Integumentary System

Question 1

What is the epidermis?

Answer 1

The outermost protective shield of the body, composed of epithelial cells

Question 2

What is the dermis?

Answer 2

A tough, leathery layer that makes up the bulk of the skin, composed mostly of dense connective tissue

Question 3

Which layer of the skin is vascularized?

Answer 3

Dermis

Question 4

What is subcutaneous tissue?

Answer 4

Tissue that lies deep to the skin (is NOT part of the skin) and consists mostly of adipose tissue with some areolar tissue

Question 5

What is the function of subcutaneous tissue?

Answer 5

1. Anchors the skin to underlying structures
2. Acts a schock absorber
3. Acts as an insulator that reduces heat loss

Question 6

Keratinocytes

Answer 6

Predominant cells of the epidermis; produce keratin.

Question 7

What are the 4 types of cells populating the epidermis?

Answer 7

Kertainocytes, Melanocytes, Dendritic cells, Tactile epithelial cells

Question 8

Melanocytes

Answer 8

Spider-shaped epithelial cells that synthesize the pigment melanin. Found in the deepest layer of the epidermis

Question 9

Dendritic Cells

Answer 9

Star-shaped cells that arise from bone marrow and migrate to the epidermis. They ingest foreign substances and are key activators of our immune system

Question 10

Tactile Epithelial Cells

Answer 10

Shaked like a spiky hemisphere, associated with disclike sensory nerve ending functioning as a sensory receptor for touch

Question 11

What are the five layers of thick skin, from deep to superficial?

Answer 11

1. Stratum basale
2. Stratum spinosum
3. Stratum granulosum
4. Stratum lucidum
5. Stratum corneum

Question 12

Stratum basale

Answer 12

A single row of cells that forms the deepest layer of the epidermis; also called stratum germinativum.

Question 13

Stratum spinosum

Answer 13

Layer of the epidermis located between the stratum basale and stratum granulosum that contains keratinocytes that appear spiny in histological preparations.

Question 14

In which layer are dendritic cells most abundant?

Answer 14

Stratum spinosum

Question 15

Stratum granulosum

Answer 15

Layer of the epidermis superficial to the stratum spinosum consisting of one to five cell layers of keratinocytes that are undergoing keratinization.

Question 16

Stratum lucidum

Answer 16

Layer of the epidermis (in thick skin only) between the stratum granulosum and stratum corneum that consists of dead keratinocytes.

Question 17

Stratum corneum

Answer 17

The outermost layer of the epidermis consisting of many layers of flattened, dead keratinocytes; also called horny layer.

Question 18

Which areas of the body are covered by thick skin?

Answer 18

Soles of feet, fingertips, palms

Question 19

What is the function of the stratum basale?

Answer 19

There is rapid cell division, so it replaces cells lost by abrasion

Question 20

Why are the desmosomes and tight junctions connecting the keratinocytes so important?

Answer 20

Desmosomes hold cells together under stress, and tight junctions reduce water movement through skin

Question 21

What are the two layers of the dermis?

Answer 21

Papillary and reticular

Question 22

Papillary dermis

Answer 22

The thin, superficial layer of the dermis composed of areolar connective tissue.

Question 23

Dermal papillae

Answer 23

Fingerlike extensions of the papillary dermis that indent the overlying epidermis.

Question 24

Friction ridges

Answer 24

Skin markings that consist of epidermal ridges that lie on top of dermal ridges; contribute to the sense of touch and may enhance the ability to grip certain kinds of surfaces.

Question 25

Reticular dermis

Answer 25

The thick, deeper layer of the dermis composed of dense irregular connective tissue.

Question 26

What is responsible for fingerprints?

Answer 26

Friction ridges

Question 27

Cleavage lines

Answer 27

Externally invisible lines that tend to run longitudinally in the skin of the limbs and in circular patterns around the neck and trunk; used by surgeons to minimize scarring and improve the healing process.

Question 28

Flexure lines

Answer 28

Permanent skin creases found on areas of the body that perform frequent flexion movements (e.g., joints, palms of the hands).

Question 29

Melanin

Answer 29

Dark pigment formed by cells called melanocytes; imparts color to skin and hair.

Question 30

Carotene

Answer 30

Yellow to orange pigment that accumulates in the stratum corneum epidermal layer and in fatty tissue of the subcutaneous tissue. Can be converted to Vitamin A in the body

Question 31

What are the 3 pigments that contribute to skin color?

Answer 31

Melanin, carotene, hemoglobin