CHAPTER 6: INTEGUMENTARY SYSTEM OBJECTIVES:
0. Name the organs and functions of the integumentary system.
Organs
Skin
Functions
Protection
Hair follicles
Regulation of Body Temperature
Sweat Glands
Sensory Reception
Sebaceous Glands
Vitamin D Synthesis
Nails
Immunity
Blood Reservoir
excretion
1.
Explain why the skin is called the cutaneous membrane.
ET = keratinized stratified squamous ET
CT – dense irregular CT
2.
Name the layers of the skin, describe the structure (tissues) of each, and name a
general function of each.
Epidermis = keratinized stratified squamous ET = protection
Dermis = dense irregular CT = strengthens skin; LACT = nourishes ET; glands =
secretion; etc
3.
Discuss the three cell types present in the epidermis.
Stratified Squamous ET cells
Melanocytes produce melanin.
Keratinocytes are old and stuck together by lots of desmosomes.
4.
List the four/five layers of the epidermis and explain the process of keratinization.
Stratum basale is on top of basement membrane = healthy cells = 0% keratinization
Stratum lucidum is in thick skin only and is above the stratum basale
Stratum spinosum are cells that have pushed toward to surface and have started to
accumulate keratin
Stratum granulosum are a few layers of squamous cells that contain granules of keratin
Stratum corneum is the outermost thick layer of dead cell full of keratin = 100%
keratinization
5.
Explain the protective role of keratin, and in turn, the epidermis.
Keratin protects from mechanical injury, water-loss, effects from harsh chemicals, and
against harmful pathogens that can cause disease.
6.
Name the pigment responsible for skin and hair color, and explain how people of
different races (i.e. and skin color) differ in regards to it, and the cell that
produces it. Melanin - melanocyte
7.
List some factors that promote the production of melanin (besides DNA).
Sunlight, UV rays, X-rays, some drugs
8.
Distinguish between the papillary layer and reticular layer of the dermis, and
locate the appropriate sensory receptor in each of these layers.
Papillary is top 20% of dermis beneath
Bottom 80% of dermis with DICT and
basement membrane with LACT and it
more
forms finger-like projections.
Meissner’s Corpuscle
Pacinian Corpuscle
Compare and contrast tactile (Meissner’s) and lamellated (Pacinian) corpuscles in
terms of their structure, function, and location.
Tactile Meissner’s Corpuscle
lamellated (Pacinian) corpuscles
9.
Specialized end of a dendrite that
resembles a Q-tip
Fine touch receptor
Specialized end of a dendrite that
resembles onion
Pressure receptor
Located in dermal papillae
Located deep in dermis and into
subcutaneous layer
10.
Describe the structure and function of the subcutaneous layer.
The subcutaneous layer lies beneath the dermis (hypodermis) and is composed of adipose
tissue = energy store; protection; and cushioning
11.
Explain what is meant by the term epidermal derivative, and list four examples.
An epidermal derivative originated from the epidermis = epithelium.
The four examples are hair follicles, merocrine sweat glands, apocrine sweat glands,
sebaceous glands.
12.
Describe the general structure of a hair follicle and identify two other structures
that are usually associated with them.
Root is down deep in dermis, the follicle runs up toward the surface, the shaft is the
exposed potion of hair. They are composed of keratinized stratified squamous ET with
melanocytes.
13.
Distinguish between merocrine (eccrine) and apocrine sweat glands in terms of
structure, secretion content and odor, activation, and major body locations.
Merocrine (Eccrine) Sweat Glands
Apocrine Sweat Glands
Respond to an increase in body temperature Respond to stress
Secretion is watery with water, salts, and
Secretion is thicker than merocrine sweat
wastes (urea and uric acid)
due to cellular debris plus water, salts, and
wastes (urea and uric acid)
No odor
Secretion does have odor
Run from coil to surface
Empty into a hair follicle
Function throughout life
Function from puberty and then through
life
Are widely distributed but are abundant on Axillary and Inguinal region
the forehead, neck m and back
14.
Name two modified apocrine glands of the skin.
Ceruminous glands in external ear = protective wax
Mammary glands of breasts = nourishing milk
15.
Describe the structure, function, secretion, and location of sebaceous glands.
Sebaceous glands are holocrine glands that produce sebum (oil). They surround hair
follicles and deposit the sebum into it. The sebum keeps skin and hair soft, pliable, and
waterproof.
16.
Discuss the many functions of skin.
Protection (see above)
Regulation of body temperature with sweating and activation/deactivation of superficial
blood vessels
Sensory reception with tactile Meissner’s and lamellated Pacinian Corpuscles
Vitamin D synthesis with sunlight (Vit D is needed for the absorption of dietary calcium)
Immunity with Langerhan cells (macrophages) and some T-cells
Blood reservoir with 10% of blood vessels located in skin
Excretion, along with kidneys. Wastes are urea from amino acid metabolism and uric
acid from nucleotide metabolism.
17.
Describe some major homeostatic imbalances of the skin. See chapter.
Burns
Wounds
Acne
Skin Cancers
18.
Sketch a typical layer of skin and label each layer and all structures. Then in
complete sentences, discuss the function of each layer and structure.
19.
Discuss heat production and loss as it relates to the integumentary system.
When body temperature rises, the hypothalamus causes sweating which cools in two
ways, and dilation of superficial blood vessels, so that the warm blood on the skin’s
surface can lose its heat to the environment.
When body temperature fall, the hypothalamus deactivates sweat glands, and causes
constriction of superficial blood vessels, so the warm blood stays deep.
20.
Define the terms hyperthermia and hypothermia and discuss the cause(s) of each
condition.
N/A
21.
N/A
Discuss the healing of cuts/wounds that occur to the skin.
22.
Distinguish between 1st degree, 2nd degree, and 3rd degree burns, and discuss the
process by which each burn heals.
1st – penetrates epidermis; no bleeding; least harmful
2nd = penetrated dermis and its tissues; bleeding; harmful
3rd = penetrated subcutaneous tissue and muscle below; most harmful