Lymphatic System

Question 1

What are the primary organs of the lymphatic system?

Answer 1

generate lymphocytes from progenitor cells
bone marrow
thymus
cloacal bursa

Question 2

What are the secondary organs of the lymphatic system?

Answer 2

site of lymphocyte activation
lymph nodes
spleen
mucosal associated lymphoid tissue

Question 3

What is the function of the lymphatic system?

Answer 3

to protect the body against pathogenic organisms

removal and disposal of cells

Question 4

What are the actions the lympathic system is involved in?

Answer 4

• phagocytosis via macrophages

- production of immunologically competent cells such as antigen presenting cells and T and B cells

Question 5

What is the mononuclear phagocytic system?

Answer 5

fixed macrophages and free macrophages

Question 6

What are fixed macrophages?

Answer 6

sinusoids of liver, spleen and lymph nodes

reticulum of bone marrow

Question 7

What are free macrophages?

Answer 7

blood, lung and serous cavities

Question 8

How does T cell differentiation come about?

Answer 8

bone marrow, lymphoid stem cell

Thymus

Question 9

How does B cell differentiation come about?

Answer 9

bone marrow, lymphoid stem cell

bursa or bone marrow

Question 10

What are the cells of the lymphatic system?

Answer 10

lymphocytes
antigen presenting cells
stromal cells

Question 11

T or F: T and B cells originate from secondary lymphatic organs?

Answer 11

False, PRIMARY

Question 12

Where do T cells migrate to from bone marrow?

Answer 12

thymus

Question 13

T or F: B cells mature in bone marrow?

Answer 13

True

Question 14

What is the cloacal bursa of birds?

Answer 14

functionally the same to mammalian bone marrow for B cell differentiation

Question 15

Where is the thymus located?

Answer 15

medastinium, cranial to heart

Question 16

What is the thymic cortex?

Answer 16

stains darker than medlla
greater number of lympocytes present
area of positive selection
macrophages

Question 17

What is the thymic medulla?

Answer 17

contains epithelial reticular cells
negative selection
form Hassals corpuscles

Question 18

What are Hassals corpuscles?

Answer 18

large central calcified cells surrounded by circles of keratinized cells

Question 19

Is the thymic cortex or medulla more tightly compact?

Answer 19

cortex

Question 20

What is the blood supply in the thymus?

Answer 20

arteries enter at corticomedullary junction within connective tissye
divide into arteriolies
branch into capillary network in cortex

Question 21

What are educated T cells?

Answer 21

leave thymus

enter blood, settle in T cell areas of secondary lymphatic tissue

Question 22

What is the function of lymph nodes?

Answer 22

filter antigens from lymph before returning it to blood stream

Question 23

T or F: lymph nodes have both efferent and afferent lymph vessels

Answer 23

True

Question 24

What are the three parts of a lymph node?

Answer 24

capsule
cortex
medulla

Question 25

What is a lymph node cortex comprised of?

Answer 25

primary and secondary follices paracortical tissue endothelial blood vessels

Question 26

What is a lymph node medulla made up of?

Answer 26

cords and sinus

Question 27

What is a hilus?

Answer 27

indentation in a lymph node where arteries enter and efferent lymphatics and veins leave

Question 28

What is a lymph node stroma?

Answer 28

reticular cells and fibers that support lymphocytes,macrophages and plasma cells

Question 29

T or F: most lymphocytes migrate through lymph nodes from peripheral blood

Answer 29

True

Question 30

What is the function of the spleen?

Answer 30

``` filters blood recovers and stores iron removes antigens from blood immune response against blood borne anitgens B and T cells stores RBC and platelets ```

Question 31

T or F: cats do not have storage type spleen?

Answer 31

True

Question 32

What is a spleens structure?

Answer 32

outer capsule=dense connective tissue capsule=trabeculae=collagen, elastic, smooth each trabeculae contain vein and artery

Question 33

What is white pulp?

Answer 33

part of spleen that contains central arterioles and follicles

Question 34

What is red pulp?

Answer 34

part of spleen that contains sinusoids

Question 35

What are the two parts of the red pulp of the spleen?

Answer 35

parenchyma and venous sinuses

Question 36

What is the parenchyma made up of?

Answer 36

macrophages and blood cells | B cells and T cells

Question 37

How does splenic blood flow work?

Answer 37

in at central artery, branches to form pencillary arteries, end in capillaries, blood enters parenchyma, then to sinus system, sinuses become larger, then into splenic vein into hepatic portal vein

Question 38

What is GALT?

Answer 38

Gut associated lymphatic tissue

Question 39

What are peyers patches?

Answer 39

aggregated lymphatic nodules | B cells maturation

Question 40

What are M cells?

Answer 40

specialized epithelial cells that cover peyers patches

Question 41

What is BALT?

Answer 41

bronchiolar associated lymphoid tissue

Question 42

What are tonsils?

Answer 42

aggregated lymphatic nodules in pharynx | no afferent vessels

Question 43

Where does local production of antibodies occur?

Answer 43

tonsils

Question 44

What are lympathic vessels?

Answer 44

lined by endothelial cells | absorb fluid from intersituoum, and pass it back to blood stream

Question 45

Where are lympathic vessels NOT found?

Answer 45

``` eye cartilage bone or bone marrow spleen CNS ```