Lymphatic System

What is lymphography?

A radiograph of a body part injected with radiopaque contrast that targets the structures of the lymphatic system.

What are lacteals? What is their function?

Specialized lymphatic capillaries that are located in the villi of the small intestine. They receive digested fats.

Where do B Lymphocytes develop immunocompetence?

The Bone Marrow

Where do T Lymphocytes develop immunocompetence?

The Thymus Gland

What lymphatic vessels are first to receive lymph?

The lymphatic capillaries

Where are superficial lymph nodes located?

cervical, axillary, and inguinal regions

Describe the function of the right lymphatic duct.

empties into the right internal jugular and subclavian veins.

Describe the location of the cicterna chyli duct.

located at the union of lumbar and intestinal trunks.

Where lymph nodes are deep?

tracheobronchial, aortic, and iliac lymph nodes

What are characteristics of lymph collecting vessels?

• Accompany blood vessels • Composed of the same three tunics as blood vessels • Contain more valves than veins do

What are characteristics of the thymus.

• An organ in the superior mediastinum where immature lymphocytes develop into T lymphocytes. • Most active in childhood • Functional tissue atrophies with age

What are primary lymphoid organs?

• Bone Marrow • Thymus

List three major Lymph Ducts

• Cisterna chyli • Thoracic duct • Right lymphatic duct

What are characteristics of lymph nodes?

• Cleanse the lymph of pathogens • Human body contains around 500 lymph nodes.

What is the function of lymphatic vessels?

• Collect excess tissue fluid and blood proteins. • Return tissue fluid and blood proteins to the bloodstream

List the 5 major lymph trunks and where they receive lymph from.

• Lumbar trunks receives lymph from the lower limbs and pelvic organs • Intestinal trunk receives chyle from digestive organs • Bronchomediastinal trunks collects lymph from thoracic viscera • Subclavian trunks receive lymph from upper limbs and thoracic wall • Jugular trunks drain lymph from the head and neck

What are the main components of the immune system?

• Lymphocytes • Lymphoid tissue • Lymphoid organs

What are the four groups of tonsils?

• Palatine • Lingual • Pharyngeal • Tubal tonsils

What are the purposes of the immune system?

• Protect the body from foreign substances • Confer immunity to disease.

What are characteristics of the tonsils?

• Simplest lymphoid organs •Arranged in a ring at the entrance to the pharynx to gather and remove pathogens

What is lymph propelled by?

• Skeletal muscles bulging • Nearby arteries pulsing • Tunica media of the lymph vessels

Compare T lymphocytes and B lymphocytes

• T lymphocytes -attack foreign cells directly • B lymphocytes -become plasma cells -secrete antibodies -respond primarily to bacteria and bacterial toxins

What are characteristics of the spleen?

• The largest lymphoid organ • Two main blood-cleansing functions: -removal of blood-borne antigens -removal and destruction of old or defective blood cells •Site of hematopoiesis in the fetus

Describe the location and function of the thoracic duct.

• ascends along the vertebral bodies. •empties into the venous circulation: -junction of left internal jugular and left subclavian veins -drains three quarters of the body.

List the Lymphoid organs

• lymph nodes • spleen • thymus • tonsils • aggregated lymphoid nodules • appendix

What are secondary lymphoid organs?

• lymph nodes, spleen, tonsils • aggregated lymphoid nodules • appendix

What are the two general locations of the lymphoid tissue?

•Mucous membranes of: -digestive, urinary, respiratory, and reproductive tracts -lymphoid organs (except thymus)

What is edema?

An abnormal accumulation of fluid underneath the skin, or in one or more cavities of the body.

What is an antigen?

Antigens are any molecules inducing a response from a lymphocyte.

What are the two main classes of lymphocytes?

B lymphocytes and T lymphocytes are the two main classes of lymphocytes

True of false: Lymph flow is aided by heartbeat

False. Lymph flow is unaided by heartbeat.

Describe the permeability of lymphatic capillaries.

High permeability allows the entrance of: • tissue fluid and protein molecules • bacteria, viruses, and cancer cells

Where do lymphocytes originate?

In the bone marrow

What is lymphangitis?

Inflammation of a lymph vessel

After Lymphocytes are immunocompetent, where do they go?

They "seed" the lymph nodes, spleen, and other lymphoid tissue where they encounter their antigen.

What is the main function of the lymphatic system?

To return excess tissue fluid to the blood vascular system via the lymphatic vessels.

What is Non-Hodgkin's lymphoma?

Uncontrolled multiplication and metastasis of undifferentiated lymphocytes

What is fatty lymph called?

Chyle

What do the lymphoid organs function together to do?

Destroy infectious microorganisms and store lymphocytes

What are antigen-activated immunocompetent lymphocytes called?

Effector cells and Memory cells -- these cells circulate the bloodstream and lymph.

What is chylothorax?

Leakage of fatty lymph into the thorax

What is the order of lymphatic vessels collecting system?

Lymphatic capillaries Lymphatic collecting vessels Lymphatic trunks Lymphatic ducts - empty into the veins of the neck *Lymph nodes are scattered along the collection vessels

What are the key cells of the immune system?

Lymphocytes

What is Hodgkin's Disease?

Malignancy of lymph nodes

What is the function of antibodies?

Mark cells for destruction by macrophages

Where are lymphatic capillaries found? What causes fluid to enter the lymph capillaries?

Near the blood capillaries. An increase volume of tissue fluid causes mini-valve flaps to open and allows fluid to enter.

When is tissue fluid termed lymph?

Once it is within the lymphatic vessels.

What pathway does lymphatic fluid flow?

Only towards the heart - a one-way path.