Flashcards in Chapter 6 - Integumentary System Deck (42):
the Integumentary System is composed of what 4 main parts?
- Skin and accessory organs including blood vessels, muscles and nerves
What are the main functions of the integumentary system? (6)
- protection against UV rays, environment, bacteria, and water loss
- Vitamin D synthesis
- Emotional Expression
name and briefly explain the 3 main layers of the skin.
1) epidermis -> outside layer of epithelial tissue
2) dermis -> composed of CT. functions in them regulation and insulation
3) Subcutaneous -> highly vascularized
what is the epidermis composed of?
-keratinized stratified squamous epithelium
- keratinocytes -> produce keratin (fibrous protein) that provides protection
- melanocytes -> produce melonin (pigment) which protects against UV
what is a Nevi?
overgrowth of melanocytes that produces a birthmark or mole
Cancer of Melanocytes is known as what?
What are tactile or Merkel cells and where are they found?
touch receptor cells that receive signals and send to nerve.
located in the stratum basal
Name the 5 layers of the epidermis from deep to superficial
1) stratum basale
5) stratum corneum
explain the processes that occur in the stratum basale
-continuous cell division that produces all other layers of epidermal tissue
what is the structure of the stratum spinosum
8-10 layers of keratinocytes (can still divide)
what are the characteristics of the stratum granulosum
layer of cells which can no longer divide, filled with keratin.
what is the significants of the stratum lucid. what is its function
only present in thick skin (fingertips, palms, soles of feet)
functions in increased protection
which layer of the epidermal is the most superficial? What are the characteristics of this layer?
composed of ~20 layers of cell remnants.
dead cells have no nucleus and are filled with keratin
cells are continuously shed and replaced by cells from deeper strata
The Dermis lies ________ to the Epidermis, and ________ to the Sub Q.
What are the 2 main regions of the dermis
papillary region and reticular region
The epidermis is vascular. True or False
False. Epidermal tissue is Avascular and receives all nutrients from underlying tissues.
List the Characteristics of the Papillary Region of the Dermis
-areolar CT that contains capillaries, tactile receptors, free nerve endings
-provides nutrients to the epidermis
What dermal layer provides nutrients to the epidermis?
what are the characteristics of the reticular region of the dermis?
- dense irregular CT containing adipose cells, hair follicles, nerves and glands.
- cells are replaced but not shed in this layer
Hair follicles, nerves and glands are located in which layer of the skin?
reticular region of the Dermis
name and describe the types of nerves found in the Dermis
sensory nerve fibers - detect pressure, vibration, and cold
motor nerve fibers - control blood vessels (body temp regulation) and gland secretion
what are the characteristics of the Subcutaneous layer
attaches the skin to underlying tissues an organs, energy reserve, thermal regulation
Hair is also known as
Characteristics of the hair include
structure - dead, keratinized, epidermal cells
function - UV protection, heat regulation, sensation, protection against foreign particles (eye lashes)
The 3 main components of the hair are..
1) shaft - above the skin surface
2) root - deep to the skin
3) bulb - epithelial cells where the hair originates
how are hair and nails similar?
both composed of dead, keratinized, epidermal cells
characteristics of the nail
structure -hard dead, keratinized, epidermal cells
location - on the dorsal surfaces if the fingers and toes
function - protects distal tips of digits, assists with grasping
what are the 3 types of glands located in the Dermis
sebaceous glands secrete ...
oily substances (sebum) which prevents dehydration of hair and skin
what type of dermal gland is connected to the hair follicles? how are these stimulated?
stimulated by a hormone called androgens
A watery odourless solution is secreted from which dermal gland? what is the purpose?
Merocrin sweat glands.
thermal regulation (cools) and eliminates small amounts of waste
(sweating due to exercise)
This type of gland is located in the axilla, groin, and areolae.
Apocrine sweat gland
when are Apocrine sweat glands activated?
Smells bad - lipid rich
replacement of damaged cells with cells of the same type
replacement of damaged cells with scar tissue (fibrosis CT)
What are the 4 stages of wound healing?
1) Blood vessels bleed into wound
2) clot forms
3) damaged blood vessels regrow, wound becomes granulation tissue
4) epithelium regeneration - CT is replaced by fibrosis
What is a granulation tissue?
during the stages of wound healing, blood vessels regrow and the wound becomes granulation tissue which is highly vascularized CT
what are the characteristics of a First Degree Burn?
involves only the epidermis
-characterized by mild pain and redness (no blisters)
How does a second degree burn differ from a first degree burn?
a second degree burn destroys the epidermis and part of the dermis.
some functions are lost
characterized by redness, blisters, edema, and pain
a first degree burn involves only the epidermis and no functions are lost
A burn that destroys the epidermis, dermis, and sub Q layers of the skin is known as? what is the result of this type of burn?
third degree burn
results in loss of skin function, region is numb
Vit D metaboilization