integumentry

order of layer of epidermis

Come Let's Get Sun Burns

-Stratum Corneum

-Stratum Lucidum

-Stratum Granulosum

-Stratum Spinosum

-Stratum Basale

epidermis is made out of

stratfied squamos epithelium, made up of most body

stratum corneum

can see dead ketoyctye that exfolate

stratum lucidum

light layer , kertincytes only in palms soles

stratum granulosm

main waterporrofing layer, kertyocytes realse lipids as they die

startum spinosum

visuble dsmoses between keratinocytes denotitic cell ( macrophing= immune cells)

startum basale

most active of epidermis layer; ketinocytes, stemm cells, prevnts water froom getting out

melanocytes= melalin (skin color) taxtile cel ( senstivivity, touch)

meloncytyes inject

melanin into new ketinocytes

more melanain granuels equals

the more rows or melanain granuels means darker skin

Epidermal water barrier

forms primarily in stratum

granulosum, locks in water to prevent dehydration

Cells above the water barrier

die, barrier cuts them off from nutrients below

• dead cells exfoliate (dander)

Dermis

connective tissue layer beneath the epidermis

▪ Composed mainly of collagen with elastic fibers,

reticular fibers, and fibroblasts

Hair follicles and nail roots are embedded in

dermis

Smooth muscle (piloerector muscles)

associated with hair follicles (contract-goose bumps)

Dermal papillae

ridges on fingertips that create

papillary layer

outer layer of the dermis, directly beneath the epidermis,superficial zone of dermis

• thin zone of areolar tissue in and near the dermal

papilla

• rich in small blood vessels

Reticular layer

deeper and much thicker layer of dermis

• consists of dense, irregular connective tissue

• stretch marks (striae) - tears in the collagen fibers

caused by stretching of the skin due to pregnancy or

obesity

• Very tough!- layer used to make leather

go against dermal tension line ir cleavage line

harder time healing , scaring but if follow line everything is fine

Hypodermis

Subcutaneous tissue,More areolar and adipose

than dermis, needles go into hypodermis

Subcutaneous fat

• energy reservoir

• thermal insulation

• 8% thicker in women

melanin

how much and how long does it last. not number of melocytes, only in epidermis

Hemoglobin

red pigment of red blood cells

Carotene

yellow pigment acquired from egg yolks and

yellow/orange vegetables.concentrates in stratum corneum and subcutaneous fat

Cyanosis

blueness of the skin from deficiency of oxygen in the

circulating blood

Erythema

abnormal redness due to dilated cutaneous vessels

• exercise, hot weather, sunburn, anger, or embarrassment

Pallor

emotional stress, low blood pressure, circulatory shock, cold,

anemia

Albinism

recessive genetic lack of melanin that results in white

hair, pale skin, and pink eyes

Jaundice

yellowing of skin and sclera due to excess of bilirubin in

blood from compromised liver function. most common in abbies its not threatning.

hematoma

(bruise) mass of clotted blood showing through skin

UVR has a desirable effect:

stimulates synthesis of vitamin D necessary for dietary calcium absorption

UVR has two adverse effects:

causes skin cancer

Friction ridges

deep dermal papillae, oily finger tips

Freckles and moles

tan to black aggregations of melanocytes. freckles is a response to light, moles is small bengin tumor, if gets bigger than harmful.

Hemangiomas

(birthmarks) - patches of discolored skin

caused by benign tumors of dermal blood capillaries

Hemangiomas

Benign tumor of the capillaries. fade later

Types of Human Hair

lanugo (only baby), vellus (arm hair, leg hair), terminal (thickest, so eyebrow , puberty hair, facial hair,, eyelash)

Types of human hair

bulb - a swelling at the base where hair

originates in dermis or hypodermis

― only living hair cells are in or near

bulb

• root - the remainder of the hair in the

follicle

• shaft - the portion above the skin

surface

dermal papilla

bud of vascular connective

tissue encased by bulb

• provides the hair with its sole source of

nutrition

hair matrix

region of mitotically active cells

immediately above papilla

• hair's growth center

Three layers of the hair in cross-section

from inside out

medulla, cortex, cuticle

medulla

core of loosely arranged cells

and air spaces, always inner or middle

cortex

constitutes the bulk of the hair

― consists of several layers of

elongated keratinized cells, outer layer

Follicle

diagonal tube that dips

deeply into dermis and may extend

into hypodermis

• epithelial root sheath

• connective tissue root

Hair receptors

are nerve fibers that

entwine each follicle that respond

sweat ans sedbucias glands

open the hair follicle.

hair eumelanin

darker shades of hiar skin , true is most common

phuemelanin

lighter shades of hair

hair cycle

Anagen (early) 2 3

(Growing phase, 6-8 years), carry buldge which is extra stem cells,

Catagen

(Degenerative phase, 2-3 weeks)

Telogen

(Resting phase, 1-3 months)

We lose about_____scalp hairs daily

50 - 100

Alopecia

thinning of the hair or baldness

Pattern baldness

the condition in which hair loss from specific regions

of the scalp rather than thinning uniformly

• combination of genetic and hormonal influence

• baldness allele is dominant in males and expressed only in high

testosterone levels

• testosterone causes terminal

Two kinds of sweat (sudoriferous) glands

apocrine and merocrine

merocrine (eccrine) sweat glands

watery substace when we sweat to cool body down, comes from blood, simple tubular glands. myoepithelial cells - contract in response to stimulation by sympathetic

nervous system and squeeze perspiration up the duct

apocrine sweat glands

only @ puberty, sweat is bacteria so causes it to smell

pheromones

chemicals that influence the physiology of behavior of other

members of the species. women syncing up so periods

whihc skin gland associates with pheromones

apocrine sweat glands

acid mantle

inhibits bacterial growth

insensible perspiration

does not produce visible wetness of skin

diaphoresis

sweating with wetness of the skin

― exercise - may lose one liter of sweat per hour

Sebum

oily substance secreted by sebaceous glands

Holocrine gland

secretion consists

of broken-down cells

Ceruminous Glands

ear wax, prevents infections, combines with sebum and dead

epithelial cells

Mammary Glands

Breasts (mammae) of both sexes contain little

glandular material

• Release milk by apocrine process

Polymastia:

additional developed breasts

Dermatitis

inflammation

UVB

is used for vitamin-D synthesis, higher energy

ABCDE rule

asymmetry, border, color, diameter, evolvingABCDE Rule

Basal Cell Carcinoma

Arises from cells of stratum basale & invades

dermis, slow growing

Squamous Cell Carcinoma

Arise from keratinocytes from stratum spinosum,scalp, ears, lower lip,

or back of the hand

▪ Chance of recovery good with early detection

Most deadly skin cancer

Most deadly skin cancer

▪ Arises from melanocytes of a preexisting mole

▪ Highly metastatic, & resistant to chemotherapy

deaths result primarily from ______, infection and toxic effects of

eschar - burned,

fluid loss

first-degree burns

partial thickness burn - involve only the epidermis

second-degree burns

- partial thickness burn - involve the epidermis and

part of the dermis

third-degree burn

full thickness burn - the epidermis and all of the

dermis, and often some deeper tissues (muscles or bones) are destroyed

Over 25% of the body has second-degree burns

• Over 10% of the body has third-degree burns

• There are third-degree burns on face, hands, or feet

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