Lymphatic System B Explain the role of the lymphatic system in protecting the human body. Include: lymph vessels, lymph nodes, and lymph

WARNING! WARNING! WARNING! White blood cells are the same as … Lymphocytes, in which there are many types… Neutrophils, eosinophil's, basophils, monocytes which are perform… Phagocytosis! Also B Lymphocytes = B Cells

Key component of immune system Like a secondary circulatory system – How does the circulatory system work?

Functions to – Filter and destroy foreign substances – Filter and destroy cell debris – Produce lymphocytes

Organization

Lymph Vessels Begins with lymphatic capillaries – Take up excess fluid Lymph Muscle contractions of vessels “squeeze” lymph along Prevented from flowing backward by one-way valves

Lymph Clear, colourless fluid collected as it filters through the capillaries of the blood

How does it work? Lymph passes from tiny capillaries to lymph vessels Flows through lymph nodes located along vessels Cells of the lymph nodes phagocytize (ingest) – Bacteria – Red blood cells – Cellular waste

How does it work? Cont… The lymph drains into either – Thoracic duct – Right lymphatic duct The lymph is then transported back into the veins of shoulder area Re-enters the general circulatory system

Where does it drain? Thoracic Duct – Below thorax – Left arm – Left side of head – Left side of neck Into the left subclavian vein Right Lymphatic Duct – Right arm – Right side of head – Right side of neck Into the right subclavian vein

Lymphatic Organs

Tissues of the Lymphatic System Contain large number of lymphocytes (WBC) – B-Cells – T-Cells

Red Bone Marrow

Network of connective tissue fibres Site of stem cells – Divide and produce lymphocytes B Lymphocytes mature

Thymus

Central organ control lymphocyte production and antibody formation Mature T lymphocytes from red bone marrow – Determines which T cells can detect antigens

Spleen

Filters the blood Harbours lymphocytes that – Remove of and defective blood cells – Phagocytize foreign particles

Lymph Nodes

Small structures along lymphatic vessels, – cleanse lymph Phagocytosis of foreign particles

Lymph Nodes During an Infection become enlarged with lymph, white blood cells, and can be felt Infections of the … can be felt … – Neck or head In the neck – Breast or arm In the axillary region – Pelvis or legs In the inguinal region