Chapter 5 Principles Of Anatomy And Physiology Flashcards
Integumentary system
System that is composed of the skin, hair, oil, sweat glands, nails, and sensory receptors
Dermatology
Medical specialty that deals with the structure, function, and disorders of the integumentary system
Cutaneous membrane
Covers the external surface of the body and is the largest organ of the body in weight. It's your skin
Components of the integumentary system
Epidermis and dermis
Epidermis
Superficial, thinner portion of integumentary system; composed of epithelial tissue; composed of keratinized stratified squamous epithelium
Dermis
The deeper, thicker connective tissue portion of integumentary system
Subcutaneous layer
Deep to the dermis, but not part of the skin. Consists of areolar and adipose tissues. Also called hypodermis
Lamellated Corpuscles
Nerve endings, Sensitive to pressure. Also known as pacinian
Pacinian corpuscles
Nerve endings, Sensitive to pressure. Also known as Lamellated
Keratinocytes
Type of epidermal cells, which are arranged in four or five layers and produce the protein keratin
Keratin
Type of protein, it is tough, fibrous and helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals
Melanocytes
Epidermis cells which develop from the ectoderm of a developing embryo and produce the pigment melanin
Melanin
Yellow-red or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet light
Langerhan cells
Cells that arise from red bone marrow and migrate to the epidermis, where they constitute a small fraction of the epidermal cells. They participate in immune responses mounted against microbes that invade the skin, and are easily damaged by UV light.
Merkel cells
The least numerous of epidermal cells. They are located in the deepest layer of the epidermis, where they contact the flattened process of a sensory neuron. These play a role in sensations
Merkel discs
Tactile discs that detect touch sensations
Thin skin
Epidermis that has 4 strata or layers. Found in most regions of the bodystratum basalestratum spinosumstratum granulosumthin stratum corneum
Thick skin
Epidermis which gets exposed to much friction and has 5 layersstratum basalestratum spinosumstratum granulosumstratum lucidiumthick stratum spinosum
Stratum basale
The deepest layer of the epidermis, composed of a single row of cuboidal or columnar keratinocytes; some are stem cells, so here cells regenerate. Contains melanocytes and merkel cells
Skin graft
The transfer of a patch of healthy skin taken from a donor site to cover a wound
Stratum spinosum
Superficial to the stratum basale; a bit of reproduction; contain lengerhan cells
Stratum granulosum
Consists of three to five layers of flattened keratinocytes that are undergoing apoptosis, as they are far from their source of nutrition (blood)
Keratohyalin
Granules of protein which assembles keratin intermediate filaments into keratin. Present in stratum granulosum
Lamellar granules
Protein granules which fuse which the plasma membrane and release a lipid-rich secretion. Present in keratinocytes
Stratum lucidum
Layer of epidermis that is present only in the thick skin of areas such as the fingertips, palms, and soles; 4-6 layers of flattened dead keratinocytes
Stratum corneum
Consists on average of 25 to 50 layers of flattened dead keratinocytes; thin, flat, plasma membrane-enclosed packages of keratin that no longer contain a nucleus or any internal organelles
Callus
An abnormal thickening of the stratum corneum, which is the result of friction
Karatinization
A process in which the cells move from one epidermal layer to the next, accumulating more and more keratin
Dandruff
An excessive amount of keratinized cells shed from the skin of the scalp
Psoriasis
chronic skin disorder in which keratinocytes divide and move more quickly from the stratum basale to the stratum corneum; make abnormal keratin that forms scales
Papillary region
Makes up about one-fifth of the thickness of the total dermis. It contains thin collagen and fine elastic fibers
Dermal papillae
small, nipple-shaped structured that project into the undersurface of the epidermis
Capillary loops
All dermal papillae contain these, they are blood vessels. Provide nutrient supply to epidermis too
Meissner corpuscles
Type of nerve endings that are sensitive to touch
Reticular region
Dermis, which is attached to the subcutaneous layer, contains bundles of thick collagen fibers, scattered fibroblasts, and various wandering cells.
Extensibillity
The ability to stretch
Elasticity
The ability to return to original shape after stretching
Epidermal ridges
Straight lines or pattern of loops and whorls (like fingers). Create strong bond between the epidermis and dermis in a region of high mechanical stress. Also increase surface area (grip)
Fingerprints (footprints)
The ducts of sweat glands open on the tops of the epidermal ridges as sweat pores that leave marks on things when you touch. Unique for everyone
Dermatoglyphics
The study of the pattern of epidermal ridges (fingerprints)
Tension lines
(lines of cleavage) in the skin that indicate the predominant direction of underlying collagen fibers
Mole
A benign localized overgrowth of melanocytes. Also known as nevus
Melanosome
Organelle where melanocytes sunthesize melanin. Exposure to UV increases the activity
vitiligo
The partial or complete loss of melanocytes from patches of skin produces irregular white spots
Hemoglobin
The oxygen-carrying pigment in red blood cells. Makes skin pinkish or reddish
Carotene
A yellow-orange pigment that gives egg yolks and carrots their color; found in stratum corneum and fatty areas of dermis and hypodermis. White people eating carrots can turn orange
Cyanotic
bluish skin due to lack of oxygen in skin
Jaundice
Yellow skin due to bilirubin. Usually due to liver disease
Erythema
Redness of skin, due to allergies or burns
Pallor
Paleness of skin. Due to shock or anemia
Accessory structures of the skin
Hair, skin glands, and nails. Develop from embryonic epidermis
Hair
Also pilli; present on most skin surfaces; composed of columns of dead, keratinized epidermal cells bonded together by extracellular proteins
Shaft
superficial portion of the hair, which projects above the surface of the skin
Root
The portion of the hair deep to the shaft that penetrates into the dermis, and sometimes into the subcutaneous layer
Hair follicle
Part of the hair that surrounds the root and is made up of an external root sheath and an internal root sheath
Epithelial root sheath
Part of the hair that extends as a downward continuation of the epidermis. Makes up hair the hair follicle.
Dermal root sheath
The dense dermis surrounding the hair follicle
Bulb
Onion-shaped structure that is at the base of each hair follicle.
Papilla of the hair
Part of the hair bulb, which contains areolar connective tissue and many blood vessels that nourish the growing hair follicle
Hair matrix
Germinal layer of cells in hair contained in the bulb. Responsible for growth and regrowth
Depilatory
A substance that removes hair
Electrolysis
An electric current is used to destroy the hair matrix so the hair can't regrow
Arrector pili
Smooth muscle that are associated with hairs. Pulls on hair when scared or cold - goose bumps
Hair root plexus
dendrites of neurons that surround each hair follicle; generate nerve impulses if their hair shafts are moved
Growth stage
Stage in which the cells of the hair matrix divide. for scalp is 2 to 6 years
Regression stage
When the cells of the hair matrix stop dividing, the hair follicle atrophies, and the hair stops growing. for scalp is 2 to 3 weeks
Resting stage
A stage the hair follicle enters after the regression stage. for scalp is 3 months
Alopecia
Partial or complete lack of hair
Lanugo
Nonpigmented, downy hairs that cover the entire body of fetus
Terminal hairs
Long, coarse, heavily pigmented hairs that replace lanugo in some areas (like eyebrows) right before birth
Vellus hairs
peach fuzz. replace lanugo in most areas before birth. During puberty, these will be replaced by terminal hair in certain areas
Hirsutism
Excessive body hair due to excessive production of androgens
Sebaceous glands
Its your oil glands. Simple branched acinar glands that are attached to hair follicles
Sebum
Substance secreted by sebaceous glands. Triglycerides, cholesterol, proteins, inorganic salts
Acne
An inflammation of sebaceous glands that usually begins at puberty
Sudoriferous glands
Sweat glands. Release sweat or perspiration into hair follicles or into the skin surface through pores
Eccrine sweat glands
Simple, coiled tubular sudoriferous glands that are much more common than apocrine sweat glands. Helps regulate body temperature through evaporation
Thermoregulation
The homeostatic regulation of body temperature is known as ______________________.
Thermoregulatory sweating
The role of eccrine sweat glands in helping the body to achieve homeostasis is known as ____________.
Insensible perspiration
Sweat that evaporates from the skin before it is perceived as moisture
Sensible perspiration
Sweat that is exerted in larger amounts and is seen as moisture
Emotional sweating
Also cold sweat. Occurs when eccrine sweat glands release in response to an emotional stress, such as fear or embarrassment. Occurs first in palms and axillae
Apocrine sweat glands
Simple coiled tubular sudoriferous glands that are found in axilla, groin, nipples. Secretory portion opens to hair folicules.
Ceruminous glands
Produce a waxy lubricaing glands, produce a waxy lubricating secretion
Cerumen
Earwax
Nails
Are plates of tightly packed, hard, dead, keratinized epidermal cells that form a clear, solid covering over the dorsal surfaces of the distal portions of the digits
Nail body
The visible portion of the nail
Free edge
The part of the nail body that may extend past the distal end of the digit
Nail root
The portion of the nail that is buried in a fold of skin
Lunula
the white crescent at the proximal end of the nail body
Hyponychium
Nail bed. Thickened region of stratum corneum beneath the nail bed
Eponychium
Cuticle. Narrow band of epidermis. Consists of stratum corneum.
Nail matrix
the proximal portion of the epithelium deep to the nail root. Nail growth
Inflammatory phase
A phase in deep wound healing where a blood clot forms and loosely unites the wound edges
Inflammation
A vascular and cellular response that helps eliminate microbes, foreign material, and dying tissue in preparation for repair
Migratory phase
A phase of deep wound healing in which the clot becomes a scab, and epithelial cells migrate neneath the scab to bridge the wound.
granulation tissue
A tissue filling the wound during the migratory phase
Proliferative phase
A phase in deep wound healing characterized by extensibe growth of epithelial cells beneath the scab
Maturation Phase
A phase in deep wound healing, in which the scab sloughs off
Fibrosis
A process of scar formation
hypertropic scar
scar that remains within the boundaries of the original wound
keloid scar
A scar tissue that extends beyound the boundaries into normal surrounding tissues
Vernix Caseosa
Fatty substance which covers and protects the fetus from constant exposure to the amniotic fluid