Chapter Five- Integumentary System Flashcards
Melanocytes
Skin colour cells that produce and store the pigment melanin
Major functions of the skin
-protection
-prevention of water loss/ secretions
-temperature regulation
-metabolic regulation
-immune system
-sensory reception
Epidermis
Epithelial tissue
-stratified keratinized
-outer thinner layer squamous
Keratinocytes
Provide replacement stem cells and new keratinocytes to replace dead cells
-inhibits evaporation
Langerhan cells
Part of the immune response (phagocytosis)
-key part in epidermal cancer cells
-5%
-present in stratum spinosum and stratum granulosum
Merkell cells
Sensory cells
-sensitive to touch
-when compressed release chemicals that stimulate sensory nerve endings
Stratum bassale
Deepest layer of epidermis
-single layer and tightly attached to underlying basement membrane
-contains merkle cells, keratinocytes and melanocytes
Stratum spinostum
Second from deepest
-non dividing keratinocytes linked together by demosomes
-macrophages and langhern cells
Stratum Granolusm
Third from deepest
-contains keratonin granules
-keratinization begins taking place
Stratum Lucium
Second from top
-thin, translucent region
-only found in thick skin, palms of hand and soles of feet
-keratinocytes
-no nucleus
Stratum Corneum
Top layer
-no nucleus
-anucleate keratinized cells (corneocytes)
-no nutrients
-desmosome breaks down
Cytokeratins
The keratins found in epidermal cells of the skin
-give skin strength and makes it waterproof
Melanin
Accumulates around the nucleus and shields the DNA within the nucleus
Darkening of skin
Takes place by the melanin production, and exposure to ultraviolet light
Keratinization
Keratinocytes fill up with protein keratin
-become thinner and flatter
-becomes a tightly interlocked layer of keratin fibres
-fully keratinized cell is dead, but strong due to keratin
A fully keratinized cell is…
Dead (no nucleus or organelles)
-strong because it contains keratin
Thick skin versus thin skin
Based on number of strata in epidermis
Thick skin
all five epidermal strata
Thin skin
lacks the stratum lucidum (only four layers)
-hair follicles, sebaceous glands, swat glands
Hemoglobin
Oxygen-binding protein present within red blood cells
-bright red colour
Amount of melanin in the skin is determined by
Heredity and light exposure
Carotene
Yellow-orange pigment
-acquired by eating vegetables such as carrots, corn and squash
Albinism
Hair is white, skin is pale, irises of eyes are pink
-lack of melanin production
-inherited recessive condition
-melanocytes cannot produce melanin
Bronzing
Skin appears golden-brown, copper or bronze in colour
-glucocorticoid hormone deficiency in adrenal cortex
-Addison disease
Cyanosis
Skin appears bluish, due to oxygen deficiency in blood
-airway obstruction, respiratory arrest, cardiac arrest or cold weather
Erythema
Skin appears abnormally red
-exercise, sunburn, heat, emotions
-increased blood flow in dermis
Jaundice
Skin and sclera appear yellowish
-elevated levels of bilirubin in blood
-liver function is disrupted
Pallor
Skin appears ashen, due to white collagen fibers in dermis
Dermis
Lies deep to the epidermis
-areolar and dense irregular
-blood vessels, sweat glands, smooth muscle tissue, hair follicles
Layers of Epidermis from deep to superficial
BSGLC
Basale
Spinosum
Granulosum
Lucidum
Corneum
Two major regions of dermis
Superficial papillary layer and a deep reticular layer
Papillary layer
-superficial region of the dermis
-areolar connective tissue
-sensory receptors
Reticular layer of the dermis
Deeper major portion of dermis
-dense irregular connective tissue
-large bundles of collagen fibers project in all directions
Lines of cleavage
Orientation of collagen fiber bundles
Perpendicular incision means
May gape, and delay healing
Incision parallel to cleavage lines
Heals much more quickly
Innervation
To supply with nerves
-nerve fibers are dispersed throughout the dermis
-skin monitor sensory receptors
Vasoconstriction
The diameters of the vessels narrow
-less blood flow
-happens when body is cold
Vasodialation
Diameter of vessels increase
-more blood flow
-when the body is hot
Subcutaneous layer
Deep to the integument
-excessively vascular
-areolar areas function to bind to the underlying tissues
-adipose areas function as fat
Nail matrix
Actively growing part of the nail
Lunula
Whitish semilunar area
Cuticle
Narrow band of epidermis, onto the nail body
Hyponychium
Region of thickened stratum Corneum, the free nail edge projects
Phalanx
Finger bone
Free edge
Part of the nail that is unvascularized
Hair bulb
Swelling at the base of the bulb
-made up by Epithelial cells
Hair papilla
Small portion of connective tissue
-tiny blood vessels and nerves
Root
Portion of the hair deep to the skin surface
Shaft
Portion of the hair that extends beyond skin surface
Hair matrix
Hair production
-specialized type of keratinization
Medulla
Remnant of the soft core of the matrix
-loosely arranged cells, soft keratin
Cortex
Several layers of flattened cells closer to the outer surface
Cuticle
Multiple cell layers around the cortex
-coats the hair
Outer most
Hair follicle
Oblique tube that surrounds the root hair
Arrector pili muscles
Stimulated in response to emotional state, or temperatures
-muscle contracts, pulling follicles elevating the hairs
-goose bumps
Functions of hair
-protection
-heat retention
-sensory reception
-visual identification
Apocrine sweat glands
Produce viscous, complex secretion
-influenced by hormones
-axillary, anal, areolar and pubic regions
Merocrine sweat glands
Watery secretion
-controlled by nervous system
-antibacterial protection, thermoregulations
Found thoughout the body, especially prominent on palms, soles and forehead
Sebaceous glands
Produce sebum
-associated with hair follicles
Sebum
Coats epidermis and shaft of hair
-lubrication and antibacterial activity
Ceruminous glands
Waterproof earwax called cerumen
-lubricates the ear
Mammary glands
Breast milk to nourish offspring
-breasts
