The Circulatory System

1. MacKenzie Smart, Leah Harris, Emma Dumford, and Anna Sivey The Circulatory System

2. The Circulatory System • The Heart • Blood Vessels • Blood Pressure • Blood Plasma • Blood Cells

4. The Heart <3 • composed mostly of muscle • hollow organ—size of clenched fist • enclosed in a protective sac of tissue called Pericardium • two thin layers of epithelial and connective tissue that surround a thick layer of muscle called Myocardium • contractions of the Myocardium (heartbeat) pump blood through the circulatory system • heart muscle contracts an average of 72 times a minute—pumps 70 mL of blood • the Septum divides the right side of the heart from the left and prevents Oxygen-poor blood from mixing with Oxygen-rich blood

5. Heart—valves • four chambers-two upper chambers (left and right atria) and two lower chambers (left and right ventricles) • right atrium has thinner walls and is larger than the left • the left ventricle is the strongest and largest chamber in the heart

6. Heart—valves • four types of valves: • Tricuspid valve- separates the right atrium from the right ventricle and regulates blood flow between them • Pulmonary valve- separates the right ventricle from the left pulmonary artery and controls blood flow from each other • Mitral valve- separates the left ventricle from the left atrium • Aortic valve- separates the left ventricle from the Aorta and controls the blood flow from the ventricle into the rest of the body

7. Heart—arteries • arteries push blood through the blood vessels when the heart relaxes from its contractions • arteries transport Oxygen-rich blood to the capillaries where exchange of CO2 and Oxygen takes place

8. Heart—arteries • arteries of the heart: • Pulmonary artery- carries deoxygenated blood from the right side of the heart to the lungs for purification, it also divides into right and left branch • Aorta-main artery of the heart which carries oxygenated blood to the rest of the body; branches off to smaller arteries that supply blood for the body • Coronary arteries- attached to the heart and supply blood to heart muscles

9. Heart—veins • veins are like arteries but do not transport blood at high pressure • after the exchange of CO2 and O, the blood containing waste products is received by the veins • Pulmonary vein- carries oxygenated blood from the lungs to the left side of the heart

10. Heart—veins • all four pulmonary veins pour oxygenated blood into the left atrium (two left and two right) • VenaeCavae- two large veins carry deoxygenated blood from the body to the heart • Superior VenaeCavae- brings deoxygenated blood from parts above heart into the right atrium • Inferior VenaeCavae- brings blood from the parts below the heart to the right atrium

11. Blood Vessels • Three types of blood vessels: • Arteries • Capillaries • Vein • Arteries: the largest vessels that carry blood from the heart to the tissues. • Except for the pulmonary and umbilical arteries, all arteries carry oxygen loaded blood. • Arteries have thick walls to withstand the pressure from the heart when it contracts and pushes blood into them.

12. Blood Vessels • Arteries have three layers…. • Adventitia: outside layer; elastic to allow the arteries to expand under pressure. • Media: middle layer; contracts to regulate the diameter • Endothelium: inside layer; smooth lining to allow blood to flow

13. Blood Vessels • Aorta: Largest vessel leaving the left ventricle and leads down to the rest of the arteries. • Arterioles: small vessels that branch off from the arteries and lead to the capillaries  • Capillaries: Smallest, “side-streets”. The walls are only one cell thick. These are the main vessels that nutrients and oxygen is brought to tissues.  • Veins: After passing through the capillary system, blood returns to the heart for oxygen • Blood flows against gravity through the veins. • Large veins, like in the leg, have valves that push the blood towards the heart. • Exercising helps keep the blood from accumulating in one spot, which produces a blood clot.

14. Blood Pressure • Blood Pressure ~ the force of blood against the walls of the arteries. • Systolic pressure: the pressure as the heart beats • Diastolic pressure: the pressure as the heart relaxes between beats • Equation: systolic/diastolic mmHg (millimeters of mercury) • the normal or “desired” number is 120/80 mmHg

15. Blood Plasma • Blood Plasma- • 55% of blood is plasma. Plasma is 90% water and 10% dissolved gasses, salts, nutrients, enzymes, hormones, waste products, and proteins. • Plasma proteins: • Albumins- helps regulate osmotic pressure and blood volume, and transports substances • Globulins- transports substances, and fights viral and bacterial infections • Fibrinogen- gives blood the ability to clot

16. Blood Cells • Red Blood Cells • 1 milliliter of blood has about 5 million red blood cells • Red blood cells transport oxygen • They get their red color from hemoglobin (iron-containing protein that binds to oxygen in the lungs and transports it to tissue throughout the body) • They are disk-shaped cells without a nucleus made from cells in red bone marrow • Red blood cells last for about 120 days before they are destroyed in the spleen

17. Blood Cells • White Blood Cells • less common, out numbered almost 1000 to 1 • guard against infections, fight parasites, attack bacteria • they can slip out of capillaries and fight infections throughout the body • the body can increase the number of white blood cells when fighting • have nuclei and are made in bone marrow • live for days, months, even years

18. Blood Cells • Platelets • there are about 150,000 to 350,000 platelets per micro liter • blood clotting is made possible by plasma proteins and platelets • they aren't actually cells, but cell fragments produced in bone marrow

19. Diseases • 2 Types • Present at Birth • Acquired • Aortic Aneurysm • Bulging in the wall of the aorta (largest artery) • Caused by a tear or defect in the aortic wall • Can be a complication of other diseases such as high blood pressure • Angina • Pain or discomfort in the chest area caused by leakage in the blood vessels leading to the heart • Pain lasts usually about 10 minutes

20. Diseases • Arrhythmia • Irregularity in the heart rhythm, varies from very slow to very fast • Can occur at any point in life • Atherosclerosis • The hardening of the arterial wall because of plaque or artheroma • Plaque is composed of cholesterol, calcium, and fatty deposits • Can slow or stop blood circulation • There is a sharp pain in the affected area

21. Diseases • High Blood Pressure • When the systolic pressure Is over 140 mmHg and disastolic pressure is over 90 mmHg • Caused by heredity or unhealthy lifestyle habits such as heavy drinking and smoking • Peripheral Vascular Disease • a disorder in the blood vessels • caused by fatty acid deposits in the arteries of the leg portion • can be hereditary or acquired by unhealthy living

22. Diseases • Ways to Prevent Circulatory Diseases: • Do not Smoke or use any other nicotine source • Exercise consistently • Eat Healthy • Get enough sleep each 24-hours • Avoid high amounts of stress

24. Overview • Three Major Parts • The Heart • The Blood • The Blood Vessels • The Heart removes waste materials and pumps and circulates blood • The Blood has the oxygen and nutrients necessary for cell survival • The Blood Vessels transport blood to and from the heart • The Circulatory System is the main transportation and cooling system of the body • It is basically like the roads in cities used to transports goods and other important materials. • When your heart beats, it forces the oxygen-rich blood through the circulatory system