The Circulatory System Consists of the heart, the blood vessels, and blood

Functions of the Circulatory System 1.Transports O 2 & nutrients (sugars, amino acids) to body cells 2.Transports hormones throughout body 3.Carries wastes away from cells 4.Works with the immune system to protect body against disease causing pathogens

Parts of the Blood 1. Plasma – fluid portion – transports all of the material 2. Red Blood Cells: (RBC’s) a.Transports oxygen to body cells b.Removes waste from body cells 3. White blood cells: (WBC’s) a.Protect against infection; fight parasites & attack bacteria 4. Platelets: cell fragments a.Release proteins that help clot blood Plasma Platelets WBC’s RBC’s

Blood Cells Red blood cells (erythrocytes) MOST NUMEROUS, DISK-SHAPED, CARRIES O 2 TO ALL CELLS IN THE BODY, HEMOGLOBIN White blood cells (leukocytes) LARGER IN SHAPE THAN RBC BUT FEWER IN NUMBER, HELP FIGHTS DISEASE

Blood Vessels 1. Arteries: large vessels; carry blood away from heart a.Most arteries carry O 2 rich blood 2. Veins: large blood vessels; return blood to heart a.Have valves to keep blood from flowing backwards 3. Capillaries – smallest blood vessels a.Bring nutrients & O 2 to cells b.Absorb CO 2 & wastes from body cells arteries veins capillaries

Pulmonary artery Left atrium Left Ventricle - Right ventricle: Superior Vena Cava AORTA Right atrium Pulmonary vein Septum Inferior Vena Cava Bicuspid Valve Tricuspid Valve Semilunar Valve

The Heart 1. Heart – muscular organ a. 4 chambers b. Pumps blood from heart to lungs & back to heart, to tissues throughout body 2. Septum: muscular wall in heart a. Separates right side from left side b. Keeps O 2 poor & O 2 rich blood from mixing

The Heart 3. Atria – 2 upper chambers a. Receive blood from body (right) or lungs (left) & pump blood into ventricles 4. Ventricles – 2 lower chambers a. Pump blood out of heart to lungs (right) or aorta (left)

2 Pathways of Circulation blood FLOW between the heart & lungs Rt A  Rt V  pulmon. Artery LUNGS  L A L A  LV  aorta  body  vena cava  Rt A

a.Transports O 2 poor blood to lungs and O 2 rich blood back to the heart b. Blood travels from right side of heart to lungs How the Heart Works: Pulmonary Circulation c. Blood picks up O2 & releases CO2 in lungs d. O2 rich blood returned to left side of heart

Blood pumped from the right side of the heart to lungs and to left side of the heart Pathway: Pulmonary Circulation

a. O 2 rich blood exits left ventricle & enters aorta b. O 2 rich blood travels through arteries then capillaries c. O 2 diffuses out of capillaries & into cells; blood picks up CO 2 & other wastes d. Veins return O 2 poor blood to right side of heart (right atria) How the Heart Works: Systemic Circulation

Blood pumped from left side of heart to the body and back to the right side of the heart. Pathway: Systemic Circulation

Circulatory System Diseases Leukemia: bone marrow produces abnormal WBCs which crowd out normal WBCs, RBCs & platelets. Hemophilia: inherited disorder; person cannot produce clotting factors and bleeds longer than normal. Also has internal bleeding, mainly into muscles & joints.

Circulatory System Diseases High Blood Pressure: AKA hypertension BP 140 / 90 or higher for an extended period of time. Damage to heart & blood vessels; makes it harder to pump the heart. Can lead to stroke or heart attack

SICKLE-CELL DISEASE Red Blood Cells are mis-shapened causing blood cells to “CLOG” vessels. Hereditary Anemia - when the blood transports too little oxygen.

Arteriosclerosis: arteries become hard & brittle because calcium is deposited in their walls. Vessels become thickened & lose elasticity. Blood pressure increases & blood clots may form.

Circulatory System Diseases Stroke: blood clot blocks artery or a blood vessel breaks, interrupting blood flow to an area of the brain. Brain cells begin to die & abilities controlled by that area of the brain are lost.