Lab Exercise 24: Lymphatic System

fx of lymphatic system

• fluid recovery

• immune surveillance

• lipid absorption

lymph

ISF (interstitial fluid) that’s been picked up by lymphatic capillaries

lymphatic vessels

carry lymph from lymph capillaries to veins

fx of thoracic duct

main lymphatic tube that collects lymph from most of the body and dumps it back into the bloodstream

fx of right lymphatic duct

• Collects lymph from the right side of the body superior to the
  diaphragm

• Returns lymph to the right subclavian vein

primary lymphoid tissue

where lymphocytes are made and trained; ex. bone marrow, thymus

secondary lymphoid tissue

where lymphocytes work and fight infection after they’re mature; ex. lymph nodes, spleen, tonsils, Peyer’s patches in SI

hilum

point where blood vessels enter and exit lymph node

afferent lymph nodes

vessel that takes lymph to lymph node

efferent lymphatic vessel

take lymph away from the node

capsule

tissue enclosing lymph node

cortex

Outer region of the node with numerous lymphatic nodules

medulla

Medullary cords & sinuses cleanse the lymph of
foreign particles and cellular debris

Mucosa-associated lymphoid tissue (MALT)

Collection of lymphatic tissues within epithelia of
digestive, respiratory, urinary, and reproductive
systems

lymphoid nodules

occur where lymphocytes are
densely packed in an area of loose connective
tissues

peyer’s patches (small intestine)

Clusters of lymphatic nodules in the mucosal
lining of the small intestine

tonsils

large nodules in the wall of pharynx

palatine tonsils

The ones you can see at the back of your throat on both sides (oral cavity)

lingual tonsils

the ones at the back of your tongue

pharyngeal tonsils

Called adenoids when swollen/enlarged

thymus

red pulp of spleen

• Filters blood
• Contains fixed and free macrophages scattered throughout

white pulp of spleen

contains lymphocytes from thymus and bone marrow and releases more of these cells during immune response

fx of the spleen

filters blood