T1 Integumentary System

components of dermis layer

ct, dense, fibrous, blood vessel, nerves

components of hypodermis

subcutaneous, ct

skin layer injections are injected into and why

hypodermis because fat absorbs well

functions of the skin

maintain homeostasis, site of Langerhans (APC), produce vitamin D

epidermis characteristics

keratinized stratified squamous, basement membrane, no vasculation

thick skin locations

palm, sole

what component is in thin skin that isn’t in thick skin

hair

epidermis layers starting from basement membrane

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

cell types of epidermis

keratinocyte (majority), melanocyte, langerhans, merkel

what cell junction is present in stratum basale

hemidesmosome

stratum basale characteristics

single layer with mitosis (stem cell), keratinocytes rest on basement membrane

stratum spinosum characteristics

spikes from cell surface (prickle cells), langerhans

function of tonofibrils

bind to desmosome for cohesion and resistance to abrasion

stratum granulosum characteristics

keratohyalin granules (cysteine), lamellar granules (lipid coats), more purple

stratum lucidum characteristics

lack nucleus, only in thick skin, contain keratin filaments and eleidin

stratum corneum characteristics

lack nucleus, contain keratin, shed every 25 days

melanocyte location

stratum basale

dermal papilla

invaginations of dermis into epidermis

epidermal ridge

invaginations of epidermis into dermis

keratinocyte characteristics

originate from stratum basale, mitosis

melanocyte characteristics

originate from neural-crest cells, round nucleus with space around it, in basale, no desmosome

langerhans cell morphology

resemble melanocyte but in spinosum

melanin pigment formation

tyrosine > DOPA > dopaquinone > phenomelanin, eumelanin > transfer from melanocyte to keratinocyte

skin brightening mechanism blocks

tyrosinase

albinism

melanocytes can’t synthesize melanin

langerhans characteristics

found in all layers (especially spinosum), no desmosome

merkel (tactile) cells

derived from neural crest, found in stratum basale, in fingertips

carotene

yellow pigment from egg and vegetables

melanin accumulate where

keratinocytes of S. basale and S. spinosum

dermis characteristics

ct with fibers, contains glands and nerve endings

dermis layers and which is majority

papillary, reticular (majority)

papillary layer

loose ct, vascularized, dermal papillae

reticular layer

dense irregular ct, glycoaminoglycan for skin hydration

bullous pemphigoid

autoimmune blistering of dermis-epidermis junction

hypodermis

superficial fascia (subcutaneous), loose ct with adipose, contain sweat glands and hair

skin aging in epidermis, melanocytes, collagen and elastin, oil, subcutaneous fat, sweat

epidermis thinning but same number of cell layers, melanocytes increase in size but less amount, changes in collagen and elastin, less oil produced, thinner subcutaneous fat, less sweat produced

1st degree burn

epidermis, sun burn

2nd degree burn

blisters, epidermis and dermis

3rd degree burn

all layers of skin, fire

4th degree burn

all layers + muscle

cutaneous wound healing

blood clot vessels bleed into wound, blood clot and leukocytes clean wound, blood vessels regrow, granulation tissue forms, epithelium regenerates and fibrosis occurs

squamous cell carcinoma

originate from keratinocyte in sun exposed areas

basal cell carcinoma manifestations

white nodules or waxy bumps

epidermal derivative groups

pilosebaceous apparatus (hair and sebaceous), sweat glands (eccrine and apocrine)

location of hair root

dermis

sebaceous gland secrete into

hair follicle

merocrine sweat gland secrete into

epidermis

apocrine sweat gland secretes into

hair follicle

arrector pilli

smooth muscle attach to hair, involuntary (ANS)

primary hair

lanugo

secondary hair

vellus

hair is

filamentous keratinized epidermal invaginations

structures of hair from outside to inside

ct sheath, root sheath, cuticle, cortex, medulla

types of sweat glands

apocrine, merocrine

sebaceous gland characteristics

flask-shaped with short ducts containing sebocyte cells

merocrine (eccrine) gland secretes ______ into ______

secrete water, nacl, ammonia, urea, uric acid; skin

apocrine gland

secrete thicker and oilier, when poor hygiene it smells

morphology of secretory vs duct portions

secretory more pale

apocrine sweat gland morphology

larger ducts, empty into hair follicle

nail characteristics

keratinized plates of s. corneum containing eponychium (cuticle), lunular (white crescent), matrix (nail growth)

sensory nerve ending types

encapsulated (wrapped in myelin), non-encapsulated

non-encapsulated receptor examples

free nerve ending, merkel’s disc

encapsulated receptors

meissner’s, pacinian, ruffini

meissner’s corpuscle

found at dermal papillae, for light touch

cutaneous plexus

supplies hypodermis, hair follicles

superficial plexus

papillary loops

outer epidermis derived from

ectoderm

deeper dermis derived from

mesoderm

layer that is only present in thick skin

stratum lucidum

what is 1

stratum basale

what is 2

stratum spinosum

what is 3

stratum granulosum

what is 4

stratum lucidum

what is 5

stratum corneum

what is 6

keratinocytes

what is 7

dendritic cell

what is 8

melanocyte

what is 9

tactile cell

stratum basale function

actively divide to produce keratinocytes and repair damage, produce intermediate keratin filaments

stratum spinosum functions

synthesize intermediate filaments called cytokeratins and tonofibrils

what is circled

dermal papilla

what is circled

epidermal ridge

what is pointed to

melanocyte

langerhans cell function

APC, contact hypersensitivity

what is labeled as 1

langerhans cells

function of merkel (tactile) cells

mechanoreceptor

psoriasis

chronic inflammatory skin disorder with demarcated plaques and white scales

cause of psoriasis

excess proliferation of keratinocytes

pemphigus

autoimmune blistering due to disrupted desmosomes

carotene accumulate where

S. corneum and subcutaneous

dermis functions

maintain body temperature, strength and flexibility

what is 1

apocrine sweat gland

what is 2

hair bulb

what is 3

hair follicle

what is 4

arrector pili (smooth muscle)

what is 5

sebaceous gland

what is 6

merocrine sweat gland

what is 1

arrector pili (smooth muscle)

what is 2

sebaceous gland

what is 3

dermal papilla