Skin Flashcards
Function of the skin is…
(1) Protection, (2) Waterproof (hydroregulation), (3) Temperature Regulation [radiation/perspiration or constriction of vessels], (4) Secretion [sweat, sebum/oil], (5) Selective Absorption, (6) Sensory Reception
Integumentary System consists of…
Skin, glands, hair, nails, associated blood vessels, associated nerves
Skin layers are…
Epidermis, dermis, hypodermis
Cell type in the epidermis
4-5 layers of stratified squamous epithelium
Thick skin consists of ____ layers of epidermis; thin has ____ layers.
Thick = 5 layers of epidermis; thin = 4 layers of epidermis.
Stratum Basale is also known as stratum ______
Stratum Basale = Stratum Germinativum
The stratum basale (germinativum) is a single layer of _____ cells resting on ______ membrane
Stratum germinativum = single layer of cuboidal cells resting on basement membrane.
Stratum germinativum cells are constantly dividing via meiosis or mitosis?
Stratum germinativum cells divide constantly via mitosis.
Superficial 3-4 layers of epidermis consist of cells that gradually do 3 things…
(1) gradually dehydrate, (2) die, (3) become keritinized (inclusion of keratin as cells die; filled with keratin). Top layer sloughs off with friction. Top layer varies a lot in thickness.
3 cell types in the epidermis
(1) Keratinocytes, (2) Melanocytes, (3) Tactile Cells (Merkel Cells)
Keratinocytes represent ___% of epidermal cells, are found in ____ layers of epidermis, and produce ______.
Keratinocytes: 90% of epidermal cells (most numerous); found in ALL layers of epidermis, and produce keratin
Melanocytes represent ____ % of epidermal cells. These cells are found in the ______, and they produce _____.
Melanocytes: ~8% of epidermal cells; found in stratum basale; produce melanin.
People with different skin colors differ in the (A) number of melanocytes or (B) the level of activity of melanocytes?
(B) The # of melanocytes does NOT vary across people of different skin colors; only the level of ACTIVITY of melanocytes differs
Heat is lost through the skin via…
Radiation and/or perspiration
Heat is conserved in the body by…
Constriction of blood vessels
Tactile Cells are also referred to as…
Merkel Cells
Tactile cells are found in the _____.
Stratum basale
For the most part, the epidermis is with or without sensation?
The epidermis is mostly WITHOUT sensation.
The dermis is the _____ layer of the integument and consists of _____, ______ connective tissue.
Dermis = middle layer of integument. Consists of dense, irregular connective tissue.
The dermis contains…
Dermis contains many blood vessels; contains nerve endings, hair follicles, glands, and dermal papillae (projections of dermal tissue into the epidermis)
What are dermal papillae?
Projections of dermal tissue into the epidermis
What are the layers of the dermis?
Papillary layer and reticular layer
The Papillary layer of the dermis is the most ____ layer, has papillae, and is the layer that creates the ____.
Papillary layer - most superficial layer of dermis, has papillae, and creates the fingerprint (epidermis follows the papillary layer indentations)
The reticular layer of the dermis is ____ to the papillary layer, contains A, B, and C, and is [thinner/thicker] in thick skin.
Reticular layer - deep to the papillary layer, contains (A) sweat glands, (B) sebaceous glands, (C) hair follicles, and is THICKER in thick skin.
Other structures found in the dermis include…
Blood vessels (arterioles and venules), lymphatics, sensory receptors, and nerve fibers (sympathetic and somatic sensory)
Epidermal derivatives (developmentally) include…
Hair, nails, and exocrine glands (sebaceous and sweat glands)
Hair consists of three parts:
Bulb, root, and shaft
The function of hair is:
Protection
The arrector pili muscle is associated with the ____ of hair and is innervated by a _____ neuron
Arrector pili: associated with the ROOT of hair and has SYMPATHETIC innervation
Exocrine glands are found in the ______.
Dermis