Lecture Quiz 3 Flashcards
(30 cards)
Integumentary System
Made up of skin and any of its accessory functions. Two layers; Epidermis, Dermis
Integument/Cutaneous Membrane
The skin covering the outside of the body. Approx 1.2 square meters. Loosely attached to muscle, but sometimes attached directly to bone (as in the knuckles or toes).
Epidermis
The outermost layer, the thinnest, comprised of stratified squamous.
Keratinocytes
The cells that make up the epidermis. They are packed with Keratin, a waterproofing protein that helps protect skin from heat, bacteria, and microbes.
Melanocytes
A cell that produces melanin.
Dendritic/Lagerhans Cells
Immune cells. Epidermis is avascular, so it has no access to white blood cells. These cells act as an immune response instead.
Merkel Cells
Touch receptors
Layers of Epidermis (lowest to highest)
Stratum Basale
Stratum Spinosum
Stratum Granulosum
Strutum Lucidum
The entire process from Stratum Basale to shedding is 3-4 wks. EGF (epidermal growth factor) is the hormone that controls this growth.
Stratum Basale
The lowest layer of the epidermis, in which cells undergo mitosis. Cells can get all the nutrients they need from blood in the dermis. As cells divide they get pushed upwards.
Stratum Spinosum
Cells are still alive in this layer of epidermis, but start to die in the upper parts of this layer.
Stratum Granulosum
As cells die they start to fill with Keratin and produce lamelar granules, which are lipids that are going to be released and move into other keratinocytes. This is another waterproofing mechanism that helps seal the skin.
Lamelar Granules
Produced when cells die, lipids that are released and move into keratinocytes. Act as another waterproofing method for the epidermis.
Stratum Lucidum
In this layer of epidermis all cells are dead.
*Only THICK skin has this layer
Stratum Corneum
The uppermost layer of epidermis, where cells fall off.
Epidermal Growth Factor (EGF)
The hormone that controls the growth of epidermis. (Typical lifecycle of Basale - shedding is 3-4 wks)
Dermis Characteristics
Much thicker than epidermis. Made up of connective tissue, both loose and dense, as well as lots of nervous tissue and blood vessels.
Papillary Region
Comprised of areolar connective tissue. Located at the top of the dermis, next to the epidermis.
Dermal Pappillae
Help anchor the dermis to the epidermis.
Meissner Corpuscles
Touch receptors in the dermis
Free Nerve Endings
In the dermis there are lots of nerve endings for sensations such as pain, temperature, itching, and tickling
Reticular Region
Region of the dermis with dense irregular connective tissue.
Epidermal Ridges
These make up our fingerprints and footprints. The pattern starts in the reticular layer, and follows all the way through to the epidermis.
Pacinian Corpuscle
Pressure receptor in the dermis.
Skin Pigmentation
Most pigment in the skin is melatonin from melanocytes. Everyone has the same number of melanocytes, but the amount of melatonin they produce varies, and is genetically determined.
