Skin Appendages Exocrine glands Nails Sebaceous glands Sweat glands Merocrine glands Apocrine glands Heat regulating Stress stimulated which include are either which are Hair which are Produce oil Empty into hair follicle Open to skin surface
Release secretions to skin surface via ducts
Two groups: sebaceous and sweat glands
Sebaceous glands: oil glands
Not on palms or soles
Usually empty into a hair follicle
Contains chemicals to kill bacteria
Keeps skin soft and prevents brittle hair
Sebum: mix of oily substances and fragmented cells.
Increased quantities during adolescence
When sebaceous glands cause problems:
Whitehead: sebaceous gland is blocked
Blackhead: accumulated material dries and darkens
Acne: active infection of sebaceous gland
Seborrhea: occurs in infants; overactive sebaceous glands
Sweat glands: Merocrine
Acidity inhibits growth of bacteria
Reaches skin surface via a pore
Sweat: 99% water, NaCl, Vit. C and metabolic wastes
Heat regulating to maintain body temp.
Found in axillary and genital areas
Ducts empty into hair follicles
Contains all merocrine fluids do, plus fatty acids and proteins. May have milky or yellow color
Odorless fluid, but bacteria feeding on fatty acids and proteins may cause odor.
Puberty stimulates glands.
Not for heat regulation. Activated by stress, fear and sexual activity.
Which kind of exocrine gland is responsible for keeping skin soft and preventing hair from becoming brittle?
Which kind of exocrine gland is stimulated at puberty?
Which kind of exocrine gland regulates heat?
Hair and hair follicles
Protect head, eyes, and nasal passageways
Produced by hair bulb
Root: enclosed hair in the follicle
Shaft: hair projecting from the scalp or skin. This part is dead.
Medulla: central core of hair surrounded by cortex.
Cortex enclosed by cuticle
Cuticle: outer section that prevents matting of hair, protects from abrasion and give strength and color to hair.
Pigment distribution in hair Human Caucasian hair Human red hair Human Mongoloid hair Dog hair