chapter 4 skin and body membranes. chapter 4 vocabulary 4a body membranes pericardium cutaneous...
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CHAPTER 4
SKIN
and
BODY MEMBRANES
CHAPTER 4 VOCABULARY 4A
body membranes pericardiumcutaneous membranes peritoneumdermis pleuraepidermis serous fluidepithelial membranes stratum basaleIntegument stratum corneumintegumentary system stratum lucidumkeratin subcutaneous tissue/hypodermismelanin synovial membranesmelanocytes
CHAPTER 4 VOCABULARY4B
acne medulla
apocrine glands Meissner's corpuscles
arrector pili nail
athlete's foot papillary layer
cold sores psoriasis
cuticle reticular layer
decubitus ulcers sebaceous glands
dermal papillae seborrhea
eccrine glands sebum
impetigo sudoriferous glands
Color Sheet Color Code-plate 104Stratum corneum – red shaft – light blue
Stratum lucidum – orange follicle – dark green
Stratum granulosum – yellowyellow bulb of follicle - tan
Stratum spinosum – light greenlight green matrix - lavendar
Stratum basale – blue dermal papilla - aquaaqua
Connective tissue – pinkpink arrector pili – dark pink
Papillae – purple sebaceous gland - goldgold
Nerve – gray sweat gland - green
Artery – dark blue superficial fascia –
Vein – orange peach/fleshpeach/flesh
Lymphatic vessel – brown
Color Code – Plate 105Epidermis – red
Dermis – pink
Superficial fascia – peach
Pain Free Nerve Endings – orange
Touch Merkel’s Discs Meissner’s Corpuscles Root Hair Plexuses – yellowyellow
Pressure Pacinian Corpuscles – green
Cold Krause Corpuscles – blue
Heat Ruffini Corpuscles - purple
I. Body Membranes
A. cover surfaces
line body cavities
form protective sheets around organs
B. classified into:
1. Epithelial membranes
2. Connective tissue membranes
II. Epithelial membranes
A. include:
cutaneous membrane (skin)
mucous membranes
serous membranes
B. Cutaneous Membrane
1. Superficial layer epidermis
2. Underlying(deep) layer dermis
C. Mucous Membranes
1. composed of epithelium resting on a loose conn. tiss. membrane called a
lamina propria
2. type of epithelium varies with the site
3. lines all body cavities that open to the exterior
4. lines hollow organs of the resp., dig., and reprod. tracts
D. Serous Membranes
1. simple squamous epithelium resting on a thin layer of areolar conn. tiss.
2. line body cavities that are closed to the exterior
3. occur in pairs:
a. parietal layer – lines a specific portion of the wall of the
ventral body cavity
b. visceral layer – covers the outside of the organs in that cavity
4. Specific name depends on location
a. peritoneum – lines abdominal cavity and covers its
organs
b. pleura – surround the lungs
c. pericardium – around the heart
5. Name examples:
a. parietal pleura – line the body cavity around the lungs
b. visceral pleura – covers the outside of the lungs
III. Integumentary System
A. skin, hair, nails, sweat & oil glands
B. cutaneous membranes skin
C. functions:
1. keeps H2O & other molecules in
2. keeps H2O & other things out (can swim and not get waterlogged)
The above is possible due to keratin
3. regulates heat loss from body surface (due to capillary network and sweat glands)
4. synthesizes vitamin D (modified cholesterol in skin is converted by sunlight)
D. structure of skin (pg. 112, 113)
1. composed outer epidermis firmly connected to underlying dermis
2. Subcutaneous tissue
a. also called hypodermis
b. deep to the dermis
c. serves as a shock absorber
E. Epidermis
1. avascular
2. layers: (from inner to outer)
a. stratum basale
*deepest cell layer
*where millions of new cells are
produced daily
*also called stratum germinativum
b. stratum spinosum – next layer
c. stratum granulosum – 3rd layer
d. stratum lucidum
*layer in wh/ cells b/c flatter, increasingly full of keratin
and finally die
*not seen in all skin regions (only where skin is hairless
and extra thick – palms and soles)
e. stratum corneum
*outermost layerA totally new epidermis occurs every 25-45 days
3. melanin
a. pigment in skin
b. ranges from yellow to brown to black
c. produced by melanocytes
(found in stratum basale)
d. a natural sunscreen
F. Dermis
1. makes up mj. portion of skin
2. made of dense (fibrous) c.t. consisting of 2 regions:
a. papillary
b. reticular
3. papillary layer
a. upper dermal region
b. has fingerlike proj. of dermis into the epidermis dermal papillae
c. many contain capillary loops
(furnish nutrients to epidermis)
d. house receptors:
*pain – free nerve endings
*touch – Meissner’s corpuscles
e. papillae form fingerprints
4. reticular layer
a. deepest skin layer
b. contains:
*blood vessels
*sweat glands
*oil glands
*deep pressure receptors
Pacinian corpuscles
G. skin appendages
1. sebaceous glands (oil glands) pg. 117
a. found all over the skin except palms and soles
b. product sebum (a lubricant)
*keeps skin soft & moist
*prevents hair from b/cing brittle
*contains chemicals that kill bacteria
c. b/c active when male sex hormones are prod. in increasing amts. (in both sexes)
2. sudoriferous glands(sweat glands) pg. 117
a. 2 types:
*eccrine glands
*apocrine glands
b. eccrine glands
*> #ous, found all over body
*produce sweat
*imp. & highly efficient part of body’s heat-regulating equipment (thermoregulators)
c. apocrine glands
*found in axillary & genital areas
*product fatty acids & proteins wh/ empty
i/t hair follicles
*minimal role in thermoregulation
3. hair (pg. 118, 119)
a. minor protective functions
b. composed primarily of dead keratinized cells
c. hair follicles
*produce hair
d. root
*part of hair enclosed in follicle
e. matrix
*÷ to form hair cells
f. layers of a hair
1) medulla
central core
2) cortex
surrounds medulla
3) cuticle
*outermost layer that encloses cortex
*single layer of overlapping cells (roof shingles)
*most heavily keratinized region
g. hair follicle structures
1) epidermal sheath
*inner part
2) dermal sheath
*outer part
3) arrector pili
*small bands of smooth muscle cells
*connect to ea. side of hair follicle
*contraction hair to be pulled upright forming “goose bumps”
(helps keep animals warm)
4. nails (pg. 120)
a. modification of epidermis
b. nail matrix
*thickened proximal area
*responsible for nail growth
c. transparent & colorless
(appear pink b/c of rich blood supply in underlying epidermis)
d. lunula
*area of thickened nail matrix
*appears as a white crescent
IV. Skin Conditions/Infections/Allergies
A. decubitus ulcers (pg. 116)
1. also called bedsores
2. occur in bedridden patients that are not turned regularly
3. weight of body puts pressure on skin
Decubitus ulcers (bedsores)
B. acne
active infection of the sebaceous glands accompanied by pimples
C. Seborrhea
1.overactivity of sebaceous glands
2.forms a yellow to brown crust that sloughs off as dandruff
D. athlete’s foot
fungal infection b/t toes
E. boils
inflammation of hair follicles and sebaceous glands
Boil
Carbuncle
Acne
Seborrhea
Athlete’s foot
F. cold sores (pg. 121 pic. A)
1.fluid-filled blisters, itch and sting 2.caused by herpes simplex infection
G. impetigo (pg. 121 pic. B)
1.H2O-filled lesions around nose & mouth
2.caused by staphylococcus infection
H. psoriasis (pg. 121 pic. C)
overprod. of skin cells dry, silvery scales
impetigo
psoriasisCold sores
I. Burns (pg. 122)
a. 2 life-threatening problems may occur:
1.dehydration & electrolyte imbalance
2. kidney shutdown & circulation shock
b. 1st degree burns
1. only epidermis is damaged
2. temporary discomfort, heals in 2-3 days
c. 2nd degree burns
1. damage to epidermis & upper dermis
2. red, painful, blisters appear
3. regrowth of epithelium can occur; usu. no permanent scars
1st & 2nd degree burns are partial-thickness burns
d. 3rd degree burns
1. destroy entire thickness of skin
2. full-thickness burns
3. since nerve endings are destroyed burned area is not painful
4. regeneration not possible skin grafting is necessary
1st degree burns
2nd degree burns
3rd degree burns
J. Skin Cancer
1. basal cell carcinoma (pg. 123 A)
a. < malignant, > most common
b. malignancy of the lowest epidermal layer
2. squamous cell carcinoma (pg.123B)
a. involves cells of stratum spinosum
b. believed to be sun-induced
3. malignant melanoma(pg. 123C)
a. cancer of melanocytes
4. ABCD rule for melanoma:
A-asymmetry
B-border irregularity
C-color (areas of diff. colors)
D-diameter (> 6mm)
Basal Cell Carcinoma
Squamous Cell Carcinoma
Melanoma
K. aging
1. amt. of subcut. tissue decreases
causes intolerance to cold
2. oil prod. decreases drier skin
3. thinning of skin > bruising
4. decrease in skin elasticity bags under eyes, sagging jowls
(sped up with smoking & sun)
5. reduction in # of hair follicles
hair thinning/balding (alopecia)