Integumentary System

Question 1

the skin is composed of two distinct layers ..

Answer 1

The epidermis
The dermis

Question 2

The epidermis

Answer 2

composed of epithelial cells, is the outermost protective shield of the body.

Question 3

The underlying dermis ..

Answer 3

making up the bulk of the skin, is a tough, leathery layer composed mostly of dense connective tissue.

Question 4

The vascularized layer is and how ? ..

Answer 4

Dermis. Nutrients reach the epidermis by diffusing through the tissue fluid from blood vessels in the dermis.

Question 5

The subcutaneous tissue ..

Answer 5

the hypodermis, deep to the skin & is not part of the skin, but it shares some of the skin’s protective functions.

Question 6

The hypodermis, also called ..

Answer 6

superficial fascia because it is superficial to the tough connective tissue wrapping (fascia) of the skeletal muscles, consists mostly of adipose tissue.

Question 7

the hypodermis function ..

Answer 7

anchors the skin to the underlying structures (mostly to muscles), but loosely enough that the skin can slide relatively freely over those structures.

acts as a shock absorber and an insulator that reduces heat loss.

Question 8

The epidermis consists of ————— cell types and ———— layers.

Answer 8

four distinct, four or five distinct.

Question 9

The cells populating the epidermis include ..

Answer 9

keratinocytes, melanocytes, dendritic cells, and tactile cells.

Question 10

The chief role of keratinocytes is ..

Answer 10

to produce keratin, the fibrous protein that helps give the epidermis its protective properties.

Most epidermal cells are keratinocytes

Question 11

keratinocytes arise in the deepest part of the epidermis from a cell layer called ..

Answer 11

stratum basale.

Question 12

keratinocytes undergo almost continuous mitosis in response to prompting by ..

Answer 12

epidermal growth factor

Question 13

epidermal growth factor ..

Answer 13

peptide produced by various cells throughout the body.

Question 14

callus

Answer 14

thickening of the epidermis

Question 15

Melanocytes

Answer 15

spider-shaped epithelial cells that synthesize the pigment melanin are found in the deepest layer of the epidermis.

Question 16

As melanin is made, it accumulates in ..

Answer 16

membrane-bound granules called melanosomes that motor proteins move along actin filaments to the ends of the melanocyte’s processes

Question 17

From melanocyte’s processes melanosomes are transferred to a number of nearby keratinocytes. The melanin granules accumulate on the ..

Answer 17

superficial side of the keratinocyte nucleus, forming a shield that protects the nucleus from the damaging effects of (UV).

Question 18

dendritic cells

Answer 18

Also called Langerhans cells, star-shaped, they arise from bone marrow and migrate to the epidermis.

Question 19

Dendritic Cells function ..

Answer 19

ingest foreign substances and are key activators of our immune system.

Question 20

tactile cells

Answer 20

Also called merkel cells, present at the epidermal-dermal junction.
Shaped like a spiky hemisphere

Question 21

tactile (Merkel) cells function..

Answer 21

each tactile cell is intimately associated with a disclike sensory nerve ending. The combination, called a tactile or Merkel disc, functions as a sensory receptor for touch

Question 22

The stratum basale

Answer 22

the deepest epidermal layer, is attached to the underlying dermis

Question 23

stratum basale consists of ..

Answer 23

a single row of stem cells—a continually renewing cell population—representing the youngest keratinocytes.

Question 24

What is the alternate name of stratum basale, and why ?

Answer 24

stratum germinativum, The many mitotic nuclei seen in this layer reflect the rapid division of these cells.

Question 25

The stratum spinosum

Answer 25

Also called Prickly Layer, several cell layers thick. These cells contain a weblike system of intermediate filaments.

Question 26

The weblike system of intermediate filaments in Prickly Layer function is ..

Answer 26

tension-resisting bundles of pre-keratin fila- ments, which span their cytosol to attach to desmosomes.

Question 27

the keratinocytes in stratum spinosum layer appear to have ..

Answer 27

spines, causing them to be called prickle cells