chapter 20:the lymphatic system and lymphoid organs and tissues
what returns fluids that have leaked from blood vascular system back to the blood?
what three parts does the lymphatic system consists?
a meandering network of lymphatic vessles, lymph, the fluid contained in those vessels, and lympph nodes that cleanse the lymph at it passes throught them.
what provides the structural basis of the immune system?
lymphoid organs and tissues
once interstitial fluid enters a cell what is it called?
where does the transport of the lymph begins?
what capillaries weave between the tissue cells and blood capillaries in loose connective tissue?
where are lymphatic capillaries absent from?
bones, teeth,bone marrow and the entire centeral nervous system.
are the endothelial cells forming the walls of lymphatic capillaries tightly joined?
what anchors the endothelial cells to surrounding structures so they can increase in interstitial fluid volume opening the minivalves, rather than causing lymphatic capillaries to collapse?
what happen when the pressure in the interstitial fluid is greater than the pressure in the lymphatic capillary/
the minivalves will open
what happen when the pressure in the lymphatic capillary is greater than the interstitial fluid?
the minivalves will close
what is the special set of capillaries called that transport absorb fat from the small intestine to the blood stream?
what is the fatty lymph called that drains from the fingerlike villi of the intestinal mucosa?
from the lymphatic capillaries , lymph flows through succesively larger and thicker walled channels- first collecting vessel then trunks, and finally the largest of all the ducts. this know by?
collecting lymphatic vessels
does the collecting lympathic vessel have all the same tunics as veins?
the largest collecting unite and form what?
what drains fairly large areas of the body?
what are the major trunks?
lumbar, bronchomediastinal, subclavin, and jugular trunks, and single intestinal trunks
what are the two large ducts of the lymph?
right lymphatic duct, and thoraic duct
what duct drains lymph from the upper right lymph and the right side of the head and thorax?
right lymphatic duct
what duct receives lymph from the rest of the body?
what collects lymph from two large trunks that drain the lower limbs and from the intestinal trunks that drains the digestive organs?
cisterna chyli(enlarge sac) thorax
as the thoracic duct run superiorly, it receive drainage from where?
left side of the thorax, left upper limbs,and the left side of the head
where does each terminal duct empties?
into the venous circulation at the junction of the internal jugular vein.
like larger blood vessels, the larger lymphatics receive it nutrients blood supply from the?
what is the condition call when there are red visible lines on the side and they are unpleasant to touch?
lymph transport is?
sporadic and slow
what are the main warriors of the immune system and arises in red bone marrow
what are the two main varieties of lymphocytes?
T cells ( T lymphocytes) B cells ( B lymphocytes)
Active__ manage the immune responses, and some directly attacks and destroy infected cells
___ protects the body by producing plasma cells, daughters cells that secrete antibodies into the blood.
what capture antigens and bring them back to the lymph nodes
what play a crucial role in body protection and the immune response by phagocytizing foreign substances and helping to active T cells
what is an important component of the immune system?
why is lymphoid tissues an important component in the immune system?
it houses and provides proliferation site for lymphocytes and it furnishes an ideal surveillance vantage point for lymphocytes and macrophages
what type of lymphoid tissue is most lymphoid organs compose of?
reticular connective tissue
which lymphoid organ is not composed of reticular connective tissue?
a loose arrangement of lymphoid cells and some reticular fibers and is found in virtually every body organ.larger collection appear in the lamina propria of mucous membranes such as those lining the disgestive tract?
diffuse lymphoid tissue
__are solid, spherical bodies consisting of tightly packed lymphoid cells and reticular fibers.
follices often haven lighter-staining___ where the proliferating___cells predominate
germinal centers and B cells
what centers can enlarge dramatically when B cells are dividing rapidly and producing plasma cells?
where does large clusters of lymph nodes occurs near the body surface in the?
inguinal, axillary, and cervical regions.
what is the two basic function of the lymph nodes?
filtration, and immune system activation
what is the structure of a lymph node?
they are surrounded by a dense fibrous capsule from which connective tissue strands called trabecule extend inward to divide the node into a number of compartments.
what are the two histologically regions of an lymph nodes?
the cortex and medulla
what does the superficial part of the cortex contains?
densely packed follicles, many with germinal centers heavy with dividing b cells
what is primary house for T cells in transit
deeper part of the cortex
what is the circulation of the lymph nodes?
afferent lymphatic vessels, subcapsular sinus, medullary sinuses and hilum
what is infected nodes known as?
the lymph nodes are the only to do what?
filters the lymph
what provides a site for lymphocytes proliferation and immune surveillance and response
what are some functions of the spleen/
stores some of the breakdown products of red blood cells for later reuse, stores blood platelets and monocytes for release into blood when need, may be a site or erythrocyte production in the fetus
what are the two components of the spleen?
white pulp and red pulp
where is the immune function taking place in the spleen?
___is where worn out blood cells and bloodborne pathogens
what contains huge numbers of erythrocytes and macrophages that engulf them?
in the____T lymphocytes precursors mature to become immounocompetent lymphocytes?
most___ cells are lymphocytes
what are involved in the development of regulatory T cells, a class of T lymphocytes that are important from preventing autoimmune responses?
how is the thymus different from other lymphoid organs?
thymus have no follicles because it lacks B cells and it is the only lymphoid organ that does not fight antigens
___ are a set of distributed lymphoid tissues located in mucous membranes through out the body
mucosa-associated lymphoid tissues (MALT)
what helps protects us from never ending on slaught of pathogens trying to enter our bodies
what are the largest collection of MALT?
TONSILS,PEYERS PATCHES, AND APPENDIX
the___paired are located on either side at the posterior end of the oral cavity
what are the largest tonsil and are likely to get infected?
The___ is collective term for a lumpy collection of lymphoid follicles at the bases of the tongue
___is refered to as adenoids if enlarged and they are located in the posterior wall of the nasopharynx
___surround the opening of the quditory tubes into the pharynx
what traps bacteria and particulated matter in the tonsils?
___are larger clusters of lymphoid follicles structurally similar to tonsils
the appendix is in the ideal position to?
destroy bacteria, and to generate many memory lymphocytes for long term memory
the two main connection of the jugular lymph sacs to the venous system are?
retained and become the right lymphatic duct and, on the left, the superior part of the thoraic duct.
all lymphoid organs develop from the mesodemal mesenchymal cells except the?
aggregates of lymphoid location in the wall of the ileum are?
what is the sequence best describe the flow of lymph through the lymphatic system.
capillaries, vessels, trunks,ducts
in addition to its lymphoid function, this organ holds reservior of platelets
what lymphatics structure absorbs excess tissue fluids.
what lymphatic structure trap bacteria in the posterior oral mucosa?
what is true about lymph nodes
they have fewer efferent vessels than afferent (incoming) vessels
all lymph is eventually return to the circulation to the?