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RESPIRATORY SYSTEM NOTES
I. INTRODUCTION
A. Introduction
1. The two systems that supply oxygen (02) and eliminate carbon dioxide (C02) are the cardio-vascular system and the respiratory system. They participate equally in respiration.
2. The respiratory system provides for gas exchange, intake of 02,and elimination of CO2, where-as the cardiovascular system transports the gases in the bloodbetween the lungs and the cells.
3. Failure of either system has the same effect on the body: disruption of homeostasis and rapid death of cells from oxygen starvation and buildup of waste products.
B. The respiratory system’s parts can be classified according to either structure or function.
1. Structurally, the respiratory system consists of two parts:
a. The upper respiratorysystem – nose, pharynx and associated structures
b. The lower respiratory system – larynx, trachea, bronchi and lungs
2. Functionally the respiratory system also consists of two parts.
a. Conduction Zone – which consists of a series of interconnecting cavities and tubes
both inside and outside of the lungs. (Nose, pharynx, larynx, trachea, bronchi,bronchioles and terminal bronchioles.)
b. Respiratory Zone – consists of the tissues of the lungs where gas exchange occurs
(Respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli)
1. Nose
a. The external portion of the nose is made of cartilage and skin and is lined with mucous membrane. Openings to the exterior are the external naresb. The internal portion communicates with the paranasal sinuses and nasopharynx through the
internal nares (choanae).
c. The inside of both the external and internal nose is called the nasal cavity. It is divided into right and left sides by the nasal septum. The anterior portion of the cavity is called the vestibule
d. Rhinoplasty (“nose job”) is a surgical procedure in which the structure ofthe external nose is altered for cosmetic or functional reasons.
e. The nose is adapted for warming, moistening, and filtering air; it also receives olfactory stimuli and provides resonating chambers to modify speech sounds.
2. Pharynx
a. The pharynx (throat) is a muscular tube lined by a mucous membrane
b. The branch of medicine that deals with the diagnosis and treatment of diseases of theears, nose, and throat is called otorhinolaryngology (or otolaryngology).
c. The anatomic regions are the nasopharynx, oropharynx, and laryngopharynx
d. The nasopharynx functions in respiration. Both the oropharynx and laryngopharynx function in digestion and in respiration (serving as a passageway for both air and food).
3. Larynx
a. The larynx (voice box) is a passageway that connectsthe pharynx with the trachea.
b. It contains the thyroid cartilage (Adam’s apple); the epiglottis, which prevents food from entering the larynx; the cricoid cartilage, which connects the larynx and trachea; and the paired arytenoid, corniculate, and cuneiform cartilages
c. The larynx contains vocal folds (true vocal cords), which produce sound. Taut vocal folds produce high pitches, andrelaxed ones produce low pitches
d. Laryngitis is an inflammation of the larynx that is most often brought on by a respiratory infection or irritants such as cigarette smoke; it causes hoarseness or loss of voice by interfering with the contraction of the folds or by causing them to swell to the point where they cannot vibrate freely.
e. Cancer of the larynx is found almost exclusively inindividuals who smoke.
4. Trachea
a. The trachea (windpipe) extends from the larynx to the primary bronchi
b. It is composed of smooth muscle and C-shaped rings of cartilage and is lined with pseudo-stratified ciliated columnar epithelium.
c. Two methods of bypassing obstructions from the respiratory passageways are trache-ostomy and intubation.
5. Bronchi
a. The bronchial tree consists of...