12/3 Histo of Skin Flashcards
(44 cards)
What are the layers of the skin from the superficial to the deep?
Epidermis; dermis; hypodermis
What is contained in the Epidermis
The Stratum: Corneum, (Lucidum), Granulosum, Spinosum. (Luc. is in Thick skin)
Keratinocytes; Langerhans cells; Melanocytes; Merkel Cells.
What is contained in the Dermis
Layers: Papillary layer (Dermal Papillae); Reticular Layer.
Hiar follicle: Root hair plexus; Hair root, hair shaft, Sebaceous gland, Arrector pili muslce
Sweat Glands: Eccrine sweat gland; Apocrine Sweat gland.
Vessels!
Corpuslces: Miesner and Painian
What is contained in the Hypodermis?
Sweat Glands: Eccrine and Apocrine
Vessels: Cutaneous vessels
Pacinian Corpuscle
What are the main functions of skin?
Protection; Prevent dehydration; temperature regualtion; synthesis of viamin D3 and Sensory receptioin.
How is the skin a protection?
physical and chemical barrier against pathogen entry. initiate immune response(capture and present atigens, release cytokines). Prevent UV damage.
where would Thick skin be found in the body?
thick is called glabrous skin and found on hands (palms) soles, thick epidermis.
Where would thin skin be found?
Hairy skin is everywhere else that isn’t the palms, soles.
what is the difference in thick and thin skin
Thick has a thick epidermis and Thin has a thin epidermis and no stratum lucidum.
the stratum granulosum is thin and the tratum corneum is thin.
But thin skin does have hairs, sebaceuos and eccrine glands.
what is a stratum lucidum
A space of the epidermis where there is more transparency in the cells ofter, where organelles start to disappear in the cells.
How do we get the differentiation of keritinized stratisfied epidermis of the skin?
Keratinocyte differentiation!
what are the layers of the differentiating epidermis?
The Stratum basali; the stratum spinosum, the stratum granulosum, the stratum corneum. (Cute ladies get smart boys)
what do we find in the stratum basalis?
we find stem cells and hemidesmosomes to hold the cells to the bsement membrane
what is found in the stratum spinosum
lots of desmosomes to hold the cells together, and look a little spiny because of it.
what is found in the stratum granulosum
Karatohyalin granules: Keratin aggregation
Lamellar granules: lipid coating
what is found in the stratum corneum (describe it)
Anucleate then acellular layer of stacks (squames) of cross linked keratin coated with lipid.
Describe the way that warts take advantage of the normal development of skin
they ride the ascending layers of epithelium during Keritinocyte differentiation.
describe the location of the 5 stratums of epidermis in thick skin.
the stratum corneum is the most superficial, then the lucidum is a light line just below that. the granulosum is below that and followed by the spinosum and the basale is right next to the basement membrane
What is the significance of the Stratum basale
It is the source of stem cells, transit amplifying cells and links to the basal lamina by hemidesmosomes.
The cells here are connected by lots of desmisomes that look like pokey little things when stained
Stratum spinosum
Deffects in this function can lead to defects in inflammatory diseases such as eczema and may contribute to asthma
Barrier Function
the aggreated keratin filaments cross-linked together to form squames and serve as a scaffold for lipids and proteins that provide the barrier function
A protein involved in aggregating keratin in the stratum corneum (contained in keratohyalin granules
profilaggrin
what do Langerhans cells do?
found in tratum spinosum, bind and process antigesn and migrate to lymph nodes or just to T cells in skin and are professional antigen presenting cell
Derived from neural crest, located in stratum basale, produce a substance too protect nuclei from UV
Melanocytes
Produce melanin (in melanosomes); inject melanin granules into keratinocytes (cytokine secretion)
