GAS EXCHANGE

What is gas exchange

It is the uptake of O2 or Oxygen FROM the environment, and the discharge of CO2 or Carbon dioxide to the environment.

Internal respiration

The process where gas exchange happens between the blood and interstitial fluids. Where oxygen moves from the blood, to the cells, and carbon dioxide moves from the cells to the blood.

External respiration

The process of gas exchange between air and the blood within the lungs. Oxygen is absorbed, carbon dioxide is released.

Respiratory surfaces

Specialized structures in organisms where gas exchange happens. Each surface has a thin, moist membrane with a relatively large surface area. These surfaces include lungs, gills, and skin.

Respiratory Medium

The environmental substance which the organism exchanges gas with. Can be water or air.

Invertebrate Respiratory Surface

In hydras, outer layer of cells is in contact with with water, allowing gas exchange to happen in the inner layer.

In earthworms, they use their skin for gas exchange.

Tracheal System

The invertebrate respiratory surface used by insects where oxygen directly enters the cells without passing through the blood. These systems are connected to the environment through an opening called Spiracles.

Vertebrae Respiratory Surface

Aquatic vertebrae use gills that extract oxygen from water.

Vertebrae lungs have a moist internal respiratory surface. Lungs are not in direct contact with the rest of the body, so the circulatory system helps gas exchange.

Ventilation

The process of air flowing into the lungs through inhalation (inspiration) and out of the lungs through exhalation (expiration)

Positive breathing pressure

Air is drawn in from the nostrils, and is forcefully pushed into the lungs. It is expelled when the body wall contracts, and the lungs recoil, pushing air out.

One-way ventilation

One way flow of air through a bird’s lungs increases efficiency of gas exchange.

Negative pressure breathing

Creating a vacuum that pulls air into your lungs naturally.

Respiratory cycle

During inhalation: chest cavity and lungs expand, letting air in.

During exhalation: chest cavity and lungs contract to original position, forcing air out.

Respiratory proteins

Any molecule that increases the oxygen carrying capacity of blood.

Hemoglobin

It is a molecule that has four polypeptide chains. Each chain folds around an iron containing group called heme. Oxygen moves from one or more of the heme group. This is called oxyhemoglobin.

Respiratory tract

The entire passageway that transports air into the lungs. Includes nose/mouth, pharynx, larynx, trachea and bronchi

Respiratory adaptations

Animals that live in extreme conditions where there is less oxygen adapt to maximize oxygen uptake efficiency.