Chapter 10- Skin

Question 1

What are the two structures of skin?

Answer 1

Thick skin- no hair and rigid surface (fingerprints)

Thin skin- smooth with hair

Question 2

What are the main cell types in the epidermis?

Answer 2

Keratinocytes- 90%

Melanocytes- 5%. Pigment and melanin production. Also filter ultraviolet light.

Tactile epithelial cells(Merkel cells)- sensory. Deep in epidermis

Question 3

What is the upper layer of the epidermis?

Answer 3

Stratum corneum- dead cells filled with keratin (barrier layer)

Question 4

What is the layer directly below the stratum corneum in the epidermis?

Answer 4

Stratum lucidum- cells filled with keratin precursor

Question 5

What is the layer of cells directly below the stratum lucidum in the epidermis called?

Answer 5

Stratum granulosum- cells arranged in 2-4 layers

Question 6

What is the layer of cells in the epidermis directly below the stratum granulosum?

Answer 6

Stratum spinosum- cells arranged in 8-10 layers. Largest layer

Question 7

What is the layer of cells in the epidermis directly below expectations the stratum spinosum?

Answer 7

Stratum basale- single layer of columnar cells. Lowest layer before dermis.

Question 8

Ow long does it take for cells at the stratum basale to reach the stratum corneum?

Answer 8

35 days.

With irritation turnover time increases- buildup of dead karatinocytes- callouses

Question 9

What is the most important part of the integumentary system and how does it perform this action?

Answer 9

Protection. It’s ability to create and repair itself after damage makes it ideal for protecting internal organs.

Question 10

What is the purpose of the dermis layer? Is it thicker or thinner than the epidermis?

Answer 10

Gives strength to skin, stores water and electrolytes, contains nerves, follicles, sweat glands, lymphatic and blood vessels (regulate body temp)

Thicker than epidermis

Question 11

Does the dermis continually repair itself?

Answer 11

No. The dermis does not continually shed and repair like the epidermis

Question 12

What are the two primary layers of the cutaneous membrane?

Answer 12

Skin

Epidermis- keratinization stratified squamous cells

Dermis- connective tissue

Question 13

What is the hypodermics composed of and what is its purpose?

Answer 13

Not part of the skin (also called subcutaneous)

Composed of adipose tissue, nerves, blood vessels, and lymphatic vessels

Forms connection between skin and muscle

Question 14

What are the 7 functions of the skin?

Answer 14

Protection- physical and chemical barrier. Keeps water in/ out. Blocks UV waves.

Sensation- somatic receptors detect stimuli allowing us to feel pressure, touch, temperature, pain, and other general senses.

Flexibility- skin is supple and elastic, permitting change in body contours without injury

Excretion- water and urea

Endocrine functions- exposure to UV converts vit D precursor to Vit D. Blood transports precursor to liver and kidneys, where vit D is produced (therefore Vit D is considered a hormone- helps body absorb calcium)

Immunity- phagocytic cells destroy bacteria

Homeostasis- body temp regulation. Increased core temp- open vessels near surface to heat up skin and release sweat

Question 15

What is the set temp of there human body?

Answer 15

37 Celsius- prevented proteins from denaturing

Question 16

How much heat is lost through the skin and how is it produced?

Answer 16

80% is lost.

Produced through metabolism of food in skeletal muscle and liver

Question 17

What are the different types of exocrine glands?

Answer 17

Sweat glands- most common.

Sebaceous glands

Ceruminous Glands

Question 18

What are the types of sweat glands are what are their purpose/where are they found?

Answer 18

Eccrine sweat glands- located in the subcutaneous layer. Covers most of body

Apocrine sweat glands- large glands found in dermis. Limited to areola, around anus, and axilla. Begin to function at puberty

Question 19

Where are sebaceous glands found and what is their purpose?

Answer 19

Linked to hair follicles

Secrete sebum- oil to keep hair and skin soft

Secretion increases during puberty

Found in dermis except palms

Question 20

Where are ceruminous glands located and what is their purpose?

Answer 20

Located in external ear canal

Modified apocrine sweat glands

Excrete waxy substance called cerumen. Protects skin of ear from dehydration

Excess secretion- blockage or loss of hearing

Question 21

How do the skins activities relate to age?

Answer 21

Child- smooth skin, few sweat glands, rapid healing

Adult- sebaceous and sweat glands develop, increased sebum production(acne)

Old age- decreased sebaceous and sweat gland activity, decline in body’s ability to cool itself