Anatomy and Physiology of the Respiratory System

Smell and Speech Production

  • Role of Smell

    • Helps create speech tone

    • Located in the very superior midsection of the nasal area

Pharynx Overview

  • Structure

    • Shared by the digestive and respiratory tracts

    • Functions:

    • Passage of food

    • Passage of air

    • Resonating chamber for speech

  • Sections of the Pharynx

    • Nasopharynx:

    • Contains internal nares and Eustachian tubes

    • May require surgery for breathing problems or snoring

    • Oropharynx:

    • Connects to the mouth

    • Laryngopharynx:

    • Connects to esophagus and larynx

Larynx Overview

  • Common Names

    • Also known as the voice box

  • Anatomy

    • Made up of supporting cartilage:

    • Thyroid Cartilage:

      • Largest cartilage; forms Adam's apple, more prominent in men

      • Hyaline cartilage and U-shaped

    • Epiglottis:

      • Elastic flap preventing food/liquids from entering the trachea

    • Cricoid Cartilage:

      • Connects first tracheal ring to the larynx

    • Arytenoid Cartilage:

      • Connects vocal cords to laryngeal muscles controlling voice

    • Corniculate and Cuneiform Cartilage:

      • Connect epiglottis and arytenoid cartilage

Voice Production

  • Vocal Cords

    • Two pairs of folds (false vocal cords and true vocal cords)

    • Highly elastic; critical for sound production

    • Glottis:

    • Opening over true vocal cords

    • Sound Production Mechanism

    • Sound produced by air vibrating over the vocal cords

    • Short slender vocal cords = high-pitched sound

    • Longer thicker vocal cords = lower-toned sound

    • Male vocal cords thicken post-puberty, resulting in lower tones

Larynx Structure Summary

  • Key Components

    • Hyoid Bone:

    • Located at the front, associated with strangulation cases

    • Cartilage Components:

    • From corniculate to cricoid cartilage

    • True and false vocal cords: contribute to voice production

Trachea Overview

  • Function

    • Tubular passage for air (windpipe)

    • Anterior portion of the esophagus

  • Anatomical Features

    • Extends from cricoid cartilage to fifth thoracic vertebrae

    • Composed of C-shaped cartilage rings:

    • Typically arranged as vacuum tube structures

    • Histology

    • Pseudostratified epithelium with cili and goblet cells

    • Contains smooth muscle and connective tissue

  • Cough Reflex

    • Stimulated by foreign objects

    • Tracheotomy:

    • Surgical intervention in case of obstruction

    • Performs incision between second and third tracheal cartilages

    • If unable to remove object via Heimlich maneuver

Lung Anatomy

  • General Structure

    • Right lung larger than left lung

    • Each lung divided into lobes: bilobes for humans (two lobes each)

  • Lung Components

    • Contains surfactant produced by alveolar membrane

    • Reduces surface tension of alveoli, supports expansion

  • Alveoli Function

    • Site of O2 and CO2 gas exchange

    • Lungs don’t completely collapse post-birth, detectable via floating lung tissue in water

Bronchi and Alveoli

  • Branching Structure

    • Trachea branches into right and left primary bronchi

    • Further divides into secondary (or lobar) bronchi

    • Additional division into tertiary bronchi

    • Final branching into bronchioles

    • Approximately 6,500 bronchioles per branch, over 30,000 in each lung

Visual References and Figures

  • Figures to Note

    • Figure 11.7: Illustrates the lungs

    • Figure 11.10: Details bronchial branching

    • Emphasizes health comparisons between healthy and unhealthy lung structures.