The Cardiovascular System

The Cardiovascular System major function - transportation. Uses blood as the vehicle the system carries: Oxygen nutrients cell wastes hormones other substances vital for body homeostasis

The Heart The heart is located in the bony thorax its apex is pointed towards the left hip and rests on the diaphragm. Your heart is roughly the size of your fist. Divided into four chambers

Heart – Coverings The heart is enclosed by a double sac called the pericardium. Parietal Pericardium- loose outer layer, reinforced with fibrous tissue that helps protect the heart and anchor it to surrounding structures. Visceral Pericardium – tightly hugs the external surface of the heart and is continuous with the heart wall.

Heart - Walls The heart walls are composed of three layers: 1. Visceral Pericardium (epicardium) 2. Myocardium – thick bundles of cardiac muscle twisted into ring-like arrangements (the contracting part) 3. Endocardium- thin sheet of epithelium that lines the chambers and is continuous with the blood vessels entering and leaving the heart.

Heart - Chambers The heart has 4 hollow chambers. The superior two “receiving” chambers are called atria. The inferior two “discharging” chambers are called ventricles.

Heart – Blood Movement Blood coming and going to and from the heart travels in blood vessels. Veins carry blood away from the tissues towards the heart. Arteries carry blood away from the heart to organs and target areas.

Major Arteries Upper Body Subclavian Axillary Brachial Radial Ulnar If cut, death occurs 5-30 minutes, depending on severity of cut. All can be treated with pressure except subclavian due to its location.

Major Arteries Lower Body Illiac Femoral Popliteal Inguinal (not pictured) Feeds femoral artery If cut, death occurs 5-30 minutes, depending on severity of cut. All can be treated with pressure except inguinal due to its location.

Major Arteries Head and Neck Carotid If cut, death occurs 2-20 minutes, depending on severity of cut. Can be treated with pressure. If flow is interrupted on both carotids, the person will pass out. If blood flow is interrupted for an extended period of time, possible brain damage becomes an issue.

Major Arteries Heart Coronary Pulmonary Artery Aorta Travels down the center of the body Supplies blood to the muscle tissue of the heart. If cut, death occurs 1-3 minutes, depending on severity of cut.

Major Arteries

Veins return blood from the body to the heart after the blood has been depleted of oxygen.

Veins of the Upper Body

Veins of the Lower Body

Pumping Blood Superior and Inferior Vena Cava – supply the right atrium. Pulmonary Trunk (with R and L pulmonary arteries)– drain the right ventricle and carry blood to the lungs. R and L Pulmonary Veins – supply the left atrium with oxygenated blood from the lungs. Aorta – drains the left ventricle out to the body.

Pumping Blood