CHAP 9 Gas Exchange Structure and Function

Vocabulary flashcards covering the key structures, tissues, and functions of the human respiratory system based on the lecture notes.

Trachea

The primary windpipe conducting air into the chest, structurally characterized by C-shaped hyaline cartilage rings, ciliated epithelium, goblet cells, smooth muscle, elastic fibres, and submucosal mucous glands.

C-shaped Cartilage Ring

The distinctive structural feature of the trachea that keeps the airway open for low air resistance and prevents it from collapsing during pressure changes during breathing.

Bronchus

An airway branching off the trachea into a lung, structurally distinguished by the presence of hyaline cartilage plates, ciliated epithelium, smooth muscle, elastic fibres, and submucosal glands.

Cartilage Plates

Irregular blocks of hyaline cartilage that form the distinctive structural feature of the bronchus.

Bronchiole

A small airway branching from a bronchus that lacks cartilage, contains elastic fibres and ciliated cells, and may display a folded epithelium when smooth muscle contracts.

Terminal Bronchioles

Bronchioles positioned closer to the bronchus that contain smooth muscle in their walls.

Respiratory Bronchioles

Bronchioles positioned further from the bronchus that lack smooth muscle and have fewer ciliated cells, branching into alveolar ducts.

Alveolus

A microscopic air sac lined with simple squamous epithelium that serves as the site of gaseous exchange in the lungs.

Goblet Cells

Specialized epithelial cells that produce mucus made of the glycoprotein mucin to trap pathogens and dust.

Mucous Gland

A gland located in the submucosal layer of the trachea and bronchi that produces mucus made of mucin to trap pathogens and dust.

Mucin

The glycoprotein component of mucus produced by goblet cells and submucosal mucous glands.

Cilia

Hair-like projections on ciliated epithelial cells that move mucus away from the lungs toward the back of the throat to be swallowed.

Cartilage

A supportive tissue in airway walls that keeps airways open to maintain low air resistance and prevents airways from collapsing during breathing due to air pressure changes.

Elastic Fibres

Fibres in airway and alveolar walls that stretch during inspiration to increase surface area and recoil during expiration to expel air and prevent bursting.

Smooth Muscle

Muscle tissue in airway walls that contracts to constrict airways and relaxes to widen airways (such as during exercise).

Squamous Epithelium

A single layer of thin, flattened cells lining the alveoli that provides a short diffusion distance for gas exchange.

Oxygen Membrane Passage

The diffusion pathway of oxygen from the alveolar air space into a red blood cell, passing through 5 cell surface membranes.

Carbon Dioxide Membrane Passage

The diffusion pathway of carbon dioxide from blood plasma or red blood cells into the alveolar air space, passing through 4 or 5 cell surface membranes.

Acute Respiratory Distress Syndrome (ARDS)

A severe lung condition featuring acute pulmonary damage and impaired gas exchange, associated with conditions such as COVID-19.