Chapter 6

Question 1

What are the primary functions of the integumentary system?

Answer 1

Protection, thermoregulation, sensation, vitamin D synthesis, excretion & absorption.

Question 2

What percentage of body weight does the skin make up?

Answer 2

About 7-8% of total body weight.

Question 3

What are the three layers of the skin?

Answer 3

Epidermis, dermis, subcutaneous layer (hypodermis).

Question 4

Which layer of skin is NOT part of the integumentary system?

Answer 4

The subcutaneous layer (hypodermis).

Question 5

What type of tissue makes up the epidermis?

Answer 5

Keratinized stratified squamous epithelium.

Question 6

What are the five layers of the epidermis (deep to superficial)?

Answer 6

Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum (only in thick skin)
Stratum corneum

Question 7

What is the main function of the stratum basale?

Answer 7

Contains stem cells that regenerate new skin cells.

Question 8

What is the function of the stratum spinosum?

Answer 8

Provides strength and flexibility to the skin.

Question 9

What happens in the stratum granulosum?

Answer 9

Keratinization begins – cells fill with keratin and die.

Question 10

Where is the stratum lucidum found?

Answer 10

Only in thick skin (palms, soles of feet).

Question 11

What is the function of the stratum corneum?

Answer 11

Protects against abrasion and water loss; made of dead keratinized cells.

Question 12

What are the three main cell types in the epidermis?

Answer 12

Keratinocytes, melanocytes, tactile (Merkel) cells.

Question 13

What is the function of keratinocytes?

Answer 13

Produce keratin, making the skin waterproof and strong

Question 14

What do melanocytes do?

Answer 14

Produce melanin, protecting skin from UV damage.

Question 15

What are tactile (Merkel) cells responsible for?

Answer 15

Detect touch and pressure.

Question 16

What three factors determine skin color?

Answer 16

Melanin, hemoglobin, carotene.

Question 17

What pigment is responsible for skin darkening and UV protection?

Answer 17

Melanin.

Question 18

What is hemoglobin’s effect on skin color?

Answer 18

Gives a reddish tint due to oxygen in blood.

Question 19

What is carotene, and where does it come from?

Answer 19

A yellow-orange pigment from foods like carrots and sweet potatoes.

Question 20

What condition results from a lack of melanin?

Answer 20

Albinism – a genetic condition where melanocytes don’t produce melanin.

Question 21

What are the two layers of the dermis?

Answer 21

Papillary layer and reticular layer.

Question 22

What tissue type makes up the papillary layer?

Answer 22

Areolar connective tissue.

Question 23

What structures are found in the papillary layer?

Answer 23

Dermal papillae, capillaries, tactile receptors.

Question 24

What is the function of dermal papillae?

Answer 24

Increase surface area for nutrient exchange, form fingerprints.

Question 25

What tissue type makes up the reticular layer?

Answer 25

Dense irregular connective tissue.

Question 26

What structures are found in the reticular layer?

Answer 26

Blood vessels, sweat glands, sebaceous glands, hair follicles, sensory receptors.

Question 27

What is the main function of the subcutaneous layer?

Answer 27

Insulation, cushioning, energy storage.

Question 28

What type of tissue is found in the hypodermis?

Answer 28

Areolar and adipose connective tissue.

Question 29

Why is the hypodermis a common site for injections?

Answer 29

Highly vascularized, allowing rapid drug absorption.

Question 30

What are the three types of hair?

Answer 30

Lanugo (fetal), vellus (fine body hair), terminal (coarse, long hair).

Question 31

What are the three parts of a hair?

Answer 31

Bulb, root, shaft.

Question 32

What causes goosebumps?

Answer 32

Contraction of the arrector pili muscle.

Question 33

What determines hair color?

Answer 33

Melanin production in the hair matrix.

Question 34

Why does hair turn gray with age?

Answer 34

Decrease in melanin production.

Question 35

What are nails made of?

Answer 35

Keratin.

Question 36

What are the three parts of the nail plate?

Answer 36

Nail root, nail body, free edge.

Question 37

What is the function of the cuticle (eponychium)?

Answer 37

Protects the nail root from infection.

Question 38

What are the two types of sweat glands?

Answer 38

Merocrine (eccrine) and apocrine.

Question 39

What is the function of merocrine sweat glands?

Answer 39

Thermoregulation – cools body by sweat evaporation.

Question 40

Where are apocrine sweat glands found?

Answer 40

Axillary, groin, nipple, and anal regions.

Question 41

What causes body odor?

Answer 41

Bacteria breaking down apocrine sweat.

Question 42

What do sebaceous glands secrete?

Answer 42

Sebum (oily substance).

Question 43

What is the function of sebaceous glands?

Answer 43

Lubricates skin and hair, prevents bacterial growth.

Question 44

What is the function of ceruminous glands?

Answer 44

Produce earwax (cerumen).

Question 45

What is the function of mammary glands?

Answer 45

Produce milk.

Question 46

What is psoriasis?

Answer 46

An autoimmune disease causing overproduction of skin cells.

Question 47

How does Botox reduce wrinkles?

Answer 47

Blocks nerve signals to facial muscles.