Integumentary System

Epidermis

Outermost avascular skin layer

Dermis

Connective tissue layer beneath the epidermis

Hypodermis

Subcutaneous layer beneath the dermis

Dermicidin

Sweat compound with antibiotic properties

Thermoregulation

Maintenance of body temperature

Melanin

Pigment that helps shield DNA from UV damage

Carotene

Pigment from vegetables that can create orange skin

Hemoglobin

Blood pigment that contributes to skin color

Stratum basale

Deep epidermal layer where new cells form

Stratum spinosum

Epidermal layer with desmosomes and keratin production

Stratum granulosum

Last living epidermal layer with keratin granules

Stratum lucidum

Clear epidermal layer found only in thick skin

Stratum corneum

Outermost layer of dead, keratinized cells

Keratinocytes

Epidermal cells that produce keratin

Melanocytes

Basal cells that produce melanin

Merkel cells

Sensory cells in the stratum basale

Papillary layer

Superficial dermal layer with loose connective tissue

Dermal papillae

Dermal projections into the stratum basale

Meissner corpuscles

Receptors for light touch

Reticular layer

Deep dermal layer of dense irregular connective tissue

Hypodermis functions

Fat storage, insulation, and cushioning

Hair follicle

Epidermal structure that houses the hair root

Hair shaft

Visible hair portion above the skin

Hair root

Hair portion anchored within the skin

Hair bulb

Expanded hair base where growth begins

Hair papilla

Hair base containing capillaries and productive cells

Eccrine glands

Glands producing watery sweat throughout the body

Apocrine glands

Glands producing watery, oily sweat in armpits and groin

Sebaceous glands

Oil

Arrector pili muscles

Smooth muscles that pull hairs upright

What are the three layers discussed with the skin?

Epidermis, dermis, and hypodermis

What does skin sensation detect?

Touch, temperature, and pain

Where are sensory receptors concentrated for heightened sensitivity?

Fingertips

How much sweat can vigorous activity produce per hour?

1.5 L

What happens to dermal blood vessels when the body needs to release heat?

Dilation

What happens to dermal blood vessels when the body needs to retain heat?

Constriction

Which epidermal layer is the only one that undergoes mitosis?

Stratum basale

Which epidermal layer provides strength through desmosomes?

Stratum spinosum

Which epidermal layer is the last living layer?

Stratum granulosum

Where is the stratum lucidum found?

Palms and soles

How long does complete replacement of the stratum corneum take?

About four weeks

What type of tissue composes the dermis?

Connective tissue

Which dermal layer contains Meissner corpuscles?

Papillary layer

Which dermal layer is dense irregular connective tissue?

Reticular layer

What are the three primary pigments influencing skin color?

Melanin, carotene, and hemoglobin

Which type of melanin produces black and brown pigments?

Eumelanin

Which type of melanin produces a red pigment?

Pheomelanin

What stimulates increased melanin production and tanning?

Sun exposure

What can prolonged oxygen deficiency cause the skin to become?

Blue

Where does hair originate?

Hair follicle

Which hair region is visible above the skin?

Shaft

Which hair region anchors the hair in the skin?

Root

What determines hair color?

Melanin

Which sweat gland produces typical watery sweat?

Eccrine gland

Which sweat gland produces oily sweat in the armpits and groin?

Apocrine gland

What causes body odor from apocrine secretions?

Bacteria

What do arrector pili muscles produce when they contract?

Goosebumps

What are lamellar (Pacinian) corpuscles?

Sensory receptors in the dermis that detect deep pressure and vibration

What are bulbous (Ruffini) corpuscles?

Sensory receptors in the dermis that detect skin stretch and sustained pressure.