Chapter 7- Skin And Its Appendages

Question 1

What are the appendages of the skin?

Answer 1

Hair
Nail
Glands

Question 2

What is the integumentary system?

Answer 2

The organs that compose the outer covering of the body.

Question 3

What are the layers of the skin?

Answer 3

Epidermis
Dermoepidermal junction
Dermis
Hypodermis

Question 4

What are the 4 main skin cells?

Answer 4

Keratinocytes
Melanocytes
Dendritic cells
Merkel cells

Question 5

What is keratinocytes?

Answer 5

Cells filled keratin.

Question 6

What is keratin?

Answer 6

Tough fibrous protein.
-makes up 90% of epidermal cells
Found in hair, nails and the organic matrix of tooth enamel.

Question 7

What are melanocytes?

Answer 7

The cells that are responsible for skin pigmentation. Dark pigmentation reduces the amount of UV damage.

Question 8

What are dendritic cells?

Answer 8

Antigen presenting cells.
Immune system cells with long finger like projections that live in all layers of the epidermis.

They identify bacteria and other invaders and present them to immune system.

Question 9

What are Merkel cells?

Answer 9

Also called “tactile cells”
Pressure sensor cells that connect to blood vessels and nerves and form complexes call tactile disks or Merkel disks.

They are found in the papillary layer, reticular layer and hypodermis layer

Question 10

What are the layers of the epidermis?

Answer 10

Surface film
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

Question 11

Describe the surface film layer of the epidermis.

Answer 11

Thin film coating of the skin that protects the skin from irritates, provides lubrication and hydration and produces antibacterial and antifungal compounds.

Made up of a mixture is sweat, sebum, dead skin cells and various chemicals

Question 12

Describe the stratum corneum layer of the epidermis.

Answer 12

“Horny layer”
Most superficial layer of skin.
Composed of several layers of dead cells (corneocytes); mostly made of dense networks of keratin fibers cemented together to form a tough waterproof barrier

Question 13

Describe the stratum lucidum layer of the epidermis.

Answer 13

“Clear layer”
Layer of squamous cells filled with a keratin precursor
Not visible in thin skin.

Question 14

Describe the stratum granulosum layer of the epidermis.

Answer 14

“Granular layer”
2-5 layers of dying, somewhat flattened cells filled with a substance needed to produce keratin.

Nuclei disappear in the layer.

Question 15

Describe the stratum spinosum layer of the epidermis.

Answer 15

“Spiny layer”

8-10 layers of cells that are pulled by desmosomes to give a spiny appearance.

Question 16

What is stratum germinativum layer of the epidermis?

Answer 16

“Growth layer”

Used to describe the stratum basale and stratum spinosum together.

Question 17

Describe the stratum basale layer of the epidermis.

Answer 17

“Base layer”
Single layer of mostly columnar cells, contains keratinocytes and melanocytes.

Only layer of the epidermis that is capable of mitosis. All layers are dying versions of this layer.

Question 18

What is the dermoepidermal junction?

Answer 18

The “basement layer”

A unique and complex arrangement of adhesive compounds the “glue” the epidermis to the dermis.

Question 19

What is the epidermis?

Answer 19

The superficial layers of skin

• Made up entirely of keratinized stratified squamous cells epithelium
• Contains hairs, sweat glands and sebaceous glands.

Question 20

What is the dermis?

Answer 20

The deep primary layers of skin
Called the “true skin”
Made up of fibrous tissues and includes some blood vessels, muscles and nerves.

Question 21

What are sebaceous glands?

What do they produce?

Answer 21

Epidermal glands that produce sebum.

Question 22

What is sebum?

Answer 22

Skin oils.

Question 23

What are the 2 layers in the dermis?

Answer 23

Papillary layer

Reticular layer

Question 24

Describe the papillary layer of the dermis.

Answer 24

“Nipple layer”
Thin layer of loose fibrous tissue with collagenous and elastic fibers.

Contains tactile disks (Merkel disks)
Forms finger and toe prints

Question 25

Describe the reticular layer of the dermis.

Answer 25

``` “Relating to little net” Tough network (reticulum) of collagenous irregular fibrous tissues and sone elastic fibers. ``` Includes Merkel disks.

Question 26

Describe the hypodermis.

Answer 26

Also call the subcutaneous layer or superficial fascia. Loose connective tissue (areolar) and adipose tissue (fat). Not part of the skin, but below it. Includes skin ligaments that strongly connect the skin to underlying structure, lamellar corpuscles and other sensors.

Question 27

What are the functions of the skin?

Answer 27

``` Protection Sensation Flexibility Excretion Hormone production Immunity Homeostasis of body temperature ```

Question 28

Describe the 4 types of skin glands.

Answer 28

- Eccrine sweat glands- the common sweat gland - Apocrine sweat gland- deep subcutaneous gland found in the armpit, areola and dark skin around the anus. - Sebaceous glands- skin oil glands - Ceruminous gland- makes ear wax