AMA 178 - Anatomy & AMA 178 - Anatomy & Physiology/Medical Physiology/Medical

Terminology/Pathology 9 Terminology/Pathology 9 Cardiovascular SystemCardiovascular System

Function:Function:

Composed of the heart, a powerful Composed of the heart, a powerful muscular pump, and blood vessels muscular pump, and blood vessels that send oxygen and nutrients to all that send oxygen and nutrients to all parts of the body via the parts of the body via the bloodstream. bloodstream.

Waste products are also eliminated Waste products are also eliminated from body tissues via the from body tissues via the bloodstream. bloodstream.

Structure of the Structure of the Cardiovascular System: Cardiovascular System:

Blood vesselsBlood vessels Three types of blood vessels: arteries, veins and Three types of blood vessels: arteries, veins and

capillaries capillaries

Arteries: Arteries: large blood vessels that carry oxygen large blood vessels that carry oxygen rich blood away from the heartrich blood away from the heart

Veins: Veins: carry deoxygenated blood to the heart carry deoxygenated blood to the heart from the tissues, and waste products to other from the tissues, and waste products to other systems of the body to be releasedsystems of the body to be released

Capillaries: Capillaries: delicate, microscopic vessels that delicate, microscopic vessels that carry nutrient rich, oxygenated blood from the carry nutrient rich, oxygenated blood from the arteries to the body cellsarteries to the body cells

Blood Circulation:Blood Circulation:

Pulmonary Circulation:Pulmonary Circulation:

Oxygen poor blood from body tissues enters the Oxygen poor blood from body tissues enters the right side of the heart via the right side of the heart via the venae cavaevenae cavae (2 (2 large veins) where it travels into the large veins) where it travels into the pulmonary pulmonary arteryartery (only artery in the body that carries (only artery in the body that carries oxygen poor blood); this branches into two oxygen poor blood); this branches into two sections, one to each lung.sections, one to each lung.

Blood passes into the Blood passes into the pulmonary capillariespulmonary capillaries where it picks up oxygen rich blood and then where it picks up oxygen rich blood and then goes back through the heart to be pumped to all goes back through the heart to be pumped to all areas of the body.areas of the body.

Blood Circulation:Blood Circulation:Systemic Circulation:Systemic Circulation:

Oxygen rich blood enters the left side of the heart from the Oxygen rich blood enters the left side of the heart from the pulmonary veinspulmonary veins. .

Blood is pumped via the Blood is pumped via the aortaaorta (largest artery in the body) (largest artery in the body) to other arteries that branch out to all parts of the body via to other arteries that branch out to all parts of the body via tissue capillariestissue capillaries near body cells, where nutrients are near body cells, where nutrients are broken down in the presence of oxygen and energy is broken down in the presence of oxygen and energy is released. released.

This chemical process releases This chemical process releases carbon dioxidecarbon dioxide as a waste as a waste product; this is taken back to the lungs and the body product; this is taken back to the lungs and the body releases it via exhalation. releases it via exhalation.

Other wastes are taken by the veins to be eliminated by Other wastes are taken by the veins to be eliminated by other systems in the body. other systems in the body.

Structure of the Structure of the Cardiovascular System:Cardiovascular System:

HeartHeart Located in the thoracic cavity between the Located in the thoracic cavity between the

lungs. lungs.

Weighs less than a pound and is about the Weighs less than a pound and is about the size of a human fist. size of a human fist.

It is a pump consisting of four chambers It is a pump consisting of four chambers and four valves; its action is controlled by and four valves; its action is controlled by electrical impulses initiating in the cardiac electrical impulses initiating in the cardiac muscle tissue. muscle tissue.

Anatomy of the Heart:Anatomy of the Heart: Atria: Atria: upper chambers of the heartupper chambers of the heart

Ventricles: Ventricles: lower chambers of the heartlower chambers of the heart

Superior vena cava: Superior vena cava: drains deoxygenated blood from the upper drains deoxygenated blood from the upper portion of the bodyportion of the body

Inferior vena cava: Inferior vena cava: carries deoxygenated blood from the lower carries deoxygenated blood from the lower portion of the bodyportion of the body

Tricuspid valve: Tricuspid valve: valve between the right atrium and right valve between the right atrium and right ventricleventricle

Pulmonary valve: Pulmonary valve: valve between the right ventricle and the valve between the right ventricle and the pulmonary arterypulmonary artery

Mitral valve: Mitral valve: valve between the left atrium and left ventriclevalve between the left atrium and left ventricle

Aortic valve: Aortic valve: valve between the left ventricle and the aortavalve between the left ventricle and the aorta

Two Phases of the Two Phases of the Heartbeat:Heartbeat:

Cardiac cycle:Cardiac cycle: occurs 70-80 times a occurs 70-80 times a minute (100,000 times a day). Heart minute (100,000 times a day). Heart pumps approximately 3 ounces of blood pumps approximately 3 ounces of blood with each contraction (5 quarts a minute)with each contraction (5 quarts a minute)

Diastole: Diastole: relaxation – ventrical walls relax relaxation – ventrical walls relax and blood flows into heart from the venae and blood flows into heart from the venae cavae and pulmonary veinscavae and pulmonary veins

Systole: Systole: contraction – ventrical walls contraction – ventrical walls contract pumping blood into the contract pumping blood into the pulmonary artery and aorta to all parts of pulmonary artery and aorta to all parts of the bodythe body

Conduction System of the Conduction System of the Heart:Heart:

Electrical impulse originates in a small region of specialized Electrical impulse originates in a small region of specialized muscle tissue (SA node) and is sent in waves through the muscle tissue (SA node) and is sent in waves through the heart causing contraction of ventricals heart causing contraction of ventricals

Sinoatrial node (SA node): Sinoatrial node (SA node): pacemaker of the heart; pacemaker of the heart; generates current of electricity that causes atria to contract generates current of electricity that causes atria to contract fording blood into the ventriclesfording blood into the ventricles

Atrioventricular node (AV node): Atrioventricular node (AV node): electrical impulse electrical impulse goes here from the SA node and on to the bundlesgoes here from the SA node and on to the bundles

Bundle of His: Bundle of His: bundle of specialized fibers that send bundle of specialized fibers that send impulse to the left and right bundle branchesimpulse to the left and right bundle branches

Left & Right bundle branches: Left & Right bundle branches: form the form the conduction conduction myofibersmyofibers (electrical muscle tissue) that extend through (electrical muscle tissue) that extend through ventricle walls and stimulate them to contract. ventricle walls and stimulate them to contract.