Respiratory System: Anatomy, Physiology, and Mechanics of Breathing, Exercises of Mechanics

Download Respiratory System: Anatomy, Physiology, and Mechanics of Breathing and more Exercises Mechanics in PDF only on Docsity!

RESPIRATORY SYSTEM

 Functions and Organization of the Respiratory System  Mechanics of breathing  VENTILATION‐REPERFUSION RELATIONSHIPS  Oxygen and Carbon dioxide Transport  Control of breathing  Alveolar - Arterial equilibration-  Effects of low and high gas pressure on the body  Effects of exercise on the respiratory system.

Learning Objectives

Functions of the Respiratory System:

Overview

• Exchange O 2

• Air to blood
• Blood to cells

• Exchange CO 2

• Cells to blood
• Blood to air

• Regulate blood pH

• Vocalizations

• Protect alveoli

Overview of external and cellular respiration

Functional Anatomy

• Organs include: nose, nasal cavity, pharynx, trachea, bronchi, bronchioles, and the alveoli.
• Divided into respiratory and conducting zones.
• Gas exchange with the blood occurs in the respiratory zones. It does NOT occur in the conducting zones.
• The conducting zones transport, cleanse, warm and humidify the incoming air.

The Nose

• Only externally visible part of the respiratory

system.

• Functions include:

• Providing an airway for respiration
• Moistening and warming air
• Filtering inspired air
• Serving as a resonating center for speech
• Housing the olfactory receptors.

Pharynx

• Funnel-shaped.
• Connects the nasal

cavity and mouth

superiorly to the

larynx and esophagus

inferiorly

• 3 regions. From

superior to inferior:

• Nasopharynx
• Oropharynx
• Laryngopharynx

Oropharynx

• Lies posterior to the oral

cavity

• Extends from the soft

palate to the epiglottis

and allows passage of

food and air

• Lined by nonkeratinized

stratified squamous

epithelium

Laryngopharynx

• Lies posterior to the epiglottis and extends to the larynx where the respiratory and digestive paths diverge
• Common passage for both food and air
• Lined by stratified squamous epithelium

• The larynx is closed by the epiglottis during swallowing.
• In addition to opening and closing the glottis for speech, the vocal folds can act as a sphincter during conditions such as coughing, sneezing or straining

Trachea • Descends from the larynx to the

mediastinum.

• Ends by dividing into the 2 primary bronchi at midthorax.
• Contains 3 layers: mucosa, submucosa, and adventitia
• Tracheal mucosa contains pseudostratified ciliated epithelium w/ goblet cells.
• Smoking destroys respiratory cilia – necessitates coughing for mucus propulsion
• Submucosa contains seromucous glands – produce the mucus that lines the trachea

• Alveoli are made of simple squamous epithelium consisting of 2 cell types: Type I and Type II alveolar cells.
• Type I alveolar cells
  • Extremely thin. Occupy most of the alveolar SA.
  • External surfaces are cobwebbed by pulmonary capillaries.
  • Together the alveolar and capillary PM’s and their fused basal laminas form the respiratory membrane which has gas on 1 side and blood on the other.
  • Lung alveoli are surrounded by elastic fibers.

• Scattered among the Type I’s are Type II cells which secrete surfactant.
• Alveolar pores connect adjacent alveoli.
• Alveolar macrophages (dust cells) crawl along the internal alveolar surfaces