Circulatory System

Components of the Circulatory System – Heart – Blood – Blood vessels: arteries; veins, capillaries

Functions of Circulatory System Transports important substances, such as oxygen, nutrients, and disease fighting materials produced by the immune system

Functions of Circulatory System Blood carries wastes away from organs Blood clotting

Functions of Circulatory System Heart pumps blood Distributes heat throughout the body to help regulate temperature

Blood Vessels Arteries: large, muscular vessels that carry blood away from the heart

Blood Vessels – Blood pressure is the force that is exerted against the walls of the artery – Hypertension (high blood pressure) Places a strain on arterial walls, increasing the chance that a vessel will burst

Blood Vessels Capillaries – A network of tiny blood vessels – This is a very extensive network…. – There are 100 trillion cells in the body. Each one of them lies within 125 nanometers of a capillary – Only one cell thick, allows for the rapid exchange of materials

Blood Vessels Veins: large blood vessels that carry blood to the heart – Thinner and less muscular than artery – Valves prevent blood from backing up

Heart A muscular organ that is about as large as your first and located in the center of your chest. Hollow Pumps blood throughout the body – Pumps oxygenated blood to organs – Pumps deoxygenated blood to lungs

Heart Structure of the Heart – Cardiac muscle – 4 chambers (compartments) 2 chambers at the top: Atria – Receive blood returning to the heart 2 chambers at the bottom: Ventricles – Pump blood away from the heart

Heart How the heart beats – 2 main phases 1 st phase: the atria fill will blood, contract and the ventricles fill with blood 2 nd phase: ventricles contract to pump blood out of heart – The heart works in rhythm A group of cells send out signals that tell the muscles to contract

Blood Flow It flows in 2 loops – 1 st : travels from heart to lungs and back to heart – 2 nd : travels from heart to body and back to heart – The right side of the heart pumps deoxygenated blood to the lungs – The left side of heart pumps oxygenated blood to body

Heart Coronary Circulation – Supplies blood to the heart – If coronary artery is blocked by blood clot or artherosclerosis a heart attack will result

Pulse – Heart pulses about 70 times a minute Blood Pressure – A measure of how much pressure is exerted against the vessel walls by the blood – Healthy 120/80

Blood Components of Blood – Plasma: liquid medium (clear, yellowish fluid) – Red Blood Cells: carry oxygen to body’s cells Contain hemoglobin (iron containing protein) that carries oxygen

Blood – Platelets Cell fragments that play an important role in forming blood clots – White Blood Cells The body’s disease fighters

Blood Circulatory System Disorders – Artherosclerosis: blocked arteries Signs: high blood pressure, high cholesterol Can lead to heart attack or stroke Sickle Cell disease – The red blood cells are shaped like sickles and can not carry oxygen as well