Unit 2 bio 2250

hemangioma

A reddish birthmark made of benign tumors of capillaries

During which phase are living cells of the hair bulb actively dividing, resulting in hair growth

Anagen

Of the three phases of the hair growth cycle, cells of the hair bulbs are dividing only during the _____ phase

Anagen

What is the composition of the subcutaneous layer

Areolar connective tissue and adipose connective tissue

Most common; originates in stratum basale

Basal cell carcinoma

stratum basale

Comprised of viable, cuboidal and columnar cells, and contains the keratinocyte stem cells that replenish the exfoliated cells at the surface.

Fingernails ____ protect the digits from damage

Do

Water ____ out of the body due to the function of the skin

Does not leak

Immune cells found in the epidermidis are called

Epidermal dendritic cells

exfoliating keratinocytes

First to be sought off

freckles

Flat, melanized patches that vary with heredity and sun exposure

stratum lucidum

Layer that is present only on the soles of the feet, hands, fingers and toes.

stratum corneum

Made up of multiple layers of dead keratinocytes that regularly exfoliate

The epidermis protects deeper tissues from solar radiation through the action of

Melanocytes

stratum granulosum

Named for the presence of dark staining keratohyalin granules which bind the cytoskeletal keratin filaments together.

dead keratinocytes

Next layer to be sought off after exfoliating keratinocytes

Nails are a scale like modification of the ______ layer of the _____

Stratum corneum, epidermis

During which phase is a hair typically shaded

Telogen

flexion creases

The skin on the anterior surface of the hand, where the skin is bound to deeper tissues

As a person ages, the skin undergoes what change

The subcutaneous tissue loses adipose tissue

living keratinocytes

These cells are active and form the stratum spinosum

tactile cell

These cells attach to sensory receptors

dendritic cell

These cells have short branched projections off the cell body

melanocyte

This cell produces pigment and passes it to the new keratinocytes

stem cell

This cell retains the ability to divide and differentiate

stratum spinosum

Towards the apical surface, the keratinocytes cease cell division, while at the deeper regions they can still undergo mitosis.

The release of water vapors from the skin when we are not sweating is called

Transpiration

True or false: melanocyte cytoplasmic processes transfer pigment granules into stratum basal keratinocytes; these pigment granules shield the nuclear DNA from UV radiation

True

True or false: regeneration in the skin replaces damaged or dead cells with the same cell type and restores organ function

True

True or false: the epidermal dendritic cells are able to play an important immune response role by their phagocytosis activity

True

True or false: the skin consist of different tissue types that perform specific activities and therefore is to be considered an organ

True

Generally, people have ________ number of melanocytes ______________.

about the same; no matter where they live

friction ridges

causes fingerprints

Most deadly skin cancer

malignant melanoma

Freckles are the result of

melanocyte activity, genetic inheritance, and sun exposure.

Arises from keratinocytes of stratum Spinosum

squamous cell carcinoma

The way in which sweat glands function in homeostasis.

temperature regulation

vellus (hair)

-90% of hair on women -10% of hair on men -Most of the hair on children

squamous cell carcinoma

-Arises from superficial cells of the epidermis -Raised, reddened, scaly appearance -Can spread from the keratinocytes to the lymph nodes

terminal (hair)

-Eyebrows, eyelashes, and scalp -Armpit and pubic hair -Male facial hair

melanoma

-If metastasized, the deadliest skin cancer -Aries from the cells that protect from UV light -Least common type -Caused by mutations commonly found in moles

basal cell carcinoma

-Most Common Type -Seldom spreads to other tissues -Arises from the deepest layer of the epidermis

lanugo (hair)

-Mostly found on a fetus -Replaced by Vellus

moles

elevated patches of melanized skin