BIO 050A - Chapter 5

The Integumentary System

tissue type of epidermis

keratinized stratified squamous epithelium

tissue type of dermis

areolar connective tissue ( papillary) & dense irregular. conn. tissue. (reticular)

func of skin

1. protectin

2. body temp regulation

3. excretion

4. prod. vit. d

5. sensory reception

list layers of epidermis

stratum basale

stratum spinosum

stratum granulosum

stratum lucidum

strarum corneum

struct & func of stratum basal

1 row of young keratinocytes that actively divide

attaches to dermis

cells - tactile epithelial cells & melanocytes

struct & func of stratum spinosum

less mitosis done here

many layers of keratinocytes united by desosomes

keratinocytes had thick bundles of intermediate filaments made of pre-keratin, which resists tension

cells - keratinocytes & dendritic cells

struct & func of stratum granulosum

layers of flat keratinocytes that contain keratohyaline granules & lamellar granules

organelles of keratinocytes begin to deteriorate at this layer bc its far from dermal capillaries

struct & func of stratum lucidum

only in thick skin, rows of dead keratinocytes

struct & func of stratum corneum

many layer of dead keratinocytes filled with keratin

protects skin from abrasion

layers of dermis

papillary & reticular

struct & func of papillary dermis

areolar conn tiss

has dermal papillae that lie on dermal ridges, which elevate dermis into epidermal ridges

struct & func of reticular dermis

dense irregular conn tissue

form cleavage lines in separations between collagen fibers

cont. collagen & elastic fibers

results in striae when streched

form flexure lines

richly vascularized; contain dermal plexus & subpapillary plexus

struct & func of hypodermis

areolar & apidose conn tiss

anchors skin to underlying structures

stores fat

insulates heat

pigments that contribute to skin color

melanin, carotene, hemoglobin

desc melanin

made from tyrosine

variety in skin color caused by dif amount of & type of melanin prod

passes from melanocytes to keratinocytes

absorbs uv to protect keratinocytes

desc carotene

orange/yellow pigment

desc hemoglobin

allows crimson color of blood to show in caucasion skin

desc structure off nails

made of hard keratin

parts - free edge, nail plate, root

rests on nail bed that thickens into nail matrix

lat & prox borders covered by nail folds; pros nail fold = eponychium

parts of hair

root - embedded in skin

shaft - extends from skin

layers of hair

medulla - central core

cortex - surrounds medulla

cuticle - outermost

parts of hair follicle

hair bulb - deep end

root plexus - sensory nerves around a hair bulb

dermal papilla - capillaries that supply substances for growth

hair matrix - grow to form hair shaft

wall of follicle

arrector pili - raises hair when musc contracts

layers of wall of follicle

peripheral conn tissue sheath - external layer

glassy membrane - basement membrane

epithelial root sheath

sturct & loc of sebaceous glands

loc all over body except palm/soles

simple alveolar gland that prod sebum using holocrine secretion

types of sweat glands

apocrine & eccrine

sturct & loc of sweat glands

all over body except nipples & external parts of genitalia

func in body temp regulation

sturct & loc of eccrine glands

palms, soles, forehead

prod true sweat

sturct & loc of apocrine glands

axilla, anal, genital areas,

prod special type of sweat

mammary glands & ceruminous are modified sweat glands

layers & symptoms of 1st degree burns

epidermis; redness, swelling, pain

layers & symptoms of 2nd degree burns

epidermis + upper part of dermis

blisters form

layers & symptoms of 3rd degree burns

epidermis + dermis & maybe hypodermis

appear white, red, black

how can burns be life threatening

causes fluid lose & can result in fatal ciruclatory shock; pathogens can also invade area

desc basal cell carcinoma

caused by cells in stratum basale, least malignant, most common

desc squamous cell carnimona

stems from keratinoctyes of stratum spinosum, common in POC, can metastisize

desc melanoma

from melanocytes, arise from existing moles, can metastasize rapidly into lymph nodes, arises in less pigmented areas

cells in epdidermis & their func

keratinocytes - make keratin & waterproof skin

melanocytes - make melanin & protect from DNA damage

tactile epithelian cells - touch receptors

dendritic cells - immune defense

loc & func of dermal plexus

loc between reticular dermis & hypodermis

supply dermis, glands, hair

loc & func of subpapillary plexus

loc - beneath papillary layer

supply superficial dermis & support epidermal nutrition

func of keratohyaline granules & lamellar granules

keratohyaline - help form keratin

lamellar - waterproofing

burns are critical if one of these exist:

1. over 10% of bady has 3rd degree burns

2. 25% of body has 2nd degree burns

3. 3rd degree burns on face, hands, or feet

func of dermal papillae

increase surface area; fingerlike projections

func of epidermal ridges

make fingerprints, palmprints, footprints; increase gripping ability

func of collagen fibers in dermis

strenght & resilence

func of elastic fibers in dermis

stretching & recoil properties

cause of flexure lines

dermis attaches tightly to underlying structures

desc holocrine secretion

whole cells break up to form a product

desc rule of nines

body divided into 11 regions, each acounting for 9%. add up the total

rule of nines rubric

ant & post head/neck = 9

ant & post U limbs = 18

ant & post trunk = 36

perinum = 1

ant & post L limbs = 36