Skin Structure and Function Flashcards
The “mortar” of epidermis layers
Lipid seal
Hemi-desmosomes
Anchor the basal cells to the lamina lucida of the basement membrane
Desmosomes
The cellular attachments between the upper layers of skin, keratinocytes
Melanocyte
Produces pigment granules which are transferred to the adjacent keratinocytes
Epidermal Melanin Unit
Melanocyte and adjacent keratinocytes
Location of Melanocytes
At the basal layer of the living epidermis
Vitiligo
Autoimmune attack of the melanocytes
Freeze Branding
Damage melanocytes so that the hair grows back white
Dermatophilosis
Reduced immunity from malnutrition and tick infestation allowing severe skin infections
Corpuscle
Like a receptor
Location of motor nerves
Ventral Horn
Location of sensory nerves
Dorsal Horn
What forms the bulk of dermis thickness
Collagen
What produces collagen
Fibroblasts
Orientation of elastic fibers in the superficial dermis
Vertical
Orientation of elastic fibers in the deep dermis
Horizontal
Ehlers-Danlos Syndrome
Skin hyperextensibility caused by collagen defects
Blood supply to the skin
Superficial, mid, and deep vascular plexus
Vasculitis
Damaged and inflamed blood supply to skin which causes devitalization
Perivascular
AROUND the blood vessels
Epitrichial
Apocrine, produces sweat within the hair follicle
Atrichial
Eccrine, produced sweat directly to the skin surface
Sebocyte
Cell of the sebaceous gland. Lipid synthesis
Sebaceous Adentitis
Glands destroyed by inflammation
Dermal Papilla
mesenchymal cells
Hair matrix
Epidermal stem cells divide to produce hair shaft and root sheaths
Hair shaft
Dead keratinocytes packed together
Outer root sheath
Continuous with the lining of the hair follicle infundibulum and the epidermis of the skin surface
Inner root sheath
Breaks down at the level of the follicular isthmus, allowing the hair shaft to separate from the infundibular lining and fall free from the skin
Telogen Phase of follicle growth
The resting phase. Long phase. This is after the inferior portion undergoes apoptosis and the hair is loosely held in the follicle
Anagen Phase of follicle growth
Active growth with hair held tightly in follicle. Short phase.
Catagen Phase of follicle growth
Short phase characterized by the involution/apoptosis of the inferior portion
Dynamic hair growing cycle
Allows for different coat colors each season. Dogs grow hair in a mosaic pattern which rodents replace hair in a wave pattern from head to tail
Exogen
Hair is lost independently of follicle cycle
Simple Follicle Anatomy
One hair in one follicle. Horses, humans, and ruminants
Complex Follicle Anatomy
Multiple hairs in one follicle. Cats and Dogs
Primary Hairs
Guard hairs, wide diameter
Secondary Hairs
Fine undercoat hairs
Dermatophytosis
Fungal spores on hair. Ringworm
Demodicosis
Mites
Miniaturization
The hairs are present, they are cycling, but very thin. Male pattern baldness
Hyperadrenocorticism
Hair anagen cycle arrested during Cushing’s
Sphynx Cat
Congenital alopecia associated with mutated KRT71
Curly coated retriever follicular dysplasia
CCR FD causes misshapen hair shaft. They get frizzy saddle side.
Shark skin
Spiky projections oriented caudally
