Bio107-ch5lab7 Flashcards
Integument (skin) is the
largest organ in the body (by weight)
Functions of the integument system (5)
- Protection- injury, infection
- Thermoregulation- shivering
- Receives environmental stimuli- nerves embedded in skin
- Excretion- waste removal
- Water balance
3 primary LAYERS of integument
- Epidermis
- Dermis
- Hypodermis
Epidermis- basic charateristics
stratified squamous epithelium
outermost layer, 5 layers within
Dermis- basic characteristics
dense IRREGULAR connective tissue
middle layer, hair follicles, nerve endings
Hypodermis- basic characteristics
areolar connective tissue with adipose cells
fat
Epidermis is composed of
keratinized (waxy) stratified squamous epithelium
Epidermis cell types include (4)
- Keratinocytes
- Melanocytes
- Merkel cells
- Langerhans’ cells
Keratinocytes
produce fibrous protein keratin (wax)
Melanocytes
produce dark brown pigment melanin
Langerhans’ cells
epidermal macrophages help activate the immune system
Merkel cells
touch receptors associated with sensory nerve endings
4/5 Layers of the Epidermis
- Stratum corneum
- *Lucidum layer- 5th layer, THICK SKIN ONLY
2/3. Stratum granulosum
3/4. Stratum spinosum
4/5. Stratum basale
- Stratum corneum
20-30 layers of dead skin, superficial
- Lucidum layer
5th layer, thick skin only
2/3. Stratum granulosum
3-5 layers thick
organelles deteriorating
3/4. Stratum spinosum
1-2 layers thick
desmosomes, “spiky shape,” where keratin is made
4/5. Stratum basale
deepest layer
stem cells, healthiest layer
Dermis is composed of
IRREGULAR dense connective tissue
2 layers- papillary & reticular
Dermis cell types (4)
- Fibroblasts
- Macrophages
- Mast cells
- WBCs
Hypodermis is composed of
areolar & adipose connective tissue
subcutaneous layer
Areolar connective tissue anchors to
what is below it (tissue, bone, cavity)
5 pigments that contribute to skin color
- Melanin
- Carotene
- Hemoglobin
- Cyan
- Jaundice
Melanin
yellow- red- brown- black (genetic descent)
responsible for dark skin colors, freckles, moles
Carotene
orange pigment
found in carrots, most obvious in palms and soles of feet
Hemoglobin
reddish pigment, pink hues
found in RBCs, “color back in your face” after illness
Cyan
blue/purple color
caused by a lack of O2 to tissues
Jaundice
yellow color
buildup of bilirubin- liver disease, new borns
Exocrine glands
have ducts that secrete products OUTSIDE
Goblet cells secrete
mucous (exocrine glands)
Endocrine glands
DUCTLESS, secretes products directly INTO the blood stream
EXOcrine modes of secretion (3)
- Merocrine/Eccrine
- Apocrine
- Holocrine
Merocrine/Eccrine
products are thin (not viscous)
diffuse through cell membrane (nervous sweat- palms, forehead)
Apocrine
products are slightly viscous
exocytosis expels product (armpit & groin sweat glands- puberty, odorous)
Holocrine
product very viscous
cell membrane ruptures, secretes cerumen (wax)
Sebaceous glands secrete
sebum (oil)
Ex. oil from hair on scalp
Characteristics of hair (3 main)
- Hair is filamentous strands of dead keratinized cells
- Has SHAFT projecting from the skin & ROOT embedded in the skin
- Pigmented by MELANIN from MELANOCYTES at the base of hair
Functions of hair (3)
- Maintain warmth
- Light touch (air, insects, etc.)
- Protects scalp from trauma, heat loss, sunlight
Hair is found everywhere on the skin except (5)
- Palms
- Soles
- Lips
- Nipples
- Portions of external genitalia
Vellus
fine body hair found in children
“baby hairs”
Terminal
coarse, long hairs
eyebrows, scalp, armpits, pubic regions
First degree burn
- damages: EPIDERMIS
- color: pink/redish
- NO permanent damage
- heals: 1-7 days
- cause: mild sunburn, touching hot surface quickly
Second degree burn
- damages: EPIDERMIS & DERMIS
- color: pink, red- water filled blisters
- MINOR permanent damage
- heals: 1-2 weeks min
- cause: excessive sunburn, touching pot on stove, cigarette burn, fire
Third degree burn
- damages: ALL 3 layers
- color: pink/red/blisters, charred appearance (black/green)
- heals: months, may need skin graft
Fries your nerves, risk of infection, high risk of death, should go to hospital
Rule of Nines
estimates fluid loss in burn patients using percentage of body surface burned
Benign- skin cancer
common, not deadly
Malignant- skin cancer
dangerous, cancer
MELANOMA
Metastasis- skin cancer
ability to spread
Acne
infection starting in oil glands and spreading to hail follice
Furuncle
“boil” infection of dermis & hypodermis
Vernix caseosa
milky coating that covers vellus hairs on a fetus after birth
Lanugo
layer of very fine vellus hair on fetus that will shed off soon after birth
ABCD rule for skin cancer screening
- Asymmetry- mole thats round throughout
- Border- smooth, clean edges
- Color- pale (noncancerous), dark (malignant)
- Diameter- should be no bigger than pencil eraser