Respiratory System Gas exchange Why do we breathe

Respiratory System Gas exchange

Why do we breathe? Think of all the reasons why we need a respiratory system. W O R K T O G E T H E R

Respiratory System Functions: • Provides oxygen to the blood • Removes CO 2 from the blood

Cells Many different types of cells are formed during embryonic development.

Organization of the Body Levels of Organization Eleven Organ System

Levels of Organization • Molecule • Cell • Tissue • Organ system • Organism

Homeostasis The body maintains stable internal conditions which are relatively constant

Homeostasis & the Respiratory System • body = trillions of cells: needs FOOD (digestive) and AIR (respiratory) • Cellular Respiration: C 6 H 12 O 6 = O 2 CO 2 + H 2 O + ATP • THEREFORE supply of O 2 in blood CRITICAL for homeostasis • Without O 2, cells cannot make energy • CO 2 must also be managed so that this waste doesn’t accumulate to problematic levels.

Respiratory System Organs • Alveoli • Bronchioles • Diaphragm • Larynx • Lungs • Nose • Trachea

Structure Bronchi/Bronchus Bronchioles

Warning: terminology! • “Respiration” is used several different ways: • Cellular respiration is the aerobic breakdown of glucose in the mitochondria to make ATP. • Respiratory systems are the organs in animals that exchange gases with the environment. • “Respiration” is an everyday term that is often used to mean “breathing. ”

Moving air in and out • During inspiration (inhalation), the diaphragm muscle moves DOWN • During exhalation, these muscles relax. The diaphragm moves upwards.

Trivia When a person inhales. . . a. the chest cavity becomes bigger b. the chest cavity becomes smaller c. it is impossible to breathe d. none of the above

Alveoli The alveoli are thinwalled pockets which are the site of gas exchange.

Gas exchange Air entering the lungs (alveoli) has more O 2 & less CO 2 than the blood that flows in the pulmonary capillaries How do these differences in concentrations assist gas exchange?

Trivia The actual exchange of gases occurs at the site of the. . . a. Trachea b. nasal passageway c. larynx d. alveoli

Circulation and Gas Exchange Gas exchange at the lungs moves oxygen into cells and carbon dioxide out (Diffusion) Clear connection between circulation and the respiratory system.

Oxygen transport Hemoglobin= iron in blood Hemoglobin binds to O 2 that diffuses into the blood stream. Red blood cell transports oxygen to all body cells

Trivia Gas exchange occurs when. . . a. oxygen in the alveoli diffuses into the blood in the capillaries b. oxygen binds with the hemoglobin in the red blood cells c. the red blood cells give up oxygen to the cells of the body tissues d. all of the above

Most of the oxygen in blood is: 1. In the white cells. 2. Bound to hemoglobin. 3. Combined with carbon to make carbon dioxide. 4. Dissolved in the plasma.