5  Chapter 5 – Integumentary System

5.1 Course Objectives

At the conclusion of this lab, you should be able to describe the structure and functions of the integumentary system, identify skin layers, and recognize accessory structures and their roles.

5.2 Layers of the Integumentary System

5.2.1 Epidermal Layers (Superficial β†’ Deep)

  • Stratum corneum

  • Stratum lucidum (thick skin only)

  • Stratum granulosum

  • Stratum spinosum

  • Stratum basale (germinativum)

5.2.2 Dermal Layers

  • Papillary layer

  • Reticular layer

5.2.3 Subcutaneous Layer

  • Hypodermis

5.3 Prelab Activity 5.1

5.3.1 Epidermal Layers

Term Definition
Epidermis Outer epithelial layer of skin
Stratum corneum Dead, keratinized cells for protection
Stratum lucidum Clear layer found only in thick skin
Stratum granulosum Keratin production and cell death
Stratum spinosum Keratinocyte reinforcement
Stratum basale Mitotically active basal layer

5.3.2 Dermal Layers

Term Definition
Dermis Connective tissue layer with vessels and nerves
Papillary layer Thin areolar layer with dermal papillae
Reticular layer Thick dense connective tissue layer

5.3.3 Subcutaneous Layer

Term Definition
Hypodermis Fatty connective tissue for insulation

5.3.4 Integumentary Structures

Structure Function
Dermal papillae Increase surface contact
Hair shaft Hair above the skin
Hair root Hair below the skin
Hair follicle Anchors hair
Pore Opening for sweat
Arrector pili Raises hair
Sebaceous gland Secretes sebum
Eccrine sweat gland Thermoregulation
Apocrine sweat gland Scent secretion
Free nerve ending Pain and temperature
Meissner’s corpuscle Light touch
Pacinian corpuscle Pressure and vibration
Keratinocyte Produces keratin
Melanocyte Produces melanin

5.4 Prelab Activity 5.2

Layers:

  • 4: Epidermis

  • 5: Dermis

  • 6: Hypodermis

Accessory Structures:

  • 15: Hair follicle

  • 21: Pacinian corpuscle

  • 14: Sebaceous gland

  • 20: Eccrine sweat gland

5.5 Epidermal Layers and Function

Layer Major Features
Stratum corneum Protective, dead cells
Stratum lucidum Extra protection
Stratum granulosum Keratinization
Stratum spinosum Cell reinforcement
Stratum basale Cell division

5.6 Lab Activity 5.1

Epidermis:

  • Composed of keratinocytes

  • No blood vessels

  • Apical surface faces exterior

  • Basal surface attached to basement membrane

Dermis:

  • Contains blood vessels

  • Has dermal papillae

5.7 Lab Activity 5.4

5.7.1 Dermal Structures and Functions

Structure Function
Dermal papillae Anchoring
Pore Sweat release
Arrector pili Raises hair
Sebaceous gland Lubrication
Eccrine gland Cooling
Apocrine gland Scent
Free nerve ending Pain
Meissner corpuscle Touch
Pacinian corpuscle Pressure
Keratinocyte Keratin
Melanocyte Pigmentation

5.8 Post Lab Activity 5.1

  • Dermal layers: Papillary and reticular

  • Three gland types: Sebaceous (oil), eccrine (temperature), apocrine (scent)

  • Protective functions: Barrier, UV protection, pathogen defense

5.9 Post Lab Activity 5.2 – Matching

# Answer
1 e
2 h
3 g
4 b
5 k
6 i
7 d
8 m
9 l
10 f
11 c
12 j
13 a

5.10 Post Lab Activity 5.6 – Fill in the Blanks

Dermis layers:
Papillary layer, Reticular layer

Three gland types:
a) Sebaceous – oil
b) Eccrine – sweat
c) Apocrine – scent

Three protective functions:
a) Physical barrier
b) UV protection
c) Pathogen defense

Four integumentary functions:
a) Protection
b) Temperature regulation
c) Sensation
d) Vitamin D synthesis

Epithelial tissue type:
Stratified squamous epithelium

Five epidermal layers (thick skin):

  • Stratum corneum

  • Stratum lucidum (not in thin skin)

  • Stratum granulosum

  • Stratum spinosum

  • Stratum basale

Accessory structures (four):

  • Hair follicle

  • Sebaceous gland

  • Sweat gland

  • Sensory receptors

5.11 Post Lab Activity 5.3 β€” Crossword Answers

Across

  • 7 Reticular layer

  • 8 Stratum granulosum

  • 9 Epidermis

Down

  • 1 Stratum corneum

  • 2 Papillary layer

  • 3 Hypodermis

  • 4 Stratum spinosum

  • 5 Stratum basale

  • 6 Stratum lucidum

βœ… End of Chapter 5