Derm - Micro/histo Flashcards
Cells within the epidermis and dermis
Keratinocytes and melanocytes
4 layers of the epidermis
From deep to superficial
Stratum basale
Stratum Spinosum
Stratum granulosum
Stratum corneum
Skin adnexa
Contains hair follicles, sebaceous glands, apocrine glands
Sebaceous glands
Mechanism of secretion: Holocrine -> plasma membrane rupture
Sweat - apocrine glands
Epitrichial
Duct enters into hair follicle
Mechanism of secretion: membrane budding
Sweat - eccrine glands
Atrichial
Duct enters directly to skin surface
Mechanism of secretion: merocrine = exocytosis
Simple hair follicle
When a singular hair follicle exits a single opening
Found in cattle, horses and pigs
Compound hair follicle
When multiple hairs exits from one opening
Found in dogs, cats and goats
Mixed hair follicles
Species contain both simple and compound hair follicles. Common in sheep
Stages of hair follicle growth
Anagen
Catagen
Telogen
Exogen
Anagen stage
Mitotic activity of hair growth
Catagen stage
Transitional stage, cell proliferation stops
Telogen stage
Resting stage
Exogen stage
Old hair shaft is shed
Occurs independent of hair cycle stage, but often follows Telogen
