Lymphoid System

Question 1

What is the lymphoid system?

Answer 1

provides a pathway for fluid that escapes the cardiovascular system to be returned to it

• provides pathway for cells of the immune system to move between different parts of the body
• protects the internal environment of the body

Question 2

three type of lymphoid tissue

Answer 2

1. unencpsulated
2. incompletely encapsulated
3. completely encapsulated

Question 3

2 major components of the lymphoid system

Answer 3

1. lymph vascular network

2. organs associated with the network

Question 4

organ/tissue of the lymphatic system (6)

Answer 4

1. lymph nodes
2. spleen
3. thymus
4. tonsils and adenoids
5. appendix
6. aggregation of lymph nodules such as Peyer’s Patches

Question 5

act to filter cellular and particulate debris out of extracellular fluids
- sites of residence, activation, and proliferation of cells of the immune system

Answer 5

lymph organs

Question 6

3 encapsulated lymph organs

Answer 6

1. thymus
2. spleen
3. lymph nodes

Question 7

incompletely encapsulated lymph organs/tissues

Answer 7

palantine tonsils
lingual tonsils
pharyngeal tonsils (adenoids)

Question 8

unencapsulated (diffuse lymphoid tissue)

Answer 8

peyer’s pathces
lymphoid tissue in appendix
temporary aggregations of lymphocytes and other immune system cells that can occur anywhere in the body

Question 9

two major cell types of lymphoid organs

Answer 9

1. fixed cells

2. motile (free) cells

Question 10

fixed cells

Answer 10

reticular cells

Question 11

connective tissue cells that secrete fine matrix of reticular fibers which these cells extend ectoplasmic processes through and around
- type of fixed cell

Answer 11

reticular cells

Question 12

motile cells (free)

Answer 12

macrophages
dedritic cells (antigen presenting cells )
T lymphocytes
B lymphocytes (plasma cells )

Question 13

antigen presenting cells

Answer 13

dendritic cells

Question 14

differentiate from monocytes and leave blood, phagocytose bacteria and particulates, involved in initiation of humoral and cell mediated immune response

Answer 14

macrophages and dendritic cells

Question 15

involved in initiation go humoral immune response, and involved in cell mediated immune response

Answer 15

T lymphocytes

Question 16

secrete specific antibodies

Answer 16

plasma cells

Question 17

3 major cell types involved in immune response

Answer 17

antigen presenting cells (dendrite and macrophages)
T lymphocytes
B lymphocytes

Question 18

process antigens and present them to T lymphocytes, this will rest in the activation of these cells which will then initiate humoral and/or cell mediated immune response

Answer 18

antigen presenting cells (dendrite and macrophages)

Question 19

once activated, these cells may be responsible for cell mediated immune responses or they may be involved in the activation of B lymphocytes to produce antibodies in a humoral immune response

Answer 19

T lymphocytes

Question 20

responsible for antibody production- the humoral immune response to an antigen that results in the secretion of antibodies by B lymphocytes that have become plasma cells

Answer 20

B Lymphocytes

Question 21

what is an immune response

Answer 21

involves the recognition of foreign antigens by certain lymphatic cells

Question 22

a molecule that, in its make up, has characteristics that will cause the activation of certain cells in the immune system

Answer 22

antigen

Question 23

the portion of foreign molecules that immune system cells recognize are called

Answer 23

epitopes

Question 24

______ are often parts of protein molecules that form part of the cell membrane or wall of organisms that invade the bodies tissues

Answer 24

epitopes

Question 25

2 types of immune responses

Answer 25

1. cell mediated immune response | 2. humoral immune response

Question 26

secretion of antibodies that bind to a foreign antigen by B lymphocyte plasma cells

Answer 26

humoral immune response

Question 27

____ ____ are activated B lymphocytes | are short lived and secrete copious amounts of antibody that are specific for a given antigen

Answer 27

plasma cells

Question 28

_____ act to identify foreign cells for attacks by other components of the immune system such as T lymphocytes and macrophages - can also identify particulates and viruses for phagocytosis and destruction by other leukocytes such as neutrophils

Answer 28

antibodies

Question 29

_____ _____ ____ remain dormant and will rapidly respond to future encounters with the same antigen by rapid clonal proliferation and differentiation into plasma cells that produce the needed antibody

Answer 29

B lymphocyte memory cells

Question 30

antigen activates T lymphocytes to produce cytotoxic substances that cause the destruction of the antigen containing cell - causes clonal proliferation of Tc lymphocytes -Tc effector cells

Answer 30

cell mediated immune response

Question 31

actively kill invading foreign cells in cell mediated immune response

Answer 31

Tc effector cells

Question 32

2 basic types of lymphoid tissue

Answer 32

1. Non-nodular lymphoid tissue | 2. Nodular lymphoid tissue

Question 33

unencapsulated, sub epithelial, aggregations of lymphocytes - diffuse lymphoid tissue, thymus lymph nodes spleen

Answer 33

non nodular lymphoid tissue

Question 34

spherically arranged aggregations of lymphocytes with a distinct cortex and medulla that are called lymphatic nodules nonencapsulated lymph nodes nodules in lymph nodes nodules in spleenic white pulp

Answer 34

nodular lymphoid tissue

Question 35

- consists of dense aggregations of lymphocytes with a few other cells types such as macrophages. - consists of a cortex and medullary germinal center - NO CT CAPSULE - found in lamina propria of digestive tract, respiratory tract and urinary passages - component of lymph nodes, spleen, tonsils and appendix

Answer 35

lymphatic nodule

Question 36

germinal center not very evident

Answer 36

primary nodule

Question 37

germinal center VERY evident

Answer 37

secondary nodule

Question 38

aggregation of lymph nodules in small intestine cell of ileum

Answer 38

Peyer's Patches

Question 39

oval or bean shaped bodies present along the course of lymphatic vessels. multiple lymph vessels my connect to this - contains a stroma consisting or reticular cells and fibers and large numbers of lymphocytes, all surrounded by a CT capsule

Answer 39

lymph nodes

Question 40

lymph nodes are surrounded by a

Answer 40

connective tissue capsule

Question 41

in a lymph node, there are ____ that extend radially into the node, part of CT capsule

Answer 41

trabeculae

Question 42

3 types of tonsils

Answer 42

1. panatine 2. pharyngeal (adenoids) 3. lingual

Question 43

on the left and right in the rear area of the oral cavity - overlying epithelium form invaginations called crypts that penetrate into the band of nodules - has capsule CT

Answer 43

palantine tonsils

Question 44

_____ in palatine tonsils act as collecting places for cellular debris and bacteria as well as a place where live lymphocytes and macrophages can wander about

Answer 44

crypts

Question 45

lie beneath a typical ciliated pseudo stratified columnar respiratory epithelium in rear roof of pharynx - diffuse lymphoid tissue containing nodules, but NO CRYPTS - a thin capsule of dense CT underlies lymphoid tisse

Answer 45

Pharyngeal tonsils (adenoids)

Question 46

situated at the base of the tongue - each one consists of numerous lymphoid nodules surrounding a single crypt - the crypt is lined by a non keratinized stratified squamous epithelium

Answer 46

lingual tonsils

Question 47

situated over the heart where great vessels connect

Answer 47

thymus

Question 48

important in early life - proliferation and maturation center for T lymphocytes - has multiple lobes, each containing a cortical and medullary region

Answer 48

thymus

Question 49

cell types found in thymus

Answer 49

``` T lymphoblasts T lymphocytes reticular cells macrophages plasma cells mast cells unidentified mesenchymal cells ```

Question 50

site of T lymphocyte production- division of T lymphoblast cells - considerable mitotic activity of T lymphoblasts - reticular cells are less numerous in this area and have thin and long processes that envelope groups of developing thymocytes

Answer 50

cortical layer of thymus ( in an active thymus)

Question 51

contains many reticular cells and fewer T lymphoblasts and lymphocytes than the cortex, also contains specialized structures known as Hassall's corpuscles

Answer 51

medullary zone of thymus

Question 52

there are no ____ lymphatic vessels connecting to the thymus

Answer 52

afferent

Question 53

only present in the cortex, acts to prevent most blood born foreign antigens from reaching developing thymocytes- presumed important in allowing T lymphocytes to develop properly

Answer 53

blood -thymus barrier

Question 54

largest piece of lymphatic tissue in the body

Answer 54

spleen

Question 55

filter of blood in an immune response, and also removing worn out erythrocytes from circulation

Answer 55

spleen

Question 56

functions of the spleen (5)

Answer 56

1. production of blood cells during embryogenesis 2. destruction of erythrocytes 3. recycling of ferritin from worn out erythrocytes for synthesis of hemoglobin 4. immune response 5. storage of erythrocytes

Question 57

in embryo, erythrocytes, neutrophils, basophils, ans eosinophils are produced in the _____. this stops around the time of birth

Answer 57

spleen

Question 58

worn out erythrocytes are phagocytosed and digested by macrophages in the

Answer 58

spleen

Question 59

hemoglobin is broken down into _____ and ____

Answer 59

bilirubin | ferritin

Question 60

_____ is returned to the blood and carried to the liver where it is excreted and passed out of body as part of the bile that is released into the lumen of the duodenum

Answer 60

bilirubin

Question 61

the spleen is surrounded by a dense connective tissue _____ that extends processes (_____) into lymphatic tissue of this organ

Answer 61

capsule | trabeculae

Question 62

pulp that has lymphatic nodules

Answer 62

white pulp of spleen

Question 63

pulp that does not have lymphatic nodules

Answer 63

red pulp of spleen