Pinna / Auricle

 Ans:A.)Ectoderm

• First branchial cleft is the precursor of external auditory canal.
• Around the sixth week of embryonic life, a series of six tubercles appear around the first branchial cleft
• Branchial clefts are ectodermal in origin.

Elastic Cartilage 

Pinna is composed of a thin plate of yellow elastic cartilage, covered with integument

It is connected to the surrounding parts by ligaments and muscles; and to the commencement of the external acoustic meatus by fibrous tissue.

Cartilage is a form of connective tissue, which contains a gel-like matrix embedded with cells.

There are of three types: Hyaline cartilage, elastic cartilage and fibrous cartilage.

Elastic cartilage consists of numerous yellow elastic fibres embedded in a matrix which explains its flexibility. It is seen in the auricle of the ear, external auditory meatus, auditory tube and the epiglottis.

The larynx is composed of several cartilages. The thyroid cartilage, cricoid cartilage, arytenoid cartilages, corniculate cartilages and cuneiform cartilages are all composed of hyaline cartilage.

Fibrocartilage is a white opaque structure due to dense collage fibres (type I and II).

When a fibrous tissue is subjected to pressure it is replaced by fibrocartilage.

It is seen in joints, symphysis, intervertebral discs, menisci and labra (shoulder joint and hip joint).

Pinna is a type of elastic cartilage. Elastic cartilages are seen at sites concerned with production or reception of sounds eg external acoustic meatus (lateral part), auditory tube and epiglottis.

Auriculotemporal nerve, a branch of mandibular nerve (V₃)(2 supplies the external acoustic meatus, external surface of auricle above this, skin of temporal region and TM joint.

D i.e. Great auricular

Skin over the pinna is closely adherent to the perichondrium on the lateral surface while it is loosely attached on the medial surface.

Ans. is d i.e. greater auricular nerve

There are three types of cartilage:

• Hyaline cartilage has a high proportion of amorphous matrix. Throughout childhood and adolescence, it plays an important part in the growth in length of long bones (epiphyseal plates are composed of hyaline cartilage). It has a great resistance to wear and covers the articular surfaces of nearly all synovial joints.
• Fibrocartilage has many collagen fibers embedded in a small amount of matrix and is found in the discs within joints (e.g., the temporomandibular joint, sternoclavicular joint, and knee joint) and on the articular surfaces of the clavicle and mandible. Fibrocartilage, if damaged, repairs itself slowly in a manner similar to fibrous tissue elsewhere.
• Elastic cartilage possesses large numbers of elastic fibers embedded in matrix. It is flexible and is found in the auricle of the ear, the external auditory meatus, the auditory tube, and the epiglottis. Elastic cartilage, if damaged, repairs itself with fibrous tissue.

Cauliflower ear (boxer’s ear, wrestler’s ear) is an acquired deformity of the outer ear.

In this injury, the ear can shrivel up and fold in on itself and appear pale, giving it a cauliflower-like appearance, hence the term cauliflower ear.

Wrestlers, boxers and martial artists in particular are susceptible to this type of injury. When the ear is struck and a blood clot develops under the skin, or the skin is sheared from the cartilage, the connection of the skin to the cartilage is disrupted.

Ans: D. Mastoidectomy with incision, drainage and antibiotics 

The patient is presenting with features of postauricular subperiosteal abscess. Treatment for this is antibiotics along with drainage of abscess and cortical mastoidectomy.

This patient has developed this abscess as a complication of CSOM (History of chronic ear discharge) for which he requires meastoidectomy.