4. What increases the surface area of attachment?
5. What is the epidemis devoid of?
6. What is principally associated with the dermal papillae?
7. What is reticular layer consists of?
8. What is typical dense irregular connective tissue?
9. What does epidermis consists of?
10. What contains the deepest portions of the cutaneous glands?
Make the sentences of your own using the new words (10 sentences).
Find the definite and indefinite articles in the text.
Find one word, which is a little bit different in meaning from others (найдите одно слово, которое немного отличается от других по смыслу):
1) a) skin; b) knife; c) dermis;
2) a) fire; b) membrane; c) cell;
3) a) connective; b) collagen; c) table;
4) a) nose; b) book; c) mouth;
5) a) ear; b) throat; c) skirt.
ЛЕКЦИЯ № 5. Cutaneous appendages
Cutaneous appendages are all derivatives of the epidermis.
Eccrine (merocrine) sweat glands are simple, coiled, tubular glands that are widely distributed over the body. Secretory portions are tightly coiled and consist of a single layer of columnar-like pyramidal cells. They extend deep with in the dermis or hypodermis, where they are surrounded by myoepithelial cells, which aid in the discharge of secretion by contraction.
Duct portions, composed of two cuboidal cell layers, are corkscrew-shaped and open onto the epidermal surface. The luminal diameter of the duct is less than that of the secretory coil. These glands are important in thermal regulation. When hypotonic sweat is released onto the body surface, heat is lost by water evaporation.
Control of the eccrine glands is mainly by the innervation of choli-nergic fibers.
Apocrine sweat glands are also simple, coiled, tubular glands but are much less abundant in their distribution than eccrine glands. They can be found in the axillary, areolar, and anal regions.
Secretory portions of these glands are composed of a single layer of cuboidal or columnar cells. They are larger and have a much wider luminal diameter than eccrine sweat glands. Myoepithelial cells surround the secretory cells within the basement membrane and contract to facilitate secretion.
Duct portions are similar to those of eccrine sweat glands but open onto hair follicles instead of onto the epidermal surfaces.
Functions of these glands in humans is not at all clear. In other mammals, apocrine sweat glands are widely distributed over the body and serve a variety of functions related to olfaction and behavior. Specialized apocrine glands in the ear canal (ceruminous glands) produce a secretion in conjunction with adjacent sebaceous glands to form the protective earwax (cerumen). Apocrine sweat is normally odorless when secreted but becomes noticeable due to the activity of cutaneous bacteria. Control of the apocrine glands is hormonal and via the innervation of adrenergic fibers. These glands do not begin to function until puberty.
