The Circulatory System Blood, Blood Vessels, Heart

Function: Carries nutrients, oxygen, hormones, and wastes through the body and distributes heat to maintain homeostasis.

Made up of…. Blood: moves through blood vessels to bring the materials a body systems needs and carries away the products and wastes the system makes. distributes heat: When the body is warm, blood vessels in the skin widen, more blood pumps through the skin allowing heat to leave the body. When the body is cold, blood vessels in the skin narrow, diverting more of the blood to deeper tissues so less heat will escape.

Blood cont. Made up of: Plasma (55%): liquid portion of the blood Red blood cells: carry oxygen White blood cells: defend the body against infection Platelets: blood clotting

Blood Vessels: Arteries: have thick, muscular walls to withstand the force of the blood pumped out of the heart. Carry blood to the capillaries. Capillaries: have extremely thin walls that allow gases and nutrients in the blood to pass across into the fluid around body cells and wastes to move into the blood. Carry blood to the veins. Veins: thinner walls with valves that prevent blood from flowing backward. Carry blood back to the heart.

Heart: Made up of: Atria: receiving chambers Ventricles: pumping chambers Valves: keep blood pumping in one direction Septum: keeps oxygenated and deoxygenated blood from mixing within the heart.

Diseases of the Circulatory System

High Blood Pressure Normal blood pressure is below 120/80; blood pressure between 120/80 and 139/89 is called "pre-hypertension", and a blood pressure of 140/90 or above is considered high. Risk Factors: high intake of salt, exceeding 5.8 grams daily advancing age African American background Obesity hereditary (genetic) susceptibility Effects Stroke, Heart Attack, Kidney Failure

Atherosclerosis Atherosclerosis (ath-er-o-skler-O-sis) is a disease in which plaque builds up on the insides of your arteries.  Plaque = fat, cholesterol, calcium, and other substances found in the blood.  Over time, plaque hardens and narrows your arteries.  The flow of oxygen-rich blood to your organs and other parts of your body is reduced.  This can lead to serious problems, including heart attack, stroke, or even death. Risk Factors: lack of physical activity, smoking, unhealthy eating, age and family history of heart disease .

Stroke Sudden interruption in the blood supply of the brain. Risk Factors: Increasing age, male gender, race family history, high blood pressure, diabetes, cigarette smoking, high blood cholesterol, obesity, heart Disease Effects: Can affect the senses, motor activity, speech and the ability to understand speech, behavioral and thought patterns, memory and emotions. Paralysis or weakness on one side of the body is common. After a stroke, most of these problems can improve over time. In some patients they will go away completely.