1. Respiratory System

2. Respiratory Tract
Conducting passageways carrying air to and from the alveoli
Upper respiratory passages filter and humidify incoming air
Nasal Cavity
Larynx
Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Lower passageways include delicate conduction passages and alveolar exchange surfaces
Trachea
Lungs
Bronchi
Bronchioles
Alveoli
Diaphragm
Pathway
nasal cavities (or oral cavity) → pharynx → trachea → primary bronchi (right & left) → secondary bronchi → tertiary bronchi → bronchioles → alveoli

3. Nasal Cavity/Nose Functions Selected anatomical features
Provides an airway for respiration
Moistens and warms entering air
Filters and cleans inspired air
Resonating chamber for speech
Detects odors in the airstream
Selected anatomical features
Vibrissae (guard hairs) – stiff hairs that filter large particles from the air
Nasal cilia – hair-like projections that propel trapped particles towards the throat for digestion by digestive enzymes
Rich supply of capillaries warm the inspired air
Nasal conchae – folds in the mucous membrane that increase air turbulence and ensures that most air contacts the mucous membranes
Olfactory mucosa – mucous membranes that contain smell receptors
Respiratory mucosa – pseudostratified ciliated columnar epithelium containing goblet cells that secrete mucus
Mucus
Stickiness traps inhaled particles
Lysozyme kills bacteria
Lymphocytes and IgA antibodies protect against bacteria

4. Paranasal Sinuses

5. Upper Respiratory Three regions of the pharynx
Nasopharynx – air passage (pseudostratified columnar epithelium)
Oropharynx – passageway for air, food, and drink (stratified squamous epithelium)
Laryngopharynx – passageway for air, food, and drink (stratified squamous epithelium)

6. Larynx Functions 1. Keeps food and drink out of the airway
2. Sound production
3. Acts as a sphincter during abdominal straining (ex. during defecation and heavy lifting)

7. Larynx Selected anatomical features
Nine c-rings of hyaline cartilage form the framework of the larynx
Muscular walls aid in voice production and the swallowing reflex
Glottis – the superior opening of the larynx
Epiglottis – prevents food and drink from entering airway when swallowing
False vocal cords – aid in closing the glottis when swallowing
True vocal cords – produce sound when air passes between them
The shorter and thinner these membranes are, the faster air moves over them – produces high pitched sounds
The longer and thicker these membranes are, the slower air moves over them – produces low pitched sounds

8. Trachea Functions Air passageway
2. Cleans, warms, and moistens incoming air
3. Selected anatomical features
Rings of hyaline cartilage – reinforce the trachea and keep it from collapsing when you inhale
Ciliated pseudostratified epithelium – traps inhaled debris and propels mucus up to the pharynx where it is swallowed

9. Lung Anatomy

10. Visceral pleura

11. Function - Solely an air passageway
Selected anatomical features
1. Left and right primary bronchi branch off from trachea
2. Once the left and right primary bronchi enter the lungs they are subdivided into smaller tubes:
Secondary bronchi (one for each lobe) → tertiary bronchi → bronchioles → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs
3. Alveolar sacs are clusters of alveoli
--Alveoli are the site of gas exchange
--Surfactant prevents from collapsing due to tension
--Other tissue types present in the alveoli
a. Smooth muscle rings aid in resistance to air flow
b. Elastic connective tissue fibers aid in expelling air from the lungs

15. Pulmonary arteriogram
Lung bronchiogram