Chapter 10 Lymph Fluid Professor A. S. Alhomida King Saud University College of Science Department of Biochemistry Disclaimer The texts, tables, figures and images contained in this course presentation (BCH 376) are not my own, they can be found on: References supplied Atlases or The web Chapter 10 Lymph Fluid Professor A. S. Alhomida

Lymphatic System Lymph Lymphatic Vessels Several structure and organs that contain lymphatic tissue Red Bone Marrow

Lymphatic System, Cont’d

Lymphatic System Functions Acts as a one-way drainage system to transport excess fluid from body tissues into the blood system Contains cells which fight infection (lymphocytes) Gets rid of waste products (chemicals) produced by cells

Lymphatic System Functions, Cont’d Transporting dietary lipids Facilitating immune responses Nonspecific Resistance to disease Includes defense mechanisms that provide immediate, but general, protection against pathogens Immunity Develops more slowly and involves the activation of lymphocytes that combat specific pathogens

Lymph Fluid The lymphatic vessels and lymph nodes contain a milky liquid called lymph fluid Lymph fluid is formed when some of the colorless liquid that surrounds all body tissues drains from the tissues into small lymph vessels, which lie between the cells Capillary walls leak fluid and some blood proteins, which return to the blood via the lymphatic system

Lymph Fluid, Cont’d This is the 1% of fluid that does not re-enter the capillaries The fluid, lymph, is similar in composition to interstitial fluid The lymph enters the system by diffusing into lymph capillaries Lymph vessels have valves that prevent back flow and depend mainly on movement of skeletal muscles to squeeze fluid along

Lymph Fluid, Cont’d Lymph nodes filter the lymph and attack viruses and bacteria. This defense is carried out by specialized white blood cells that inhabit the lymph nodes Lymph capillaries penetrate small intestine villi and absorb fats, thus transposing them from the digestive system to the circulatory system

Lymph Fluid, Cont’d

Lymph Vessels The small lymph vessels join together to form larger lymph vessels, which pass through a number of lymph nodes In the lymph nodes, bacteria and harmful substances are broken down The lymph fluid then travels through larger lymph ducts and drains into the bloodstream

Lymph nodes Lymph nodes vary in size, number, location Lymph nodes are found throughout the body, but mainly in the neck, armpit and groin They are made of lymphoid tissue This tissue contains special cells that can help to fight infection and other diseases such as cancer Lymph nodes vary in size, number, location

Lymph node Functions As lymph fluid flows through the lymph nodes, the nodes collect and filter out anything the body does not need or that could harm the body This includes bacteria, viruses, other infectious organisms, damaged cells or cancer cells

Lymph node Functions, Cont’d Inside the lymph nodes, white blood cells (lymphocytes) attack and break down bacteria or other harmful cells Waste products and the destroyed bacteria are then carried in the lymph fluid into the bloodstream and are got rid of with other body waste

Blood Capillaries (blood) Interstitial Spaces (interstitial fluid) Lymphatic Capillaries (lymph) Lymphatic Vessels (lymph)

Lymphatic Trunks (lymph) Lymphatic Ducts (lymph) Subclavian Veins (blood) Contraction of skeletal muscles and breathing help the flow of lymph

Probable Approximate Protein Content of Lymph in Humans Lymph From Protein Content (g/dL) Choroid plexus Ciliary body Skeletal muscle 2.0 Skin Lung 4.0 Gastrointestinal tract 4.1 Heart 4.4 Liver 602

THE END Any questions?