Week 1 Tuesday - Downing - Histology of Skin Flashcards
Sebaceous gland
Oily gland of the skin (usually of the hair folicle).
- Holocrine secretion
- Causes acne
Meissner’s corpuscle
Nerve ending in the superficial part of the dermis sensitive to light mechanical touch.
Pacinian corpuscle
Nerve ending in the deep dermis sensitive to pressure.
It’s big and round, like PAC-man
Lamellar bodies
Contain lipids. Secreted from a granular cell superficially. Form a lipid coat (water barrier).
Keratohyaline granules
Present once an epithelial cell enters the Stratum granulosum stage. Eventually these consolidate into a fibrous amorphous mass when the cell enters the Stratum Corneum.
Psoriasis
Increase in # of proliferating cells in Stratum basale, increase in cell turnover.
Papillae
Secondary dermal ridges; exist in epithelial tissues subject to stress e.g. palms.
Where do melanin granules come from and how do they mature?
Golgi of melanocyte, are matured via tyrosinase activity, which is active in the first two steps of the following reaction:
tyrosine peptide -> dopa peptide -> [indole 5,6 quinone]n -> Melanin polymer
Rete cutaneum (cutaneous plexus)
Supply of veins and arteries in the reticular (deep) layer of the dermis.
Rete subpapillare (subpapilary plexus)
Supply of veins and arteries in the papilary (superficial) layer of the dermis. (sometimes just referred to as the papilary plexus).
Arteriovenous anastomoses
(AV shunts) Shunts that allow blood flow to bypass the papilary plexus.
Thermoregulated; open when cold, closed when hot.
This muscle stands hair ‘on end’ and moves sebaceous gland products. What is it and where is it anchored?
Arrector pili muscle. Bundle of smooth muscle that in innervated sympathetically. Anchored from the hair follicle sheath to the papillary layer of the dermis.
Lanugo, vellus, and terminal hair
Lanugo - Newborn hair
Vellus - fine hair that covers most of the body
Terminal hair - rougher hair (pubic hair, facial hair)
This tissue is located superficially to finger nail root.
Eponychium.
This tissue is located under the tip of the fingernail.
Hyponychium.
This is the light crescent on the most proximal part of the finger/toe nail.
Lunula.
Eccrine sweat glands
Major sweat glands of the body, active when working out. Sympathetic innervation.
Apocrine sweat glands
Sweat glands restricted to the axilla; areolae, and anogenital locations. Activated when nervous. Odorless secretion becomes odored when acted on by bacteria. Sympathetic innervation.
Peritrichial nerve endings
They allow feel for when a hair is touched.
