5. The Integumentary System, Lecture Questions
What does melanin do?
-protein that determines the color of hair, skin, and eyes -Major function is to protects the DNA from UV light
The composition of the secretions of the eccrine glands is:
99% water, salt (sodium chloride), trace amounts of waste products, and vitamin C.
Dendritic cells (DCs)
Activate the immune system. They engulf and degrade microbes and display them to T cells
A patient has a skin that is slightly blue in color. An immediate treatment for this person will likely be:
Administration of supplemental oxygen.
Ceruminous glands are specialized ____________ glands
Apocrine
The type of sudoriferous glands that have thick organic secretions that produce body odor as a consequence of bacterial breakdown?
Apocrine sweat glands
tactile cells (Merkel cells)
Are sensitive to touch. They signal the brain that an object has touched the skin
The dermis is composed of _____________ and ______________.
Areolar connective tissue Dense irregular connective tissue
What is the composition of the subcutaneous layer (hypodermis)?
Areolar connective tissue and adipose connective tissue.
Describe the ABCDE's of malignant melanoma
Asymmetry Border irregularity Color variations (more than one color) diameter over 6 mm Evolving (changing). E can also stand for Elevation.
What are the functions of the skin?
Barrier -- keeps the insides distinct from the outside. Protection Temperature regulation (via sweat glands and dermal blood vessels) Synthesis of cholecalciferol (vitamin D precursor)
The most common type of skin cancer?
Basal cell carcinoma
Basal cell carcinoma from invasive, uncontrolled growth of the cells of the stratum ____________.
Basale
Along with sweat glands, what ACTIVELY regulates body temperature.
Blood vessels
In order to retain heat, what occurs in the skin on a cold day?
Blood vessels of the dermis constrict (narrow)
How do physicians estimate the extent of burn damage ?
By using the rule of nines
Why might someone become more pale when exposed to cold temperatures.
Constriction of blood vessels within the dermis redirects blood flow to the vital organs in order to maintain core body temperature.
Another name for the skin is the ___________ membrane.
Cutaneous
Skin cells play an important role in the production of vitamin
D
Excess heat can be removed from the body by (dilation/constriction) of blood vessels in the skin.
Dilation. The blood vessels of the skin widen in order to release heat.
The glands that play an important role in regulation:
Eccrine
_____________ sweat glands occur over all of the body and secrete a watery perspiration to cool the body.
Eccrine
Sudoriferous (sweat) glands are categorized as two distinct types. What are the two categories of sweat glands?
Eccrine and Apocrine
What protects against excessive water loss through the skin?
Glycolipids that are secreted into extracellular spaces by keratinocytes.
The process of keratinization begins in the stratum ________________.
Granulosum
What type of stimulus is detected by the sensory receptors of the skin?
Heat Cold Pressure Vibration
The reason the hypodermis acts as a shock absorber is that:
It contains a large amount of adipose tissue which serves as an effective shock absorber.
What type of epithelium forms the epidermis?
Keratinized stratified squamous epithelium
The skin's immune response would be diminished by a decrease in the number of _____________ cells of the epidermis.
Langerhan's (dendritic) cells
What epidermal cells play a role in immunity?
Langerhan's (dendritic) cells
Immune cells in the stratum spinosum which protect against invaders are the ______.
Langerhans cells (dendritic cells)
Skin color is primarily determined by the pigment _____________
Melanin
The most dangerous form of skin cancer?
Melanoma
______________is the most dangerous type of skin cancer because it rapidly metastasizes.
Melanoma
Although melanomas are rare, they must be removed quickly to prevent them from _____________.
Metastasizing.
describe the stratum corneum
Most superficial layer (strata) of the epidermis Cells are dead It is made up of interlocking keratinized cells. Cells are anucleates (lack a nucleus)
What is the actively growing part of the nail?
Nail matrix
What compromises the nail plate?
Nail root Nail body Free edge
The single most important risk factor for skin cancer is:
Overexposure to UV radiation.
The reticular layer of the dermis contains _______ and ________ to detect pressure.
Pacinian corpuscles; Ruffini's corpuscles.
A pale or white discoloration of skin due to reduced blood flow
Pallor or blanching
The dermis consist of two layers: the __________, which is characterized by loops and ridges, and the ___________ which accounts for 80% of the skin's thickness.
Papillary layer Reticular layer
Melanocytes:
Protects cells in the stratum corneum from the damaging effects of sun's rays.
The type of gland that secretes an oily liquid that lubricates skin and hair and protects against some bacteria.
Sebaceous
_________ is a secretion that helps lubricate skin and helps defend against bacteria.
Sebum
In a(n) _____ burn, the epidermis and upper region of the dermis are damage. Blistering is common.
Second
What are stretch marks and what causes them?
Silvery white or pink scar tissue formed by stretching of the dermis.
______________ is the most common type of cancer.
Skin cancer
____________ carcinoma results from transformation of cells in the stratum spinosum leading to invasive, uncontrolled growth.
Squamous cell carcinomas
Which of the following layers of the epidermis is responsible for cell division and replacement?
Stratum basal
The deepest layer of the epidermis is:
Stratum basal (or stratum germinativum)
In which layer of the epidermis are cells constantly dividing?
Stratum basale
The layer of the epidermis that contains living (viable) cells that are rapidly undergoing mitosis.
Stratum basale
Layer that renders the skin relatively impermeable to trauma, chemicals, ultraviolet rays, biologic assaults.
Stratum corneum
Which layer of the epidermis is closest to the surface?
Stratum corneum
A splinter would penetrate the epidermal layers of the palm of the hand in which order?
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale
Identify the layers of the epidermis from superficial to deep:
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale
The layer of the skin where cells are considered protective, but nonviable (non-living):
Stratum corneum (stratum lucidum in thick skin).
A very thin layer called the _________ is in the epidermis but is only present in thick skin.
Stratum lucidum
Apocrine and eccrine glands are both ________________ glands.
Sudoriferous (sweat) glands
Keratinocytes are:
The most abundant cell type in the epidermis. They can be found throughout all layers of the epidermis. They may be alive or dead depending upon the epidermal layer in which they are located. They function to synthesize the protein keratin
The dermis has two layers. Which layer comprises 80% of the dermis?
The reticular layer
The portion of the hair that is above the surface of the skin is called:
The shaft
What role do karatinocytes play in protecting the skin from UV damage?
They accumulate melanin granules on their superficial portion, forming a UV-blocking pigment layer.
What do keratinocytes do?
They produce keratin (hard protein that protects the skin).
What do melanocytes do?
They produce melanin
In a(n) _____ burn, the entire thickness of the skin is damaged.
Third degree
What is the function of melanin in the skin?
To protect against UV light
Within the body, carotene is converted to:
Vitamin A which is vital for visual function.
What vitamin is crucial for regulation of calcium and phosphate and is attained via exposure to the sun?
Vitamin D
The inability to produce the pigment melanin is called:
albinism
Loss or thinning of hair is called:
alopecia
Keratinocytes
an epidermal cell that produces keratin.
The type of gland that secretes sweat into a hair follicle that is found in the axillary and genital regions is the __________ gland.
apocrine
The hypodermis is composed of ___________ and _______________.
areolar connective tissue dense irregular connective tissue
The band of smooth muscle that is responsible for pulling on a follicle and causing goose bumps is the:
arrector pili muscle
Least malignant and most common skin cancer
basal cell carcinoma
Pressure (decubitus) ulcers are usually associated with skin overlying:
bony projections.
What is the FIRST threat to life from a massive third-degree burn?
catastrophic fluid loss
Which glands produce ear wax?
ceruminous glands
Which of the following prevents the skin from overstretching and gives it strength?
collagen fibers
The two major fibers found in the dermis are _______ fibers, which provide its strength, and ________ fibers, which allow it to resume its original shape after stretching.
collagen fibers elastic fibers
A blue discoloration of the skin due to poor oxygenation of the blood.
cyanosis.
Fingernails and toenails are composed of:
dead, keratinized cells.
Cyanosis is caused by:
decreased oxygen content of blood
What are the greatest dangers to a patient following a burn?
dehydration and then infection
The reticular layer of the dermis consists primarily of:
dense irregular connective tissue
Blood capillaries that supply nourishment for the epidermis are located in the:
dermal papillae
Epidermal cells are s upplied with nutrients from blood vessels located in the:
dermis
The __________is composed of fibrous connective tissue whose strength and toughness results from abundant _________ fibers.
dermis collagen
What are the two types of sudoriferous glands?
eccrine and apocrine glands
The epidermis derives from:
ectoderm
Most textbooks define the skin as having two layers: The ________, and deep to it, the ___________ (or true skin). The third layer covering the body is said to be deep to the skin and is called the _________ or ___________.
epidermis dermis Subcutaneous layer or hypodermis
The integument consists of an outer _________ and an underlying ________.
epidermis; dermis
What cell types are likely to be found in the dermis?
fibroblasts, macrophages, and mast cells.
a burn in which only the epidermis is damaged
first degree burn
The sheath within which a hair is held is called:
follicle
The friction ridges (fingerprints) that are seen in finger, palm and footprints differ between various people but are similar between identical twins. This evidence suggests what?
friction ridges are genetically determined.
In hair, cell division occurs only in the:
hair matrix
The pinkish hue of individuals with fair skin is the result of oxygenated ___________ circulating in the dermal capillaries and reflecting through the epidermis.
hemoglobin
What is responsible for skin color?
hemoglobin, melanin, carotene
Adipose tissue in the ______ provides insulation that reduces the body's heat loss or gain.
hypodermis
A yellowish discoloration of the skin (including yellow tone to whites of eyes) is called ________ and is due to a build up of bile in the blood, often due to liver dysfunction.
jaundice
The epidermis is composed of:
keratinized stratified squamous epithelium
The majority of the cells of the epidermis are ___________
keratinocytes
Cerumen is a secretion that:
lubricates the ear canal and traps debris before it reaches the eardrum (tympanic membrane)
The stratum _______ is found only in thick skin (like the palms of the hands and soles of the feet).
lucidum
The white crescent at the proximal end of the nail plate is called the:
lunula
Normally, skin color results from a combination of:
melanin Hemoglobin Carotene
What causes freckles?
melanocytic activity genetic inheritance sun exposure
The ______________ of the dermis contains capillary loops from which nutrients diffuse to nourish the epidermis.
papillary layer
The main function of melanocytes is to:
produce melanin
What is the function of adipose tissue in the dermis?
protection of organs energy storage thermal insulation
Keratin is a __________ that is secreted by cells of the epidermis to waterproof the skin and protect against abrasion.
protein
Thick skin lacks _________ glands.
sebacous
The epidermis and part of the dermis are damaged from a _____________ degree burn.
second
The part of the hair that extends beyond the skin surface is called the:
shaft
The integumentary system comprises
skin, glands, hair, and nails.
The integumentary system comprises:
skin, glands, hair, nails
The stratum _______ derives its name from the spiny appearance of desmosomes that connect adjacent cells.
spinosum
Immune cells of the epidermis are most commonly located in the stratum ____________.
spinosum.
The epidermis is formed of _________ epithelium, and its outermost layer consists of dead cells filled with ________.
stratified squamous; keratin
The epidermis is formed of ______________ epithelium, and its outermost layer consists of dead cells filled with __________________.
stratified squamous; keratin
In what layer of the epidermis are melanocytes located?
stratum basal (or stratum germinativum)
Which layer of the epidermis will be supplied with the highest levels of oxygen from the blood?
stratum basale
The layers of the epidermis that is rapidly undergoing cell division (mitosis) is:
stratum basale (or stratum germinativum)
Most (~3/4) of the epidermal thickness is accounted for by:
stratum corneum
The most superficial layer of the epidermis is called the ________, and forms a waterproof shell around the body.
stratum corneum
Keratinocytes in the _____ of the epidermis produce lamellated granules filled with a water proofing glycolipid .
stratum granulosum
Which layer of the epidermis protects from abrasion and is only found in thick skin?
stratum lucidum
What type of skin gland secretes sweat?
sudoriferous glands
What are some of the components of the dermis?
sweat glands hair follicles collagen fibers sensory nerve endings arrector pili muscles
If body temperature increases above normal, what occurs?
sweating occurs and the blood vessels of the dermis dilate.
Coarse hair, such as the hair of the head, a mans bear, etc., is called _________ hair.
terminal
What happens as cells are pushed from the deeper part of the epidermis towards the surface and away from the blood vessels in the dermis
the cells die once they are pushed too far away from the blood vessels to receive oxygen and nutrients via diffusion.
Where are living epithelial cells found in each hair?
the hair bulb?
How does older adults skin compare to a younger adult?
thinner slowed regenerative capacity less hair less pigment fewer Langerhans cells Reduced cutanous gland activity
Tactile (merkel) cells are sensitive to:
touch
Regardless of race, all human beings have about the same number of melanocytes (true or false)
true
Pale, fine hair like that found on the face of a child is ________ hair.
vellus
Many of the molecules in the dermis bind with ______, which give it a resilient, shock-absorbing quality.
water
