Cardiovascular System Sec 5 PDF

CARDIOVASCULAR SYSTEM sec 5 dr/ Basma Ahmed The cardiovascular system includes the heart & blood vessels. I- The Heart - The heart is a muscular pump, located in the thoracic cavity between the two lungs with slight deviation to the left side. - The heart has four chambers; it is d...

CARDIOVASCULAR SYSTEM sec 5 dr/ Basma Ahmed The cardiovascular system includes the heart & blood vessels. I- The Heart - The heart is a muscular pump, located in the thoracic cavity between the two lungs with slight deviation to the left side. - The heart has four chambers; it is divided into left & right sides. The chambers of the heart are: 1- Right atrium (RA) 2- Right ventricle (RV) 3- Left atrium (LA) 4- Left ventricle (LV) - The right side of the heart (RA & RV) contains deoxygenated blood. - The left side of the heart (LA & LV) contains oxygenated blood. Valves of the heart: 1- Tricuspid valve: connects the RA with the RV. 2- Mitral valve: connects the LA with the LV. 3- Pulmonary valve: between the RV & the pulmonary artery. 4- Aortic valve: between the LV & the aorta - The RA receives deoxygenated blood from superior vena cava & inferior vena cava. - The RV pumps deoxygenated blood to the pulmonary trunk. - The LA receives oxygenated blood from the four pulmonary veins. - The LV pumps oxygenated blood to the aorta. II- The blood vessels Blood vessels are the highways that allow blood to flow from & to the heart. There are three major types of blood vessels: arteries, capillaries & veins. Capillaries: - Capillaries are the smallest & thinnest of the blood vessels. - They connect to arterioles on one end & to venules on the other end. Body circulations: There are 3 circulations in the human body: 1- Systemic circulation: carries oxygenated blood from the LV via the aorta to all body tissues. Where exchange of gases occur, then systemic circulation carries CO2 from the tissues & returns deoxygenated blood to the RA via superior & inferior vena cava. 2- Pulmonary circulation: carries deoxygenated blood from the RV via the pulmonary artery to the lungs, the blood is oxygenated & returns to the LA via the four pulmonary veins.