Diploma in Physiotherapy: Anatomy II Quiz

Diploma in Physiotherapy

• Offered by Cyberjaya College, Kota Kinabalu

Anatomy II: Pharynx, Larynx, Trachea

• Learning Outcomes:
  • Students will be able to describe the structure, divisions, muscles, action, and innervation of the pharynx
  • Students will be able to identify and explain the hyoid bone
  • Students will be able to describe the larynx, laryngeal cartilages, muscles, and movements
  • Students will be able to explain the trachea
  • Students will be able to describe the mechanics of phonation and speech

Pharynx

• Funnel-shaped passageway, commonly called the throat
• Connects nasal cavity and mouth superiorly to the larynx and esophagus inferiorly
• Descends from the base of the skull to the level of the sixth cervical vertebra
• Serves as a common passageway for food and air
• Divided into three regions based on location and function:
  • Nasopharynx
  • Oropharynx
  • Laryngopharynx

Nasopharynx

• Nasal part of the pharynx
• Respiratory function
• Lies superior to the soft palate
• Posterior extension of the nasal cavity
• Nose opens into the nasopharynx via large posterior apertures called choanae

Oropharynx

• Oral part of the pharynx
• Digestive function
• Continuous with the oral cavity through the oropharyngeal isthmus

Laryngopharynx

• Laryngeal part of the pharynx
• Lies posterior to the larynx
• Extends from the superior border of the epiglottis to the inferior border of the cricoid cartilage
• Narrows to become continuous with the esophagus
• Posteriorly related to the bodies of C4 to C6 vertebrae

Layers of the Pharyngeal Wall

• Five layers from internal to external:
  • Mucous membrane
  • Submucosa
  • Pharyngobasilar fascia (fibrous layer attached to the skull)
  • Muscular layer (inner longitudinal and outer circular parts)
  • Buccopharyngeal fascia (loose connective tissue layer)

Muscles of the Pharynx

• Group of muscles acting upon the pharynx:
  • Three constrictor muscles
  • Three muscles descending from the styloid process
  • Muscles associated with the cartilaginous part of the auditory tube and the soft palate
  • Inferior, Middle, Superior constrictor muscles
  • Stylopharyngeus muscle
  • Salpingopharyngeus muscle
  • Palatopharyngeus muscle
• External muscles form the external circular part of the muscular layer, overlapping each other

Muscle Action

• Muscles contract involuntarily, sequentially from the superior to inferior end of the pharynx
• This action propels food into the esophagus

Internal Muscles of the Pharynx

• Chiefly longitudinal muscular layer:
• Stylopharyngeus
• Palatopharyngeus
• Salpingopharynges
• Elevate the larynx and pharynx during swallowing and speaking

Innervation of the Pharynx

• Motor and sensory supply derived from the pharyngeal plexus of nerves on the pharynx's surface
• Plexus formed by pharyngeal branches of the vagus (CNX) and glossopharyngeal (CN IX) nerves, and by sympathetic branches for the superior cervical ganglion
• Motor fibers in the pharyngeal plexus are derived from the cranial root of accessory nerve (CN XI), carried by the vagus nerve to all muscles of the pharynx and soft palate
• Exceptions: stylopharyngeus (CN IX) and tensor veli palatini (CN V3)

Hyoid Bone

• Location: inferior to the mandible, in the anterior neck
• Associated with the skull
• Only bone in the skeleton that doesn't articulate directly to another bone
• Attaches via ligaments to the temporal bone and larynx
• Composed of: body and two pairs of horns

Hyoid Bone Functions

• Movable base for the tongue
• Attachment points for larynx and neck muscles (sternohyoid, thyrohyoid)

Larynx

• Voice box, extending from C4 to C6
• Attaches to the hyoid bone
• Opens into laryngopharynx
• Continues with the trachea
• Four basic components: cartilaginous skeleton, intrinsic and extrinsic muscles, and mucosal lining

Laryngeal Cartilages

• Cartilaginous skeleton housing vocal cords
• Composed of nine cartilages: three unpaired (thyroid, cricoid, epiglottis) and three paired (arytenoid, corniculate, cuneiform)
• Cartilages connected to head and neck through extrinsic muscles

Muscles of the Larynx

• Intrinsic muscles (pass between larynx and parts around it)
• Extrinsic muscles (confined entirely to larynx)
  • Cricothyreoideus
  • Cricoarytænoideus lateralis
  • Cricoarytænoideus posterior
  • Arytænoideus
  • Thyroarytænoideus

Actions of Laryngeal Muscles

• Open and close the glottis
• Regulate tension of vocal folds
• Cricoarytænoidei posteriores open the glottis
• Cricoarytænoidei laterales close the glottis
• Arytænoideus closes the glottis

Nerve Supply (Larynx)

• Vagus and recurrent laryngeal nerve

Functions of Pharynx

• Deglutition
• Respiration
• Phonation

Trachea

• Windpipe, 12 cm long, 2.5 cm diameter
• Descends from larynx, through neck into mediastinum
• Divides into two main bronchi
• Tracheal wall contains 16-20 C-shaped hyaline cartilage rings joined by connective tissue
• Carina (ridge) at the internal aspect of the last tracheal cartilage, where the trachea branches into two main bronchi
• Lining of trachea prevents entry of hazardous particles

Mechanics of Phonation and Speech

• Sound production relies on several mechanical properties:
  • Adequate breath support (subglottic pressure)
  • Adequate control of laryngeal musculature (glottic closure, vocal fold length, tension)
  • Favorable pliability and vibratory capacity of vocal fold tissues
• Phonemes are created with diaphragm forcing air from lungs to trachea

Test your knowledge on Anatomy II focusing on the pharynx, larynx, and trachea. This quiz covers the structure, function, and innervation of these important anatomical parts. Additionally, examine the mechanics of phonation and speech as part of your learning outcomes.