Respiratory System Cellular Respiration Occurs in the Mitochondria

Respiratory System

Cellular Respiration Occurs in the Mitochondria Release of energy from breakdown of food (glucose) Occurs in the presence of oxygen

Organism Respiration • Occurs in the Lungs • Moves O 2 into body tissues (needed for cellular respiration) • Removes CO 2 from cells/tissues

Function Exchange of oxygen and carbon dioxide between the: Blood Air Tissues

Components Nose Pharynx Epiglottis Larynx Trachea Bronchus Bronchiole Alveoli Diaphragm

Nose The nose warms and moistens the air. Nose hairs filter large dust particles. Aids in smelling.

Pharynx The pharynx serves as a passageway for both air and food.

Epiglottis A flap of cartilage tissue that prevents food from entering the trachea.

Larynx AKA voice box. Involved in breathing, sound production and prevents food from entering the trachea through coughing.

Trachea AKA windpipe. Connects pharynx and larynx to the lungs. Composed of rings of cartilage.

Bronchus The trachea divides to form the right and left bronchi that travel to each of the lungs.

Bronchiole • The bronchus subdivides into smaller airway passages called bronchioles. • The bronchioles terminate into air sacs called alveoli.

Alveoli are tiny sacs at the end of the smallest airways. Exchange of O 2 and CO 2 occur here.

Diaphragm The diaphragm the major muscle of respiration.

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Mechanics of Breathing Inhalation • Air inhaled • Rib cage rises up • Diaphragm contracts downward • Active process

Mechanics of Breathing Exhalation • Air exhaled • Rib cage lowers • Diaphragm relaxes and domes upward • Passive process

Movement of O 2 and CO 2 in and out of the respiratory sys.

Healthy Lungs Air entering it must be: Warmed, moistened, filtered

Healthy Lungs Nose hairs: trap large dust particles

Healthy Lungs Mucus: moistens air, traps inhaled dust or smoke particles

Healthy Lungs Cilia: hair-like structures found in the nose and airways of the resp. sys. Sweeps trapped particles and mucus away from lungs

Breathing is Controlled Breathing is controlled by the medulla oblongata

Tobacco and the Respiratory System Nicotine: • Stimulant • Increases heart rate and blood pressure • Very addictive

Carbon Monoxide Poisonous gas Blocks transport of O 2 by hemoglobin in blood Decreases blood’s ability to supply O 2 to tissues

Tar in Cigarettes Contains many cancer-causing compounds

Smoking Paralyzes Function of the Cilia Inhaled smoke particles stick to respiratory walls or enter lungs. Smoked filled mucus becomes trapped along airways.

Smoking Causes the Lining of Respiratory Tract to Swell Reduces airflow to the alveoli

Respiratory Diseases Emphysema Bronchitis Reduces life expectancy Lung Cancer

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Gas Exchange at Inner surface of alveoli 1. 2. 3. 4. O 2 dissolves in moisture Diffuses across wall of air sac Enters capillary O 2 binds hemoglobin on RBC 1. CO 2 diffuses from cells/tissues to capillary 2. CO 2 carried by blood to alveoli 3. CO 2 diffuses out of blood to inner surface of alveoli 4. CO 2 exhaled out of lungs

Gas Exchange in the Lungs Gas exchange into blood occurs in the alveoli/capillaries

Hemoglobin Increases the oxygen-carrying capacity of blood (otherwise you would need 300 L of blood)