module 8 Flashcards
Skin is also called what?
Integument or cutaneous membrane
What do desmosomes and hemidesmosomes do?
hold cells together. These junctions are critical for skin structure and function. (desmosomes- verticle spot weld.) (Hemidesomes- hold to basement membrane by protein integrin)
Epidermis-
epidermis- outside layer of the skin, mostly made up of dead cells which have expelled their nucleus and all organelles and become simply bags of a protein keratin. VASCULAR
Keratin-
what is left after organelles and nucleus have been expelled from a cell. Its a protein
dermis-
the living layer of tissue underneath the epidermis. contains the blood vessels, nerves, glands, and living skin cells. hair roots are found in the dermis and there is a small bit of muscle which controlls the angle of each hair. CONNECTIVE TISSUE
Arrector pili
are small muscles which attach to the hair follicles in mammals
subcutaneous layer
not technically part of skin but is a layer of areolar and/ or adipose connective tissue. FAT!
Pemphigues
a disease where the patient mounts an immune defense against the porteins of his own desmosomes and hemidesmosomes. autoimmune attack against desmosomes.
Deepest to most superficial layers of skin are?
Stratum basal, stratum spinosum, stratum granulosum, stratum lucidum, stratm corneum. (BEFORE SINGING GET LEGAL COUNSEL)
kerantinocytes or caled corneocytes
all layers of the epidermis contain karatinocytes. living keratinocytes are found in the deeper layers. as you move more superfically, dead kerantinocytes predominate. the stratum corneum consists of two dozen rows of dead flat kerantinocyes with no other cell types present.
Squames
the shed flakes from the corneocytes of keratinocytes
Stratum Basale
cells divide and grown in basale, then migrate upwards, losing their nuclei and becoming bags of keratin. STEM CELLS
Stratum corneum:
(horn like)
Stratum Lucidum:
(clear) Only thick skin
Stratum Granulsodum
(grainy) Lipid granules water proofing
Stratum spinosum:
(spiny)
Thin Skin ( hairy skin)
lacks stratum lucidum . covers everything but palms, fingertips and soles of the feet. about 0.1mm thick
Thick skin or Glabrous
has a prominent stratum lucidum. Found on palms, palamr surface of digits, and soles of feet
Stem cells:
found in stratum basale. full of intermediate filament protein keratin. these divide into keratinocytes, cells divide as they move more superfically, lose their nuclei and become just kearin surround by a membrane, also secrete lipids that give skin waterproof and flexible properties
Dead keratinocytes
cell membrane surround the protein keratin make up about 90% of cells epidermis
Melanocytes:
cells which carry pigment granules that give the skin color .Carry MELANIN (pigment granules that give color)
Langerhans Cells:
skins version of a type of immune cell called a dendritic cell.PROVIDE IMMUNE DEFENSE. (MACROPHAGES OF EPIDERMIS)
Merkel Discs:
light touch receptors. Type of nervous system that can detect light touch. (NEUROLOGICAL AND SENSORY)
what are the two types of Melanin
PHEOMELANIN AND EUMELANIN
PHEOMELANIN:
yellow to red- freckles
Eumelanin:
Brown to black- moles
Mealanocytes:
pigments are found in cells called melanocytes. almost everyone has same number of melanocyrtes