Which type of gland is depicted here?
A. Holocrine glands
B. Endocrine glands
C. Merocrine glands
D. Apocrine glands
Ans: A. Holocrine glands
(Ref Gray’s 40/e p153; Ross Histology 6/e p147)
The given histologic image is of sebaceous glands, which is a type of holocrine gland.
- Amall saccular structures lying in the dermis; together with the hair follicle and arrector pill muscle, they constitute the pilosebaceous unit.
- They are present over the whole body except the thick hairless skin of the palm, soles and flexor surfaces of digits.
- Typically, they consist of a cluster of secretory acini, which open by a short common duct into the dermal pilary canal of the hair follicle.
- They release their lipid secretory product, sebum, into the canal by a holocrine mechanism.
- At the margins of the eyelids, the large complex palpebral tarsal glands (Meibomian glands) are of this type.
- They are also present in the external auditory meatus