Bio112 Topic 14: The Respiratory System

Flashcards covering key vocabulary and concepts from the Bio112 lecture on The Respiratory System.

Air Pressure

Weight of Air (mmHg)

Partial Pressure (mmHg)

The contribution to total pressure made by one gas

Fick’s Law of Diffusion

Rate of Diffusion = k * A (P2 – P1) / D, where k is the diffusion constant, A is the surface area, P2-P1 is the difference in partial pressure, and D is the thickness of the membrane.

Gills

Respiratory organs which extract O2 from water

Flow Through Systems

Active, unidirectional movement of water across the gills

Countercurrent exchange

Blood flows in the opposite direction of water movement

Pharynx

Place where air & food paths cross

Larynx

Upper part of respiratory tract; also functions as voice box (with vocal cords)

Epiglottis

Shifts when food is swallowed to close glottis (opening of trachea (windpipe)

Trachea (windpipe)

Transports air from larynx to bronchi

Bronchi

Lead to each lung, branch into smaller & smaller tubes (bronchioles); Epithelia covered by cilia & mucus, forming “mucus escalator”

Alveoli

Dead-end air sacs at tips of bronchioles where gas exchange occurs

Surfactants

Substance secreted by alveoli to decrease surface tension, prevent collapse

Tidal Volume

Volume of air moved into the lungs with a normal breath

Inspiratory Reserve Volume

Volume of air that can be forced into the lungs beyond tidal volume

Expiratory Reserve Volume

Volume of air that can be forced out of the lungs after normal exhalation

Residual Volume

Volume of air remaining in the lungs after forced expiration

Positive pressure breathing

Inflating lungs with forced air flow (buccal pumping)

Negative pressure breathing

Pulling air into lungs by making air pressure in lungs lower than outside

Diaphragm

Sheet of skeletal muscle forming bottom wall of chest cavity

Medulla oblongata

Sets basic rhythm of breathing; Uses pH of cerebrospinal fluid as measure of blood CO2 concentration

Pons

Smooths out transitions in breathing

Hemoglobin

Iron based O2-binding protein in vertebrates

The Bohr Effect (Shift)

A shift in the oxygen dissociation curve caused by environmental changes, such as in the concentration of carbon dioxide or the pH

Carbon Dioxide Transport

CO2 is transported by blood in several ways: 7% dissolved in blood plasma, 23% bound to hemoglobin, and 70% as bicarbonate ions (HCO3-)