The Circulatory System Chapter 42: Part II

Human Circulatory System a.k.a cardiovascular system 3 parts: 1. heart 2. blood 3. blood vessels

Human Circulatory System Double Circulation: 1. systemic circuit – blood leaves heart and tours body 2. pulmonary circuit – blood leaves heart to go to lungs and back to heart

Human Circulatory System Systemic Circuit Tour 1. Oxygenated blood leaves left ventricle via aortic semilunar valve & enters the aorta, the largest artery in the body

Human Circulatory System Systemic Circuit Tour 2. Aorta branches into arteries 1. coronary arteries – supply O2 to heart 2. ascending arteries – supply O2 to head & arms 3. descending arteries – supply O2 to abdominal organs and legs “Away, thick”

Human Circulatory System Systemic Circuit Tour 3. Arteries  arterioles  capillaries Get smaller & smaller Capillaries: Where exchange of gases, nutrients, hormones, & waste occurs

Human Circulatory System After exchange, blood is deoxygenated & needs to go to lungs, but first must go to heart. Capillaries  venules  veins Get larger and larger Toward, thin

Human Circulatory System Systemic Circuit Tour 4. Blood from superior body parts enters right atrium through superior vena cava Blood from inferior body parts enters right atrium through inferior vena cava

Human Circulatory System Systemic Circuit Tour 5. Blood moves from right atrium to right ventricle through the right atrioventricular valve (tricuspid)

Human Circulatory System Pulmonary Circuit Tour 6. From right ventricle blood goes out again through pulmonary semilunar valve and enters pulmonary artery Carries deoxygenated blood to lungs Branches into left and right pulmonary arteries Arteries  arterioles  capillaries in alveoli

Human Circulatory System Pulmonary Circuit Tour 7. Blood enters back into heart via pulmonary veins into left atrium

Human Circulatory System Pulmonary Circuit Tour 8. Blood moves from left atrium to left ventricle through left atrioventricular valve (bicuspid, mitral)

Human Circulatory System Recap of Systemic Circuit: Blood leaves heart’s left ventricle via aorta It travels through arteries  arterioles  capillaries of heart & superior/inferior body parts Gas, nutrient/waste exchange occur between blood & tissues through capillary walls Deox. blood leaves capillaries  venules  veins It enters into heart’s right atrium via superior/inferior vena cava it flows into hearts right ventricle via right atrioventricular valve (tricuspid)

Human Circulatory System Recap of Pulmonary Circuit: Deox. blood leaves heart’s right ventricle via pulmonary artery Artery branches right & left into each lung Blood travels from arteries  arterioles  capillaries of alveoli Gas exchange occurs at alveoli Oxygenated blood returns to heart’s left atrium through pulmonary veins It flows into left ventricle through the left atrioventricular valve (bicuspid, mitral)