Integument Flashcards
Types of cells in the epidermis?
Keratinocytes
Non keratinocytes
1. Langerhans
2. Merkels
3. Melanocytes
4. Intraepithelial lymphocytes
Papillary vs Reticular layer
Papillary:
- type 1 & 3 collagen
- loose CT
- macrophages and mast cells
Reticular:
- type 1 collagen
- deeper layer
- dense irregular CT
- elastic fibers
Apocrine sweat gland
- apical budding
- help from myoepithelial cells
Functions as COMMUNICATION
Mesocrine sweat gland
- Exocytosis
- Functions for THERMOREGULATION and ELECTROLYTE BALANCE
-secretes fluid when body temp rises
What are the layers of skin from deep to most superficial?
Stratum basale
spinosum
granulosa
Stratum lucidum
Stratum corneum
What are the steps to the hair cycle?
Anagen- hair bulb mitotically active
Catagen- metabolic slows, follicle moves to surface
Telogen- grow stops, base of bulb at sebaceous canal, new hair underneath
What are the steps of the hair cycle controlled by?
- temp
- hormones
- daylight
- nutrition
What are the function of sebaceous glands?
Antibacterial, waterproof
Arrector pili
smooth muscle attached to primary cells
Functions as INSULATION
Ex: goosebumps
Layers of the hoof wall
- Stratum externa- perioplic epidermis
- Stratum medium- main support, coronary groove with tubular and intertubular horns
- Stratum interna (lamellatum)- insensitive lamellae
Underlying dermis in hoofs
corium, sensitive laminae
What part of the dermis carries blood to the cells of the hair?
Dermal papilla
Characteristics of stratum basale
- most active (mitotic), deepest layer of epidermis
-single cuboidal
-attached to basal lamina w hemidesmosomes
-keratinocytes, melanocytes, langerhans, merkels
What layer of the epidermis has many tonofilaments and desmosomes?
Stratum spinosum
Stratum Corneum
- most superficial, thick layers of keratin
-dead cells, horny cells
What layer of the epidermis has keratohylan and lamellar granules?
Stratum granulosa
Merkels
- A non keratinocyte
- in stratum basale of thick skin
Functions as a MECHANORECEPTOR for sensation
Langehans
- a non keratinocyte
- in the basale and spinosum layer
- intra epidermal macrophages
- from bone marrow monocytes
Functions as IMMUNITY (T cells, tolerance)
Nociceptors
free nerve ending goes to stratum granulosa
Detects pain, itch, temp
What layer of the epidermis has eleidin?
Stratum Lucidum
Primary vs Secondary hair follicle
Primary:
1. larger diameter
2. deep in dermis
3. sebaceous glands, arrector pili, sweat glands
Secondary:
1. smaller
2. near surface
3. no sweat glands or arrector pili
Compound hair follicle
many hair follicles, 1 primary and several secondary
Ex: carnivores
Components of hair
Medulla- loose cuboidal areas in middle of hair follicle
Cortex: dense keratin (pale yellowish area)
Cuticle: single layer, flat keratin cells
Ex of special apocrine glands
- Mammary gland
- Moll
- Anal sac
- Ceruminous (ear wax)
