Lecture 4: Integument: Structure and Function

Question 1

Integument

Answer 1

Protects the rest of the body from the environment (cutaneous membrane + accessory structures)
- Barrier: Immune and osmotic homeostasis
- Thermal homeostasis
- Vitamin D + Ca 2+ Homeostasis
- Sense organ

Question 2

Hypodermis

Answer 2

Not apart of the integument

Question 3

Thick Skin( hairless skin)

Answer 3

Palmar and plantar surfaces
- Stratum Corneum
- STRAUM LUCIDUM
- Stratum Granulosum
- Stratum Spinosum
- Statum Basale

Question 4

Thin skin (hairy skin)

Answer 4

Everywhere else
- Stratum Corneum
- Stratum Granulosum
- Stratum Spinosum
- Statum Basale

Question 5

Epidermis

Answer 5

• Consist of stratified squamous epithelium
• keratinized (filled with keratin)

Question 6

Epidermal Cells

Answer 6

• Continuously generated in deepest layer by basal cells (proliferation/renewal)
• Differentiated in middle layers (keratinocytes)
• Shed from superficial layers

Question 7

Keratin

Answer 7

Tough cross-linked, water resistant protein, limits insensible perspiration

Question 8

Melanocytes

Answer 8

• Stratum basale
• Produce melanin pigments which are transfer to keratinocytes

Question 9

Melanin

Answer 9

Absorbs UV light (that damages DNA) and releases energy safely (form of heat)

Question 10

Dermis

Answer 10

Contains connective tissue and accessory structures that support the epidermis or allow secondary skin functions

Question 11

Stratum reticulare

Answer 11

Dense, irregular, elastic

Question 12

Stratum Papillare

Answer 12

Loose connective tissue proper

Question 13

Somatosensory Neurons

Answer 13

Touch

Question 14

Nociceptive Neurons

Answer 14

Pain

Question 15

Hair and Nails

Answer 15

• Protective roles
• Highly keratinized
• Accessory structures

Question 16

Glands

Answer 16

• Epithelial structures
• protection
• homeostasis
  Sebaceous and sweat (apocrine [puberty] and eccrine) glands

Question 17

Inflammation

Answer 17

• Increased blood flow
• Attraction of immune phagocytic cells

Question 18

Repair of epidermis

Answer 18

Proliferation of basal cells

Question 19

Repair of dermis

Answer 19

Recruitment, proliferation, differentiation
Granulation tissue: Mixture of new blood vessels, mesenchymal cells, fibroblast
SCAR TISSUE formed

Question 20

Keloid Scar

Answer 20

Very high proliferation and secretion from fibroblast

Question 21

Skin and Thermal Homeostasis

Answer 21

Sensor: Thermoreceptors (free nerve endings and sensory nerve)
Control Center: Brain (hypothalamus)
Effector: Sweat glands and smooth muscle in walls of blood vessels supply respond

Question 22

Calcium Homeostasis

Answer 22

Epidermis participates in calcium homeostasis by synthesizing Vitamin D (needed for synthesizing calcitriol)