Integument System Flashcards
What makes up the integumentary system?
Skin, hair, nails, sweat glands, sebaceous glands
The skin or integument is the body’s ____?
Largest organ
What is the function of the integumentary system?
Protect internal body structure
The two layer of the integument are ______ and _______.
Epidermis and Dermis
The epidermis is made of ____.
Stratified squamous epithelium
The dermis is the deeper layer, and made primarily up of _____.
Dense irregular connective tissue
The subcutaneous layer is:
Deep to dermis, with a layer of a replace connective tissue, also called hypodermis, not apart of integumentary system, involved in structure and function of skin
The epidermis is made of what?
Karatinized, stratified squamous epithelium
What are the layers of strata in the epidermis? Which are live and which are dead?
Stratum corneum -dead
Stratum lucidum -dead
Stratum granulosum -live
Stratum spinosum -live
Stratum basal -live
Stratum Basale:
Deepest layer in epidermis,
One layer thick,
Attached to basement membrane,
Have 3 cell types: keratinocytes, melanocytes, and tactile or merkel cells
Define keratinocytes
Most abundant cell type in epidermis, can be found on all layers of epidermis, make keratin, keratin strengthen skin and waterproof it
Define melanocyte
Produce melanin, then the melanin gets packaged and internalized by keratinocytes in higher layers
Define Tactile cells/ merkel cells
Sensitive to touch,
Pressure causes them to release Chemicals which are then detected by free nerve endings
Stratum spinosum:
Several layers of polygonal keratinocytes,
Spiny layer,
Has epidermal dendritic or Langerhans cells (immune cells),
Keratinocytes make keratin, strengthening tissue
How do epidermal dendritic, langerhans cells fight infection?
By phagocytosing pathogens and starting an immune response
Stratum granulosum:
Three to five layers of keratinocytes,
Granular layer,
First layer of keratinization,
What is keratinization?
The process where keratinocytes fill with keratin causing nucleus and organelles to disintegrate. The fully keratinized cell is dead but the structurally sound process is not complete until there are more superficial layers.
Stratum Lucidum
Two to three layers of keratinocytes,
Translucent/ clear layer,
Found on thick skin- palms and soles,
Filled with translucent protein called eledin, intermediate product in keratin maturation, protects skin form UV light
Stratum corneum:
20-30 layers of dead, interlocking keratinized cells,
Cells annucleate and tightly packed plasma membrane enclosing keratin protein,
Hornlike layer,
Unsuitable layer for growth of microorganisms,
Secretion of exocrine glands help with growth prevention,
Originate from stem cells in basale,
Migrate through starts to stratum corneum over two weeks undergoing structural changes, renewing in corneum another two weeks,
are shed
What are the variations in the epidermis:
Different body regions,
Between individuals,
Thickness, color, and skin markings
Characteristics of thick skin:
On palms, soles, fingers and toes
5 layers of epidermal strata
Sweat glands
No hair follicles or sebaceous glands
.4- .6 mm thick
Characteristics of thin skin:
Covers most of body,
Lacks a lucidum,
Has sweat glands, hair follicles, and sebaceous glands,
.075 to .150 mm thick
What are some variations in the epidermis in regards to color and skin markings?
Hemoglobin,
Melanin,
Carotene,
Nevis,
Freckles,
Hemangioma,
Friction ridges
Coloring from hemoglobin?
An oxygen binding compound that is present in red blood cells.
Bright red color upon binding oxygen,
Gives blood vessels in dermis a reddish tint,
Seen most easily in those who are fair skinned,
More visible if the blood vessels dilate
Color from melanin:
Produced and stored in melanocytes,
Black, brown, tan, and yellow brown shades,
Transferred to keratinocytes in stratum basale,
Amount depends on heredity and light exposure,
UV light stimulates melanin production,
All people have same amount of melanocytes- the activity and color depends on individual
Color from carotene:
Yellow orange,
From yellow orange veggies,
Accumulate inside subcutaneous fat and keratinocytes of corneum,
Converted to vitamin A within body,
Plays a role in vision and reducing free radicals in immune function
What is a Nevus?
Mole,
Harmless overgrowth of melanin,
Rarely malignant
What are freckles?
Yellowish or brown spots,
Area of increased melanocyte activity,
Based on sun exposure and heredity
What is hemangioma?
Skin discoloration due to benign blood vessel tumor
Capillary hemangiomas
Bright red to deep purple nodules,
Present at birth but disappear in childhood,
Strawberry colored birthmarks
Cavernous hemangioma’s
Larger dermal blood vessels,
may last lifetime,
Port wine stains
What are friction ridges?
Complex arches and whorls on finger, palms, soles and toes.
Form large folds and valleys of dermis and epidermis,
Help increase friction on contact,
Each individual has a unique pattern of friction ridges, allows for personal identification.
Dermis:
Deep to epidermis, .5 mm to 3 mm,
composed of connective tissue,
collagen elastic and reticular fibers,
Motile dendritic cells serving immune function,
Blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings, arrector pili,
Divided between papillary layer and deeper reticular layer.
Papillary layer of dermis:
Composed of areolar connective tissue,
Contain capillaries and sensory nerve endings,
Projection of epidermis in interdigitating with papillae is called epidermal ridges,
Interlock and increase the area of contact between layers
Reticular layer of dermis:
Deep and major portion of dermis,
Extends from papillary to subcutaneous layer,
Consists of dense irregular connective tissue,
Large bundles of collagen fibers,
Interwoven to a mesh work surrounding structures in dermis.
