integument Flashcards
What does the integumentary system consist of?
skin, hair, nails, exocrine glands
What Are the 7 functions of the skin?
protection, water resistant, temperature regulation, secretion, sensory reception, vitamin D synthesis, immune defense
How does the skin regulate temperature?
To lose/dissipate heat: Blood vessels dilate more blood comes to surface and sweat glands secrete sweat which evaporates to gain heat,
to conserve heat: Blood vessels in dermis constrict at surface and blood is shunted deeper to lose heat
how does the skin defend against immune system?
Epidermal dendritic cells phagocytize(eat up) foreign material
most superficial layer of skin
epidermis
What tissue is in the epidermis?
keratinized stratified squamous epithelium
is the epidermis vascular or avascular?
avascular
how many layers of epidermis thick skin are there?
5 layers
how many layers of thin skin?
4
What are the epidermal ridges?
rounded projections that interlock with the dermis
What is stratified squamous epithelium?
superficial cells that are flattened and deeper cells that are cuboidal and serve for protection, consists of keratinized stratified squamous epithelium
What is nonkeratinized stratified squamous epithelium and where are they?
Alive cells kept moist, oral cavity, pharynx, vagina (openings to body)
what is the dermis and what does it consist of?
the second layer of skin, contains nerve endings, hair follicles, and glands
what tissue is in the dermis?
dense irregular tissue and some areolar connective tissue
What is dermal papillae and where is it?
projections interlocked with epidermal ridges in the dermis
What does areolar connective tissue consist of and what is its function?
fibroblasts, lots of ground substance
function: Packing and binding material together around organs
Is Areolar connective tissue vascular or avascular?
vascular
what does dense irregular tissue consist of and what is its function?
fibroblasts, only a little ground substance, collagen in tightly packed clumps
function: Strength and support, withstands stresses in many directions (pulling skin)
is dense irregular tissue vascular or avascular?
vascular
Where is the subcutaneous layer and what is the function?
the bottom layer of skin deep to integument (technically not part of integument)
function: Stores fat and anchors integument to underlying tissue
What are the features of adipose connective tissue and its function?
Adipocytes and the nuclei are pushed to the periphery of the cell by the fat droplet
function: Energy storage, insulation, protection, support
what tissue is in the subcutaneous layer?
Areolar connective tissue and adipose connective tissue
What do keratinocytes do and where are they found?
found throughout all layers of skin and they produce keratin
what is the life cycle of keratinocytes?
They undergo mitosis, move through all layers and are sloughed off
What do melanocytes do and where are they?
Found in the stratum basale only and Produce melanin
What are freckles?
irregular patches of melanin
What are tactile cells and where are they?
connected to nerve endings for touch and found in the stratum basale only
What are epidermal dendritic cells and where are they?
Ingest bacteria and foreign debris including epidermal cancer cells and found in the stratum spinosum
What is the stratum basale layer?
deepest layer of epidermis, single layer of columnar and cuboidal keratinocytes resting on basement membrane where keratinocytes are constantly dividing mitotically
What is the stratum granulosum layer?
Superficial to stratum spinosum, the 3-5 layers of granular, flattened keratinocytes begin keratinization (die off)
What is the stratum spinosum?
Superficial to the stratum basale, several layers of polygonal shaped keratinocytes (still alive)
What is keratinization?
process where the nucleus shrivels up, cell dies, and cell fills up with protein keratin (barely alive or dead). completes by the corneum layer
What is the stratum lucidum?
Clear layer that’s Superficial to stratum granulosum, only in thick skin, 2-3 layers of pale, flattened anucleate keratinocytes (dead cells)
What is the stratum corneum?
hornlike later that is the most superficial, 20-30 layers of dead anucleate keratinocytes constantly shed
what is the reticular layer and where is it?
Below the papillary layer, direct contact with the subcutaneous layer, contains the secretory portion of sweat glands, oil glands, and hair follicles, and dense irregular tissue
What is the papillary layer and where is it?
Superficial layer of the dermis and contains dermal papillae
What are nails formed by and what is the function?
formed by stratum corneum and its serves for protection for tips of fingers and foes and helps grasp objects
What is the function of hair and what does it consist of?
associated with sebaceous glands and arrector pills muscle,
function: protection against UV rays, sensory reception and heat retention
What does the arrector pili muscle do?
Smooth muscle that causes goose bumps
What do exocrine glands do and where are they found?
found in the secretory portions found in reticular layer of dermis, and they release their secretions through ducts that open onto the service of the epidermis
What are the two exocrine glands?
sebaceous and sweat glands
Most common sebaceous gland and what does it do?
holocrine glands, associated with hair follicles, secretes sebum for lubrication and water proofing of epidermis to prevent brittle hair and causes zits
Function of sweat glands?
excrete waste and cools body
What are the thin skin layers?
Basal layer
Spinous layer
Granular layer
Stratum corneum
