Chapter 5: Skin and the Integumentary Membrane (Skin and it's tissues…
Chapter 5: Skin and the Integumentary Membrane
Skin and it's tissues (Cutaneous membrane)
Two distinct regions or layers compose the skin:
Epidermis = outermost layer;
keratinized stratified squamous ET.
Dermis = inner layer;
keratinized epithelium (hair follicles),
glandular epithelium (sweat, sebaceous glands),
dense irregular CT (collagen),
smooth muscle tissue (arrector pili muscles),
nervous tissue (Meissner"s & Pacinian Corpuscles), and
Subcutaneous layer = adipose tissue; distinct layer beneath the skin also called hypodermis
from water loss;
from chemicals and microorganisms.
pH or 5-6
Langerhans cells (epidermis)
macrophages and mast cells (dermis)**
Excretion (minimal, most through kidneys)
Light touch detection = Messner's Corpuscle's;
located in dermal papillae;
populate areas in the fingerprints, palms, soles, eyelids, tip of tongue, nipples, clitoris, tip of penis.
Pressure detection = Pacinian Corpuscle's
located in deep dermis and subcutaneous regions;
Vitamin D Synthesis
UV rays in sunlight activate its synthesis;
Vitamin D is required for bone homeostasis.
The dermis houses about 10% of the body's blood vessels.
Skin only requires 1-2% of the body's blood
Langerhan's cells (macrophages);
interact with T-helper cells in immune responces.
Which of the following is the correct order of the layers of the cutaneous membrane?
epidermis, dermis, hypodermis
The tissue under the skin is called the
hypodermis or subcutaneous layer
As cells are pushed from the deeper portion of the epidermis toward the surface,
The layer of the epidermis at the surface is the
Thick skin can be found on the
The skin is also called the
Thin skin is defined by the thickness of the
An epidermal layer that produces large amounts of keratin is the
Epidermal cells are supplied with nutrients from blood vessels in the
Drugs suspended in
can penetrate the epidermis.
Functions of the skin include
regulating body temperature
An individual with excessive epidermal sheddig on the scalp may be prone to develop this condition.
The primary mode of the heat loss from the body is
Which of the following is a function of the integumentary system that aids the endocrine system?
synthesis of vitamin D
Epidermal cells synthesize this vitamin when exposed to sunlight.
The skin may turn orange as a result of
The pigment melanin
A and C only
The most important factor in skin color is
Exposure of the skin to ultraviolet light
can stimulate the production of melanin
When a person becomes "pale," what is the physiologic basis?
The number of red melanocytes in the skin increases.
The dermis is composed largely of
dense irregular connective tissue.
When smooth muscles in the walls of dermal blood vessels contract,
body heat is conserved.
The layer of the skin that provides themoregulation via changing blood flow is the
Folds of the dermis that cause fingerprints are called
Nerve fibers in the skin are associated with
smooth muscles, blood vessels, sensory never endings, and hair follicles; all of the above.
When the body is overheated, the skin responds by
increasing blood flow to the dermis.
The subcutaneous layer is made of
loose connective and adipose tissues.
The hypodermis contains mostly
Injections made under the skin are called
Shafts of hair are made by
dead epidermal cells.
When the arrector pili muscles contract, "goose bumps" are formed.
Hairs are shed.
Accessory structures of the skin include
hair follicles, arrector pili muscles, sebaceous glands, and apocrine sweat glands; All of the above.
The pale cresent area of the nail is called the
The fold of stratum corneum over the base of a nail is called the
The type of burn that may require a skin graft is a
A burn that penetrates the epidermis and part of the dermis is classified as a
second degree burn.
Why would an elderly person be more prone to skin infections than a younger person?
All of the above
This type of burn appears inflamed and tender but has no blisters.
The most severe type of skin cancer is most likely to develop from
A "rug burn" is an example of an
A burn that involves only the epidermis, such as a mild sunburn, is classified as
Glands that are located in the ear canal are called
Perspiration produced by apocrine sweat glands
is limited to the hair follicles of the axilla, nipples, and groin
The condition that results from clogged sebaceous glands is
Eccrine sweat glands
respond primarily to elevated body temperature.
Sweat helps to cool the body by
Eccrine and sebaceous glands differ in
type of secretion, material secreted, location in the body, their association with hair follicles; All of the above.
The glands that develop at puberty are
Specialized sweat glands that produce milk are called
What are the 5 layers of thick skin?
spinosum, granulosum, lucidum, corneum.
Structure = keratinized stratified squamous epithelium
4 distinct layers in the epithelial cells:
Stratum corneum = outermost layers
Stratum lucidum = translucent layer cells separating.
Stratum granulosum = composed of 3-5 layers of flattened granular cells cells.
Stratum spinosum = composed of many layers of spiky cells with large nuclei.
Stratum basale (germinativum) = inner most layer
Main Function = Protection (keratin)
a. prevents moisture loss (waterproof)
b. prevents injury by penetration
c. prevents microorganisms/chemicals entry
Pigment = melanin
produced by melanocytes in stratum basale (germinativum)
People of diff races have the same # of melanocytes, but the amount of melanin produced varies (determined by DNA)
affect melanin production: by affecting gene expression
may affect skin color (but not melanin production)
Vitamin D3 (sunlight converts a cholesterol related steroid)
Liver converts into calcitrol
Basal cell carcinoma
Squamous cell carcinomas
Avoid mid-day sun, & were sun block
Dermis = inner layer of skin
Two distinct layers:
Papillary layer (20%) is below epidermis:
Composed of loose areolar CT
Reticular layer (80%) = dense irregular CT
bundles of collagen fibers
Main Function = nourishment of epidermis
Subcutnaeous Layer (hypo dermis) = beneath skin
Structure = adipose tissue and blood vessels
Function = insulation
hair root or base in deep dermis
follicle throughout dermis
hair shaft in epidermis
grows for 2-5 years / new cycle pushes old hair out
cells are epithelium
= melanin decreases with age
peg of connective tissue
Arector pili muscle
= a bundle of smooth muscle associated with every hair follicle.
Causes hair to stand on end (goose bumps) when frightened of cold.
holocrine gland (simple cuboidal epithelium)
Sebum is secreted into hair follicle
Function: sebum keeps skin and hair soft, pliable and virtually waterproof