Respiratory SystemWhat is its primary function?

Gas exchange:

Exchanging carbon dioxide (CO2)for oxygen (O2).

Primary Function:

Secondary (additional, important) functions:

Olfaction

Sense of smell

Sound production

Vocal cord vibration coupled with resonance

The primary components of the Respiratory system include:

• Nose

• Pharynx

• Larynx

• Trachea

• Lungs– Bronchial Tree– Alveoli

The Nose

Nose

Special organ for the sense of smell, but it is also the entrance to the respiratory tract. It warms, moistens, and filters the incoming air, and it serves as a resonating chamber for producing sound.

The external nose

There are actually two parts to the nose:

This consists of a triangular framework of bone and hyaline cartilage covered with skin and lined internally with mucous membranes.

The internal nose

This consists of extensive nasal cavities, most of which lie above the mouth. The cavities are separated by the nasal septum and they open to the exterior via the nostrils.

The Pharynx

Pharynx

Pharynx

Common tube 5 inches long which functions as an important junction point for several passages leading into and out of the body.

Pharynx

Pharynx

Substances entering the body, thus passing through the pharynx, can exit the pharynx via the larynx & trachea or the esophagus, or can be ejected from the pharynx back out the nasal cavity (internal nose) or oral cavity (mouth), due to the “gag” reflex. There are three parts to the pharynx: Pharynx

Pharynx(above the “throat”)

• Nasopharynx

• Behind the nasal cavity

• Above the soft palate

• Respiratory tract only

• Eustachian or Auditory tubes open here

N

O

• Oropharynx• Behind the oral cavity• Between the palate and

epiglottis• Ends at the respiratory &

digestive tract junction

Pharynx(the “throat”)

• Laryngopharynx

• Behind the larynx

• Splits to the esophagus & larynx

L

Pharynx(below the “throat”)

The pharynx also contains the tonsils:

Tonsils act as first line defenders, screening out microorganisms from the air, food, and liquids that enter the body through the nose and mouth, and attacking them with phagocytic cells.

Humans actually have three sets of tonsils – one set per subdivision of the pharynx.

Nasopharynx

1.Pharyngeal tonsils – found in the posterior wall of the nasopharynx. When inflamed they are called adenoids and can obstruct the opening to the nasal cavity.

#1

#2

Oropharynx

2. Palatine tonsils – often called “the tonsils” they are found in the walls of the oropharynx (throat).

#3

Laryngopharynx

3. Lingual tonsils – lie at the back of the tongue just below the palatine tonsils and above the epiglottis.