immune Flashcards
(19 cards)
The lacteals
transport emulsified fats from the intestine to the blood absorb chylomicrons (made by the liver, into the lymphatic system)
Following an infection the lymph nodes
produce antibodies to protect the body against subsequent infection
Lymph flow
Lymph flows
down the pressure
gradient.
2) Muscular and
respiratory pumps push lymph forward due to
function of the
semilunar valves
Lymphatic Capillaries
weave b/t tissue cells and blood capillaries in the loose connective tissues unlike blood capillaries, lymph is carried only one To heart
Lymphatic Capillaries:
are absent from
bones and teeth, bone marrow, and the CNS (CSF)
are very permeable due to
2 modifications of lymphatic capillaries
First Modification:
Endothelial cells that form the walls of lymphatic capillaries are not tightly joined.
Instead they are arranged in a slightly overlapping pattern, much like the shingles on a roof.
2- Second Modification
Collagen filaments anchor the endothelial cells to surrounding structures to withstand any increase in interstitial fluid.
Increases in interstitial fluid opens minivalves to prevent collapse.
lymphatic flow
From the lymph capillaries, lymph flows into successively
larger and thicker walled channels.
EDCBA
capillariescollecting vessels nodestrunkducts
Lymphatic Collecting Vessels
have same 3 tunics as veins, but are thinner walled, have more internal valves and anastomeose more.
dermal lymphatics travel along with superficial veins, while the deep lymphatic vessels of the trunk and digestive viscera travel with deep arteries.
Lymphatic Nodes
cluster along the
lymphatic vessels
large clusters of lymph
nodes occur near the body surface in the inguinal, axillary, and cervical regions
Two functions of lymphatic node
1-Filter lymph that is transported back into the bloodstream.
Macrophages in the nodes remove and destroy microorganisms and other debris in the lymph
2-Activate the immune system.
Lymph nodes and other lymphoid organs are strategically placed in sites where lymphocytes encounter antigens
Node Structure:
1-Capsule: outer covering 2- Internal Regions: a) Cortex: contain lymphatic follicles germinal centers b) Medulla
3-Afferent lymphatic vessels bring lymph into the lymph node 4-Efferent lymphatic vessel leave the lymph node through the hilus.
right lymph duct (thoracic ducts) drains
The right lymph duct drains
the right arm, shoulder area,
and the right side of the
head and neck.
left lymph duct (thoracic ducts) drains
The left lymph duct, or thoracic duct, drains everything else, including the legs, GI tract and other abdominal organs, thoracic organs, and the left side of the head and neck and left arm and shoulder.
The left and right ducts then drain
into the subclavian veins on each side where they join the internal jugular veins to form the brachiocephalic veins.
Spleen
served large splenic artery and vein that enter and exit at the hilum surrounded by a fibrous capsule white pulp area with mostly lymphocytes red pulp remaining splenic tissue provides site for lymphocyte growth and immune survey stores some of the RBC break down byproducts ex Fe+2 stores platelets site of fetal erythropoeisis
Thymus
bilobed, inferior neck and superior larynx site where T lymphocytes mature to immunocomptetent lobules contain : 1-outer cortex 2-inner medulla
Tonsils
entrance of pharynx collection of lymphoid follicles lymphoid tissue contain follicles with germinal centers invaginations that form blind ended tonsillar crypts gather and remove many of the pathogens entering the pharynx in food or inhaled air the gathered pathogens are entered into the memory of immune cells for future ref
Peyer’s Patches
Clusters of lymphoid follicles are found in the wall of the distal portion of the small intestine called the ileum responsible for immune reaction within the intestinal lumen
