Exam 3: skin

Question 1

What are exocrine glands composed of?

Answer 1

Epithelial tissue

Question 2

Types of skin glands

Answer 2

Sebaceous gland
Sudoriferous gland
Ceruminous gland
Mammary gland

Question 3

Which gland typically release oil into the hair follicle?

Answer 3

Sebaceous gland (sebace=greasy)

Question 4

This substance prevents dehydration and inhibits bacterial growth. It is made mainly of triglycerides and cholesterol.

Answer 4

Sebum

Question 5

Which gland releases sweat to surface (via pore) or into hair follicles and regulates body temperature via homeostasis?

Answer 5

Sudoriferous glands (sudori = sweat; ferous = bearing)

Question 6

Deep layer of the skin and have mainly connective tissue, with embedded blood vessels,nerve glands and hair follicles.

Answer 6

Dermis

Question 7

Two main regions of the dermis

Answer 7

Papillary region and reticular region

Question 8

Papillary region

Answer 8

Superficial
Thin (relative to reticular region)
Dermal papillae (papillae = nipple) project into epidermis, supplying it with blood vessels and nerves

Question 9

Reticular region

Answer 9

Deep
Thick (relative to papillary region)
Many collagen and elastic fibers for extensibility and elasticity

Question 10

Location of thick skin

Answer 10

Palms, fingertips, and soles

Question 11

Structure of thick skin

Answer 11

5 layers in epidermis
Hair absent
Many sensory receptors
Epidermal ridges present

Question 12

Location and structure of thin skin

Answer 12

Everywhere else
4 layers of epidermis
Few sensory receptors
Epidermal ridges absent

Question 13

Increase surface area of epidermis for better grip, reflect contours of underlying dermal papillae, and are the basis for fingerprints (and footprints)

Answer 13

Epidermal ridges

Question 14

What are the pigments that produce skin color?

Answer 14

Melanin
Hemoglobin
Carotenes

Question 15

Pigment that is synthesized by melanocytes in epidermis and transferred to keratinocytes

Answer 15

Melanin

Question 16

Why is melanin transferred to keratinocytes?

Answer 16

It accumulates above nucleus to shield nucleus from UV radiation in sunlight

Question 17

Two forms of melanin

Answer 17

Pheomelanin (yellow to red)

Eumelanin (brown to black)

Question 18

Pigment found within red blood cells in capillaries of dermis that shows through if there is little melanin; red-colored

Answer 18

Hemoglobin

Question 19

A dietary pigment that can accumulate in stratum corneum and subcutaneous adipose tissue; orange colored

Answer 19

Carotenes

Question 20

Accessory structures of the skin

Answer 20

Hair
Nails
Skin glands

Question 21

Also called pilus/pili

Answer 21

Hair

Question 22

Structure of hair

Answer 22

• Columns of dead keratinizes cells held together by extracellular proteins
• Shaft extends above surface of skin
• Root penetrates epidermis and dermis

Question 23

Base of the hair follicle

Answer 23

Bulb

Question 24

Bulb consists of:

Answer 24

Epithelial root sheath

Dermal root sheath

Question 25

Epidermal tissue around hair root

Answer 25

Epidermal root sheath

Question 26

Dermal tissue around hair root

Answer 26

Dermal root sheath

Question 27

Structures associated with hair follicle

Answer 27

``` Papilla of hair Hair matrix Sebaceous glands Arrector pili Hair root plexuses (branching network of nerves) ```

Question 28

Supplies hair follicle with blood vesicles

Answer 28

Papilla of the hair

Question 29

Layer of epithelial stem cells that give rise to the hair and are derived from stratum basale. It is responsible for growth of existing hair and production of new hair

Answer 29

Hair matrix

Question 30

Produces and secrete oil

Answer 30

Sebaceous glands

Question 31

Smooth muscle associated with follicle and pulls hair upright

Answer 31

Arrector pili

Question 32

Neurons sensitive to tactile stimuli (ex: feeling slight brush on arm hair)

Answer 32

Hair root plexuses

Question 33

Where does the melanocytes occur?

Answer 33

Hair matrix

Question 34

Hair color depends on what?

Answer 34

Amount and type of melanin in keratinized cells

Question 35

Composed of tightly packed, dead, keratinized epidermal cells

Answer 35

Nails

Question 36

Responsible for nail growth

Answer 36

Nail matrix

Question 37

Two types of sudoriferous glands

Answer 37

Eccrine sweat glands | Apocrine sweat glands

Question 38

Eccrine sweat glands

Answer 38

Located across body surface | Help to cool the body

Question 39

Apocrine sweat gland

Answer 39

Located in axilla (armpit), groin, areolae, and bearded facial regions Secrete sweat during emotional stress or sexual excitement (haha..)

Question 40

Modified sweat glands that are located in external ear and produces a waxy secretion

Answer 40

Ceruminous glands

Question 41

Combined secretions of ceruminous and sebaceous glands in ears

Answer 41

Cerumen (earwax)

Question 42

Functions of the skin

Answer 42

``` Thermoregulation Protection Cutaneous sensations Excretion and absorption Synthesis of vitamin D ```

Question 43

What are the two mechanisms of thermoregulation?

Answer 43

- Secreting sweat | - Adjusting blood flow to dermal capillaries by dilation and constriction of capillaries

Question 44

The skin protects by:

Answer 44

Physical barrier to invasion by pathogens Physical protection from abrasion, heat, and some toxic chemicals Lipids in epidermis retard dehydration Protection from UV radiation (melanins)

Question 45

What are the cutaneous sensations?

Answer 45

Tactile sensation Thermal sensation Pain

Question 46

How is water lost in skin?

Answer 46

By evaporation of water across skin and via sweat

Question 47

What are excreted along with water by skin?

Answer 47

Sal amounts of salts, CO2, ammonia, and urea and some lipid-soluble substances

Question 48

Describe the synthesis of vitamin D

Answer 48

Precursor molecule of vitamin D activated by exposure to UV radiation in skin Precursor molecule then modified in liver and kidneys to produce calcitriol (a form of vitamin D)