Lymphoid Organs

Question 0

Primary lymphoid organs?

Answer 0

Thymus - t cell production ( cell mediated immune response)

Bone marrow - b cell production (proliferate, plasma cells, humoral response & pre-t cell production)

Question 1

6 lympoid organs

Answer 1

Bone marrow (hematopoietic process)
Spleen
Thymus ( t cell production )
Lymph nodes
Tonsils
Peyers patches

Question 2

Secondary lymphoid organs ?

Answer 2

Spleen, lymph nodes (peripheral organs) - surrounded by CT capsule
- find antigens -> immune reponse

Question 3

Where lymphatic nodules contain no capsule?

Answer 3

Digestive system, respiratory system.

Question 4

Where are peyers patches? (4)

Answer 4

Small intestine - Ileum.
Resemble tonsils in structure.
Capture and destroy bacteria
Therefore can distinguish ileum from duodenum.

Question 5

Which is the only lymphoid organ not to fight antigen?

Answer 5

Thymus

Question 9

Diffuse lymphatic tissue. 3 main located and Where located within these. Specific characteristic….

Answer 9

GALT digestive tract
BALT respiratory tract
Genital urinal tract
Located in lamina propria
No capsule

Question 10

Maturation of lymphocytes? (7)

Answer 10

Bone marrow, pluripotent lymph cells, thymus, t-cells, maturation, leave via blood or lymph nodes, circulate in blood or pop. 2nd lymphoid organs

Question 11

Thymus structure (3)

Answer 11

Connective capsule, 2 lobes, cortex and medulla (lobules)
Cortex - close packed, dark basophilic
Medulla - less dense, less close cells.

Question 12

Thymus medulla differs from cortex (3)

Answer 12

Less closely packed, hassal corpuscle, dendritic cells

Question 13

Hassal corpuscle (3) and which type of cell and what stain color with h and e?

Answer 13

Formed by epithelioreticular cells (type 6)
Production of factors - regulate maturation of t cells
H and e - pink

Question 14

Thymus cells in cortex?

Answer 14

Epithelioreticular (type 1 under capsule, type 2 in cortex), thymocytes, macrophages

Question 15

Thymus cells in medulla?

Answer 15

Epithelioreticular cells (5, 6 around hassal corpuscle)
Dendritic cells,
Macrophages,
Thymocytes

Question 16

Blood-x barrier (3)

Answer 16

Brain - astrocytes (CNS) - perivascular feet
Thymus (4) - epithelioreticular cells, macrophages, capillary endothelium and basal lamina
Testis - occluding junctions - prevent exposure of immune response cells and testosterone to spermatogonia.

Question 17

Importance of blood thymus barrier?

Answer 17

Prevent antigen into thymus.

Therefore protect immature t cells from immunocompetent lymphocytes

Question 18

Thymus - cortex medulla boundary contain?

Answer 18

Type 3&4 epithelioreticular cells - selection of lymphocytes with specific receptors - pass thru barrier

Question 19

Thymus and lymphatic follicles?

Answer 19

Contains none, found in spleen and lymph nodes.

Question 20

Where are lymph nodes located?
Purpose?
And 2 types of defence cells in lymph and function?
In terms of lymphocytes competancy?

Answer 20

Along lymphatic vessels
Filter lymph - returned to blood
Macrophages - engulf and destroy foreign substances
Lymphocytes - immune response to antigens.
Lymphocytes maturation and competency organs

Question 21

Regional lymph nodes? (5)

Answer 21

Axillary, inguinal, neck, abdomen, mediastinum

Question 22

4 cell types in lymph nodes?

Answer 22

Macrophages, lymphocytes, dendritic cells, reticular cells (type 3 collagen production - provide structural framework for organ)

Question 23

What is lymph?

Answer 23

Similar to blood plasma, no proteins.

Seeps out of blood from peripheral capillaries.

Question 24

What is purpose to lymphatic vessels?

Answer 24

Convey fluid from peripheral capillaries to veins

Question 25

Lymph nodes structure?

Answer 25

Capsule, sub-capsular sinus ( specific to lymph node, contain lymph from lymphatic vessels).
Cortex - b cells, primary and secondary follicles ( germinal + mantle)
Para cortex - mainly t cells
Medullary cords - macrophages and plasma cells
Medullary sinus
Hilum(artery and vein)

Question 26

Lymph nodes follicles?

Answer 26

Primary - lymphocytes not stimulated by antigen
Secondary - lymphocytes stimulated - proliferation of cells
- mainly b cells
- germinal - lymphocytes recognised antigen.

Question 27

Spleen dimensions and weight? Which artery connects and how effects?

Answer 27

L - 12-15cm, W - 4-8cm, Thickness 3/4cm
Weight 120-140g, Dark red
Splenic artery - important branching - influences structure of spleen,

Question 28

Functions of spleen (4)

Answer 28

Blood reservoir,
hemocatalysis,
hemopoiesis (2nd trimester of birth),
activation of b and t lymphocytes

Question 29

If organ dark strain - contain lymphocytes….

Answer 29

Spleen, lymph nodes, thymus - contain lymphocytes

Question 30

Structure of spleen? 2 area of arteries

Answer 30

Connective capsule - thick trabeculae
Arteries - central and penicillar aterioles
Malpighian corpuscle - accumulation of lymphocytes, cover central artery, lymphatic nodules, specific to spleen
Sheated capillaries - by macrophages
Splenic sinus - net of capillaries connect to venules - splenic vein - exit organ.

Question 31

Spleen white pulp?

Answer 31

20% White - immune response - Malpighian corpuscles encircle branches of splenic artery (central arteries).

Question 32

Spleen red pulp

Answer 32

80% red pulp - hemocatalysis, blood reservoir - macrophages and blood cells - red pulp sinus (wide sinusoids)

Question 36

Thymus (2) peak and endocrine function

Answer 36

Peak during childhood. Adult converted into white adipose tissue.
Produce hormones (thymosin) program lymphocytes

Question 37

Where are lymph nodules located? And lined by?

Answer 37

Lamina propria of mucosa

lined by epithelium

Question 38

Tonsils, where, 4 locations which form………ring

Answer 38

Lymphoid nodules mouth.
Entrance to respiratory and digestive system.
Contain crypts - increase SA.

Tubaric, pharyngeal, lingual, palatine form “weldeyer ring”