Chapter 5 - The Integumentary System Flashcards
(46 cards)
Functions of skin
- protection
- thermoregulation
- cutaneous sensation
- vitamin D synthesis
- blood reservoir
- excretion and absorption
Epidermis
- superficial layer
- keratinized stratified squamous epithelium
- avascular/own nerve supply
4 cell types of epidermis
- keratinocytes (90%)
- melanocytes (8%)
- Langerhans cells
- Merkel cells
Langerhans cells
immune function
Merkel cells
touch
Epidermal layers (deep to superficial)
- stratum basale
- stratum spinosum
- stratum granulosm
- stratum lucidum
- stratum corneum
Stratum basale
- contains all 4 cell types
- deepest layer
- mitosis occurs here
Stratum spinosum
- keratinocytes and Langerhans cells present
- projection of melanocytes (cells alive)
Stratum granulosm
- lamellar granules
- transitional layers (apoptosis)
- water repellent layer
Apoptosis
programmed cell death
Stratum lucidum
- present only in thick skin
- 10-15 layers fo dead skin cells
Stratum corneum
- keratin
- continuously shed (20-30 layers)
- most superficial
Psoriasis
shed cells rapidly
Skin graft
possible with stratum basale injury (mitosis disrupted)
Dermis
- deep layer
- vascular/nerves
- papillary layer
- reticular region
Papillary layer
- 1/5 of dermis
- areolar connective tissue
- dermal papillae
Dermal papillae
- finger-like projections
- superficial part of dermis
- contact point between dermis and epidermis
Reticular region
- attached to subcutaneous layer
- thickest
- dense irregular connective tissue (can’t be replaced, CT)
- oil, sweat glands, hair follicles
Hypodermis
- not layer of skin
- subcutaneous layer
- areolar connective adipose tissue
- stores fat; abundance of blood vessels
- Pacinian corpuscles (pressure)
Hemoglobin
- pigment in red blood cells that carrie oxygen
- degree of oxygenation of blood; amounts of blood in area
Carotene
- ingested (precursor of vitamin A)
- accumulates in stratum corneum with excessive dietary intake
Melanin
- only pigment synthesized in skin
- differences in color reflect amount of pigment and kind made
Albinism
inability to produce melanin (still have melanocytes)
Vitiligo
- loss of melanocytes from patches of skin
- symmetrical
- usually occurs later in life
- auto immune disease(?)