Anatomy and Physiology Practical 3 Functions

PRACTICAL 3 FUNCTIONS
RESPIRATORY:
UPPER RESPIRATORY
NASAL CAVITY:
● External nares (nostrils):
○ Allow air to enter the nasal cavity
● Olfactory nerves and olfactory epithelium:
○ Detect odors
● Nasal septum:
○ Divides nasal cavity into left and right sides
● Inferior, middle, and superior nasal conchae:
○ Increase surface area for filtering, warming, and humidifying air
● Inferior, middle, and superior nasal meatuses:
○ Increase surface area for filtering, warming, and humidifying air
● Internal nares:
○ Passage to the pharynx
PARANASAL SINUSES:
● Frontal, sphenoid, ethmoid, and maxillary sinuses:
○ Lighten the skull, enhance voice resonance, and produce mucus
● Mastoid sinus:
○ Has mucus lining that communicates with the middle ear
PHARYNX (THROAT):
● Nasopharynx:
○ Connects nasal cavity to oropharynx
○ Houses pharyngeal tonsil and opening of the eustachian tube
● Oropharynx:
○ Passage for food and air
○ Contains palatine and lingual tonsils
● Laryngopharynx:
○ Pathway to the larynx and esophagus
ORAL CAVITY:
● Hard palate:
○ Forms roof of mouth and separates the oral and nasal cavities
● Soft palate:
○ Closes off nasal passages during swallowing
○ Contains the uvula
HYOID:
● Hyoid bone:
○ Supports tongue
○ Provides attachment for muscles associated with swallowing and speech
LARYNX:

, ● Thyroid, cricoid, arytenoid, and corniculate cartilages:
○ Provide structure and support to the larynx
○ Help with voice production
● Vestibular folds:
○ False vocal cords
○ Protec the true vocal cords
● Vocal folds:
○ True vocal cords
○ Produce sound
● Epiglottis:
○ Covers the trachea during swallowing to prevent food from entering the airway
● Glottis:
○ Space between the vocal folds
LOWER RESPIRATORY:
TRACHEA:
● Tracheal rings:
○ Maintain the trachea’s open structure
● Carina:
○ The point where the trachea splits into primary bronchi
● Psuedostratified columnar epithelium:
○ Lines the trachea
○ Traps and moves debris
● Goblet cells:
○ Produce mucus
● Mucous glands:
○ Secrete mucus to trap particles
CONDUCTING ZONE:
● Primary (main) bronchi:
○ Direct air into each lung
● Secondary (lobar) bronchi:
○ Supply each lung lobe
● Tertiary (segmental) bronchi:
○ Further distribute air within each lung lobe
● Terminal bronchioles:
○ Last part of the conducting zone, lead to respiratory zone
RESPIRATORY ZONE:
● Respiratory bronchioles:
○ Start of gas exchange
● Alveolar ducts:
○ Channels leading to alveolar sacs
● Alveolar sacs:

, ○ Clusters of alveoli
● Alveoli:
○ Site of gas exchange
● Type I alveolar cells:
○ Provide a thin surface for gas exchange
○ Mainly simple squamous epithelium
○ Patrolled by alveolar macrophages
● Type II alveolar cells:
○ Secrete surfactant that coats the alveolar surface and reduces surface tension
● Alveolar macrophages:
○ “Dust cells”
○ Phagocytize debris
LOBES OF THE LUNG:
● Left lung:
○ Superior lobe: includes the cardiac notch
○ Inferior lobe
● Right lung:
○ Superior lobe
○ Middle lobe
○ Inferior lobe
● Horizontal fissure:
○ Only in the right lung
○ Separates the superior and middle lobes
● Oblique fissure:
○ Separates the superior and inferior lobe in the left lung
○ Separates the middle and inferior lobe in the right lung
● Hilum:
○ Entrance and exit point for the bronchi, blood vessels, and nerves
PLEURA:
● Parietal pleura:
○ Lines the thoracic cavity
● Visceral pleura:
○ Covers the lungs
● Pleural cavity:
○ Contains serous fluid that reduces friction
● Pulmonary circuit:
○ Circulates blood between the heart and the lungs for oxygenation
THORACIC CAGE:
● Sternum:
○ Protects vital organs in the chest
○ Provides attachment for ribs and clavicles