Unit 7: Lymphatic System

What are the 3 main functions of the lymphatic system?

Fluid balance, fat absorption, immunity.

What is lymph?

Interstitial fluid inside lymphatic vessels.

What causes edema?

Excess interstitial fluid.

What do lymphatic capillaries collect?

Excess tissue fluid.

Where does lymph eventually empty?

Subclavian veins.

What are the two lymphatic ducts?

Thoracic duct and right lymphatic duct.

Which duct drains most of the body?

Thoracic duct.

Which duct drains the right upper body?

Right lymphatic duct.

What moves lymph through vessels?

Skeletal muscle contractions.

Do lymphatic vessels have valves?

Yes.

Lymphatic vessels are most similar to what blood vessel?

Veins.

What is the largest lymphatic organ?

Spleen.

Function of the spleen?

Filters blood and destroys old RBCs.

What organ matures T cells?

Thymus.

Where is the thymus located?

Behind the sternum.

What happens to the thymus after puberty?

It shrinks (atrophies).

What is a lymph node?

A lymph-filtering organ.

Function of lymph nodes?

Filter lymph and activate immunity.

What enters a lymph node?

Afferent lymphatic vessels.

What leaves a lymph node?

Efferent lymphatic vessels.

What cells remove pathogens in lymph nodes?

Macrophages.

What cells produce antibodies?

Plasma cells.

What are plasma cells derived from?

B cells.

What are memory cells?

Long-lived cells for faster future responses.

What are Peyer's patches?

Lymphoid tissue in the ileum.

Function of Peyer's patches?

Protect the small intestine.

What are the tonsils?

Lymphoid tissue in the throat.

Function of tonsils?

Trap inhaled and swallowed pathogens.

What is MALT?

Mucosa-associated lymphoid tissue.

Function of MALT?

Protect mucosal surfaces.

Where are Langerhans cells found?

Epidermis.

Function of Langerhans cells?

Capture antigens.

What are macrophages?

Phagocytic immune cells.

What is phagocytosis?

Engulfing and destroying pathogens.

What drains the upper limbs?

Subclavian trunks.

What drains the lower body?

Lumbar trunks.

What drains the intestines?

Intestinal trunk.

What drains the head and neck?

Jugular trunks.

What drains the lungs?

Bronchomediastinal trunks.

Which side of the body drains into the right lymphatic duct?

Right head, right arm, right chest.

Which side of the body drains into the thoracic duct?

Everything else.

What is the cisterna chyli?

Dilated sac below the thoracic duct.

What does the cisterna chyli collect?

Lymph from lower body.

What absorbs dietary fats?

Lacteals.

Where are lacteals found?

Small intestine villi.

What is chyle?

Fat-rich lymph.

What is immunocompetence?

Ability to recognize specific antigens.

What is an antigen?

A substance recognized as foreign.

What is an antibody?

A protein that binds an antigen.

What happens to lymph after entering the bloodstream?

It becomes plasma.

Does the CNS contain lymph nodes?

No.

Where are axillary lymph nodes located?

Armpits.

What do axillary lymph nodes drain?

Upper limbs and breast.

Where are inguinal lymph nodes located?

Groin.

What do inguinal lymph nodes drain?

Lower limbs.

Where are supratrochlear lymph nodes located?

Above the medial elbow.

Magic word for this lecture?

Lymphatic system = fluid balance, fat absorption, immunity.