BIOS 251 Week 5 Integumentary system lab

Student Name

Chamberlain University

BIOS-251 Anatomy & Physiology I

Prof. Name

Date

Integumentary System

The integumentary system serves as the body’s outermost protective layer and plays a critical role in maintaining homeostasis. Its primary functions include protection from external factors, regulation of body temperature, synthesis of vitamin D, and sensory reception. Additionally, it contributes significantly to wound healing and immune defense.

Learning Objectives

To identify tissue and cellular characteristics of the skin.
To analyze the structures associated with the skin and their functions.
To connect anatomical features to their physiological roles.
To understand the role of skin in thermoregulation and wound repair.

Part A: Anatomy of the Skin

I. Microscopic Anatomy of the Skin

The skin is composed of multiple layers, each with specialized structures designed to provide protection, flexibility, and sensory input.

Structure	Function
Stratum Corneum	Serves as the body’s first defense against environmental factors.
Stratum Granulosum	Forms a water-resistant barrier, minimizing dehydration.
Stratum Spinosum	Provides structural integrity and resilience to mechanical stress.
Stratum Basale	Responsible for continuous cell division and attachment of the epidermis.
Basement Membrane	Anchors the epidermis to the dermis and supports communication between layers.
Sensory Neuron	Relays impulses to the central nervous system, enabling sensory perception.
Dermis	Offers cushioning, strength, and elasticity to the skin.
Langerhans Cell	Initiates immune responses by migrating to lymph nodes.
Merkel Cell	Detects fine touch and pressure stimuli.
Keratinocyte	Produces keratin for protection; arises from the basal layer.
Melanocyte	Produces melanin, which determines skin pigmentation and UV protection.

II. Gross Anatomy of the Skin

The skin’s gross anatomy encompasses visible and underlying structures that aid in thermoregulation, sensation, and overall protection.

Structure	Function
Hair	Provides protection and assists in regulating temperature.
Cutaneous Blood Vessels	Deliver oxygen and nutrients while removing waste.
Arrector Pili Muscle	Contracts to raise hair in response to cold or stress.
Sebaceous Gland	Produces sebum, lubricating and protecting the skin.
Merocrine Sweat Gland	Releases sweat to cool the body through evaporation.
Hair Follicle	Serves as the root structure for hair growth.
Hypodermis	Stores energy and insulates the body.
Pacinian Corpuscle	Detects pressure and vibrations.
Epidermis	Creates a waterproof barrier and maintains skin tone.
Papillary Region	Supplies nutrients necessary for epidermal growth.
Reticular Region	Provides structural support and elasticity.
Dermis	Protects the body from external mechanical stress.

Part B: Thermoregulation

The skin plays a pivotal role in maintaining body temperature through a negative feedback system involving receptors, control centers, and effectors.

Receptors: Thermoreceptors in the skin detect temperature changes.
Control Center: The hypothalamus interprets signals and initiates responses.
Effectors: Sweat glands, muscles, and blood vessels regulate heat loss or retention.

Physiological Events

When body temperature decreases, shivering occurs through rapid muscle contractions that generate heat. In contrast, sweating during elevated body temperature promotes heat loss through evaporation.

Condition Due to Increased Temperature

Excessive heat can result in hyperthermia, where the body’s heat-dissipating mechanisms fail, causing dangerously high internal temperatures.

Part C: Skin Wound Healing

Comparison of Epidermal and Dermal Healing

Type of Healing	Characteristics
Epidermal Healing	Involves only the epidermis, faster, and less complex.
Dermal (Deep) Healing	Affects deeper layers, slower, and results in scar tissue formation.

What is the First Step in Wound Healing and Why is it Important?

The initial step is hemostasis, where clotting mechanisms prevent excessive blood loss. This stage is critical for stabilizing the injury site.

Why is Inflammation Important in Wound Healing?

Inflammation is essential because it prevents infection and activates immune responses. Leukocytes remove pathogens and necrotic tissue, creating a foundation for repair.

What is Fibrosis in Deep Wound Healing?

Fibrosis refers to the replacement of damaged tissue with scar tissue, which restores function but often reduces elasticity.

Part D: Case Studies

Case Study 1: Jane’s Partial Thickness Burns

Definition: Partial-thickness (second-degree) burns affect the epidermis and dermis, causing redness, blistering, and swelling.
Loss of Sensation: Likely due to nerve involvement within the dermis.
Burned Surface Area: Using the Rule of Nines, Jane’s burns cover approximately 36% of her body surface.

Case Study 2: Tom’s Hypothermia

Definition: Hypothermia occurs when body temperature drops below 95°F (35°C) due to excessive heat loss.
Which Skin Receptors Detect This? Thermoreceptors in the skin detect the drop in temperature.
Which Control Center Monitors Signals? The hypothalamus processes thermal signals.
What Happens to Blood Vessels? Vasoconstriction occurs to conserve core heat.
How Does Hair Respond? Piloerection raises hairs, trapping a layer of warm air.
What Type of Feedback Mechanism Restores Temperature? Negative feedback mechanisms restore homeostasis.

References

Hall, J. E. (2021). Guyton and Hall Textbook of Medical Physiology (14th ed.). Elsevier.

Martini, F. H., Nath, J. L., & Bartholomew, E. F. (2021). Fundamentals of Anatomy & Physiology (11th ed.). Pearson.

BIOS 251 Week 5 Integumentary system lab

Tortora, G. J., & Derrickson, B. (2023). Principles of Anatomy and Physiology (16th ed.). Wiley.