Dermis and Adnexal Structures Flashcards
The synthesized collagen proteins are ____ and then are assembled into collagen fibrils.
secreted
What is an eccrine gland?
generic sweat gland
Name an acquired disorder of elastin.
solar elastosis
What are apoeccrine gland?
modified sweat glands found only in the axilla
Name the 2 layers of the dermis.
- papillary dermis 2. reticular dermis
The dermal matrix is synthesized by ____.
dermal fibroblasts
What is hyperhidrosis?
excessive sweating
What are the adnexal structures?
hair follicles, sebaceous glands, sweat glands
____ is synthesized by fibroblasts and cleaved enzymatically by _____; the final product is ___.
Procollagen; tropocollagen; collagen
How does pruritis work?
originates in free nerve endings conducted centripetally by afferent nerves entering dorsal root on small, unmyelinated C fibers synapse w/ 2a neurons on opposite side of the body interpreted by cerebral cortex
Type III collagen description?
fetal dermis; resistant to scar formation
What is the most important cofactors for collagen assembly?
vitamin C
What is another name for skin appendages?
adnexal structures
What are verruca?
warts
What is a free nerve ending?
nerves that pass thru the upper dermis to the dermo-epidermal junction involved in pain and itching
Name an external skin finding in pseudoxanthoma elasticum (PXE).
flexural areas have “plucked chicken” appearance (increased skin redundancy)
Procollagen is synthesized intracellularly within ____.
fibroblasts
Type IV collagen description?
basement membrane; problem in Ehlers-Danlos syndrome
_____ is pure hyaluronic acid produced via recombinant technology used cosmetically to remove lines and wrinkles
Restylane
What is a Pascinian corpuscle?
pressure and vibration receptors
What are terminal hairs?
large, thick, course, and pigmented
What are apocrine glands?
glands only found in axillary and anogenital area for 2a sexual characteristics and function
What are the features of scurvy?
- wounds fail to heal 2. corkscrew hairs 3. fragile BVs/perifollicular hemorrhage 4. teeth fall out
What is ground substance?
gelatinous material btw the collagen and elastin consisting of hyaluronic acid and dermatan sulphate (GAGs)
What is a disorder of the pilosebaceous unit?
acne
What is a pilosebaceous unit?
the combined hair follicle and oil glands
Sebaceous glands are the classic example of a ____ in that the method of secretion involved entire sebocytes (sebaceous gland cells) being secreted and in the process breaking-down to extrude the contents.
holocrine gland
What is a type II reaction? Example?
antibody mediated; bullous pemphigoid (blistering)
What are the 2 types of nerve fibers to know?
- type A- heavily myelinated, fast conduction (alpha, beta, gamma, and delta) 2. type C- unmyelinated, slow (diffuse, dull, temperature, itch)
What is a Sucquet-Hoyer canal?
a smooth muscle derived valve-like structure that allows for control of temperature homeostasis by BVs
What muscle causes hairs to stand up?
erector pilli
What is leukocytoclastic vasculitis?
palpable purpura; a disease of the post-capillary venules leading to deposition of immune complexes (type III)
What drug decreases sebum secretion?
isotretinoin (Accutane)
Describe Anhidrotic ectodermal dysplasia.
a mutation of the EDA gene resulting in aberrant eccrine development, decreased sweating, poor temp regulation, sparse hair, abnormal teeth, etc
What is pseudoxanthoma elasticum (PXE)?
a mutation in the “multidrug resistance complex” gene, causing elastin in the dermis to become enlarged, tangled, and calcified; purple-blue under histology
What is the dermal matrix?
the admixture of collagen fibers, elastic fibers, and ground substance
Palpable purpura is BLANCHABLE/NON-BLANCHABLE.
non-blanchable
What is the derm term for itching?
pruritis
What is millaria?
prickly heat- blocked sweat ducts- an acquired disorder of eccrine function
_____ provide the skin with tensile strength, but ____ provide the skin with resiliency.
Collagen fibers; elastic fibers
What is solar elastosis?
an acquired disorder in which sunlight causes degeneration of elastin, causing them to clump and aggregate; they’re blue/basophilic in microscopy
What are the upper third, middle, and lower third of a hair follicle called, respectively?
infundibulum isthmus matrical area
Eccrine glands are a classic example of a ____ secretion.
merocrine
Name a genetic disorder of eccrine function.
Anhidrotic ectodermal dysplasia
What happens with vitamin C deficiency?
collagen fibers aren’t as strong- Scurvy
What is a Meissners corpuscle?
fine touch and tactile discrimination
Name an inherited disorder of elastin.
pseudoxanthoma elasticum (PXE)
What is a type III reaction? Example?
immune complex mediated; leukocytoclastic vasculitis (palpable purpura)
Procollagen consists of _____ of proteins arranged in an α-helical structure.
three separate chains
What is chromohidrosis?
an apocrine gland disorder where the sweat is colored
Even though sweating is mediated by the sympathetic portion of the ANS, it is triggered via ______ secretion.
acetylcholine
The dermis is composed of ____, ____, and _____.
- collagen 2. elastin 3. ground substance
What are intracellular adhesion molecules (ICAMs)?
molecules that allow for diapedesis when expressed by binding to WBCs
What is anhidrosis?
the inability to sweat
_____ glands are not derived from the PEG.
Eccrine glands
What is required for sebum secretion?
sex hormones
What is a type I reaction? Example?
immediate IgE mediated; urticaria (hives)
What is Restylane?
pure hyaluronic acid produced via recombinant technology used cosmetically to remove lines and wrinkles
What is the prominent mode of apocrine secretion?
decapitation
What is a type IV reaction? Example?
delayed type hypersensitivity; allergic contact dermatitis
The most common acquired disorder of elastic is ____.
solar elastosis
Type I collagen description?
85% wt. of dermis
Type VII collagen description?
anchoring fibrils that attach the dermis to the epidermis
Name a treatment for hyperhidrosis and how it works.
Botox injections to block the secretion of ACh
What are vellus hairs?
small, fine, apigmented- ear, female face, body
What is Ehlers-Danlos syndrome?
a disorder of collagen synthesis due to genetic defects characterized by: 1. hyperflexible skin 2. joints hypermobile 3. fragile tissues 4. poor wound healing
