Respiratory System 7 TH GRADE SCIENCE Function Exchanges

Respiratory System 7 TH GRADE SCIENCE

Function �Exchanges oxygen and carbon dioxide between blood and air FYI te. u n i : e m / t s a r n: n a o y i r t m u ato ala h r i h e p n i rag e Res to 14 s v e a m i 10 , an , 000 t ir y a a f ne d hes 20 unds o o In o at p 5 Bre 3 s e l a Inh

Pathway of Inhaled Air 1. Nasal cavity 2. Pharynx (Throat) 3. Larynx (Voice Box) 4. Trachea (Windpipe) 5. Bronchi 6. Bronchioles 7. Alveoli (Site of gas exchange) Exhaled air follows reverse pathway.

Nasal cavity �Where air enters the body �Air enters nostrils, is filtered by hairs, warmed, humidified, and sampled for odors as it flows through a maze of spaces.

Throat (pharynx) �Pathway that allows air to travel to the lungs and food down the esophagus.

Larynx (voice box) � Allow us to make sounds by voluntarily tensing muscles. High pitched: Vocal cords are tense, vibrate fast. Low pitched: Vocal cords are relaxed, vibrate slowly.

Trachea Rings of cartilage maintain shape of trachea.

Bronchi �Each bronchus leads into a lung and branches into smaller and smaller bronchioles, resembling an inverted tree.

Bronchioles Fine tubes that allow passage of air.

Alveoli �Site of gas exchange

Diaphragm A muscle that controls our breathing.

Hiccups �Hiccups occur when the diaphragm becomes irritated. When this happens, it pulls down in a jerky way, which makes you suck air into your throat suddenly. When the air rushing in hits your voice box, you're left with a big hiccup. �Things that irritate the diaphragm: eating too quickly or too much an irritation in the stomach or the throat feeling nervous or excited.

Click on Lungs for Kids Health Video Link

Diseases of the Respiratory System � Asthma: Condition in which breathing is impaired by constriction of bronchi and bronchioles, cough, and thick mucus secretions. The severity and incidence of asthma has risen dramatically in recent years, especially in children. May be fatal if not treated. Causes: Attacks may be precipitated by inhalation of allergens (e. g. : pollen, cats, and cockroach proteins), pollutants, infection, or emotional stress. Treatment: Alleviates symptoms (e. g. : immunosuppressors, bronchodilators), but is not a cure.

Diseases of the Respiratory System � Bronchitis: Inflammation of the mucous membranes of the bronchi. May present with cough, fever, chest or back pain, and fatigue. Causes: Associated with smoking, pollution, and bacterial or viral infections. � Pneumonia: Acute inflammation of the lungs. Symptoms include high fever, chills, headache, cough, and chest pain. Causes: Bacterial, fungal, or viral infections. Treatment: Antibiotics or other antimicrobials.

Diseases of the Respiratory System �Emphysema: Permanent and irreversible destruction of alveolar walls, resulting in loss of lung elasticity and gas exchange surface. Symptoms include shortness of breath, difficulty exhaling, cough, weakness, anxiety, confusion, heart failure, lung edema (swelling), and respiratory failure. Causes: Smoking, pollution, old age, and infections. Treatment: Oxygen to help breathing. No cure.

Diseases of the Respiratory System � Lung Cancer: Cancerous growth that invades and destroys lung tissue. Very high fatality rate. Symptoms include bloody sputum, persistent cough, difficulty breathing, chest pain, and repeated attacks of bronchitis or pneumonia. Causes: Smoking (50% of all cases) and pollution (radon, asbestos). Smokers are 10 times more likely to develop lung cancer than nonsmokers. Treatment: Surgery is most effective, but only 50% of all lung cancers are operable by time of detection. Other treatments include radiation and chemotherapy.