Module 20: ENT Anatomy Quiz

Cochlea and Vestibular Labyrinth

• Basilar membrane in the cochlea contains hair cells that convert mechanical vibration into electrochemical impulses.
• The vestibular labyrinth is composed of the utricle, saccule, and three semicircular canals, crucial for detecting angular acceleration during movement.
• Semicircular canals trigger impulses through the vestibular branch of the acoustic nerve (8th cranial nerve).

Anatomy of the Nose

• The nose is a prominent facial feature, susceptible to trauma and consists of skin supported by cartilage and bone.
• Two external nares serve as air passages to the nasal cavity, which humidifies and filters air before it reaches the lungs.
• Alar cartilages shape the nose's tip and nostrils; the columella separates the nares.
• Nasal cavity divided into right and left parts by the nasal septum, composed of nasal cartilage, the perpendicular plate of the ethmoid bone, and the vomer bone.
• Rich blood supply in the septum warms and moistens air, while mucus traps dust and small particles.
• Nasal sinuses (frontal, ethmoid, sphenoid, maxillary) communicate with the nasal cavity via the meatus.

Throat Structure

• The throat includes the oral cavity, pharynx, and larynx, facilitating both digestion and respiration.
• The oral cavity is composed of the mouth, salivary glands, and structures like cheeks, hard palate, tongue, teeth, and lips.
• Pharynx connects to multiple cavities, serving as a passageway from the nose to the larynx and esophagus.
• Larynx acts as an airway, containing the epiglottis that prevents aspiration and the vocal cords (supraglottis, glottis, subglottis).

Perioperative Nursing Considerations

• Pre-operative respiratory assessment involves evaluating breathing quality, smoking history, and nutritional status.
• Facial structures must be assessed for symmetry, color, lesions, and patient pain levels.
• Surgical considerations may affect body image and can lead to long-term issues like hearing loss or facial numbness.

Anaesthesia Considerations

• Local anaesthetic with neurolept is used for minor procedures; patients must remain immobile.
• General anaesthesia may be necessary based on patient health and surgical requirements.
• For rhinologic surgeries, nasal packing with vasoconstrictor-soaked patties is common.

Surgical Prep and Positioning

• Hair removal for surgeries is performed only if it obstructs the surgical field, preferably using clippers.
• Surgical site disinfectant commonly used is povidone-iodine unless allergic; chlorhexidine is avoided due to ototoxicity.
• Position patients according to surgical needs; supine position with should rolls is standard for head and neck surgeries.

Instrumentation and Counting

• Otorhinolaryngology surgeries require specific instruments for delicate handling.
• Key instruments for otologic surgeries include myringotomy knives and middle ear tools.
• Rhinologic surgeries utilize tools like sinus scopes and alar retractors.
• Comprehensive instrument counting is necessary before and after surgeries to ensure all tools are accounted for.

Equipment Requirements

• Operating rooms must be equipped with cautery tools, suction, and monitoring systems.
• Surgical microscopes provide illumination and magnification, while power drills assist in ear surgeries.
• CO2, KTP, Er:YAG, and Nd:YAG lasers are utilized for delicate procedures without damaging surrounding tissue.
• Continuous patient temperature monitoring with warming blankets prevents hypothermia during surgeries.

Surgical Interventions

• Otologic procedures often performed via the ear canal or behind the ear, including:
  • Myringotomy involves incising the tympanic membrane and placing a tube.
  • Mastoidectomy, with types categorized by approaches and related risks.
  • Tympanoplasty for tympanic membrane repair, utilizing grafts from various ear parts.
  • Cochlear Implantation involves inserting a device into the cochlea for sensory hearing loss.

Rhinologic Surgery Details

• Functional Endoscopic Sinus Surgery (FESS) employs an endoscope to address sinus issues, ensuring drainage by resecting tissue.
• Local infiltration aids in surgery, and the postoperative care includes nasal packing, typically with moustache dressings.