1. Transports (air to lungs)

2. Exchanges (CO2 and O2 between air and blood)

3. Produces (sound, speech, laughing, crying)

4. Sense of smell

5. Controls pH level (of body fluids by releasing H+ ions)

6. Regulates (blood pressure)

7. Creates pressure gradients which help with the flow of lymph and venous blood

8. Deep breaths help with expelling abdominal contents (childbirth, urination, etc.)

1. The nose

2. Nasal cavity

3. Pharynx

Their functions include air intake, moistening, filtering and sensing.

1. Larynx

2. Bronchi

3. Trachea

4. Lungs

Functions include sound production, transporting air, and exchanging gas.

Sphenoid, ethmoid, frontal and maxillary.

They are lined with a mucous membrane and are connected by the cavity.

They lighten the anterior portion of the skull, produce mucus, and add response to the voice (and sound production).

Paranasal sinuses empty into the nasal cavities.

Respiratory epithelium, psuedostratified ciliated columnar epithelium, has many goblet cells that secrete mucus. The cilia entraps and removes dust and other particles.

It also moistens incoming air and dissolves airborne chemicals for olfactory sensation. Capillaries under the epithelium warm incoming air.

The pharynx is about 5 inches (13 cm), and extends from the choanae to the larynx.

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

(all shared by digestive and respiratory systems)

The space between the soft palate and root of the tongue. It extends inferiorly, sometimes as far as the hyoid bone, and its anterior border is formed by the tongue base and openings of the oral cavity into the pharynx.

It contains the palatine and lingual tonsils, which have antibody response to the flu, polio, diphteria, and others.

It begins where the other two regions meet, at the level of the hyoid bone. It passes downward, posteriorly to the larynx. It endswhere the esophagus begins near the cricoid cartilage.

Nasopharynx=psuedostratified columnar

Other two=stratified squamous

Nasopharynx=pharyngeal tonsils

Oropharynx=palatine and lingual tonsils

1. Thyroid cartilage-the largest, covers anterior&lateral larynx. "Adams apple" (stimulates growth)

2. Cricoid cartilage-forms a complete ring, connects larynx to trachea. Located inferior to the thyroid cartilage.

3. The epiglottis (glottis=opening to trachea) is the superior opening of the larynx, surrounds larynx

4. 2 arytenoid cartilages-posterior to thyroid cartilage, connect with two corniculate cartilages for speech function (they are attached to the vocal cords)

1. Extrinsic muscles pull larynx upward toward the epiglottis

2. The tongue pushes the epiglottis downward to meet it

3. The epiglottis closes the airway

4. The epiglottis directs the food and drink into the esophagus behind it

1. Tongue forces bolus into the oropharynx

2. Larynx is elevated

3. The epiglottis covers the glottis

4. Pharyngeal muscles push the bolus into the esophagus

5. The larynx returns to its normal position

The trachea divides into left and right bronchii.

Before entering the lung, the right main (primary) bronchus gives off a superior lobe, which enters the hilum of the lung together (the lobar and primary bronchii). The primary bronchii then divide into secondary bronchi, giving each lungs its own secondary bronchus.

1. The trachea divides into primary R&L bronchii

2. Primary bronchi divide into secondary bronchi

3. Secondary bronchi divides into tertiary bronchi

4. Tertiary bronchi divides many times, giving rise to the bronchioles

5. Bronchioles divide into 50-80 terminal bronchioles (65,000 per lung!), then respiratory bronchioles

6. The respiratory bronchioles divide into 2-10 alveolar ducts, which end in alveoli.

Alveoli are microscopic little sacs that provide 70m2 of surface area for gas exchange with blood.

The exchange occurs through diffusion (high to low concentration), the greater oxygen in alveoli instead of capillary beds moves to the bed.

There are 150 million in the lungs.

1. Wall of capillary

2. The wall of the alveolus

1. Squamous Alveolar Cell (Type I)--lines alveolis, allows diffusion of gases. Covers 95% of the alveolar surface area.

2. Great Alveolar Cell (Type 2)--repair alveolar epithelium when squamous alveolar cells are damaged, secrete pulmonary surfactant (coats alveoli and smallest bronchioles), which prevents collapse during exhalation. Think of surfactant as soap that doesn't allow sinking.

3. Macrophages (dust cells)--most abundant, remove dust particles and carbon from the mucus in the higher parts of the respiratory tract. This keeps alveoli clean. They also eat loose cells and bacteria from infected/bleeding lungs.

Intrapleural-pressure in the pleural cvavity

Intrapulmonary-pressure in the lung

Intrapleural pressure allows the lungs to "stick" to the thoracic cage and move along with it.

Less pressure would inflate the chest cavity!

1. Diaphgram--separates thoracic cavity from abdominal cavity, prime mover

2. The internal&external intercostal muscles-synergists to the diaphgragm, stiffen thoracic cage during respiration to prevent inward caving when the diaphgragm descends.

Inspiration=diaphgragm contracts, ribs elevate. Thoracic cavity is enlarged because air is flowing IN.

Expiration=diaphragm is released, ribs depress. Thoracic cavity is reduced because air is flowing OUT.

The dorsal respiratory group is located in the medulla oblangata and is responsible for inspiration.

Axons move via the phrenic nerve to the diaphragm, and via intercostal nerves to the external intercostal muscles.

The ventral respiratory group is active during both inspiration and expiration. It is located in the medulla oblangata, just anterior to the DRG.

It is important in heavy breathing because it stimulates abdominal muscles and other accessory muscles which produce deep breaths.

The stronger the output, the breath comes shorter and the respiratory rate faster.

Weak input produces slow, long breaths.

When mucosa of the lower respiratory passages become severely inflammed, mucus production increases. Pooled mucus impairs ventilation and gas exchange. Pneumonia is common because the risk of lung infection increases. Cyanosis and hypoxia (low oxygen) can occur early.

Lung elasticity, volume of air inhaled, blood oxygen levels, and stimulating effects of carbon dioxide all decrease with age.

This puts them in danger of respiratory tract infections.

1. Pharynx

2. Oral Cavity

3. Tongue

4. Lips

Air forced between the tight adducted vocal cords makes them vibrate, producing high-pitch.

When abducted, they are more relaxed and therefore make low-pitched sound.

Chemoreceptors-peripheral and central

Stretch&irritant receptors

They are found in the aortic arch and carotid bodies.

They respond to changes in pH, PCO2, and PO2.

Stretch receptors are found in smooth muscle of the bronchi, bronchioles and visceral pleura.

They inhibit overinflation of the lung via the vagus nerve.

They are found in the epithelium of the airway and respond to smoke, dust, pollen, cold air, etc. Communicates with DRG.

i.e. coughing!=bronchoconstrict=hold breath=etc.