A&P Chapter 6

true regarding the subcutaneous layer (hypodermis).

-The subcutaneous layer is not part of the integument. -The subcutaneous layer consists of areolar and adipose connective tissue. -One of the functions of the subcutaneous layer is thermal insulation.

Cells are mitotic; deepest epidermal layer

Stratum basale

Contraction of the arrector pili muscles causes the hair follicle to

become perpendicular to the skin, resulting in the hair "standing on end."

Lines of cleavage indicate the predominant orientation of _________ fibers in the skin

collagen

The dermis is composed largely of

dense irregular connective tissue.

the incision runs parallel to the lines of cleavage, would result in a _________ healing time.

faster

Vasodilation of dermal blood vessels results in ________of body heat.

loss

If a person is experiencing vasoconstriction of the dermal blood vessels, their skin will look more________ than usual.

pale

Vasoconstriction of dermal blood vessels results in ____________ of heat.

Conservation

Which statement is true regarding the subcutaneous layer (hypodermis)?

It stabilizes the position of the skin and binds it to underlying structures.

If melanin is so important for protection against mutagenic UV exposure, why is it that some people are light skinned and obviously deficient in melanin?

People of northern climates historically have had less sun exposure and the decreased skin melanin content is necessary for vitamin D production.

If a person is experiencing vasodilation of dermal blood vessels, their skin will look more _____ than normal.

Pink

These dead cells have a hard protein envelope, contain keratin, and are often peeled or scraped off

Stratum corneum

. Keratinization begins; keratinocytes begin to fill with keratin

Stratum granulosum

The keratinocytes within this layer are flattened and filled with the protein called eleidin

Stratum lucidum

Contains several layers of polygonal keratinocytes

Stratum spinosum

The oily, waxy secretion called sebum is produced by

sebaceous glands.

the incision runs perpendicular to the lines of cleavage, would result in a ________ healing time.

slower

The integument consists of the epidermis, which is composed of _____________, and the dermis, which is composed primarily of ____________ connective tissue.

stratified squamous epithelium; dense irregular

Light-skinned people are at greatest risk for malignant melanoma because

the decreased amount of melanin allows more UV light penetration into the skin, therefore increasing the risk of cancer development.

In response to cold temperatures outside, dermal blood vessels ___________.

vasoconstrict.

In response to hot temperatures outside, dermal blood vessels _________.

vasodilate.