Anatomy of the Respiratory System Exercise 36 Anatomy of the Respiratory System

Objectives Respiratory system structures Respiratory system, pulmonary ventilation, external respiration, internal respiration Bronchi vs. bronchioles—structure and function

Respiratory system structures Nasal cavity External nares (nostrils) Conchae (lobelike structures—increase air turbulence) Superior, middle, inferior Fig. 23-3

Nasal cavity Meatuses: passageways between conchae Superior, middle, inferior Fig. 23-3

Nasal cavity Internal nares Fig. 23-3

Palate Separates nasal and oral cavities Hard palate Soft palate Uvula anterior Soft palate posterior Uvula Fig. 23-3

TONSILS Pharyngeal Palatine Lingual Paired masses of lymphoid tissue (protect respiratory passages from pathogens) Palatine Laterally located near soft palate Lingual Covers base of tongue Fig. 23-3

Paranasal Sinuses Resonance chambers in speech, mucosae warm/moisten incoming air Sphenoidal Frontal

PHARYNX “throat”—connects nasal/oral cavities to larynx and esophagus below Nasopharynx Posterior to nasal cavity, above soft palate Pharyngeal tonsils on posterior wall Eustachian tubes drain into it laterally Fig. 23-3

PHARYNX Oropharynx Laryngopharynx Posterior to oral cavity Soft palate to epiglottis Palatine tonsils, lingual tonsil Laryngopharynx Epiglottis to larynx Fig. 23-3

LARYNX (“voicebox”) Epiglottis—flap-like, flexible elastic cartilage; lid over the larynx when swallow Hyoid bone Fig. 23-3

LARYNX (“voicebox”) Fig. 23-4

LARYNX (“voicebox”) False vocal cords (vestibular folds)—superior True vocal cords (vocal folds)—inferior, vibrate expelled air (speech) Fig. 23-4

LARYNX (“voicebox”) Glottis—slit-like passage between the folds Fig. 23-5

LARYNX (“voicebox”) Arytenoid cartilages Corniculate cartilages Ladle-shaped; attach vocal cords posteriolaterally Corniculate cartilages Horn-shaped; articulate w/arytenoid cartilages Fig. 23-4

LARYNX (“voicebox”) Thyroid cartilage—large, shield-shaped. Anterior = “adam’s apple” Cricoid cartilage—inferior to thyroid cartilage; ring-shaped Fig. 23-4

TRACHEA (“windpipe”) Fig. 23-6 (pseudostratified columnar epithelium, secretes mucous via goblet cells…cilia propel foreign objects in the mucous toward the throat)

TRACHEA (“windpipe”) Tracheal cartilages/bands (c-shaped cartilage rings--reinforcement) Down to sternal angle (T4-T5), then splits: Primary bronchi (right, left) into each lung, then Secondary bronchi Tertiary bronchi Bronchioles “Respiratory Tree” Fig. 23-6

Primary bronchi (right, left) into each lung, then Secondary bronchi Tertiary bronchi Bronchioles Fig. 23-10

BRONCHIOLES then divide into: Terminal bronchioles which divide into Respiratory bronchioles (terminal branches) which divide into several Alveolar ducts, which terminate into Alveolar sacs—look like grape clusters Alveoli—balloon-like expansions of sacs, simple squamous epithelium, combined with capillaries surrounding them, make the RESPIRATORY MEMBRANE---GAS EXCHANGE OCCURS HERE

BRONCHIOLES then divide into: Fig. 23-10 Terminal bronchioles Respiratory bronchioles (terminal branches) Alveolar ducts Alveolar sacs Alveoli

ALVEOLI: Alveolar ducts Alveolar sacs (common to many alveoli) Alveoli (~150 million per lung) Fig. 23-10

LUNGS Pulmonary artery (blood away from heart to lung) Pulmonary vein (from lung to heart) Lungs Right has 3 lobes (superior, middle, inferior) Left has 2 lobes (superior, inferior)

RIGHT: 3 lobes LEFT: 2 lobes Fig. 23-7

PLEURAE (serous membrane, double-layered) Parietal layer = outer layer Attached to thoracic walls and diaphragm (Diaphragm = muscle) Visceral layer = inner layer Covers lung tissue

Additional terms: Respiratory System Pulmonary ventilation Using respiration, it supplies the body with oxygen, gets rid of carbon dioxide Pulmonary ventilation Movement of air into/out of lungs (breathing) so gas exchange can occur at alveoli

Additional terms: External respiration Internal respiration Gas exchange between blood and air-filled chambers of lungs Oxygen loading, CO2 unloading Internal respiration Gas exchange between systemic blood and tissue cells Oxygen unloading, CO2 loading

Microscope Work Lung tissue Trachea