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Lecture 8

BIOB33H3 Lecture Notes - Lecture 8: Bronchodilator, Submucosa, Pulmonary Artery

Biological Sciences
Course Code
Connie Potroff

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Lecture 8
The Respiratory System
(based on chapter 24)
**Assigned readings: p.639 (tracheal blockage) + p.650 (respiratory changes at birth)
An Overview of the Respiratory System
The upper respiratory system consists of:
nose, nasal cavity, sinuses, and pharynx
The lower respiratory system consists of:
larynx, trachea, bronchi, bronchioles, and alveoli
Functions of the Respiratory System
Provides an area for gas exchange between the air and the blood
Protects the respiratory surfaces (for example: from dehydration)
Provides protection against invading pathogens
*Produces sound involved in verbal communication (larynx- voicebox)
*Assists in the regulation of blood volume, blood pressure, and body fluid pH
The Respiratory Epithelium
Consists of:
1)Pseudostratified, ciliated, columnar cells (except for the pharynx, smaller
bronchi, and alveoli)
2)Mucus-producing cells
*Pharynx consists of 3)stratified squamous cells
Ciliated columnar cells move mucus in an upward manner (mucus escalator)
so debris can be coughed out
Mucous cells produce mucus so inhaled debris will get stuck and not enter the
Stratified squamous cells provide protection against abrasion
Protection of the Respiratory System
*Hairs in the nose called vibrissae block some of the inhaled debris
Nasal cavity produces mucus to trap inhaled debris
Sneezing will remove this debris
Respiratory epithelium mucus will trap inhaled debris
Coughing will remove this debris
The Upper Respiratory System
The following is the pathway of air:
Air enters the external nares (nostrils)
Passes by the nasal vestibule (area surrounded by the two pairs of alar cartilage)
Enters the nasal cavity
Air flows in and around the nasal conchae
Inferior, middle, and superior conchae
As air swirls around the conchae, debris gets stuck in the mucus
As air swirls around the conchae, the air warms and gets humidified (moistened)
a bit before entering the trachea
Air enters the internal nares
Air enters the nasopharynx area
The Pharynx
The pharynx (throat or gullet) is a funnel shaped passageway that connects the nose to
the larynx of the respiratory system and the esophagus of the digestive system
© 2012 Pearson Education, Inc.
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