Integumentary System

Question 1

Composition

Answer 1

Body membrane (epithelial & connective membrane)
Skin appendages
(Hair, nails, sweat and oil glands)

Question 2

Functions

Answer 2

• protect, insulate, cushion the body organs
• protect against mechanical, chemical, thermal, UV damage, and bacteria
• regulate heat loss by the NS
• Vit D synthesis

Question 3

Structure

Answer 3

(Cutaneous membrane)

• epidermis (stratified squamous epithelium)
• dermis (dense connective tissue)
  
  • (hypodermis (adipose tissue))

Question 4

Homeostatic imbalance

Answer 4

Cancer

• highest factor: UV radiation
• either benign or malignant

Question 5

Epidermis

Avascular

Answer 5

-five layers (strata)
-mostly keratinocytes
-stratum basale (base): active division of daughter cells
-stratum spinosum, granulosum: cells become flatter and keratinize. Cells die after stratum granulosum
-stratum lucidium: (clear layer, only on hairless areas)
-stratum corneum: (3/4 of epidermis thickness)
Protects body from blood loss, physical, chemical damage

Question 6

Melanin

Answer 6

• pigment produced by melanocytes
• mostly in stratum basale
• colour goes from yellow to brown to black
• melanosomes: melanin accumulated membrane-bound granules
• amount produced dependent on genetics and exposure to sunlight

Question 7

Epidermal dendritic cells

Answer 7

-alert and activate immune cells to a threat (bacterial or viral invasion)

Question 8

Merkel cells

Answer 8

• Associated with sensory nerve endings
• at the junction of the epidermis-dermis
• serve as touch receptors (Merkel discs)

Question 9

Dermis

Answer 9

Two layers: papillary (upper dermal region) and reticular

Question 10

Papillary layer of dermis

Answer 10

• superficial layer of areolar Tissue
• uneven, peg-like projection indenting epidermis (dermal papillae)
• many projections contain capillary loops, and others house pain and touch receptors
• on hairless surface, there is increased friction and gripping ability
• fingerprints are identifying films of sweat

Question 11

Reticular layer of the dermis

Answer 11

• deep layer of dense connective Tissue
• contains blood vessels, sweat and oil glands
• deep pressure receptors: lamellar corpuscules