Respiratory System

Respiratory System• 4 important structural features

– thin permeable respiratory membrane – large surface area – good supply of blood – breathing system for bringing air to

respiratory membrane

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Nasal Cavity• Air first enters the respiratory system

• Lined with tiny hairs and mucus

• Warms, moistens, & filters air

• tube connecting the nasal cavity to the larynx

Epiglottis• flap-like piece of cartilage • moves to cover trachea when swallowing

Pharynx

Larynx• “voice box”

• contains the vocal chords

• connects the pharynx to the trachea

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• “wind pipe”

• tube of soft tissue with bands of cartilage • lined with goblet cells and ciliated cells that help

clean the lungs

Goblet Cells• mucous-producing cells

Trachea

Bronchus• there are two bronchi, one to each lung

• tube structure with cartilage

• lined with goblet cells and cilia

Bronchioles• branches off of the bronchi

• form a “respiratory tree”

• contain some goblet cells and cilia

• connect to clusters of alveoli

Alveoli• tiny sac-like structures

• very thin, only one cell thin • surrounded by capillaries

• where gas exchange occurs

Diaphragm• dome-shaped muscle

• helps control breathing

• moves up when exhaling