Integumentary

Question 1

Which layer of the skin has capillary region and is vascular?

Answer 1

Dermis

Question 2

What is the epidermis composed of?
What do the following cells of the epidermis do:

Keratinocytes
Melanocytes
Langerhans’ cells
Merkel cells

Answer 2

Keratinized stratified squamous

Keratinocytes
- produces keratin
- fibrous for protection

Melanocytes
- produces melanin

Langerhans’ cells
- immune system, macrophages

Merkel cells
- touch receptors

Question 3

What does the stratum basale layer contain, what occurs

Answer 3

• has a single row of youngest KERATINOCYTES (PRODUCES)
• have MERKEL cells
• have melanin granules from melanocytes to protect from UV light

Question 4

What does the stratum spinosum have?

Answer 4

• intermediate filaments attached to desmosomes
• abundant with melanin and LANGERHAN CELLS (macrophages)
• have keratohyaline granules and lamellar granules

Question 5

Compare between keratohyaline and lamellar granules in the stratum spinosum

Answer 5

keratohyaline granules
- cross linking keratin
- Celullar dehydration

lamellar granules
- glycolipid granules secreted into spaces between cells
- waterproofing

Question 6

Why do cells in epidermis die?

Answer 6

because they move away from source of nutrients and oxygen from the dermal capillaries

Question 7

What does the stratum granulosum layer have?
“toughen up”

Answer 7

• PM thickens
• still continue to accumulate
  -Above the granulosum layer, epidermal cells are too far from dermis (capillary layer) and die

Question 8

What is the stratum lucidum for? How is it formed?

Answer 8

• Thick skin (palms, feet soles)
• exocytosis of lamellar bodies secretes this oily thin transparent layer

Question 9

What does the stratum corneum layer have?
What are some functions of this layer?

Answer 9

• has dandruff

Functions
- waterproofing (glycolipids)
- Protection from abrasion (scraping something) and penetration (from keratin)

Question 10

What is the role of the exfoliating keratinocytes?

Answer 10

Clean up excessive cells that are dead

Question 11

What are the 2 layers of the dermis and what type of connective tissue do they have?

Answer 11

Papillary layer
- loose areolar connective tissue

Reticular layer
- Dense irregular connective tissue (a lot of collagen)

Question 12

What is the role of dermal papillae?

What does the dermal papillae contain? (3)

Answer 12

Gives nutrients to epidermis
- helps increase SA for this action

Contains
- Capillary loops
- Meissner’s corpuscles (superficial, fast)
- Free nerve endings

Question 13

What does the subcutaneous layer (hypodermis) have

Answer 13

Fat cells to provide insulation to keep blood vessels warm

Question 14

What are the 3 pigments that contribute to skin colour?

Answer 14

1. Melanin
   - For dark skin colours
2. Carotene
   - For palms and soles of feet
   - Accumulates in stratum corneum + hypodermis
3. Hemoglobin
   - Pinkish hue of the skin
   - Cyanosis due to poorly oxygenated bood

Question 15

What do the sudoriferous sweat glands have (2)
What are their roles?

Answer 15

1. Apocrine glands
   - Highly vascularized
   - hypodermis
   - increased activity by sexual foreplay
2. Merocrine glands
   - Helps cooling down of the body

Question 16

What do the ceruminous sweat glands do?

Answer 16

Secrete earwax to block entry of foreign stuff

Question 17

What do the mammary sweat glands do?

Answer 17

Glands that secrete milk

Question 18

What do the sebaceous oil glands do?

Answer 18

-Holocrine type (looses cell after they die) oil secretion called sebum
- Activated during puberty when androgens begin to rise
- Acne is caused by a blockage of this gland

Question 19

What are the 3 layer of a hair follicle

Answer 19

Medulla
Cortex
Cuticle

Question 20

How are hair colours made?

Answer 20

Pigment by melanocytes at the base of the hair follicle

Question 21

What are the steps for hair growth?

Answer 21

1. Growth stage
   - Cells of matrix differentiate, keratinize, and die
   - forms root sheath and shaft
   - 2-6 years
2. Resting stage
   - Growth hair stops (can last 3 months on scalp)
3. After resting stage
   - Hair replaced and new growth stage

Question 22

Where are nail cells produce

Answer 22

nail matrix

Question 23

What are functions of the integumentary system?

Answer 23

Protection
- chemical and physical barierr

Cutaneous sensation
- Merkel discs, Meissners, Pacinian (deep)

Body temp
Metabolic functions (makes vitD in dermal blood vessels)

Blood reservoir
- skin blood vessels store up to 5% of the body’s blood volume

Excretion

Question 24

What type of Cancer is Carcinoma? Sacroma? Leukemia, Lymphoma?

Answer 24

1. Cancer derived from epithelial cells

Sacroma
- connective tissue cancer

Leukemia, Lymphoma
- derived from hematopoietic cells

Question 25

Differentiate between the 3 major types of skin cancer:

Basal cell carcinoma
Squamous cell carcinoma
Melanoma

Answer 25

Basal cell carcinoma
- least malignant, most common
- stratum BASALE cells invade the dermis and hypodermis
- Slow growing do not metastasize

Squamous cell carcinoma
- Arise from keratinocytes of stratume SPINOSUM
- grow rapidly and can metastasize

Melanoma
- Most dangerous
- Highly metastatic, resistant to chemo
- BASALE

Question 26

What are the characteristics of Melanoma? ABCD

Answer 26

A: asymemtry: both sides don’t match
B: border is irregular
C: colour: black, brown or red /blue
D: diameter larger than 6mm

Question 27

Which part of the skin is affected in:

1st degree burn
2nd degree
3rd degree
4th degree
5th degree

Answer 27

1st degree
- Epidermis

2nd degree
- Papillary dermis

3rd degree
- Reticular dermis

4th degree
- Epidermis, dermis, partial hypodermis

5th degree
- All layers

Question 28

When is a burn considered critical (3)

Answer 28

• over 25% of body has 2nd degree burns
• Over 10% of body has 3rd degree burns
• 3rd degree on face, hands, or feet