Ceruminous glands present in the ear are (AIPG 2010)
|A||Modified eccrine glands.|
|B||Modified apocrine glands|
|D||Modified holocrine glands|
Modified apocrine glands
The external ear canal is lined with skin (stratified squamous keratinised epithelium)
The outer one third is cartilaginous; the inner two thirds, bony.
The skin covering the cartilaginous part of the canal is similar to that elsewhere in the body.
The bony inner part of the canal is lined by highly specialised stratified squamous epithelium which is devoid of hair cells and does not desquamate
It contains sebaceous and ceruminous glands(modified apocrine sweat glands) which together, make wax
Sweat glands are simple, coiled tubular glands originating in the dermis of the skin.
There are two key types of gland:
a. Eccrine sweat glands
b. Apocrine sweat glands
Apocrine sweat glands arise deep in the dermis and emerging into hair follicles superficial to the duct of sebaceous glands. Apocrine glands are found in limited areas, predominantly in hairy areas:
d. Nipples and areola
e. Ceruminous glands
Under the action of the sympathetic nervous system and hormones, apocrine sweat glands produce regionally-specific organic secretions (viscous) which are acted upon by skin bacteria. The result is distinctive body odour that may have a role in courtship and social behaviour.
Eccrine sweat glands are buried deep in the dermis or in the upper portion of the hypodermis. Abundant in distribution particularly:
o Palms and soles
o Hairless areas
Eccrine glands produce sweat (watery secretion) as a means of thermoregulation and as an emotional response.
The control mechanism for sweat secretion is both neural - cholinergic fibres of the thoracolumbar sympathetic nervous system descending from the anterior hypothalamus - and hormonal - adrenaline
As usual to any exocrine gland the ducts of sweat glands are lined by stratified cuboidal epithelium