BIO chapter 6 study guide

which is more superficial epidermis or dermis

epidermis- outside

dermis-middle

6 functions of the skin and hypodermis

regulates body temperature

stores blood

protects body from the external environment

detects cutaneous sensations

non-verbal communication

synthesizes vitamin d

thin skin

covers most of the body

4 layers of keratinocytes

thick skin

found in the palms and heels

stratified squamous epithelium

avascular

keratinocytes

epithelial cells of epidermis

several layers of skin

protein that helps the skin and underlying tissues

melanocytes

found in the deepest layer, produce brown/black melanin

skin color and absorbs UV light

transfers melanin to keratinocytes

melanin granules congregate over the necleus to protect dna from uv light

merkel cells

connected to sensory neuron called Merkel disc- touch sensation

stem cells

give rise to keratinocytes

stratum basale

deepest layer

single row of stem cells that reproduce to replace shed keratinocytes

merkel cells

melanocytes

stratum spinosum

8-10 layers of keratinocytes that migrate from the stratum basale

cells have lost some cytoplasm- looks spiky under microscope

spines are not present in life

stratum granulosum “grainy layer”

contains keratinocytes from the stratum spinosum

cells are undergoing apoptosis-programed death

cells are too far from blood supply

nuclei break down so cells can no longer carry on normal cell function

stratum lucid

only present in thick skin

cells are flatten, packed together, and full of keratin

stratum corneum

most superficial layer 20-30 layers of cells

made up of dead cells filled with keratin that are tightly connected by desmosomes

shed 50,000 cells per min, (40 pounds lifetime)

role melanocytes have in skin color

we all have the same number of melanocytes but determined by the amount of melanin produced and how long it persists in the keratinocytes

effects of sunlight on melanocytes normal exposure

melanin provides protection for the nuclei of keratinocytes (tan)

effects of sunlight on melanocytes overexposure

damage dna leads to skin cancer

how does carotene contribute to skin color

orange/yellow pigment

converted to vitamin a, eye function

how does hemoglobin contribute to skin color

gives skin pink color

skin turns red when blood vessels near the skin dilate

redness (erythema)

indicates embarrassment, fever, hypertension, inflammation, or allergies

pallor (blanching)

emotional stress, anemia, hypotension

jaundice

liver malfunction, causes skin and eyes to be yellow

Addisons disease

pituitary gland malfunction, causing bronzing

vitiligo

immune system attacks normal melanocytes

skin lightens in patches

What are the three types of cancer?

Basal cell carcinoma, squamous, cell carcinoma, melanoma

Basal cell metastasize

Doesn’t matter size before it’s noticed

Squamous cell carcinoma, metastasize

Grows and metastasize as rapidly, but can be surgically removed or with radiation

Melanoma metasize

Highly metastatic and resistant to treatment

What cells are affected in basal cell carcinoma?

Affects Stratham Basale

Type of cell affected in squamous cell carcinoma

Affects the keratinocytes of the stratum spinosum

What cells are affected melanomas

melanocytes

Treatment success for basal cell carcinoma

Five years survival is 95%

What is the survival rate for squamous cell carcinoma?

First five years is around 99%

What is the survival rate with melanomas

Five year survival rate is 95%

ABC DE melanoma rules for checking moles and spots

A symmetry border, irregularity, color diameter elevation

Papillary components and functions

Made up of loose aerial connective tissue contains the blood vessels, lymphatic vessels, and nerves that supply the skin

Dermal papillae Components and function

Projections up to the epidermis contains Meissners corpuscles Who are capillaries and free nerve endings

Reticular layer function, and components

Made up of dense, irregular, connective tissue contains both collagen and elastic fibers allow some flexibility, but limit it to prevent damage. Water content also helps skin maintain flexibility and resilience collagen fibers extent into popular layer and hypodermis holds the body together.

What is the hypodermis made up of?

Adipose and aerolar tissue

What are the five functions of hair?

UV radiation cushion blows, insulates the head traps particles sensory receptors

Describe the hair shaft

Projects from the skin

Describe the hair root

Deep part to the shaft that penetrates down to the dermis, and sometimes the hypodermis

Describe the hair follicle

Extend from the surface to the dermis and the hypodermis

Describe the hair root plexus

Bundle of sensory nerves

Describe arrector pili

Muscle connected to each hair

Describe the hair bulb

Made up of epithelial cells and responsible for producing Hair

Describe the hair papilla

Peg a blood vessels and nerves that nourish growing hair

What is the function of sebaceous glands?

Discharge oil into the hair, follicles, arrector pili, muscle contract, squeezing gland and pushing oil onto the surface of the skin

What are the three functions of sebum

Inhibits growth of bacteria Lubricate and protects hair shaft condition skin

Where are the eccrine sweat glands located?

Coiled gland duct goes up to the surface and opens through a pore

Eccrine Secretion and control

sweat is 99% water, but also contain salt, antibodies proteins and waste controls, body temperature regulation Excretion of water and electrolytes

Apocrine Location

Found in the armpits around nipples and in the pubic region

Apocrine secretion and function

Empty into hair, follicles secretions contain water and salts, as well as fatty acids and proteins odor less but decompose as rapidly

What are nails made up of?

Hard keratin

Immediate danger of severe burn

Fluid loss leads to renal failure and circulatory shock

Secondary danger for severe burns

Infection because of the loss of Protective coating

First-degree burns

Damage is only the epidermis, redness, swelling, and pain

Second-degree burns

Same symptoms as first-degree burns, but with blisters damages, the epidermis and possibly the upper part of the dermis

Third-degree burns

Affects the entire thickness of the skin appears gray or blackened, but is not painful because the nerve endings have been destroyed

When are burns considered critical?

If over 25% of the body has second-degree burns, over 10% has third-degree burns, 3rd degree burns on face hands or feet, burns on the face affecting the nervous system