Integumentary System Flashcards
General characteristics of the Integumentary System:
- protective covering
- composed of several tissues
- maintains homeostasis
- retards water loss
- regulates body temperature
- houses sensory receptors
- contains immune system cells
- synthesizes chemicals (vitamin D)
- excretes small amounts of waste
- help synthesize vitamin D
- Keratinocytes
produce substances which stimulate the development of white blood cells
keratinocytes
active form
calcitrol
aid in the development of bone and teeth
vitamin D
Layers of skin:
- Epidermis
- Dermis
- Subcutaneous layer
- below the dermis
- not a true layer of skin
subcutaneous layer
*hypodermis
made up of:
- loose connective tissue
- adipose tissue
- contains: some blood vessels
Subcutaneous Layer
What is the function of the subcutaneous layer?
Insulates
-Keritonized
-Lack blood vessels
Basement membrane
Stratified Squamous Epithelium
where is simple squamous the thickest?
on the soles and palms (.8-1.4 mm thick)
produce melanin
melanocytes (simple squamous epithelium)
Layers of the epidermis:
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
What are the two regions of the dermis:
- Papillary
- Reticular
What is the dermis made up of?
Mostly connective tissue with collagen and elastic fibers
- Dermal Papillae
- areolar tissue with elastic fibers
Papillary Region
- deeper portion of the dermis
- has dense irregular connective tissue
Reticular Region
Pigment released so it only covers superficial portion of keritanocytes
melanocytes
General characteristics of dermis:
- bind epidermis to underlying tissue
- is about 1.0-2.0 mm thick
- includes nerve processes and sensory receptors, blood vessels, muscle tissue, hair follicles, and glands
Structural basis of skin color:
melanin, carotene, hemoglobin
What leads to an increase in melanin production?
UV light stimulates enzymatic activity within the melanosome, leading to an increase in melanin production
melanin-forming organelle in malanocytes
melanosome
Yellow-orange pigment and a precursor to Vitamin A
Carotene
When oxygenated it has a bright red color
Hemoglobin
Lack of (functional) melanocytes
Albinism