Integument Flashcards
What are the four components of the integument system?
Skin Sweat glands Sebaceous glands Hair Nails
What are the five functions of thick skin?
Protection Regulation Reception Absorption Excretion
What areas have thick skin?
Palms and soles
Does thick skin have hair follicles, errector pilli, or sebaceous glands?
No
Does thick skin have sweat glands?
Yes
Where is thin skin found?
Over most of the body
Does thin skin have hair follicles, sebaceous glands and/or sweat glands?
Has all
The skin arises from what part of the trilaminar disc?
Ectoderm
Is the epidermis vascular?
Negative–receives nutrients from dermis
What is the layer of skin that is damaged in first degree burns?
Epidermis
What are the two layers of the skin?
Epidermis
Dermis
What is the type of epithelium in the epidermis?
Stratified squamous keratinized
What two types of connective tissue comprises the dermis?
Loose CT
Dense, irregular collagenous
What are the two types of cells that comprise the epithelium?
Keratinocytes and nonkeratinocytes
What are the layers of the epidermis that extend down into the underlying dermis?
Epidermal ridges
What are the projection of the dermis into the epidermis called?
Dermal papilla
What are the filaments that accumulate as keratinocytes approach the surface?
Keratin filaments
What ensures that the epidermis and the dermis do not separate?
The increased surface area formed by the interdigitation of the dermis and the epidermis
What is the basal layer of the epidermis?
Basal facali
Where does intense mitotic activity take place in the epidermis?
At the basal facali
How long does it take for cells to migrate from the basal facali (dermis) to the epidermis?
20-30 days
When does most of the mitotic activity take place in the dermis?
At night
What are the three types of nonkeratinocytes?
- Langerhans cells
- Merkel cells
- Melanocytes
Langerhans cells are derived from what?
Bone marrow
What is the general function of langerhans cells?
Defense
What is the route by which langerhans cells migrate to the epidermis?
- bone marrow
- Blood stream
- epidermis
What part of the epidermis do langerhans cells reside in?
Stratum spinosum
What are the histological characteristics of langerhans cells?
long, thin cytoplasmic processes which extend into the intercellular space
Prior to taking up residence in the dermis, what are langerhans cells known as?
Dendritic cells
What happens when a langerhans cell detects an antigen?
Migrates to a lymph node to aid in the immune response
What are birbeck grnules?
Rod-like structures that are unique to langerhan cells, whose function is not well understood
What is the general function of merkel cells?
Mechanoreceptors
Where are Merkel cells found?
Between keratinocytes in the stratum basale
Where are Merkel cells particularly present?
Fingertips
What are Merkel dics?
Enlarged part of a dendritic process that attaches to a Merkel cell
What are the two components of the Merkel cell-neurite processes?
Unmyelinated nerve terminals and Merkel cells
What is the general function of melanocytes?
Protect DNA of skin
Melanocytes arise from what type of cells?
Neural crest cells
Melanocytes synthesize what? Where does this go?
Melanin, which goes to surrounding keratinocytes
Where are melanocytes generally found?
In the stratum basale and superficial dermis
What is the bottom-most layer of the epidermis called?
The stratum basale
What is the enzymes that synthesizes melanin from Y?
Tyrosinase
What are melanosomes?
Packed up tyrosinase and melanin, which receive Y from vesicles that enter the melanocyte
What happens to melanosomes when they receive enough Y?
Become melanin granules, that are secreted through cytoplasmic processes