ENT (Otorhinolaryngology) · MU Sofia

18. Clinical anatomy of the external nose.

Covers the clinical anatomy of the external nose, starting with its skeletal framework of nasal bones and upper and lower lateral cartilages, then the skin and soft tissue, the facial muscles, and the nasal valve area. It goes on to describe arterial supply, venous drainage with the danger triangle of the face, and sensory and motor innervation, ending with clinical topics such as nasal fracture, rhinoplasty, saddle nose deformity and basal cell carcinoma. A tabulated classification is not included, but the note draws out surgical relevance throughout.

Inside: 1 section · 9 labelled pictures · 14 flashcards · 5 min

Topic 18 of 52 in the MU Sofia syllabus for ENT (Otorhinolaryngology) (Medicine, Year 4). The free AceMed note covers it in 1 section, about 786 words (5 min of reading), with 14 flashcards.

In this note

  1. Clinical anatomy of the external nose.

Clinical anatomy of the external nose.

I. Structural Components of the External Nose

The external nose is a pyramidal structure on the midface composed of skin, osteocartilaginous framework, muscles, and soft tissue, supported superiorly by bones and inferiorly by cartilage.

A. The Skeletal Framework - The nose is fixed superiorly and mobile inferiorly.

  • Bony framework- upper 1/3rd: Nasal Bones (paired), Frontal Process of the Maxilla, Nasal part of the Frontal Bone.
  • The point where the nasal bones meet the frontal bone is the Nasion.
  • Provides rigidity and protection
  • 🔹 Commonly involved in nasal fractures

Lower 2/3rd-

  • Upper cartilaginous vault: Upper Lateral Cartilages (ULCs)(paired).
  • Lower cartilaginous vault: Lower Lateral Cartilages (LLCs) / Alar Cartilages (paired).
  • Form the tip and the alae of the nose. They have a medial crus (forming columella) and a lateral crus (forming the dome and ala)
  • Septal cartilage: Forms the median partition between the two nasal cavities.
  • Determines shape of nasal tip and nostrils
  • 🔹 Critical in rhinoplasty.

II.

A. Skin and Soft Tissue

  • Skin: Thicker and more mobile over the bony framework, but thinner and loosely attached over the middle cartilaginous vault. It is especially thick and rich in sebaceous glands over the tip and alae (nasal lobule).
  • Clinical Relevance: Acne or cellulitis on the nasal tip can be cosmetically significant and, due to venous drainage.
  • Injuries to tip skin heal poorly due to tenuous blood supply.
  • Sebaceous skin heals with wider scars → important in rhinoplasty
  • Vibrissae: Coarse hairs found in the vestibule (the entrance to the nasal cavity) that filter particulate matter.
  • Soft Tissue Components include Fibrofatty connective tissue, Nasal superficial musculoaponeurotic system (SMAS), Nasal ligaments (scroll region between ULC and LLC)
  • Clinical relevance: The scroll area is a key surgical landmark in rhinoplasty.

B. Muscles of the External Nose - Muscles insert into the skin and alar cartilages; derived from facial expression muscles.

  • Levator labii superioris alaeque nasi → elevates nostril, dilates nasal vestibule.
  • Nasalis (transverse + alar portions) → compresses or widens nostrils.
  • Depressor septi nasi → pulls nasal tip down during smiling.
  • Procerus → wrinkles nasal dorsum.
  • Dilator naris → widens nostrils.
  • Clinical relevance: Overactivity affects nasal valve function.

🎬 Control nostril size

🎬 Aid in respiration and expression

C. The Nasal Valve Area

The nasal valve is the narrowest point of the nasal airway and is crucial for regulating airflow.

  • Internal Nasal Valve (Main Limiting Factor): Normally 10–15°

Continue reading free

The whole note is free with an AceMed account, with its 14 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note