Unit 3 - Integumentary System

Question 1

Define the integumentary system

Answer 1

Complex set of organs that includes skin and its derivatives

Question 2

What does the integumentary system include?

Answer 2

Sweat and oil glands, hairs, and nails

Nerves, blood vessels, muscles, sensory elements

Question 3

List the 6 functions of skin

Answer 3

Protection
Thermoregulation
Cutaneous sensation
Metabolic functions
Blood reservoir
Excretion

Question 4

Explain the difference between the epidermis and the dermis

Answer 4

Epidermis is made of stratified squamous epithelium

Dermis includes papillary and reticular layers

Question 5

Describe the structure of the subcutaneous layer.

Answer 5

The hypodermis is the subcutaneous layer lying below the dermis; it consists largely of fat. It provides the main structural support for the skin, as well as insulating the body from cold and aiding shock absorption. It is interlaced with blood vessels and nerves

Question 6

Explain what happens to epidermal cells as they undergo keratinization.

Answer 6

Keratinocytes arise from the deepest layer of the epidermis produced by stem cells in the stratum basale. They undergo continuous mitosis, those cell push up by the production of new cells beneath them. By the time they reach the new skin surface, they die and create a scale-like structure with more than a keratin-filled plasma membrane. Millions of these dead cells rub off daily and humans replace their skin completely ever 25-45 days.

Question 7

List the 5 layers of the epidermis

Answer 7

Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

Question 8

The outermost layer of the epidermis and marks the final stage of keratinocyte maturation and development

Answer 8

Stratum corneum

Question 9

A thin somewhat translucent layer of cells lying superficial to the stratum granulosum and under the stratum corneum especially in thickened parts of the epidermis

Answer 9

Stratum lucidum

Question 10

A layer of granular nondividing cells above the stratum spinosum

Answer 10

Stratum granulosum

Question 11

The layers of prickle cells over the layer of the stratum basale capable of undergoing mitosis.

Answer 11

Stratum spinosum

Question 12

The deepest layer, separated from the dermis by the basement membrane and attached to the basement membrane by hemidesmosomes.

Answer 12

Stratum basale

Question 13

Describe the location, structure, and function of melanocytes.

Answer 13

Found in deepest layer of epidermis
Synthesizes melanin
Accumulated in melanosomes
Moved along actin filaments to melanocyte’s processes

Question 14

Describe the structure of the dermis

Answer 14

Strong flexible connective tissue layer beneath epidermis which consists of two layers (papillary, reticular)

Question 15

What makes up the dermis?

Answer 15

The dermis contains nerve endings, sweat glands and oil glands (sebaceous glands), hair follicles, and blood vessels.

Question 16

Explain the functions of the subcutaneous layer.

Answer 16

Binds skin to underlying tissues

Subcutaneous fat which acts as an energy reservoir and thermal insulation

Question 17

Explain the structure and function of sebaceous glands.

Answer 17

Sebaceous glands secrete sebum which coats and protects the hair shaft

Question 18

Explain the importance of body temperature regulation.

Answer 18

Body temperature must be controlled within a very narrow range so that the body can function properly. In particular, enzymes in a body’s cells must have the correct temperature to be able to catalyze chemical reactions. High temperatures can cause dehydration, heat stroke and death if untreated.

Question 19

Explain the role of the skin in promoting the loss of excess body heat.

Answer 19

In intense heat, the nerve impulses stimulate the skin and other organs to release heat. The muscles, when active, release heat. As excessive body heat is lost, the brain triggers responses in skin structure.

Question 20

Explain the body’s response to decreasing body temperature.

Answer 20

The body decreases blood flow to conserve body heat

Question 21

Explain how environmental factors affect skin color.

Answer 21

• Populations native to tropics and their descendants tend to have well-melanized skin to screen out excessive UVR
• Populations native to far northern or southern latitudes have light skin to allow for adequate UVR penetration
• Ancestral skin color is a compromise between vitamin D and folic acid requirements

Question 22

Describe three physiological factors that affect skin color.

Answer 22

Melanin
Hemoglobin
Carotene

Question 23

Distinguish between the healing of shallow and deeper breaks in the skin.

Answer 23

• Shallow - Epithelial cells along the margin divide more than usual, new cells fill the gap.
• Deep - Cut into dermis or subcutaneous. Blood vessels break, escaping blood forms a clot, mostly fibrous protein (fibrin), blood cells, and platelets trapped fibers. Tissues fluids seep into the area and dry. Clot and dry fluids create a scab that covers and protects the healing tissue. Fibroblasts begin forming new collagenous fibers tag bind edges of wound together.

Question 24

Describe the characteristics of a first-degree burn

Answer 24

Marked by redness, slight edema, and pain

Question 25

Describe the characteristics of a second-degree burn

Answer 25

Blisters; skin regeneration occurs with little or no scarring

Question 26

Describe the characteristics of a third-degree burn

Answer 26

Burned area appears gray-white, cherry red, or blackened; excessive scar tissue forms

Question 27

What percentage of the body burned is considered a threatening 2nd degree burn?

Answer 27

Over 25%

Question 28

What percentage of the body burned is considered a threatening 3rd degree burn?

Answer 28

Over 10%

Question 29

Explain what types of burns pose a threat to life and describe the most significant threats major burns pose.

Answer 29

• 3rd degree burns of face, hands, or feet
• Burns at joints can cause scar tissue formation which may severely limit joint mobility
• Deaths result primarily from fluid loss, infection, and toxic effects of eschar

Question 30

What is a possible treatment for 3rd degree burns?

Answer 30

Skin grafts

Question 31

What are the 3 effects of aging on the skin?

Answer 31

Appearance
Temperature regulation
Vitamin D activation

Question 32

What is the appearance effect of aging on the skin?

Answer 32

Epidermis thins with age. Skin may appear scaly. Patches of pigment called age spots. Shrinking dermis and loss of some fat from subcutaneous layer results in wrinkling and sagging. Decrease in oil from subcutaneous glands dries the skin. Pale complexion from fewer blood vessels

Question 33

What is the temperature regulation effect of aging on the skin?

Answer 33

Less able to tolerate the cold and cannot regulate heat.

Question 34

What is the vitamin D activation effect of aging on the skin?

Answer 34

Less exposure to sun and skin needs it to produce Vitamin D.