integumentary system

integumentary

system consists of: skin, hair, nails

epidermis

skin layer consisting of

• stratified squamous (keratinized) epithelium

• (avascular)

• self repairing

• protective and flexible

basement membrane

in between the epidermis and dermis skin layers.

• basal: toward

• apical: away

dermis

skin layer consisting of

• connective (vascular) tissue

hypodermis

below the skin layer. NOT A SKIN LAYER.

• aka subcutaneous

• adipose connective tissue

skin

largest/main organ of the body.

accessory structures:

• hair/pilus

• nails

• glands

apoptosis

programmed cell death (cell suicide); removes abnormal or unnecessary cells. often blocked in cancer cells

necrosis

uncontrolled death of cells/tissues due to

• injury,

• disease,

• infection,

• lack of blood flow,

• or extreme conditions

cancerous

abnormal cells that divide uncontrollably and destroy tissue

benign

non-cancerous tumor; grows slowly and does not spread

malignant

cancerous tumor; can spread to other areas

metastasis

spread of cancer from original site to other body parts

oncogene

mutated gene that promotes cancer development

lesion

area of damaged tissue

scab

dried blood clot protecting a wound

scar tissue

repaired tissue with fewer collagen fibers and blood vessels

regenerative

able to regrow or repair damaged tissue

debridement

removal of dead (necrotic) tissue to promote healing

erythma

skin color: red

cause: increased blood flow

cyanosis

skin color: blue

cause: low oxygen

pallor

skin color: pale

cause: reduced blood flow or anemia

jaundice

skin color: yellow

cause: buildup of bilirubin

hematoma

skin color: black/blue

cause: blood vessel injury

dermatitis

name the skin condition: skin inflammation

vitiligo

name the skin condition: loss of melanocytes causing patchy skin color

albinism

name the skin condition: little or no melanin production

alopecia

name the skin condition: hair loss

stretch marks

name the skin condition: torn collagen fibers.

cutaneous

skin or ________ membrane

pilus

(aka hair)

types

1. lanugo

2. vellus

3. terminal

lanugo

hair structure: fine fetal hair before birth

vellus

hair structure: thin body of hair of children and adults

terminal

hair structure: coarse hair of scalp, eyebrows, beard, etc

epidermal cells

• keratinocytes: produces keratin protein, most abundant

• melanocytes: produces melanin

• merkel (tactile): touch sensation

• langerhans (dendritic): immunity

thick skin

the mnemonic Come Let’s Get Sun Burnt is used to memorize the ____ skin layer of the epidermis from superficial → deep.

• stratum corneum

• stratum lucidum

• stratum granulosum

• stratum spinosum

• stratum basale

stratum basale

deepest epidermal layer.

• cell division

• a single layer of stem cells and keratinocytes rests on basement membrane

  • also contains some: few melanocytes and merkel cells

stem cells

• in the stratum basale

• divide and give rise to keratinocytes, which replace worn-out epidermal cells

stratum spinosum

• spiny layer

• several layers of keratinocytes

• joined together by desmosomes and tight junctions

• also contains some dendritic cells

• keratin productions begins

stratum granulosum

• three to five layers of flat keratinocytes

• cells have: dark-staining keratohyalin granules

• keratinization begins

stratum lucidum

• thin, pale layer only found in thick skin (palms and soles)

• thin, translucent layer of dead keratinocytes

• provides extra protection