BIOS 255 Week 4 Lymphatic System

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Chamberlain University

BIOS-255: Anatomy & Physiology III with Lab

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Lymphatic System: Overview and Learning Objectives

Introduction

The lymphatic system is an intricate network comprising lymph, lymphatic vessels, lymphatic tissue, and lymphatic organs distributed throughout the body. Its primary functions include draining excess interstitial fluid from tissues, initiating immune responses by producing and transporting lymphocytes, and transporting dietary lipids absorbed in the gastrointestinal tract into the bloodstream. Lymphatic capillaries are embedded among blood capillary beds, where interstitial fluid—similar in composition to blood plasma—performs vital tasks such as delivering oxygen, nutrients, and water while removing waste, carbon dioxide, and excess water.

Approximately 30 liters of fluid exit the arteriolar end of capillaries daily, with only 27 liters returning via venous capillaries. The lymphatic system collects the remaining 3 liters and returns it to the venous system. Its widespread presence underscores its critical roles in maintaining bodily homeostasis.

Key Components and Functions of the Lymphatic System

Component	Description
Lymph	A clear fluid derived from interstitial fluid that transports immune cells and nutrients.
Lymphatic Vessels	A network of vessels that return lymph to the circulatory system, preventing fluid accumulation.
Lymphatic Tissue	Specialized connective tissue containing lymphocytes that aid in immune defense.
Lymphatic Organs	Includes primary (thymus and bone marrow) and secondary organs (spleen, lymph nodes, diffuse tissue).

BIOS 255 Week 4 Lymphatic System

Function	Explanation
Immune Defense	Protects against disease by producing lymphocytes and initiating immune responses.
Fluid Balance	Drains excess interstitial fluid and prevents edema.
Nutrient Transport	Absorbs dietary lipids via lacteals in the gastrointestinal tract.

Mechanisms, Structures, and Clinical Insights

Aspect	Details
Lymphatic Movement Mechanisms	Skeletal muscle pump and respiratory pump facilitate lymph flow through vessels.
Thoracic Duct	The largest lymphatic vessel, originating at the cisterna chyli, empties into the left subclavian vein.
Role of Intestines	Lacteals in the small intestine absorb dietary fats; GALT in intestines provides immune defense.
Clinical Consequences of Splenectomy	Increases susceptibility to infections due to impaired immune functions.
Skeletal System Contribution	Supports lymph circulation and nutrient transport, aiding immune and cardiovascular systems.

References

American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.). Washington, DC: Author.
Marieb, E. N., & Hoehn, K. (2018). Human anatomy & physiology (11th ed.). Pearson Education.