The Circulatory, Respiratory System
The Function of the Circulatory System
Structure and Function of Arteries,Capillaries, and Veins.
Veins:Blood pressure is low and walls are thinner than arteries but has the heaviest wall layer.
Capillaries:They are the link between arteries and veins,walls are very thin.
Plasma:is a clear extracellular fluid
Erythrocytes: are also known as red blood cells
Leukocytes: Are also known as white blood cells
Platelets: are the protection of the blood cells.
-High Blood pressure: Which causes the heart to work harder than what it should. Which can lead to a heart attack or stroke.
As we breathe, oxygen enters the nose or mouth and passes the sinuses, which are hollow spaces in the skull. Sinuses help regulate the temperature and humidity of the air we breathe.
The trachea, also called the windpipe, filters the air that is inhaled, according to the American Lung Association. It branches into the bronchi, which are two tubes that carry air into each lung. The bronchial tubes are lined with tiny hairs called cilia. Cilia move back and forth, carrying mucus up and out. Mucus, a sticky fluid, collects dust, germs and other matter that has invaded the lungs. We expel mucus when we sneeze, cough, spit or swallow.
The bronchial tubes lead to the lobes of the lungs. The right lung has three lobes; the left lung has two. Lobes are filled with small, spongy sacs called alveoli, and this is where the exchange of oxygen and carbon dioxide occurs.
The alveolar walls are extremely thin (about 0.2 micrometers). These walls are composed of a single layer of tissues called epithelial cells and tiny blood vessels called pulmonary capillaries.
Blood passes through the capillaries. The pulmonary artery carries blood containing carbon dioxide to the air sacs, where the gas moves from the blood to the air. Oxygenated blood goes to the heart through the pulmonary vein, and the heart pumps it throughout the body.
The diaphragm, a dome-shaped muscle at the bottom of the lungs, controls breathing and separates the chest cavity from the abdominal cavity. When a breath it taken, it flattens out and pulls forward, making more space for the lungs. During exhalation, the diaphragm expands and forces air out.
Asthma is a chronic inflammation of the lung airways that causes coughing, wheezing, chest tightness or shortness of breath. These signs and symptoms may be worse when a person is exposed to their triggers, which can include air pollution, tobacco smoke, factory fumes, cleaning solvents, infections, pollens, foods, cold air, exercise, chemicals and medications.
Lung cancer is often associated with smoking, but the disease can affect non-smokers as well. Every year, about 16,000 to 24,000 Americans die of lung cancer, even though they have never smoked. Like all cancers, lung cancer is caused by the uncontrolled growth of abnormal cells.