dermis and hypodermis

Question 1

Dermis

Answer 1

The middle layer of skin, contains collagen, blood vessels, glands, hair follicles, and nerve endings support and protect the skin and deeper layers, assist in thermoregulation, and aid in sensation.

Question 2

Hypodermis (subcutaneous)

Answer 2

The innermost layer of skin, storing energy, connecting the dermis layer of your skin to your muscles and bones, insulating your body, and protecting your body from harm.

Question 3

Dermal papillae

Answer 3

Protrusions of dermal connective tissue into the epidermal layer.

Question 4

Melanocytes

Answer 4

produce and distribute melanin, which is a skin pigment.

Question 5

Sebaceous glands

Answer 5

Microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum

Question 6

Sudiferous (sweat glands)

Answer 6

Found in the dermis, sweat duct that transports the secretion to the surface of the epidermis (eccrine glands) or into a hair follicle (apocrine glands).

Question 7

Eccrine

Answer 7

Sweat glands that are the most numerous and widely distributed over the body.

Question 8

The dermis

Answer 8

the middle layer of the integument. The dermis consists of loose connective tissue and houses a number of accessory structures of the skin.

Question 9

The dermis connects to

Answer 9

the epidermis by dermal papillae

Question 10

The dermis contains a variety of accessory structures of the integument. These include: 6

Answer 10

Hair follicles
Arrector pili muscles
Sweat glands
Sebaceous glands
Sensory receptors
Blood vessels

Question 11

Hair is not alive and develops from old dead cells pushed outward by new cells. The cells contain

Answer 11

keratin for hardness and melanin for color.

Question 12

Hairs can be very sensitive. This is due to

Answer 12

a tiny plexus of nerves that surround each hair follicle

Question 13

A band of smooth muscle connects to each hair follicle

Answer 13

• arrector pili muscle
• is capable of moving each follicle causing it to stand up in times of sympathetic nervous system activity such as emotional stress.

Question 14

the hair bulb

Answer 14

Hair begins to grow at the base of the hair follicle in a structure

Question 15

There are 2 types of hair.

Answer 15

• Vellus hairs are the fine hairs located on much of your body’s surface.
• Terminal hairs are thicker, more pigmented and are found on your head as well as genitals and axillary region.

Question 16

A small sebaceous gland surrounds each hair follicle. The sebaceous glands secrete an oily substance known as

Answer 16

sebum

Question 17

Sebum is secreted in response to

Answer 17

contraction of the arrector pili muscle.

Question 18

Sebum contains

Answer 18

triglyceride, protein, cholesterol and some electrolytes

Question 19

Sebum makes

Answer 19

the hair more flexible and hydrated.

Question 20

Sweat glands (aka sudoriferous glands) are located

Answer 20

the dermis

Question 21

There are 2 types of sweat glands

Answer 21

apocrine
eccrine

Question 22

Apocrine sweat glands secrete their substances into

Answer 22

the hair follicles

Question 23

The secretions of apocrine glands can develop

Answer 23

odor. The odor can increase because the secretion acts as a nutrient for bacteria that enhance the odor. Apocrine glands begin to secrete substances at puberty and are located in the axilla and genital regions.

Question 24

Eccrine sweat glands secrete their substances

Answer 24

directly onto the surface of the skin. They are coiled tubular glands that secrete a substance that mostly consists of water with a trace of some electrolytes and a peptide with antibiotic properties.

Question 25

The eccrine sweat glands primary function is to

Answer 25

help to regulate body temperature. The sweat can evaporate and carry away heat. The sweat also excretes water and electrolytes.

Question 26

The nail body is the

Answer 26

visible portion of the nail sits over the nail bed.

Question 27

The nail begins deep in the skin proximal to

Answer 27

where it is seen at the nail matrix. The nail begins to grow at the nail root which is close to the bone.

Question 28

A portion of the superficial epidermis (stratum corneum) extends over the proximal portion of the nail forming

Answer 28

the eponychium or cuticle. Blood vessels deep to the nail give it a pink color.

Question 29

The skin is very important in

Answer 29

regulating body temperature. The skin helps keep in heat produced by skeletal muscles and liver cells. When the body gets too hot the skin opens up the sweat pores so that the sweat can carry the heat away by evaporation

Question 30

Heat can be lost by the body in a number of ways. Heat always moves along a gradient from

Answer 30

warmer to cooler temperatures. Heat can radiate from the body to the surrounding areas at lower temperatures.

Question 31

In conduction, heat moves via molecules from the warmer body to cooler objects. An example of conduction

Answer 31

would be to lean against a cooler concrete wall. The heat flows from your body into the wall.

Question 32

In convection, heat moves via

Answer 32

air molecules circulating around body.

Question 33

In evaporation fluid on the surface of the body

Answer 33

carries heat away

Question 34

Body temperature is primarily regulated by an area in the brain known as

Answer 34

the hypothalamus. The hypothalamus sets the body’s temperature and controls it by opening and closing sweat glands and contracting muscles.

Question 35

Now let’s say that you’ve finished mowing the lawn and you go inside of your air conditioned home. Your body’s temperature will begin to drop. The hypothalamus

Answer 35

senses this and sends a message to your sweat glands to close. If your body’s temperature continues to drop the hypothalamus may send a message to your muscles to contract or shiver. The muscles will generate heat to help maintain your core temperature. In more severe cases of cold your blood vessels will constrict in your extremities in an attempt to conserve heat at the core of your body for survival.

Question 36

If your core body temperature continues to drop you may develop a condition called

Answer 36

hypothermia. You will progress from feeling cold to shivering, experiencing mental confusion, lethary, loss of reflexes and eventually loss of consciousness and shutting down of organs.

Question 37

after hypothermia if your core body temperature increases too much, you can develop

Answer 37

hyperthermia. This can develop in humid conditions because of lack of evaporation. The signs of hyperthermia include light headedness, dizziness, headaches, muscle cramps, fatigue and nausea.