Exam 4 Part 1 Flashcards
Integumentary system is made up of?
Skin + accessory organs (hair, nails, glands, & sensory organs)
Functions of the integumentary system?
- Protective covering
- Regulation of heat
- Housing of sensory receptors
- Synthesis of vitamin D
- Excretion of waste materials (perspiration)
How does skin eliminates excessive body heat?
- Radiation of heat through subcutaneous dilated blood vessels
- Conviction & conduction of heat directly through skin
- Evaporation of perspiration on surface of skin
What are the layers of the skin?
Epidermis
Dermis
Subcutaneous layer ( hypodermis, superficial fascia)
Epidermis is composed of _____ stratified squamous epithelium
Keratinized stratified
Epidermis contains 4 types of cells, what are they?
- Keratinocytes cells
- Melanocytes cells
- Dendritic cells
- Merkel cells
Predominate cell type; manufacture keratin
Keratinocytes
Structural protein which toughens & waterproofs the surface of the epidermis
Keratin
Manufacture melanin, brown pigment
Melanocytes
Immune cells (aka Langerhans)
Dendritic cells
Type 1 tactile mechanoreceptors (aka disc)
Merkel cells
What are the 4 or 5 layers of the epidermis (5 depending on the thickness of the skin) Deepest to superficial
- Stratum Basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stractum corneum
Deepest layer, HIGHLY mitotic
Stratum basale
Mitotic only in its deepest layers; begins synthesis of keratin
Stratum spinosum
Stratum basale + stratum spinosum =
Stratum germinativum
Flattened cells, filling up with keratin
Stratum granulosum
Present ONLY in thick skin
Stratum lucidum
20-30 layers of flattened, keratinized dead cells (skin you touch)
Stratum corneum
Composed of connective tissue, housing muscle fibers, blood vessels, hair follicles, exocrine glands, & nerve fibers
Dermis
What are the 2 layers of the dermis?
- Papillary layer
- Reticular layer
Loose connective tissue directly underlying the epidermis
Papillary layer
Dermal ridges (fingerprints) are due to the pulling of elastic fibers in the ______ layer
papillary layer
Dense irregular connective tissue underlying the papillary layer
Reticular layer
Layer that when over-stretched, this layer tears producing “stretch marks”
Reticular layer
Adipose tissue & loose connective tissue, interlaced w/ blood vessels
Subcutaneous layer (hypodermis)
T/F adipose tissue DOES NOT serve as a heat insulator & energy reservoir
False; It does
Subcutaneous layer: conserves ______ _____ _____or impedes entrance of external heat
Internal body heat
Binds skin to underlying organs
Subcutaneous layer (hypodermis)
