Biology 01 - Accessory Structures of Skin

Question 1

What do the epithelial cells do at the base of the nail plate?

Answer 1

they divide and the newly formed cells become keratinized.

Question 2

result of keratinized nail cells?

Answer 2

This gives rise to tiny, keratinized scales that become part of the nail plate pushing it over the nail bed.

Question 3

The keratinize of the nail is stronger than what?

Answer 3

the stratum corneum

Question 4

The plate extends beyond the nail bed and gradually wears away with what?

Answer 4

with normal use.

Question 5

Hair is present on all skin surfaces except what?

Answer 5

The palms, soles, lips, nipples, and parts of the external reproductive organs

Question 6

Though not well developed on every surface..

Answer 6

like the forehead.

Question 7

90% of hair is in the what?

Answer 7

growth phase..

Question 8

What is the hair follicle?

Answer 8

A tube-like depression of epidermal stem cells from which the hair develops.

Question 9

What is the hair root?

Answer 9

Can extend from the surface into dermis or subcutaneous layer.

Question 10

What is a hair bulb?

Answer 10

The deepest portion of the hair root located at the base of the follicle. Composed of epithelial cells that are nourished from the dermal blood vessels.

Question 11

What is the hair shaft?

Answer 11

The older, dead keratinized cells that have been pushed towards the surface and away from nutrients.

Question 12

What determines the hair color?

Answer 12

Genes they direct the type and amount of pigment melanocytes produces.

Question 13

The smooth muscle cells form..

Answer 13

arrector pili muscles that attach to each hair follicle. Nervous stimulation causes these muscles to contract if a person is emotionally upset or cold.

Question 14

Each hair follicle is associated with how many glands?

Answer 14

one or more sebaceous glands.

Question 15

Sweat Glands

Answer 15

• Also called sudoriferous glands
• widespread in skin
• consists of a tiny tube that originates as a ball shaped coil in the deeper dermis or superficial subcutanous layer.
• Most numerous sweat glands are the merocrine sweat glands.
• Other sweat glands are called appocrine sweat glands.

Question 16

Merocrine Sweat Glands

Answer 16

• AKA eccrine sweat glands
• respond throughout life
• Responds to body temperature and environmental heat or the physical exercise.
  -Abundant on forehead, neck, back responding to heat or intense activity.
  Also release moisture on palms and soles when emotionally stressed.

Question 17

What is sweat?

Answer 17

Sweat is mostly water but contains small amounts of urea and uric acid waste.

Question 18

Apocrine Sweat Glands

Answer 18

• Become active at puberty
• Can wet certain areas of the skin when a person is upset, frightened, or in pain.
• Almost active during sexual arousal
• Most numerous in axillary region and groin.
• Secretions of these glands include proteins and lipids that produce body odor when metabolized by skin bacteria.

Question 19

What is Ceruminous glands?

Answer 19

• In the external acoustic meatus

- Secretes ear wax

Question 20

What is the Mammary Glands?

Answer 20

• In the breasts

- Secretes milk

Question 21

Skin is one of the most versatile organs and is vital in maintaining homeostasis..

Answer 21

• preventing harmful substances from entering the body.
• preventing disease causing microorganisms from entering the body.
• Retarding water loss by diffusion from deeper tissues
• Housing sensory receptors
  -Secreting small amounts of waste
  AND playing a role in Vitamin D production.

Question 22

Vitamin D production

Answer 22

Vit D. is necessary for normal bone and tooth development