Integumentary System

Question 1

The skin accounts for ____% of body weight

Answer 1

7%

Question 2

What are the 3 layers of the skin from superficial to deep? What type of tissue are they?

Answer 2

epidermis: keratinized stratified squamous epithelium
dermis: connective tissue
hypodermis: areolar and adipose connective tissue

Question 3

Functions of the skin?

Answer 3

• protection: cushions organs and protects from chemicals, H2O loss, UV radiation, and bumps
• regulation of body temp.
• excretion: urea, salts, and H2O lost through sweat
• absorption: vitamins, lead, mercury, poison ivy/oak
• production of vitamin D
• sensory reception: keeps us aware of conditions at body’s surface

Question 4

The epidermis is composed of_________ and _______

Answer 4

90% keratinocytes

10% melanocytes

Question 5

Where are keratinocytes located? What are their functions?

Answer 5

• located at stratum spinosum and dead at skin surface

- produce keratin for protection

Question 6

Where are melanocytes located? What are their functions?

Answer 6

• located at stratum basale

- manufacture and secrete melanin

Question 7

What are the layers of the epidermis (top to bottom)?

Answer 7

• Stratum corneum (cornified layer)
• Stratum lucidum (clear layer)
• Stratum granulosum (granular layer)
• Stratum spinosum (spiny layer)
• Stratum basale (basal layer)

Question 8

Stratum corneum

Answer 8

• 25-30 cell layer thick of dead keratinocytes (keratin)
• continuously shed/ dandruff
• protects skin from abrasions and penetration

Question 9

Stratum lucidum

Answer 9

• occurs in thick skin on palms of hands and soles of feet

- composed of a few rows of flat, dead keratinocytes

Question 10

Stratum granulosum

Answer 10

• 1-5 layers of flat dying keratinocytes

- contains granules that release waterproofing glycolipid

Question 11

Stratum spinosum

Answer 11

• 8-10 cell layers thick
• some mitosis
• contains thick bundle of intermediate filaments
• contains star shaped Langerhans cells; macrophage

Question 12

Stratum basale

Answer 12

-attached to underlying dermis
-cells actively divide; single row of youngest keratinocytes
-contains melanocytes
~secrete melanin

Question 13

Callus vs. blister

Answer 13

• thickening of epidermis due to repeated friction

- separation of epidermis from dermis by fluid filled pocket

Question 14

What is psoriasis?

Answer 14

• autoimmune skin disorder
• keratinocytes divide and move more quickly through epidermis
• cells pile up on surface and resemble flaky silvery scales

Question 15

Process of epidermal growth

Answer 15

• stem cells divide and produce keratinocytes
• they are then pushed to the surface and fill with keratin
• 4 week process
• 30-40k shed/ minute

Question 16

What is the purpose of the dermis? What are its layers?

Answer 16

• strong and flexible connective tissue that is richly supplied with nerves and blood vessels
• holds body together like a body stocking

-papillary and reticular layer

Question 17

What type of tissue is the papillary layers composed of?

Answer 17

areolar connective tissue

Question 18

Functions of the papillary layer?

Answer 18

• anchors epidermis to dermis
• contains capillaries that feed epidermis
• increase SA for exchange of gases, nutrients, and waste

Question 19

How are finger/palm/footprints formed?

Answer 19

the papillae lie on dermal ridges which elevate epidermis to epidermal ridges

Question 20

What type of tissue is the reticular layer composed of?

Answer 20

DICT with thick interlacing collagen and elastic fibres

Question 21

Functions of the reticular layer?

Answer 21

• provides strength, extensibility, and elasticity to skin

- gives stretch and recoil properties to skin

Question 22

What happens with extreme stretching of skin?

Answer 22

-collagen fibres in the dermis tear causing pink/ white scars (stretch marks)

Question 23

What type of tissue is the hypodermis layer composed of?

Answer 23

areolar and adipose connective tissue

Question 24

Functions of the hypodermis layer?

Answer 24

• anchors skin to underlying structures

- helps insulate the body and protect against skin infections

Question 25

Where are sebaceous glands located?

Answer 25

- palms and soles of feet | - large on face, neck, chest

Question 26

Function of sebaceous glands?

Answer 26

- secrete sebum which collect dirt and kills bacteria on skin - impedes H2O loss - prevents brittle hair

Question 27

What happens when sebaceous glands become overly filled with sebum?

Answer 27

- they burst and expel contents onto skin or into hair follicle - acne results from inflammation of gland caused by bacterial infection

Question 28

______ and ______ is a result of _________ stimulation which forces sweat onto skin (sudoriferous glands)

Answer 28

contraction and secretion | nervous system

Question 29

What are the two types of sudoriferous glands?

Answer 29

- eccrine | - apocrine

Question 30

Purpose of eccrine glands? Location?

Answer 30

- to secrete sweat onto skin surface | - located on palms and soles of feet

Question 31

What is sweat?

Answer 31

- 99% water | - contains microbe killing peptide to eliminate harmful microorganisms on skin

Question 32

What stimulates sweat? Why?

Answer 32

the sympathetic nervous system - to prevent the body from overheating - or caused by stress and nervousness

Question 33

Purpose of apocrine glands? Location?

Answer 33

- to secrete sweat like substance into hair follicles - become active during puberty - located in axillary, anal, and genital areas

Question 34

What is sweat like substance that comes from apocrine glands?

Answer 34

- contains fat and protein making it viscous | - odourless until combined with bacteria on skin

Question 35

3 cells of skin colour

Answer 35

melanin, carotene, hemoglobin

Question 36

Melanin

Answer 36

- most important | - ranges from yellow, red, brown, black

Question 37

Carotene

Answer 37

-yellowish pigment obtained from carrots and tomatoes that accumulates in stratum corneum and hypodermis

Question 38

Hemoglobin

Answer 38

- Caucasians have a nearly transparent epidermis | - allows blood colour to show through

Question 39

1st, 2nd, 3rd degree burn

Answer 39

1st: epidermis is damaged 2nd: upper part of dermis and epidermis is damaged 3rd: entire thickness of skin

Question 40

Malignant Melanoma

Answer 40

- rapidly metastasize - most common in young women - arise from melanocytes - risks of sun exposure, family history, age

Question 41

Process of aging

Answer 41

- epidermis thins as germinative cell activity declines - melanocyte activity declines - dermis thins, loses elastic fibres and collagen production slows causing wrinkles