Dermis And Hypodermis

Question 1

What is the dermis?

Answer 1

The middle layer of skin containing collagen, blood vessels, glands, hair follicles, and nerve endings.

Supports and protects the skin and deeper layers, assists in thermoregulation, and aids in sensation.

Question 2

What is the hypodermis?

Answer 2

The innermost layer of skin, storing energy and connecting the dermis to muscles and bones.

Insulates the body and protects it from harm.

Question 3

What are dermal papillae?

Answer 3

Protrusions of dermal connective tissue into the epidermal layer.

Question 4

What do melanocytes produce?

Answer 4

Melanin, which is a skin pigment.

Question 5

What are sebaceous glands?

Answer 5

Microscopic exocrine glands in the skin that secrete an oily or waxy matter called sebum.

Question 6

What are sudiferous glands?

Answer 6

Sweat glands found in the dermis that transport secretion to the surface of the epidermis or into a hair follicle.

Question 7

What are eccrine glands?

Answer 7

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

Question 8

Fill in the blank: The dermis connects to the epidermis by means of _____ structures called dermal papillae.

Answer 8

wavy

Question 9

List three accessory structures contained in the dermis.

Answer 9

• Hair follicles
• Arrector pili muscles
• Sweat glands

Question 10

True or False: The dermis is the outermost layer of the skin.

Answer 10

False

Question 11

What is the primary function of the hypodermis?

Answer 11

To store energy and insulate the body.

Question 12

What is the dermis?

Answer 12

The middle layer of the integument consisting of loose connective tissue

The dermis houses a number of accessory structures of the skin.

Question 13

What structures connect the dermis to the epidermis?

Answer 13

Wavy structures called dermal papillae

Question 14

Name three accessory structures found in the dermis.

Answer 14

• Hair follicles
• Sweat glands
• Sebaceous glands

Question 15

How many hairs does the human body have approximately?

Answer 15

About 2.5 million

Question 16

Where is hair not found on the human body?

Answer 16

• Palms of the hands
• Soles of the feet
• Lips
• Parts of the external genitalia
• Sides of the feet and fingers

Question 17

What are the main components that make up hair?

Answer 17

• Keratin for hardness
• Melanin for color

Question 18

What is the function of the arrector pili muscle?

Answer 18

To move each hair follicle causing it to stand up during sympathetic nervous system activity

Question 19

Where does hair growth begin?

Answer 19

At the base of the hair follicle in a structure called the hair bulb

Question 20

What is the hair papilla?

Answer 20

A structure that surrounds the hair bulb containing blood vessels and nerves

Question 21

What is the average rate of hair growth per day?

Answer 21

About 0.33 mm per day

Question 22

How many hairs do normal adults lose per day?

Answer 22

About 50 hairs

Question 23

What condition results in a net loss of hair?

Answer 23

Loss of over 100 hairs per day

Question 24

What are the two types of hair?

Answer 24

• Vellus hairs
• Terminal hairs

Question 25

What is sebum?

Answer 25

An oily substance secreted by sebaceous glands

Question 26

What triggers the secretion of sebum?

Answer 26

Contraction of the arrector pili muscle

Question 27

What are the components of sebum?

Answer 27

* Triglyceride * Protein * Cholesterol * Some electrolytes

Question 28

What are the two types of sweat glands?

Answer 28

* Apocrine sweat glands * Eccrine sweat glands

Question 29

True or False: Apocrine sweat glands secrete their substances into the hair follicles.

Answer 29

True

Question 30

What are the two types of sweat glands?

Answer 30

Apocrine sweat glands and eccrine sweat glands ## Footnote Apocrine glands secrete into hair follicles, while eccrine glands secrete directly onto the skin surface.

Question 31

Where are apocrine sweat glands primarily located?

Answer 31

In the axilla and genital regions ## Footnote Apocrine glands begin to secrete substances at puberty.

Question 32

What can cause odor from apocrine sweat glands?

Answer 32

The secretion acts as a nutrient for bacteria ## Footnote Bacteria enhance the odor from the secretions.

Question 33

What is the primary function of eccrine sweat glands?

Answer 33

To help regulate body temperature ## Footnote Eccrine sweat glands secrete mostly water with trace electrolytes and a peptide with antibiotic properties.

Question 34

What does the sweat produced by eccrine glands consist of?

Answer 34

Water, trace electrolytes, and a peptide with antibiotic properties ## Footnote The primary function is to regulate body temperature through evaporation.

Question 35

What is the visible portion of the nail called?

Answer 35

Nail body ## Footnote The nail body sits over the nail bed.

Question 36

Where does nail growth begin?

Answer 36

At the nail root ## Footnote The nail root is close to the bone.

Question 37

What forms the cuticle of the nail?

Answer 37

Eponychium ## Footnote A portion of the superficial epidermis (stratum corneum) extends over the proximal portion of the nail.

Question 38

What role does the skin play in temperature regulation?

Answer 38

It helps keep in heat and facilitates heat loss through sweat ## Footnote The skin opens sweat pores when the body gets too hot.

Question 39

How does heat move from the body to the surrounding areas?

Answer 39

Heat moves along a gradient from warmer to cooler temperatures ## Footnote Heat can radiate, conduct, convect, or evaporate.

Question 40

What is conduction in the context of heat loss?

Answer 40

Heat moves via molecules from the warmer body to cooler objects ## Footnote An example is leaning against a cooler concrete wall.

Question 41

What is convection in heat loss?

Answer 41

Heat moves via air molecules circulating around the body ## Footnote This process helps cool the body down.

Question 42

What is the role of the hypothalamus in body temperature regulation?

Answer 42

It sets and controls the body's temperature ## Footnote The hypothalamus opens and closes sweat glands and controls muscle contractions.

Question 43

What happens when the body's temperature rises?

Answer 43

The hypothalamus sends a message to open sweat glands ## Footnote Sweat evaporates to cool the body down.

Question 44

What may the hypothalamus signal when the body's temperature drops?

Answer 44

To close sweat glands and contract muscles ## Footnote This generates heat to help maintain core temperature.