lecture_24_KM_ch48b_for_class

Partial Pressure

The pressure exerted by a particular gas in a mixture of gases.

Gas Exchange

The process of moving CO2 and O2 in opposite directions between the environment, bodily fluids, and cells.

Diffusion

Movement of gases from regions of high pressure to regions of lower pressure.

Ventilation

The process of bringing oxygenated air into contact with a gas-exchange organ.

O2 Availability in Water

Aquatic animals face less available oxygen and fluctuating oxygen levels with temperature changes.

External Gills

Uncovered extensions from the body surface found in many invertebrates and larval amphibians.

Internal Gills

Gills of fishes covered by an operculum; they contain filaments composed of lamellae.

Countercurrent Exchange

A mechanism that maximizes oxygen diffusion where water and blood flow in opposite directions.

Tracheal Systems

Respiratory systems in insects consisting of spiracles and tracheae that branch into tracheoles.

Negative Pressure Ventilation

A method of breathing where volume expansion creates negative pressure to draw air into lungs.

Positive Pressure Ventilation

A method used by amphibians where air is forced into lungs by creating pressure gradients.

Tidal Ventilation

Air leaves via the same route it entered during inhalation; less efficient than flow-through systems.

Surfactant

A mixture produced by type II alveolar cells that reduces surface tension in the alveoli.

Hemoglobin

An iron-containing respiratory pigment in red blood cells that binds oxygen.

Hemocyanin

A copper-containing respiratory pigment found in some arthropods that binds oxygen.

Erythropoiesis

The process of producing new erythrocytes (red blood cells) from stem cells in the bone marrow.

Asthma

A condition where muscles around bronchioles are hyperexcitable, leading to constricted airways.

Emphysema

A respiratory condition causing extensive lung damage, reduced elasticity and total surface area of alveoli.

SARS-CoV-2

The virus causing COVID-19 that binds to cell membranes in lungs, heart and blood vessels.

Respiratory Pigments

Proteins that increase the amount of oxygen available to cells compared to dissolved oxygen.

Oxygen Transport

The mechanisms by which oxygen is carried in the blood, primarily by hemoglobin.

Diaphragm

A muscle that divides the thoracic cavity from the abdomen and plays a key role in ventilation.

Trachea

The windpipe that branches into bronchi leading to the lungs.

Bronchioles

Small branches of bronchi that lead to the alveoli, where gas exchange occurs.

Alveoli

Tiny air sacs in the lungs that are the primary site of gas exchange.

Type I Cells

Cells in the alveoli through which gases diffuse across due to their thin structure.

Type II Cells

Alveolar cells that produce surfactant to reduce surface tension.

Chemoreceptors

Sensory receptors that monitor levels of O2, CO2, and pH in the blood.

Metabolic Needs

The requirements for oxygen by cells to support energy production.

Gas-Exchange Organs

Structures specialized for the exchange of gases in an organism.

Air Composition

Air is composed of approximately 21% O2, 78% N2, and 1% other gases.

Gills

Respiratory organs in aquatic animals that extract oxygen from water.

Adaptations to Altitude

Physiological changes such as higher red blood cell count to cope with reduced oxygen.

Inhalation Process

The action during which air is drawn into the lungs, facilitated by diaphragm contraction.

Exhalation Process

The action of expelling air from the lungs, occurring when the diaphragm relaxes.

Respiratory Distress Syndrome (RDS)

A condition in newborns caused by insufficient surfactant production.

Myoglobin

An oxygen-binding protein found in muscles that helps store oxygen for metabolic needs.

Bronchodilators

Medications that expand the air passages of the lungs to alleviate asthma symptoms.

Carbon Dioxide

A waste product of metabolism that affects blood pH and triggers breathing responses.

Respiratory Control Centers

Brainstem nuclei that generate signals to regulate breathing rate and depth.

Air Movement Direction in Lungs

Air flows into the lungs during inhalation; remains open during rest.

Vascular Problems from COVID-19

Issues such as blood clots resulting from viral infection of blood vessels.

Blood Flow in Lungs

Blood flows into avian lungs in a crosscurrent direction relative to air movement.

Heat Removal in Water

Water removes heat from the gill surface, affecting gas exchange.