ch3 bio310

The lymphatic system consists of lymphatic vessels, lymph, and lymph nodes that work to return leaked fluids from the blood vascular system back into the bloodstream.
Primary functions include: transporting excess interstitial fluid, producing and housing lymphocytes, and absorbing fats from the intestines.

Head & Neck: Occipital, Submental, Deep cervical, and Parotid lymph nodes.
Thoracic Region: Axillary, Mediastinal, and Pulmonary lymph nodes.
Abdominal & Pelvic: Celiac, Lumbar, and Internal iliac lymph nodes.
The lymph nodes serve as filters that cleanse lymph as it passes through, containing defense cells (macrophages and lymphocytes).

Lymph nodes are typically kidney-shaped, with a cortex (outer part containing lymphocytes) and a medulla (inner part housing macrophages).
Lymph enters through afferent vessels, flows through sinuses, and exits via efferent vessels, which slows the flow for better filtration.

Fluid Regulation: Returns excess interstitial fluid (lymph) from tissues back to veins.
Immune Function: Houses lymphocytes for immune responses, providing defense mechanisms against pathogens.
Fat Transport: Transports absorbed fats from the intestines into the bloodstream.

Composition of Lymph: Includes water, proteins, blood cells, and harmful materials (bacteria, viruses, cancer cells) for filtration.
Lymphatic Vessels: Function through a one-way system towards the heart, relying on skeletal muscle contraction and smooth muscle constriction as there is no pump.

Lymphatic Capillaries: Smallest vessels that allow entry of interstitial fluids, proteins, microorganisms, and fats.
Lymphatic Ducts: Collect lymph from capillaries and transport it to the circulatory veins, including the right lymphatic duct and thoracic duct.

Spleen: Filters blood, destroys worn-out cells, and is a site for lymphocyte proliferation.
Thymus: Programs lymphocytes and is involved in T lymphocyte maturation, functioning at peak levels during childhood.
Mucosa-Associated Lymphatic Tissue (MALT): Protects the respiratory and digestive tracts, including tonsils and Peyer’s patches in the intestines.
Tonsils: Trap and eliminate bacteria and foreign materials, with tonsillitis resulting from bacterial congestion.
Peyer’s Patches: Located in the small intestine, resembling tonsils and capturing intestinal bacteria.

Define and explain the functions of the lymphatic system.
Describe the formation of lymph and compare it to blood and tissue fluid.
Discuss lymphatic vessels, ducts, and pathways along with lymph nodes, spleen, thymus, tonsils, and Peyer’s patches.

Returns leaked fluids from blood vascular system to bloodstream.
Primary functions: fluid transport, lymphocyte production/housing, fat absorption.

Lymphatic Capillaries: Allow entry of fluids, proteins, microorganisms, fats.
Lymphatic Ducts: Transport lymph to veins; right lymphatic duct and thoracic duct.