major Blood Vessles
Venae Cavae
Superior Vena Cava: Brings de-oxygenated blood from the head, neck, arm and chest regions of the body to the right atrium. Inferior Vena Cava: Brings de-oxygenated blood from the lower body regions (legs, back, abdomen and pelvis) to the right atrium.
Aorta
Carries and distributes oxygen rich blood to all arteries. The aorta is the curved portion and the top part of the heart. It includes the aortic root, ascending aorta, aortic arch, descending aorta, thoracoabdominal aorta, and abdominal aorta. The aortic root is responsible for carrying oxygen-rich blood to the heart muscle. The abdominal aorta supplies blood to the kidneys.
Capillaries
Capillary to tissue fluid exchange
Arteries
The arteries carry blood away from the heart. An artery is an elastic blood vessel. There are pulmonary and coronary arteries. The pulmonary artery is the vessel transporting de-oxygenated blood from the right ventricle to the lungs. The coronary arteries supply blood to the heart muscle.
Veins
A vein is an elastic blood vessel that transports blood from various regions of the body to the heart
Blood Flow & Conduction System of the Heart
Electrocardiogram (EKG) Test
- Check the heart's electrical activity.
- Find the cause of unexplained chest pain.
- Find the cause of symptoms of heart disease, such as shortness of breath, dizziness, fainting, or rapid, irregular heartbeats.
- Find out if the walls of the heart chambers are too thick (hypertrophied).
- Check how well medicines are working and whether they are causing side effects that affect the heart.
- Check how well mechanical devices that are implanted in the heart are working to control a normal heartbeat.
- Check the health of the heart when other diseases or conditions are present, such as high blood pressure, high cholesterol, cigarette smoking, diabetes, or a family history of early heart disease.
Influences in Blood Pressure
2) Strength of Heart Contractions- The stronger the heart beat, the increase in blood pressure. The weaker the heart beat, the decrease in blood pressure.
3) Heart Rate- When the heart beats faster, more blood enters the aorta, and therefore the arterial blood volume and blood pressure would increase.
4) Blood Viscosity- If blood is less viscous than normal, blood pressure will decrease.
5) Resistance to Blood Flow- Peripheral resistance describes any force that acts against the flow of blood in a blood vessel. When vessel wall muscles are contracted, resistance increase and therefore so does the blood pressure.
Tests
Normal Heart Sounds
The patient should be examined in the supine position, and while sitting and leaning forward. The doctor will use a stethoscope on the surface of the chest to listen for heart sounds. Each area should be systematically auscultated for S1, S2, physiologic splitting, and respiratory variations. Murmurs are blowing, whooshing, or rasping sounds heard during a heartbeat. The sound is caused by turbulent blood flow through the heart valves or near the heart.Murmurs occur when a valve does not close tightly and blood leaks backward.
Blood Tests
Blood tests help doctors check for certain diseases and conditions. They also help check the function of your organs and show how well treatments are working.
- Evaluate how well organs are workings—such as the kidneys, liver, thyroid, and heart
- Diagnose diseases and conditions such as cancer, HIV/AIDS, diabetes, anemia, and coronary heart disease
- Find out whether you have risk factors for heart disease
- Check whether medicines you're taking are working
- Assess how well your blood is clotting
Polycythemia
High Red Blood Cells Count
• Gender -- Men may be slightly more likely than women to develop the condition.
• Age -- People older than 60 are most likely to develop the condition, though it may occur at any age.
• Environment – Exposure to intense radiation may increase the risk for the condition.
If you have polycythemia, the thickness of your blood and the slowed blood flow can cause serious health problems.
Blood clots are the most serious complication of polycythemia.
- They also can cause your liver and spleen to enlarge. Blood clots in the liver and spleen can cause intense pain.
- Slowed blood flow also prevents enough oxygen-rich blood from reaching your organs. This can lead to chest pain or discomfort and heart failure. The high levels of red blood cells that PV causes can lead to stomach ulcers, gout, or kidney stones.
- Some people who have PV may develop myelofibrosis, which is a condition in which your bone marrow is replaced with scar tissue. Abnormal bone marrow cells may begin to grow out of control.
- This abnormal growth can lead to acute myelogenous leukemia, a cancer of the blood and bone marrow. This disease can worsen very quickly.
Electrocardiogram
Pulse
Blood Pressure
Stroke Volume
Cardiac Output
Heart Sounds
Blood Tests
Polycythemia Treatments
Sources
"Cardiac Output." SBCC Biological Sciences Department. N.p., n.d. Web. 13 Mar. 2013. <http://www.biosbcc.net/doohan/sample/htm/COandMAPhtm.htm>. (tags: none | edit tags)
"How Is Polycythemia Vera Treated? - NHLBI, NIH." NIH Heart, Lung and Blood Institute. N.p., n.d. Web. 13 Mar. 2013. <http://www.nhlbi.nih.gov/health/health-topics/topics/poly/treatment.html>. (tags: none | edit tags)
"Polycythemia vera - MayoClinic.com." Mayo Clinic. N.p., n.d. Web. 13 Mar. 2013. <http://www.mayoclinic.com/health/polycythemia-vera/DS00919>. (tags: none | edit tags)
"Understanding Blood Pressure Readings." www.heart.org. N.p., n.d. Web. 13 Mar. 2013. <http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/AboutHighBloodPressure/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp>.