-
The stratum spinosum produces spine-like substances that literally connect one layer of cell to another. These spine-like substances are called_________.
desmosomes
-
The epidermis and dermis are colletively called the ________ membrane.
cutaneous
-
New skin cells are derived from which layer of the skin
stratum basal or basal layer
-
Which skin layer consists of cells that produce a pigment to create a darker skin color?
stratum basale or basal layer
-
Which skin layer produces sweat in the axillary region?
reticular layer
-
What is the name of the muscle that causes hair to stand erect?
arrector pili
-
What is the name of the area on the fingernail that is light in color and is ocated at the root of hte nail?
lunula
-
Which gland is involved in acne production?
sebacious
-
Which gland produces natural body odor?
apocrine
-
What are the four main components of the integumentary system?
-
Which layer of hte epidermis consists of cells that are undergoing interphase, prophase, metaphase, anaphase, telophase, and cytokinesis?
stratum basale or basal layer
-
Which glands produce the oily substance called sebum?
sebaceous glands
-
Arrector pili muscles are ________ muscle.
smooth
-
Arrector pili muscles are under ___________ control.
involuntary
-
The most superficial layer of the epidermis is the ________.
stratum corneum or horney layer
-
Which layer of the dermis consists of the sebaceous glands?
papillary layer of the dermis
-
What layer of tissue is located between ther dermis and muscle?
hypodermis
-
What is the most superficial layer of skin
stratum corneum or horney layer
-
What layer of the skin are melanocytes found in
stratum basale or basal layer
-
dandruff is due to rather large sheets of epidermal cells flaking off the body. What is the name of this layer?
stratum corneum or horney layer
-
Which layer of skin consists of the accessory sx such as glands?
papillary and reticular layers
-
A blocked sebaceous gland could result in what type of skin condition?
acne
-
Which layer of the dermis consists of the sebaceous glands?
reticular layer
-
Serous membranes have _______ and ________ layers.
-
_____________ secrete a lubricating fluid.
Serous membrane
-
Sweat consists of
- water
- sodium chloride
- ammonia
-
-
What is associated with the production of perspiration?
- sweat glands
- sweat pores
- eccrine gland
- apocrine gland
-
What structure provides protection from ultraviolet radiation?
melanocytes
-
What provides insulation and energy storage?
hypodermis
-
What layer provides waterproofing and preventing water loss?
Stratum corneum or horney layer
-
What structure provides temperature regulation?
dermal blood supply
-
Excretion of water, urea, and salts happens were
eccrine sweat glands
-
What produces the patterns for fingerprints?
papillary layer of the dermis
-
The integumentary system is composed of the sking and a number of derivatives such as hair, nails, and __________.
glands
-
The largest organ of the body is the
skin
-
The skins accounts for approximately _______ of the total body weight.
15%
-
The skin protects the body from fluid loss or gain and serves as a barrier to
microorganisms
-
Water soluble substances may not enter the body becasue the skin contains a waterproof protein known as
keratin
-
At the foundation of the epidermis, a barrier of protection is provided by the
basement membrane
-
The pigment formed in the skin is called
melanin
-
Skin pigments protect the body against radiation from sunlight called
ultra violet rays
-
Skin pigments are synthesized by special cells called
melanocytes
-
When the body cannot produce the skin pigment melanin, the condition that results is called
albinism
-
Heat is lost at the body surface in sweat during hte process of
evaporation
-
The skin conserves heat by reducing its secretions of sweat and by constricting its
blood vessels
-
Glands in the skin release water and fatty substances in the process of
excretion
-
Ultraviolet radiation from the sun brings about the synthesis in the skin of vitamin
D
-
Amoung the vitamins absorbed in the skin, when applied to the surface, are the fat soluble vitamins E, K, and
A
-
The skin tissue absorbs certain steroid hormones released by the skin's
glands
-
Environmental stimuli are received by specialized skin
sensory receptors
-
The skin detects sensations such as pressure, touch, temperature, and
pain
-
The dermis is the inner, thicker layer of the skin, while the epidermis is the outer
thinner layer
-
The loose subcutaneous layer of fat rich tissue beneath the dermis is the
hypodermis
-
The layers of cells within the epidermis are also referred to as
strata
-
The epidermis is composed of
stratified spuamous epithelium
-
The skin of thin epidermis has ____ layers.
4
-
The skin of the thick epidermis has _____ layers.
5
-
The innermost layer of epidermis lying on the basement membrane atop the dermis is the
stratum basale or basal layer
-
The cells synthesizing melanin are melanocytes which are found in the
stratum basale or basal layer
-
The predominant epidermal cells are the
keratinocytes
-
The protein keratin is produced by epidermal cells known as
keratinocytes
-
The epidermal cell layer lyin atop the stratum basale is the
stratum spinosum or spiny layer
-
Cells called epidermal dendritic cells provide the immune system functions and are located in the
stratum basale or basal layer
-
In thick skin, closely packed cells and dead keratinocytes are found within the layer of epidermis known as the
stratum lucidum or clear layer
-
At the body surface, the uppermost layer of hte epidermis is the
stratum corneum or horney layer
-
The cells in the uppermost layer of epidermis are rich in the waterproofing substance called
keratin
-
The keratinocytes of hte stratum corneum are connected to one another by junctions called
desmosomes
-
Most cells of the stratum corneum are ultimately derived from cells produced in the lower layer called the
stratum basale or basal layer
-
The cells of the epidermis receive their nourishment from blood vessels found in the
dermis
-
The epidermis borders ridges from the dermis that help anchor the two layers together and are called
dermal papillae
-
The layer of the dermis containing fat cells, sweat glands, and blood vessels is the
reticular layer
-
The papillary layer of hte dermis consists of connective tissue that is loose or
areolar
-
Most skin sensory receptors are found in the
dermis
-
The two major structures of the hair fiber are the shaft and the
root
-
Nerve endings are associated with each hair together with a sebaceous gland and a muscle known as
arrector pili
-
The nail is a protective plate consisting of the protein
keratin
-
At its proximal end, the nail is covered partially by a piece of tissue called the
cuticle
-
The most numerous skin glands are the sweat glands, also known as
sudoriferous glands
-
What is the largtest organ in the body
skin
-
In the skin layers, the protein keratin
forms a barrier to water soluble substances
-
The skin conserves body heat by
reducing secretions of sweat
-
The pigment melanin
protects the skin against ultraviolet rays from the sun
-
One of the fx of the skin is to serve in the absorption of
Vitamin D
-
Heat is lost from the body by
- evaporation
- conduction
- convection
-
The superficial fascia is located
beneath the dermis
-
Intercellular junctions occurring within the stratum spinosum (spiney layer) are referred to as
desmosomes
-
Two important cells found in teh stratum basale are
-
The reticular layer of the dermis contains
- fat cells
- blood vessels
- sweat glands
-
In the stratum corneum (horney layer), the cytoplasm of most cells has been replaced by
keratin
-
All living cells of hte epidermis receive their nourishment from blood vessels located in the
dermis
-
The dermis and epidermis are anchored to one another by bumps in ridges known as
dermal papillae
-
Sensory receptors are found in the
- reticular layer
- papillary layer
-
Smooth muscle may be located in the ________ but not the _________.
-
Arrector pili muscles are associated with the
hair follicles
-
The lanugo is the extremely fine hair of
the fetus
-
-
The nail consists of
keratin
-
The secretion of sebaceous glands enter the
hair follicle
-
Four main tissue types
- epithelial
- connective
- muscle
- nervous
-
Classification of epithelial tissues
- number of cell layers
- shape of cells
- combine number and shape to get tissue name
-
Number of cell layers are known as
- simple-one cell layer thick
- stratified-two or more layers
-
The shape of the layers are known as
- squamous-flatten
- cuboidal-cube shaped
- columnar-column cells
-
Characteristics of connective tissue
- variations in blood supply
- many different cell types
- extracellular matrix
-
Types of connective tissue
- collagen fibers-tough fibers w/ firm support
- elastic fibers-stretchy fibers
- reticular fibers-usually mixed with other fibers
-
Connective tissue classification is determined by the type and amount of fibers present in the
matrix
-
Classes of connective tissue include
- bone
- cartilage
- dense connective tissue
- loose connective tissue
- blood
-
The physical fx of the skin is
- physical barrier contains keratin
- fat cells cushion blows
- pressure receptors alert nervous system to possible damage
-
The bacterial fx of hte skin is
- secretions are acid and inhibit bacteria growth
- phagocytes ingest foreign substances and pathogens
-
Ultraviolet fx of the skin is
melanin produce by melanocytes offer protection from UV rays
-
Temperature regulation of the skin is
- heat loss-activates sweat glands and allows blood to flush into capillaries
- heat retention-by not allowing the blood to flush into capillaries
-
Excreation of the skin is when the skin
excretes urea and uric acid through perspiration through sweat glands
-
Vitamin D synthesis occus when
cholesterol molicules in skin is converted to Vitamin D by sunlight
-
What are the three major regions of the skin
- epidermis
- dermis
- hypodermis
-
Stratum basale or basal layer is
- one cell layer thick
- rapid cell division
- most cells are keratinocytes
- 25% of hte cells are melanocytes
-
Stratum spinosum or spiny layer
- several cell layers thick
- cell division is less rapid
- most cells are keratinocytes
-
Stratum granulosum or granular layer
- usually 3 to 5 cell layers thick
- keratinization first takes place
- most cells are keratinocytes
- cell death begins
-
Stratum lucidum or clear layer
- very thin and transparent
- present only in areas of hairless skin
- most cells are keratinocytes
-
Stratum Corneum or horney layer
- broad layer 20-30 cells in thickness
- makes up 3/4 thickness
- cells are cornified keratinocytes
-
The epidermal strata from bottom to top is
- basal layer
- spiny layer
- granular layer
- clear layer
- horney layer
-
The dermis is
- composed of connective tissue
- varies in thickness
- contains nerve fibers, blood vessels, lymphatic vessels, hair follicles, oil/sweat glands
-
The papillary layer of the dermis
- superficial 20% of dermis
- composed of loose connective tissue
- superficial surface has projections called dermal papillae
-
Dermal papillae are
projections that cause finger prints and wrinkles
-
The reticular layer of the dermis
- deep 80% of dermis
- composed of dense connective tissue
- contains nerve fibers, blood vessels, lymphatic vessels, hair follicles, oil/sweat glands, deep pressure receptors
-
What is the sx and fx of Keratinocytes
- most abundant cell in the epidermis
- arise from lowest levels of epidermis
- produce the protein deratin
- become filled with keratin and die
- lose millions everyday
- replaced every 35-45 days
-
What is the sx and fx of melanocytes
- arise from the lowest levels of epidermis
- produce the pigment melanin
- melanin is engulfed y keratinocytes
- everyone has relatively the same number of melanocytes
-
What is the sx and fx of merkel cells
- occur in small numbers
- locate at the junction of epidermis and dermis
- form touch receptors
-
What is the Pacinian corpuscle
- located in the reticular layer
- deep pressure receptor
- phagocytes prevent bacteria from penetrating deep sx
-
The Meissner's corpuscle
- located in the papillary layer
- pain and touch receptors
-
Thre arrector pili muscle
- small bands of smooth muscle
- connected to each side of the hair follicle to the dermal layer
- when muscle contracts the hair is pulled upright causing goosebumps
-
Sebaceous glands
- oil glands
- all over the skin except plam of hands and soles of feet
- ducts usually empty into hair follicle
- produces sebum
-
Sebum
- is oily excretion
- keeps skin soft and moist
- has chemicals that kills bacteria
-
Sudoriferous glands
sweat glands
-
Eccrine sweat glands
- found all over the body
- produce sweat
-
Apocrine sweat glands
- found in the axillary and genital areas
- lorger than eccrine glands
- empty into hair follicles
-
Hair follicles are
- flexible epithelial sx
- a dermal and epidermal sheath that surrounds the hair root
-
Nail are
- scale like modifications of the epidermis
- heavily keratinized
-
Nail sx
- free edge-tip
- body-nail bed
- root of nail-under the skin behind cuticle
- eponychium-proximal nail fold that projects onto the nail bed
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