Module 5: Integumentary System

Question 1

Integumentary System includes:

Answer 1

skin, nails, hair, sudoriferous glands, sebaceous glands

Question 2

Functions of Integumentary System

Answer 2

Protection
Regulation of body temp
Receptors of stimuli
Metabolic activity
Storing blood
Excretion

Question 3

Protection

Answer 3

Skin protects body from bacterial invasion, physical injury, fluid loss
Acidic oils stop growth of pathogenic invaders
Skin is waterproof due to protein, Keratin

Question 4

Regulation of Body Temp

Answer 4

Dilation and constriction of blood vessels and activity of sweat glands
Too hot = vessels dilate, sweat glands excrete water
Too cold = vessels constrict and warm blood temporarily bypasses the skin

Question 5

Receptors of Stimuli

Answer 5

Skin has receptors that indicate heat, cold, touch, pressure

Exteroceptors relay info about environment so brain can make changes to prevent or minimize injury

Question 6

Metabolic Activity

Answer 6

UV rays assist skin cells in producing Vit D (needed for normal bone growth and development)

Question 7

Blood Reservoir

Answer 7

5% of body’s blood is in the skin
When extra blood is needed, nervous system constricts vessels in skin and more blood is free to flow into other areas of the body

Question 8

Excretion

Answer 8

Excess water and salts excreted by skin

Question 9

Layers of the skin

Answer 9

Epidermis (outer layer) and dermis (inner layer)

Question 10

Epidermis

Answer 10

Outer layer (stratified squamous epithelium)
Closely packed cells form barrier to protect body (with keratin)
Surface cells are dead
Deeper layers are alive and constantly dividing to replace surface cells
No blood supply
Deep layers contain melanin

Question 11

Layers of Epidermis

Answer 11

Deep to superficial:
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum (found in palms and soles only)
Stratum corneum 
"CORi's GRANny SPINs BASketballs"

Question 12

Dermis

Answer 12

Called corium (True skin)
Found beneath epidermis
Strong, flexible loose and dense connective tissues
Contains blood and lymph vessels, nerves, hair follicles, sweat glands
Composed of 2 layers: Upper papillary layer and lower reticular layer

Question 13

Upper Papillary Layer

Answer 13

Composed of papillae that extend into epidermis
Blood vessels, nerve endings, sensory receptors extend into these to bring them closer to the skin surface
Papillae form distinct patterns on hands and feet (fingerprints)

Question 14

Lower Reticular Layer

Answer 14

Attached to underlying hypodermic

Reticular layer is strong

Question 15

Skin Color Pigments (3)

Answer 15

Melanin, carotene, hemoglobin

Question 16

Melanin

Answer 16

Brown-black pigment found in epidermis
Formed in cells called Melanocytes (Plentiful mucous membrane, penis, nipples, face, arms, legs)
All races have same # of melanocytes but amount of melanin produced is different

Question 17

Carotene

Answer 17

Yellow-orange pigment found in vegetable build ups in the Stratum corneum and fatty parts of dermis

Question 18

Hemoglobin

Answer 18

Reddish pigment (NOT found in skin cells; in RBCs)
Oxygenated blood flowing through dermis gives skin pinkish color
Significant decrease in O2, skin will have bluish color

Question 19

Cyanosis

Answer 19

bluish color of the skin

Question 20

Sudoriferous (sweat) glands

Answer 20

Secrete sweat
3 Million/person
Found in dermal region of skin
Lots in palms and soles
2 Types: Apocrine Glands and Eccrine Glands

Question 21

Apocrine Glands

Answer 21

Associated with hair follicles found in armpits/genitals
Become active during puberty
Accumulation of sweat changed by bacteria into unpleasant smelling chemical (aka body odour)

Question 22

Eccrine Glands

Answer 22

Not associated with hair follicles
Function throughout lifetime
Found all over body (esp. forehead, upper lips, palms, soles)

Question 23

Sebaceous (oil) Glands

Answer 23

Secrete Sebum (oily substance)
Associated with hair follicles
Found in all areas with hair
Sebum helps to waterproof hair and skin, and inhibit growth of bacteria on the skins surface

Question 24

Hair

Answer 24

Found on nearly all surfaces except palms and soles, ends of fingers/toes, lips, nipples
Hair grows 1mm/3 days, when it becomes long it stops growing

Question 25

Functions of hair

Answer 25

Protections
Eyebrows, eyelashes, nostril hairs protect from particles in the air
Hair on scalp provides “cushion” for head injury

Question 26

Structures of Hair

Answer 26

Shaft, roots, medulla

Question 27

Nails

Answer 27

Epidermal cells that have been converted to hard Keratin
Free edge, nail body, nail root
Eponychium (cuticle) is a fold of stratum corneum
Lunula (whitish crescent-shaped part)
Protect underlying tissue from trauma

Question 28

First-degree burn

Answer 28

eg. sunburn
Superficial cells of epidermis are destroyed
Skin is inflamed and tender

Question 29

Second-degree burn

Answer 29

Superficial and deeper cells of epidermis are destroyed (dermis may be affected)
Blisters on skin, burn is painful

Question 30

Third-degree burn

Answer 30

All epidermal and dermal cells are destroyed
Skin is charred, no sensation at all
Immediate threat to life is loss of body fluids (several litres/day)