Anatomy of the Integumentary System Flashcards
What does hirsute skin mean
hairy skin (covers most of the body)
what does glaborous skin mean
hairless skin (palm, sole, flexor aspects)
Histology of skin (superficial to deep)
epidermis
dermis
hypodermis/panniculus
5 layers of the epidermis
Stratum:
- corneum
- lucidum
- granulosum
- spinosum
- basale
Cells making up the epidermis
Other term for stratum basale
stratum germinativum (because it is the source of all epidermal cells)
How long is the typical cycle of cells from basale to corneum?
25-45 days
How many rows is stratum basale?
single row of stem cells
how many rows is stratum spinosum?
8-10 layers of spiny cells and weblike system of prekeratin filaments
what is abundant in the stratum spinosum
melanin granules and dendritic cells
Where do merkel cells hang out
stratum basale
where do langerhans cells hang out
stratum spinosum
how many layers is stratum granulosum?
3-5 layers of flat cells rich in lipids and filaggrin (water sealant)
How many rows are in the stratum lucidum?
a few rows of flat dead keratinocytes (palms and soles)
How many rows is stratum corneum?
20-30 rows of dead flat keratinized membranous sacs (dust)
Intercellular matrix is composed of
How many types of corpuscles are in the epidermis?
one, the merkel cell
What are the proteins in the epidermis?
keratine and fillagrin
what are the 4 types of cells in the epidermis?
keratinocytes, melanocytes, merkel cells, langerhan cells
What are the corpuscles of the dermis?
pacinian, meissner, and free nerve endings
What does the pacinian corpuscle sense?
pressure/vibrationwh
What does the Meissner corpuscle sense?
light touch
What does the Merkel’s corpuscle sense?
touch
What does the free nerve ending sense?
heat
What happens in bullous pemphigoid
autoantibodies form against antigens beneath the basale layer of the epidermis at the dermoepidermal junction
What happens in pemphigus vulgaris
autoantibodies form against antigens in the intercellular spaces of the epidermis leading to decreased adhesion of the cells and skin breakage
What happens in psoriasis
the rate of epidermal turnover is increased, not enough time for differentiation/maturation of cells
What happens in atopic dermatitis
mutations in filaggrin in the epidermis
melanocytic nevi is defined as
a benign collection of melanocytes