Chapter 6: Integumentary System

Question 1

What are the cells of the epidermis?

Answer 1

• stem cells–produce keratinocytes (involved in mitosis)
• keratinocytes–produce the fibrous protein kertain (melanin is thrown in here)
• Melanocytes–produce the pigment melanin
• Dendritic cells–(Langerhan’s cells) macrophages that are part of the immune system
• Tacticle cells–(Merkel cells) touch receptors

Question 2

How is thick skin different from thin skin?

Answer 2

• Thick skin is found only on palms of hands and soles of feet
• thick epidermis with ridges (make fingerprints!) and thick stratum corneum
• Has Stratum lucidum
• No hair follicles or sebaceous glands
• has more sweat glands and sensory receptors

Question 3

What are the functions of the integumentary system?

Answer 3

• regulation of body temperature
  
  • sweating, vasodilation and constriction of blood cells
• protection
  
  • against bacteria, UV, light, abrasion, dehydration, chemicals
• sensory receptors
• excretion and absorption
• synthesis of Vitamin D

Question 4

What are the layers /sublayers of the integumentary system and their components?

Answer 4

Cutaneous membrane (skin)

• epidermis
  
  • 5 layers
• dermis
  
  • Papillary
    
    • areolar tissue
    • tactile (Meissner corpuscles)
  • Reticular
    
    • dense irregular connective tissue
    • oil glands, sweat glands, fat, and hair follicles, Lamellar (Pacinian) corpuscles

Subcutaneous membrane

• hypodermis or superficial fascia
  
  • adipose and areolar
  • thicker in women, thinner in children and elderly
  • on top of muscle

Question 5

What is the structure of the 5 layers of the epidermis?

Answer 5

Stratum Basale

• combination of tactile cells, melanocytes, keratinocytes, and stem cells
• cells journey from here to the surface

Stratum Spinosum

• 8 to 10 cell layers held together by tight junctions and desmosomes

Stratum Granulosum

• 3-5 layers of flat, dying cells
• contain dark keratohyalin granules

Stratum Lucidum

• 3-5 layers of clear, flat, dead cells

Stratum Corneum

• 20 to 30 layers of flat dead cells filled with Keratin and surrounded by lipids
• continually shed
• resist abrasion, water loss, penetration of bacteria and chemicals

Question 6

Where are friction ridges formed?

Answer 6

Where dermal papillae are more pronounced in thick skin (palms, soles, finger prints, and footprints)

Question 7

What are the 3 skin color pigments?

Answer 7

• Melanin
  
  • same number of melanocytes in everyone (some are stronger)
  • yellow to tan to black
• Carotene
  
  • yellow-orange pigment
  • fat and stratum corneum
• Hemoglobin
  
  • red, oxygen-carrying pigment in blood cells

Question 8

What are conditions in which skin color may act as a diagnostic clue?

Answer 8

• Cyanosis: blue, lack of oxygen
• Hematoma: bruise
• Alibinism: no melanin
• Pallor: white, shock
• Erythema: red, infection, fever
• Jaundice: yellow, liver problems

CHAPEJ

Question 9

What are the accessory structures of the integumentary system?

Answer 9

• Hair
• nails
• Sudoriferous glands
• Sebaceous glands

Question 10

What is the structure of hair?

Answer 10

• Bulb
  
  • contains matrix (which makes hair)
• Root (below skin)
• Shaft (above skin)
  
  • medulla / cortex / cuticle
  • center layer/ outer layer / outmost layer
• hair is packed Keratin cells (all dead)

Question 11

What are the accessory structures and functions of hair?

Answer 11

Structures

• accertor pili (Piloerector)
  
  • smooth muscle contracts in cold or fear, forms goosebumps
• Hair root plexus (nerves, detect hair movement)

Function

• protection
• heat retention
• light touch
• excretion

Question 12

What is the structure of a nail?

Answer 12

• scalelike modification of epidermis
• nail matrix produces tightly packed keratinized cells

Question 13

What are the 4 glands and their components?

Answer 13

• Merocrine (Eccrine) glands
  
  • ducts open to surface
  • most areas of skin
  • sweat glands
• Apocrine
  
  • misnamed (function through exocytosis like eccrine)
  • duct opens into hair follicle
  • secretes pheromones
  • respond to stress and sexual stimulation
  • pubic area, armpit, develop after puberty, form BO
• Mammary Glands
  
  • milk
• Ceruminous glands
  
  • ear wax

Question 14

What are the 3 major types of skin cancer and their components?

Answer 14

• Basal cell carcinoma
  
  • most common
  • least malignant
  • small, shiny bump with central depression and beaded edges
  • form in stratum basale
• Squamos cell carcinoma
  
  • may metastasize if not removed
    
    • early detection and surgical removal
    • spread to lymph nodes = lethal
  • arises from keratinocytes on stratum spinosum
  • raised, reddened, scaly appearance (turn into concave ulcer)
• Melanoma
  
  • arises from melanocytes
  • least common (>5%) but very malignant
  • can be removed if caught early
  • higher in men, redheads, bad sunburns as child, genetic risk greatest

Question 15

What are the warning signs of Melanoma?

Answer 15

Asymmetry

Border

Color

• normal has one color, abnormal has 2 or more or changes color

Diameter

• normal is size of pencil eraser

Elevation / evolution

• normal is flat and doesn’t change

Question 16

What are burns and their types?

Answer 16

• Burns are caused by heat, electricity, and chemicals
• May result in shock due to dehydration and loss of plasma proteins, circulatory and kidney problems from loss of plasma, and bacterial infection
• First degree
  
  • only epidermis (sunburn)
• Second degree
  
  • destroys epidermis and part of dermis
  • fluid filled blisters separater dermis and epidermis
  • heals with grafting in 3-4 weeks, may scar
• Third degree
  
  • destroy epidermis, dermis, and possibly muscle
  • damaged area numb due to loss of sensory nerves