TEAS® Science Study Guide
Respiratory System
The respiratory system brings oxygen into the body and removes carbon dioxide.
Path of air
Nose/mouth → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
- Larynx — The voice box.
- Trachea — The windpipe. Splits intotwo bronchi, one per lung.
- Bronchioles — Small branchingairways.
- Alveoli — Tiny air sacs where gasexchange actually occurs. Surrounded by capillaries.
Gas exchange
At the alveoli, oxygen diffuses into the blood and carbon dioxide diffuses out of the blood. Diffusion moves each gas from higher to lower concentration — no energy required.
Breathing mechanics
- Inhalation — The diaphragm contracts and flattens, the chest cavity expands, and air rushes in.
- Exhalation — The diaphragm relaxesand domes upward, the cavity shrinks, and air is pushed out.
The diaphragm is the primary muscle of breathing.
Terms to know
- Alveoli — Air sacs where gasexchange happens.
- Diaphragm — Dome-shaped musclebelow the lungs that drives breathing.
- Epiglottis — Flap that covers theairway during swallowing so food doesn’t enter the trachea.
- Diffusion — Movement of a substancefrom high to low concentration.
What the TEAS asks most
- Where does gas exchange occur? Alveoli.
- What happens to the diaphragm during inhalation? Itcontracts and moves down.
- What prevents food from entering the airway? The epiglottis.
- Which system does the respiratory system work most closelywith? Cardiovascular — the blood carries the oxygen the lungscollect.