HRCT Temporal Bone

Contents:

• External ear

• Middle ear

• Relations of the middle ear

• Middle ear contents

• Facial Nerve anatomy

• Inner ear

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External ear

The external ear consists of:

1. Pinna

   
   

2. External Auditory canal

   1. Lateral 1/3rd - Cartilaginous part

   2. Medial 2/3rd - Bony part

The tympanic membrane attaches to Scutum above and Annulus at rest of the circumference.

Middle ear

Middle ear cavity is divided into 3 parts: the Epitympanum, Mesotympanum and the Hypotympanum

Prussak's space:

• Space between head of Malleus and Scutum.

• Common origin site for: pars flaccida acquired cholesteatoma typically originates here.

1. Roof:

1. Formed by a thin plate of the petrous part of the temporal bone - called Tegmen tympani.

2. It extends posteriorly to form the tegmen mastoideum, which covers the mastoid antrum and air cells.

2. Floor:

1. Formed by Jugular plate.

2. Separates the hypotympanum from the underlying jugular bulb.

Jugular plate

3. Medial wall

Contains three important structures:

1. Promontory

2. Round window

3. Oval window

How to find round and oval window: https://youtu.be/WFL6QNQINXU?si=z2adQaF6XAo6iEi7