KEY CONCEPT The respiratory and circulatory systems bring oxygen and nutrients to the cells.

There are three major functions of the circulatory system. The respiratory and circulatory systems work together to maintain homeostasis. There are three major functions of the circulatory system. transporting blood, gases, nutrients collecting waste materials maintaining body temperature Oxygen-poor blood Oxygen-rich blood

The circulatory system moves blood to all parts of the body. The system includes the heart, arteries, veins, and capillaries. heart pumps blood throughout body arteries move blood away from heart veins move blood back to heart capillaries get blood to and from cells veins arteries

The tissues and structures of the heart make it an efficient pump. Cardiac muscle tissue works continuously without tiring. NORMAL HUMAN HEART

The heart has four chambers: two atria, two ventricles. Valves in each chamber prevent backflow of blood. aortic valve left atrium mitral valve left ventricle septum pulmonary valve right atrium tricuspid right ventricle Muscles squeeze the chambers in a powerful pumping action.

Blood flows through the heart in a specific pathway. 3 1 4 2

KEY CONCEPT The respiratory system exchanges oxygen and carbon dioxide.

The respiratory system is where gas exchange occurs. picks up oxygen from inhaled air expels carbon dioxide and water nose sinus mouth epiglottis trachea lungs

The respiratory system moves gases into and out of the blood. The lungs contain the bronchi, bronchioles, and alveoli. Millions of alveoli give the lungs a huge surface area. The alveoli absorb oxygen from the air you inhale. alveoli bronchiole

Breathing involves the diaphragm and muscles of the rib cage. Air flows from areas of high pressure to low pressure. Air inhaled. Muscles contract and rib cage expands. Diaphragm flattens and moves downward. Air exhaled. Muscles and rib cage relax. Diaphragm relaxes and rises.

Gas exchange occurs in the alveoli of the lungs. Oxygen and carbon dioxide are carried by the blood to and from the alveoli. oxygen diffuses from alveoli into capillary oxygen binds to hemoglobin in red blood cells carbon dioxide difuses from capillary into alveoli ALVEOLI GAS EXCHANGES alveolus capillary co2 o2 Co2 diffuses into alveolus. O2 diffuses into blood. capillaries

Smoking is the leading cause of lung diseases.