Breathing and Exchange of Gases Flashcards

Vocabulary practice flashcards covering respiratory structures, mechanics of breathing, and respiratory volumes and capacities based on Chapter 14 lecture notes.

Breathing

The process of exchange of $O_2$ from the atmosphere with $CO_2$ produced by the cells, commonly known as respiration.

Cutaneous Respiration

Respiration carried out through the moist skin, as observed in amphibians like frogs.

Branchial Respiration

Respiration carried out using special vascularised structures called gills, used by aquatic arthropods, molluscs, and fishes.

Pulmonary Respiration

Respiration carried out using vascularised bags called lungs, used by terrestrial forms such as reptiles, birds, mammals, and adult amphibians.

Pharynx

A portion of the respiratory path that serves as the common passage for food and air.

Larynx

A cartilaginous box which helps in sound production and is commonly called the sound box.

Epiglottis

A thin elastic cartilaginous flap that covers the glottis during swallowing to prevent the entry of food into the larynx.

Trachea

A straight tube extending up to the mid-thoracic cavity, which divides at the level of the 5th thoracic vertebra into right and left primary bronchi.

Incomplete Cartilaginous Rings

Structures supporting the tracheae, primary, secondary, and tertiary bronchi, and initial bronchioles to keep them open.

Alveoli

Very thin, irregular-walled, and vascularised bag-like structures arising from terminal bronchioles that form the exchange part of the lungs.

Pleura

A double-layered membrane covering the lungs with pleural fluid in between to reduce friction on the lung surface.

Conducting Part

The region starting from the external nostrils up to the terminal bronchioles that transports atmospheric air to the alveoli, clears it of foreign particles, humidifies it, and brings it to body temperature.

Exchange Part

The site formed by the alveoli and their ducts where actual diffusion of $O_2$ and $CO_2$ between blood and atmospheric air occurs.

Thoracic Chamber

An anatomically air-tight chamber formed dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and on the lower side by the dome-shaped diaphragm.

Inspiration

The stage of breathing during which atmospheric air is drawn in, initiated by contraction of the diaphragm and external intercostal muscles when intra-pulmonary pressure is less than atmospheric pressure.

Expiration

The stage of breathing by which alveolar air is released out, taking place when intra-pulmonary pressure is higher than atmospheric pressure following relaxation of the diaphragm and intercostal muscles.

Spirometer

An instrument used to estimate the volume of air involved in breathing movements for clinical assessment of pulmonary functions.

Tidal Volume (TV)

The volume of air inspired or expired during a normal respiration, approximately $500\,\text{mL}$ (or $6000$ to $8000\,\text{mL}$ per minute in a healthy man).

Inspiratory Reserve Volume (IRV)

The additional volume of air a person can inspire by a forcible inspiration, averaging $2500\,\text{mL}$ to $3000\,\text{mL}$.

Expiratory Reserve Volume (ERV)

The additional volume of air a person can expire by a forcible expiration, averaging $1000\,\text{mL}$ to $1100\,\text{mL}$.

Residual Volume (RV)

The volume of air remaining in the lungs even after a forcible expiration, averaging $1100\,\text{mL}$ to $1200\,\text{mL}$.

Inspiratory Capacity (IC)

The total volume of air a person can inspire after a normal expiration, calculated as $\text{TV} + \text{IRV}$.

Expiratory Capacity (EC)

The total volume of air a person can expire after a normal inspiration, calculated as $\text{TV} + \text{ERV}$.

Functional Residual Capacity (FRC)

The volume of air that remains in the lungs after a normal expiration, calculated as $\text{ERV} + \text{RV}$.

Vital Capacity (VC)

The maximum volume of air a person can breathe in after a forced expiration (or breathe out after a forced inspiration), calculated as $\text{ERV} + \text{TV} + \text{IRV}$.

Total Lung Capacity (TLC)

The total volume of air accommodated in the lungs at the end of a forced inspiration, calculated as $\text{RV} + \text{ERV} + \text{TV} + \text{IRV}$ or $\text{VC} + \text{RV}$.