Flashcards in Chapter 28: Lymphatic System Deck (49):
What are the functions of the lymphatic system?
1.) Produce, maintain, and distribute lymphocytes
2.) Maintain normal blood and interstitial fluid volume
3.) Alternate route for the transport of materials
lymphatic vessels transport fluid called ______ from tissues to the _______
lympth; venous system
lymphatic vessels can range in size... give some examples (4)
Small lymphatic capillaries
Medium lymphatic vessels
Large lymphatic trunks
lymphatic vessels are almost always found associated with _________
lymphatic vessels are found where?
Found in most tissues
Absent in avascular tissue and the CNS
what is lymph?
Lymph is a fluid connective tissue
It occurs ONLY in the lymphatic vessels
what is lymph derived from?
Interstitial fluid of the tissues
describe lymphatic capillaries (5)
-Closed ended tubes
-In interstitial spaces
-Single layer of squamous cells with incomplete basal lamina
How are lymphatic capillaries different from blood capillaries? (5)
-Flat and irregular
-Have anchoring filaments to keep the passage open
-Overlapping endothelial cells
describe the formation of lymph
Interstitial fluid enters capillaries
-Overlapping cells function as one way valves
-Moves through fenestrations
-Large things such as viruses and debris follow
describe medium lymphatic vessels
Merging of lymph capillaries
Similar to veins
Merge to form trunks
Travel with arteries of same size
__________ are named for the _______
Lymphatic Trunks, region they drain
Ex. Lumbar, Intestinal, Broncomediastinal, Subclavian, Jugular
____ drain into _______
what are the two lymphatic ducts?
thoracic and right lymphatic
What do lymphatic ducts do?
Deliver lymph to venous circulation at subclavians
-Reintroduced to bloodstream
-Becomes part of plasma and is circulated
where does the thoracic duct drain?
drains lower body, left arm, head & neck
describe the route of the thoracic duct
arises from cisterna chyli
ascends in front of vertebral column
empties into left subclavian vein
where does the right lymphatic duct drain?
drains right side of head, neck & right arm
describe the route of the right lymphatic duct
starts in right thorax
To the right subclavian vein
lymphatic ducts (Evenly/Unevenly) drain fluid from body
Thoracic does the majority
It is much longer and drains the entire inferior half of the body
describe the movement of lymph
-Occur at bulges
--Pressure is lower in lymphatics than in veins)
--Lymph is moved using similar methods to veins)
What is it called If drainage does not occur?
Primary cells of the lymphoid system are called what?
Lymphocytes allow for......
specific (or adaptive) immunity
-multi-faceted immune response to the detection of specific foreign antigens
when it comes the lymphocytes what are the three cells?
describe NK cells (4)
-Natural killer (NK) cells
-Derived directly from bone marrow
-Detect chemical signals other than specific antigens (like all the other leukocytes) and induce apoptosis
describe B cells (3)
-Originate and develop in the bone marrow (B-cells)
-Stimulated by an antigen to produce antibodies
-Can survive for years as memory cells, and become active once exposed to a similar antigen
describe T cells (4)
-Originate in the bone marrow but develop in the thymus (T-cells)
-Attack cells with antigens indicating viral infection or detrimental mutations (cancer)
-Have memory cells similar to B-cells
what are lymphoid nodules?
Reticular connective tissue dominated by lymphocytes
what is M.A.L.T
(Mucosa associated lymphoid tissue)
Digestive lymph nodules
where are tonsils positioned and what do they do?
-Positioned around the pharanx
-Remove pathogens that enter via air or food
what are the three types of tonsils? describe
1.) Pharyngeal tonsil
-one nodule in nasophranx
2.) Palatine tonsils
-two nodules on the soft palate
3.) Lingual tonsils
-two nodules at the base of the tongue
what MALT lines mucosa of the small intestine
Aggregated lymphoid nodules
what is the appendix?
Blind tube at the beginning of small intestine
Area prone to infection
-Intestinal flora enter underlying tissues
lymphatic organs are surrounded by.....
a fibrous, connective tissue capsule
what are the three lymphatic organs?
describe lymph nodes (3)
-Between several afferent and one efferent vessel
(indented region where BV’s, nerves, and efferent lymph vessels connect)
lymph nodes have a cortex and medulla.. describe both sections
-capsule has trabeculae that subdivide it
Has two regions:
(consists of aggregated B-cells)
(T cells enter blood here)
B-cells leave through the efferent vessel
what are the 6 locations of lymph nodes?
Where is the spleen located?
the left side of the stomach
True or False: the spleen is the largest lymphatic organ
the spleen is made up of 2 types of pulp... what are they and describe them
-resembles lymph node
-large amounts of RBC
-sinuses, macrophages, T/B cells
what are the functions of the spleen? (5)
Remove old RBC’s
Initiate immune response
RBC production in fetus
where is the thymus located?
describe the size and development of the thymus over time as you age
first lymph organ to develop
grows until puberty
Shrinks with age
replaced by fibrous & adipose tissue
the thymus has 2 lobes with lobules. what are they?
Cortex-mostly immature T-cells
Medulla-mostly reticular epithelial cells
describe the T cells in the thymus
Cortex produces T-cells
Mature and migrate into medulla
Enter blood vessels and go into circulation