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www.cardiophile.com Also known as the circulatory system The cardiovascular system is made up of the heart, blood, and blood vessels www.hcplive.com Our heart is a muscle that keeps blood flowing through our body, bringing nutrients and oxygen to every cell It circulates about two gallons of blood throughout the body The system begins in our lungs, where blood picks up oxygen The heart takes the oxygen-rich blood and pumps it out to all parts of the body After the cells in the body take in the oxygen from the blood, the deoxygenated blood returns to the heart and is sent to the lungs to get more oxygen The heart is made up of four chambers separated by one-way gateways called valves It is divided into a right and left side www.uptodate.com The atria have relatively thin walls and function as collection chambers They only pump blood to the ventricles Left atrium is a hollow chamber that collects oxygen-rich blood from the pulmonary vein before sending it to the left ventricle. Right atrium is a hollow chamber that collects blood lacking oxygen from the vena cava before sending it to the right ventricle The chambers that pump blood out of the heart are called the ventricles. The ventricles have thicker walls and are much more powerful than the atria The ventricles are the major pumping chambers for delivering blood to the pulmonary (right ventricle) and systemic (left ventricles) circulations Left ventricle is a hollow chamber that collects oxygen-rich blood from the left atrium before sending it to the aorta Right ventricle is a hollow chamber that collects blood lacking oxygen from the right atrium before sending it to the pulmonary artery The valves each consist of flaps of connective tissue that prevent backflow of blood Atrioventricular valves and Semilunar valves Pressure generated by powerful contraction of the ventricles closes the AV valves, keeping blood from flowing back into the atria Tricuspid valve- valve with three cusps; situated between the right atrium and the right ventricle; allows blood to pass from atrium to ventricle and closes to prevent backflow when the ventricle contracts Mitral valve- valve with two cusps; situated between the left atrium and the left ventricle Semilunar valves are located at the two exits of the heart The blood is pumped out into the arteries through semilunar valves, which are forced open by pressure created by ventricular contraction The semilunar valves close when the blood starts to flow back toward the heart, so this prevents blood from flowing back into the ventricles Pulmonary valve- between the right ventricle and the pulmonary artery; prevents blood from flowing from the artery back into the heart Aortic valve- between the left ventricle and the aorta; prevents blood from flowing from the aorta back into the heart Aorta- Large artery that distributes oxygen-rich blood from the heart to the rest of the body. Pulmonary Artery- carries blood lacking oxygen from the hearts right ventricle to the lungs Pulmonary vein- carries oxygen-rich blood from the lungs into the hearts left atrium Coronary arteries- vessels that provide the heart muscle with the oxygen-rich blood it needs to keep its tissues healthy. Two main coronary arteries branch off from the aorta, and each of these arteries branches again into yet more arteries that supply oxygenated blood to the different parts of the heat Vena Cava (superior)-Carries blood lacking oxygen from the head, neck, and arms into the right atrium Vena Cava (inferior)- carries blood lacking oxygen from legs and other lower parts of the body into the right atrium When it contracts it pumps blood When it relaxes its chambers fill with blood Complete sequence of pumping and filling is called the cardiac cycle Contraction phase is called systole Relaxation phase is called diastole The cardiac output is the blood volume pumped per minute 3 basic blood vessels include capillaries arteries and veins Transport blood from the arteries to the veins Oxygen, carbon dioxide, nutrients, and wastes are exchanged through the walls Capillaries are so small that red blood cells can only travel through them in single file! Carry blood away from the heart Walls provide strength and elasticity Deliver oxygen-rich blood to the capillaries We can measure heart rate by counting the contractions of the artery. That’s how a pulse is taken. Convey blood back to the heart at low velocity and pressure after the blood has passed through the capillaries Blood flows through veins as a result of muscle action The Respiratory System Trachea (wind pipe) Ribs Alveoli Bronchus Bronchioles Intercostal muscles Lung Diaphragm The Respiratory System The purpose of the respiratory system is to… bring the air we breathe into close contact with the blood so that oxygen can be absorbed and carbon dioxide removed. Basically it consists of: A pair of lungs connected to the mouth via the trachea and bronchi. The ribs and intercostal muscles of the chest which protect the lungs, trachea and bronchi. Air enters the nostrils passes through the nasopharynx, the oral pharynx through the glottis into the trachea into the right and left bronchi, which branches and rebranches into bronchioles, each of which terminates in a cluster of Alveoli (Only in the alveoli does actual gas exchange takes place). The trachea or windpipe is about 10 cm long and is supported by C-shaped rings of cartilage to prevent the tube from collapsing during breathing. The trachea subdivides into the left and right bronchus. The bronchi are also strengthened by cartilage. The two bronchi subdivide to form an extensive network of Bronchioles that deliver air to the gas exchange surfaces – the alveoli. Air enters the body through the nasal passages and mouth, and passes via the pharynx and larynx to the trachea. Air is delivered to the alveoli as the trachea branches into bronchi and bronchioles. Lungs main organs of the respiratory system. oxygen taken into the body and carbon dioxide is breathed out. red blood cells pick up the oxygen in the lungs and carry it to all the body cells that need it. Then they pick up the carbon dioxide which is a waste gas product produced by our cells. The red blood cells transport the carbon dioxide back to the lungs and we breathe it out when we exhale. The Exchange of Gases within the Lungs The 2 bronchi, which lead to each lung divide into many bronchioles. These are less than 1mm in diameter and terminate in grape-like clusters of tiny sacs called alveoli. Thorax Section of lung Single alveolus Gas Exchange Occurs in the alveloi (air sacs) Capillaries surround the alveoli and allow gas exchange to occur between the blood and the lungs Gases diffuse from an area of high concentration to an area of low concentration Deoxygenated blood - high CO2 low O2 Alveoli - low CO2 high O2 Therefore the CO2 goes from the blood to the lungs and O2 goes from the lungs to the blood Gas Exchange Alveoli have low CO2 high O2 Deoxygenated blood Oxygenated blood Alveoli CO2 O2 Deoxygenated blood has Oxygenated blood has high CO2 low O2 low CO2 high O2 Trachea The trachea is sometimes called the windpipe. The trachea filters the air we breathe and branches into the bronchi. Bronchi The bronchi are two air tubes that branch off of the trachea and carry air directly into the lungs. Diaphragm Breathing starts with a dome-shaped muscle at the bottom of the lungs called the diaphragm When you breathe in, the diaphragm contracts. When it contracts it flattens out and pulls downward. This movement enlarges the space that the lungs are in. This larger space pulls air into the lungs. When you breathe out, the diaphragm expands reducing the amount of space for the lungs and forcing air out. The diaphragm is the main muscle used in breathing. Negative Pressure Breathing -we pull air instead of pushing it