Chapter 5: The Integumentary System Flashcards
cutaneous membrane
another name for skin
functions of the integumentary system
- Regulates body temperature.
- Stores blood.
- Protects body from external environment.
- Detects cutaneous sensations.
- Excretes and absorbs substances.
- Synthesizes vitamin D.
components of the integumentary system
- epidermis
- dermis
- subcutaneous layer
- hairs
- nails
- glands
epidermis is composed of
keratinized stratified squamous epithelium
keratinocytes
- 90% of epidermal cells
- produce keratin
- produce lamellar granules
keratin
- tough,
- fibrous
- intracellular protein that helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals
lamellar granules
- release a water‐repellent sealant
- decreases water entry and water loss and inhibits the passage of foreign materials
melanocytes
-produce the pigment melanin
melanin
- yellow‐red or brown‐black pigment
- contributes to skin color
- absorbs damaging ultraviolet (UV) light
UV protection
- Once inside keratinocytes, the melanin granules cluster to form a protective veil over the nucleus,
- on the side toward the skin surface. In this way, they shield the nuclear DNA from damage by UV light.
- Although their melanin granules effectively protect keratinocytes, melanocytes themselves are particularly susceptible to damage by UV light.
Langerhans cell
Epidermal dendritic cell that functions as an antigen‐presenting cell (APC) during an immune response. Also called an intraepidermal macrophage.
Merkel cell
Type of cell in the epidermis of hairless skin that makes contact with a tactile (Merkel) disc, which functions in touch. Also called a tactile epithelial cell.
the five layers of the strratum
- basale
- spinosum
- granulosum
- lucidum
- corneum
basale
deepest layer
-composed of a single row of cuboidal or columnar keratinocytes
Stratum Granulosum
consists of three to five layers of flattened keratinocytes that are undergoing apoptosis
- water proofing
- last layer of O2, too far
Stratum Spinosum
numerous keratinocytes produced by the stem cells in the basal layer, arranged in 8–10 layers
Stratum Lucidum
present in the thick skin of areas such as the fingertips, palms, and soles
four to six layers of clear, flat, dead keratinocytes that contain large amounts of keratin and thickened plasma membranes
-thick dead skin
Stratum Corneum
consists on average of 25 to 30 layers of flattened dead keratinocytes
dermis
A layer of dense irregular connective tissue lying deep to the epidermis.
region of the skin that leather is made from
dermis
papillary region of the dermis
The superficial portion of the dermis (about one‐fifth); consists of dense irregular connective tissue with thin collagen fibers and fine elastic fibers; contains dermal papillae that house capillaries, corpuscles of touch, and free nerve endings.
reticular region of the dermis
The deeper portion of the dermis (about four‐ fifths); consists of dense irregular connective tissue with bundles of thick collagen and some coarse elastic fibers. Spaces between fibers contain some adipose cells, hair follicles, nerves, sebaceous glands, and sudoriferous glands.
hypodermis
- subcuatneous layer
- areolar and adipose tissue
- attaches dermis to the fascia of the body
hypodermis function
- attaches dermis to facia of the body
- allows movement of muscle tissue below
- protection
skin pigments
- melanin
- carotene
- hemoglobin
melanin
A brown pigment produced by melanocytes.
-freckle/ moles
Albinism
bnormal, nonpathological, partial, or total absence of pigment in skin, hair, and eyes.
vitiligo
the partial or complete loss of melanocytes from patches of skin, produces irregular white spots. The loss of melanocytes may be related to an immune system malfunction in which antibodies attack the melanocytes.
tyrosine
- amino acid
- produce melanin
carotene
Antioxidant precursor of vitamin A, which is needed for synthesis of photopigments; -yellow‐orange pigment present in the stratum corneum of the epidermis. -Accounts for the yellowish coloration of skin.
-accumulates in the stratum corneum and the fat of the hypodermis
hemoglobin
The skin of light‐skinned individuals, which has little melanin in the epidermis, appears translucent and its color ranges from pink to red depending on the oxygen content of the blood moving through capillaries in the dermis
skin appendages
- hair
- sebaceous glands (grease)
- sweat glands
- nails
hair
dead keratinized cells secreated from the living hair follicle
sebaceous glad (grease)
-secreate sebum which protects and condions the skin
sweat glands
- secreat sweat (blood filtrate)
- 99% water
- sudoriferous
nails
-scale like modication of the epidermis
burns
- caused by rapid fluid loss and reduced blood flow
- infection risk is high
- classified by severity
canser of the epithelia (carcinoma)
-fastest growing canser in the western hemisphere
melanoma
-greater than or equal to 4mm in length
The substance that prevents excessive evaporation of water from the skin, keeps the skin soft and pliable, and inhibits the growth of bacteria is:
sebum
Tyrosinase is an enzyme necessary for the production of:
melanin
the most abundant cell in the epidermis, and produces a tough, fibrous, protective protein?
keratinocytes
the correct order of epidermal layers from deep to superficial (in thick skin)?
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
The layer of the skin that contains both interwoven bundles of collagen fibers and the protein elastin, and is responsible for the strength of the skin, is the
reticular layer
____________ are cells that produce the skin pigment that absorbs ultraviolet light.
melanocytes
The layer immediately deep to the stratum basale (germanitivum) of the epidermis is the
papillary layer
The layer of the skin that contains sweat and oil glands, as well as hair follicles would be which of the following?
reticular layer
Which epidermal cell is part of your immune system, helping to recognize foreign substances or antigens?
Langerhan cells
Which layer of the epidermis contains three to five layers of keratinocytes undergoing apoptosis?
stratum granulosum
The dermis is comprised of what tissue type?
dense irregular connective tissue
reticular region
The reticular region of the dermis is a thin, superficial layer with projections into the epidermis.
The most superficial layer of the dermis is the:
papillary region
