Makindo Medical Notes

Related Subjects: |Anatomy of the Oesophagus |Anatomy of the Diaphragm |Anatomy of Large Bowel |Anatomy of Small Bowel |Anatomy of the Biliary system |Anatomy of the Eye |Anatomy of the Larynx |Anatomy of the Ear |Anatomy of the Pharynx |Anatomy of the Nose |Anatomy of Male Genitalia |Anatomy of Breast |Anatomy of the Stomach |Anatomy of the Rectum |Anatomy of the Spleen

👂👃👄 The Ear, Nose, and Throat (ENT) region is an intricate anatomical system. Each structure contributes to vital functions: hearing, respiration, olfaction, filtration, resonance, and phonation. This section focuses on the detailed anatomy of the nose, with clinical correlations.

👃 Detailed Nose Anatomy

• 🌐 External Nose
  • Nasal Bridge: Bony framework (nasal bones + frontal processes of maxilla). 📌 Clinical: Fractures cause cosmetic deformity & airway obstruction.
  • Nostrils (Nares): Openings for air entry, lined with vibrissae (hairs) filtering dust. 📌 Clinical: Site of foreign body impaction in children.
• 🏠 Nasal Cavity
  • Nasal Septum: • Cartilaginous (anterior) + bony (vomer & perpendicular plate of ethmoid). • Covered by mucous membrane. 📌 Clinical: Septal deviation may cause chronic obstruction or epistaxis.
  • Nasal Conchae (Turbinates): • Superior, Middle, Inferior → curved bony plates. • Function: ↑ surface area for warming, humidifying, and filtering air. 📌 Clinical: Hypertrophy linked to allergic rhinitis.
  • Nasal Meatuses: • Channels beneath each concha. • Superior → drains posterior ethmoids. • Middle → drains frontal, maxillary, anterior ethmoids (common sinusitis site). • Inferior → drains nasolacrimal duct. 📌 Exam tip: “Maxillary sinus drains high into middle meatus → poor drainage when infected.”
• 🌀 Paranasal Sinuses (air-filled cavities in skull bones, lined by mucosa)
  • 🟩 Maxillary sinus – largest, drains to middle meatus.
  • 🟦 Frontal sinus – above orbits, frontal bone.
  • 🟨 Ethmoid sinuses – multiple small air cells.
  • 🟥 Sphenoid sinus – deep, close to optic nerve & pituitary. 📌 Clinical: Sinusitis → pain localises (maxillary = cheeks, frontal = forehead, ethmoid = medial eye, sphenoid = deep retro-orbital).

🩸 Blood Supply & Epistaxis

• Rich anastomosis in Kiesselbach’s plexus (Little’s area, anterior septum) → common site of nosebleeds.
• Arterial sources: branches of facial, maxillary, ophthalmic arteries.
• Posterior bleeds (sphenopalatine artery) → harder to control, may require packing or cautery.

🌟 Key Points for Students

• Nasal conchae = ↑ surface area for air conditioning 🌬️.
• Middle meatus = drainage point for most sinuses (exam favourite).
• Little’s area = most common site of epistaxis 🩸.
• Close relation of sphenoid sinus to pituitary → surgical access for trans-sphenoidal surgery 🧠.