EXSC Human Anatomy Ch 5

reticular layer

Deeper layer of the dermis that supplies the skin with oxygen and nutrients

keratohyaline granules

Involved in keratin formation

Keratinocytes

The most abundant epidermal cells, they function mainly to produce keratin.

stratum spinosum

a layer of the epidermis that provides strength and flexibility to the skin

eleidin

a transparent, intermediate product of keratin maturation

axillary, anal, areolar, and pubic regions

apocrine

secrete proteins and lipids

apocrine

Melanocytes

cells that produce melanin - absorbs UV light to prevent DNA damage

The specific orientation of ______ fiber bundles in the dermis is a result of the direction of applied ______ during routine movements.

collagen; stress

The epidermal ridges interdigitate with the ______.

dermal papillae

As a result of aging, sweat production ______

diminishes

A function of cerumen is to lubricate the ______.

external acoustic meatus

two ways damaged skin tissues are normally repaired

fibrosis and regeneration

Friction ridges are used as forensic tools because they can leave noticeable prints on touched surfaces, commonly called

fingerprints

Cerumen, together with tiny hairs along the ear canal, helps trap ______ and keeps them from reaching the eardrum.

foreign particles and small insects

Blanket of thick hair on scalp

heat retention

Sebaceous glands are classified as ______ glands that discharge an oily, waxy secretion called ______.

holocrine; sebum

The subcutaneous layer is also known as the ______ or superficial fascia.

hypodermis

Which describes the tissue type of the epidermis?

keratinized stratified squamous epithelium

The most numerous and widely distributed sweat glands in the body are ______.

merocrine

distributed throughout the body

merocrine

function in thermoregulation and excretion

merocrine

The two types of sweat glands in the skin are ______ sweat glands and ______ sweat glands.

merocrine; apocrine

nevus

mole; localized overgrowth of melanocytes

The accessory organs of the epidermis are hair, ______, ______ glands and sweat glands.

nails, sebaceous

skin markings

nevus, freckles, hemangioma, friction ridges

subcutaneous layer

not part of skin; lies under dermis; composed of areolar and adipose tissue

Sebaceous glands produce (an) ______ material that coats hair shafts and the epidermal surface

oily

papillary layer

outer layer of the dermis, directly beneath the epidermis

hair is found almost everywhere on the body except the ____

palms of hands, lips, soles of feet

two layers of the dermis

papillary and reticular

integument functions

protection, prevention of water loss, temperature regulation, metabolic regulation, immune defense, sensory reception, excretion by means of secretion

Functions of subcutaneous layer

protects underlying structures, stores energy, thermal insulation

lamellar granules

release contents into extracellular space; help form water barrier

dense irregular connective tissue surrounding blood vessels, hair follicles, nerves, sweat glands, and sebaceous glands

reticular layer

associated with hair follicles over much of the skin

sebaceous

lipid material called sebum

sebaceous

The secretions of sebaceous glands, called ______ is usually deposited into a ______.

sebum; hair follicle

The skin is said to be ______ because some materials are able to pass through it.

selectively permeable

hair root plexuses

sensory reception

tactile cells

sensory touch receptors

integumentary system

skin, nails, hair, sweat glands, sebaceous glands

Contains keratinocytes and melanocytes, and tactile cells

stratum basale

what stimulates sensory nerve endings in response to touch?

tactile cells

stratum corneum

the most superficial layer of the epidermis consisting of dead cells -thickness varies 20-30 layers -cells lack nucleus and are tightly packed

There are three main variations in the epidermis. These variations are ______, ______, and skin markings.

thickness; coloration

stratum lucidum

thin, translucent layer of dead cells found only in thick skin -2-3 cell layers thick -cells lack organelles -cells filled with eleidin

The substances that make sweat feel gritty are ______.

waste substances

freckles

yellow or brown spots of high melanocyte activity

thick skin

5 layers in epidermis -found in palms of hands and soles of feet epidermis is .4 to .6 mm thick -no hair follicles or sebaceous glands

The integument accounts for about _____% of the body weight.

8%

The layer of the skin from which most new epidermal cells are derived from is the ______.

stratum basale

From deep to superficial

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

most superficial layer of epidermis

stratum corneum

Keratinization begins in this layer

stratum granulosum

seen only in thick skin

stratum lucidum

keratinocytes attached to neighbors by desmosomes

stratum spinosum

not considered part of the integument

subcutaneous layer

epidermis

superficial layer of stratified squamous epithelium

The secretion from merocrine sweat glands are carried to the surface of the epidermis via ______. The secretions of apocrine sweat glands are carried into __________.

sweat ducts; hair follicles

secretion

sweating; lubrication of hair & skin with sebum

In male pattern baldness, hair is first lost mainly from the ______ region of the scalp

crown

Another name for the skin is the ______ membrane.

cutaneous

The exposed parts of nails and hair are composed of ______, keratinized cells.

dead

Vasoconstriction means that the diameter of the vessels ______, so relatively ______ blood can travel through them.

decrease; less

dermis

deeper layer of areolar & dense irregular connective tissues

stratum basale

deepest layer of epidermis -single layer of cells, cuboidal to low columnar in appearance -cells are attached to basement membrane and adjacent to the dermis

The reticular layer contains ______.

dense irregular connective tissue

Nerve fibers in the skin monitor sensory receptors in the ______.

dermis and epidermis

what helps remove microbes & initiate immune responses?

epidermal dendritic cells

The dermal papillae interlock with deep projections of the epidermis called ______

epidermal ridges

The skin is made up of two distinct layers, the _____ and the _____.

epidermis; dermis

There are two types of melanin, _________ and pheomelanin, together they produce various ratios of yellow, reddish, tan, brown, and black shades.

eumelanin

Fingerprints are useful as a forensic tool because each individual has a unique pattern of ______.

friction ridges

color and density of hairs of scalp

visual identification

Carotene exhibits a ______ color.

yellow or orange

hemangioma

proliferation of blood vessels that form a benign tumor

Scalp hair covers the scalp and shields it from sunburn and injury.

protection

nerve fibers control

blood flow, gland secretions, sensory receptors

In the nails, the lunula appears whitish because a thickened underlying stratum basale obscures the underlying ______.

blood vessels

The three recognizable zones along the length of a hair are ______.

bulb, root, shaft

external acoustic meatus

ceruminous

dead, scaly, interlocking keratinized cells called

corneocytes

Nails are derived from the same type of cells that produce the stratum ______ layer of the epidermis.

corneum

The epidermis of thick skin ranges from 0.4mm to ______ mm thick.

0.6

stratum granulosum

3-5 layers of keratinocytes undergoing keratinization -cyotplasm fills with keratin filaments -organelles begin to degrade

Skin repair and regeneration usually takes about ______ weeks in a healthy young person but can often take ______ that time for a person in his or her 70s.

3; twice

thin skin

4 layers in epidermis (lacks stratum lucid) -covers most of body -epidermis is .075-.150 mm thick

The two types of connective tissue in the dermis are ______.

areolar and dense irregular

Extending from the hair follicle to dermal papillae are muscles called _____.

arrector pili

The cells of the epidermis that produce keratin are called ______.

keratinocytes

cell types of basale

keratinocytes, melanocytes, tactile cells

two types of keratin granules in cells of stratum granulosum

keratohyalin granules, lamellar granules

Skin is classified as either thick or thin based on two parameters. These are the number of ______ in the epidermis and the relative thickness of the epidermis, rather than the thickness of the entire integument.

layers (statra)

The whitish semilunar area of the proximal end of the nail body is called the ______.

lunula

breasts

mammary

Which pigments contribute to skin color?

melanin, carotene, hemoglobin

composed of areolar connective tissue; contains dermal papillae

papillary layer

______ cuts to the lines of cleavage often results in slow healing and increased scarring.

perpendicular

Melanosomes are transferred to keratinocytes in the stratum basale via the process of ______ or exocytosis.

phagocytosis