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