4.8 Lymphoid tissues and lymphatics

Question 1

what are the primary and secondary lymphatic organs?

Answer 1

Primary: bone marrow, thymus
secondary: lymph node, spleen

Question 2

______ produces all multipotential lymphoid stem cells. ______ cells mature here and ____ cells migrate to the thymus

Answer 2

Bone marrow
B-cells
T-cells

Question 3

The _____ is the site of T lymphocyte maturation

Answer 3

Thymus

Question 4

When epithelial reticular cells die, they become _____

Answer 4

Hassells corpsucles

Question 5

does final maturation occur in the thymus?

Answer 5

no, final maturation occurs in secondary organs

Question 6

_____ is the only route by which cells enter and exit the thymus

Answer 6

blood

Question 7

The ________ filters substances that travel through the lymphatic fluid, and contain lymphocytes (white blood cells) that help the body fight infection and disease.

Answer 7

lymph nodes

Question 8

the _____ is the largest secondary lymphoid organ and is posterior to stomach

Answer 8

spleen

Question 9

how does the spleen have a dual function?

Answer 9

It has both red and white pulp

• Red- filters blood of aged or abnormal RBC
• White- site of immune response for blood borne antigens

Question 10

difference between lymphatic system and general circulation?

Answer 10

• The Blood vascular system pumps and carries blood with O2, CO2, electrolytes, hormones and metabolites.
  IT also carries lymphocytes to spleen
• The Lymph vascular system filters tissues fluid (lymph) through lymph nodes and returns lymph to BVS via thoracic duct

Question 11

_____ are similar, but thinner than same size veins. They are often found next to circulatory vessels

Answer 11

lymph vessels

Question 12

You can see lymphocytes but not RBC in lymph vessels. Lymph vessels stain blue with eosin.

First true second false

First false second true

both true

both false

Answer 12

First true, second false

Lymph vessels stain pink with eosin

Question 13

______ have very thin endothelium and begin as close ended vesicles

Answer 13

lymphatic capillaries

Question 14

Lymphatic capillaries have Zona Occludens between cells. They also have a discontinuous basal lamina and microfibers that anchor vessels to surrounding CT

first false second true

first true second false

both false

both true

Answer 14

BOTH false

Lymphatic capillaries do NOT have zona occludens between cells. They do have a discontinuous basal lamina, but microFIBRILS attach to surrounding CT, not microfibers

Question 15

What are the two different sections of a lymph node?

Answer 15

Cortex, medulla

Question 16

What does the outer cortex consist of?

Answer 16

1. Network of reticular cells/fibers, meshwork populated by B-cells
2. spherical structures called nodules (follicles)
   
   1. primary and secondary nodules

Question 17

Primary nodules have naive T lymphocytes, while secondary nodules have germinal centers with B cells differentiating into plasma cells

First true, second false

First false, second true

both true

both false

Answer 17

First false, second true

Primary nodules have naive B cells, not T cells. but second is true!

Question 18

The _____ cortex is rich in lymphocytes with few nodules

Answer 18

primary

Question 19

recognize outer vs Inner cortex

Answer 19

left is outer, right is inner

Question 20

The ____ consists of cords interspersed with sinuses

Answer 20

medulla

Question 21

Medullary _______ are irregular extension of the inner cortex containing B lymphocytes and some plasma cells, while medullary ______ are irregular dilated spaces containing lymph

Answer 21

Cords, sinuses

Question 22

Medullary sinuses secrete medullary cords. Medullary sinuses are partially lined by reticular cells and macrophages

First true, second false

First false, second true

Both false

both true

Answer 22

Both are true

Question 23

How does lymph travel from tissues to hilum?

Answer 23

Afferent lymphatic vessels receive lymph from tissues → lymph passes through trabecular sinuses and reaches medullary sinuses → lymph is collected by efferent lymphatic vessels at the hilum

Question 24

_____ is the dense CT that surrounds lymph nodes. The ______ is the loose network of macrophages, reticular cells and fibers that Communicates with medullary sinuses through trabecular sinuses

Answer 24

capsule, subscapular sinus

Question 25

What are the MALTs?

Answer 25

Adenoids, tonsils \*you drink a MALT after you get your tonsils removed!\*

Question 26

\_\_\_\_ are aggregates of incompletely encapsulated lymphoid tissue, usually associated with the epithelium

Answer 26

tonsils

Question 27

what are the different types of tonsils?

Answer 27

palatine, lingual, pharyngial

Question 28

What are the GALTs?

Answer 28

Peyers patches, appendix

Question 29

\_\_\_\_\_\_\_ are groups of well-organized lymphoid follicles located in the lamina propria and submucosa of the distal portion of the small intestine

Answer 29

peyers patches

Question 30

\_\_\_\_\_\_ is the small finger-shaped pouch of intestinal tissue located between the small intestine (cecum) and large intestine (colon), fxn unknown

Answer 30

the appendix

Question 31

what are the arrows in this pic pointing at? Where is this located?

Answer 31

Peyers patches (in small intestines)

Question 32

What are the arrows in this picture pointing at?

Answer 32

lymphatic nodules of appendix

Question 33

What are the BALTs?

Answer 33

lymphoid follicles in the [lungs](https://en.wikipedia.org/wiki/Lung) and [bronchus](https://en.wikipedia.org/wiki/Bronchus).

Question 34

\_\_\_\_\_\_ are unencapsulated lymphoid tissues and lymphoid aggregates (nodules) that monitor for foreign substance between the internal and external environment

Answer 34

MALTs (mucosa associated lymphoid tissue)