Respiratory System I

A series of vocabulary flashcards summarizing key terms and concepts related to the respiratory system.

What do the Upper and Lower RT/Respiratory system include?

Upper RT: Nose, Nasal cavity, Sinuses, Pharynx

Lower RT: Larynx, Trachea, Bronchus, Bronchioles, Lungs, Alveoli.

Vital Lung Capacity

The maximum amount of air a person can exhale after maximum inhalation; generally larger in men than women.

Female < 4 L

Male > 4 L ~ difference about 1.5 L

What is lung size related to and which sex has larger vital lung capacities.

Lung size is related to body size and O2 demand for metabolism.

Men typically have larger vital lung capacities than women

Cardiac Notch

A concave space on the left lung which accommodates the heart.

How are the lobes structures in the lungs?

The right lung has 3 lobes but the left lung has 2 lobes: ~ different shapes due to the cardiac notch on the left.

Anatomy of Trachea and Bronchi

Hyoid bone

• Sits above the larynx

Larynx

• Connects pharynx to trachea

Trachea

• Rigid air-conducting tube

• Extends from larynx to carina

Tracheal cartilages

• C-shaped rings of hyaline cartilage

• Prevent tracheal collapse during inspiration

Why C-shaped? Open posteriorly to allow the oesophagus to expand during swallowing

Carina

• Internal ridge where trachea divides

• Very sensitive → triggers cough reflex

Primary bronchi

• Right and left main bronchi

• Conduct air into each lung

Difference:

• Right bronchus = wider, shorter, more vertical

• Left bronchus = narrower, longer (heart space)

Trachea structure

Lumen of trachea

• Central open space

• Where air flows

Respiratory epithelium

This is VERY important. Full name (learn this):

Pseudostratified ciliated columnar epithelium with goblet cells

Break it down:

• Ciliated → move mucus

• Goblet cells → secrete mucus

• Columnar cells → tall cells for surface interaction

Function:

Traps particles and moves them OUT of the lungs

Trachealis muscle

• Smooth muscle at the open end of cartilage rings

• Contracts to:

  • Reduce tracheal diameter

  • Increase airflow velocity (e.g. coughing)

“The trachealis muscle allows flexibility and regulates airflow.”

Tracheal cartilage

• Hyaline cartilage

• Prevents airway collapse

If you see cartilage → think airway support

Mucociliary Escalator

A mechanism in the respiratory system that moves debris from small bronchioles out of the lungs, to the top of the trachea to be swallowed.

Bronchial Tree

The structure formed by the branching airways from the trachea to the alveoli.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Oxygen Absorption

The process in which oxygen is taken up by the blood from the alveoli.

Carbon Dioxide Elimination

The process of removing carbon dioxide from the blood, occurring in the alveoli.

Alveolar Epithelium

The thin layer of cells lining the alveoli, maximizing gas exchange.

Surfactant

A substance secreted by Type II alveolar epithelial cells that reduces surface tension in the alveoli.

Type I Cells

Alveolar epithelial cells responsible for gas exchange.

Type II Cells

Cells that secrete surfactant in the alveoli.

Inspiration

The active process of inhaling; involves diaphragm and intercostal muscle contraction.

Expiration

The typically passive process of exhaling; involves relaxation of respiratory muscles.

Negative Pressure

The pressure created in the thoracic cavity that helps draw air into the lungs during inhalation.

Positive Pressure

The pressure that pushes air out of the lungs during exhalation.

Chemoreceptors

Sensors in the body that detect changes in blood chemistry, influencing breathing rate.

Medulla Oblongata

The part of the brain that regulates autonomic functions, including breathing.

Pons

A part of the brain that regulates voluntary control and smooth transitions in breathing.

Respiratory Rate

The number of breaths taken per minute; influenced by CO2 and O2 levels.

Partial Pressure Gradient

The difference in pressure of gases in the alveoli and blood, driving gas exchange.

Cerebrospinal Fluid

Fluid surrounding the brain and spinal cord, involved in monitoring blood pH and CO2 levels.

Proprioceptors

Sensory receptors in muscles and tendons that contribute to regulating breathing during movement.

Respiratory Distress Syndrome

A condition resulting from insufficient surfactant production, particularly in premature infants.

Gas Exchange

The process by which oxygen is absorbed and carbon dioxide is removed in the alveoli.

Lung Surface Area

The area available for gas exchange, maximized by the presence of numerous alveoli.

Autonomic Nervous System

Part of the nervous system that controls involuntary bodily functions, including breathing.

Respiratory Volumes

Measurements of the volume of air inhaled and exhaled during breathing.