Lecture 3A- The Lymphoid Organs and Lymphatic System

Question 1

What are the primary (central) lymphoid organs?

Answer 1

• Bone marrow
• Thymus

Question 2

What are the secondary (peripheral) lymphoid organs?

Answer 2

• Lymph nodes
• Spleen
• Peyer’s patches
• Adenoid
• Tonsils
  -Bone marrow (technically)

Question 3

What is the function of the secondary lymphoid organs?

Answer 3

Lymphocyte localization and activation

Question 4

What is the function of the primary lymphoid organs?

Answer 4

Leukocyte development; where they originate from and mature.

Question 5

The lymphoid organs include the ______ system in combination with the _______ system.

Answer 5

lymphatic; cardiovascular

Question 6

Where do leukocytes develop in rabbits, ruminants, and pigs?

Answer 6

Intestinal lymphoid tissue

Question 7

Where do leukocytes develop in primates and rodents?

Answer 7

The bone marrow

Question 8

Where do leukocytes develop in avain?

Answer 8

the bursa of fabricius

Question 9

Where are secondary/peripheral lymphoid organs located?

Answer 9

throughout the body

Question 10

The secondary/lymphoid tissues have ___ concentrations of B and T cells.

Answer 10

high

Question 11

Secondary lymph nodes are sites of immune activation through a process of _______.

Answer 11

priming

Question 12

Leukocytes refer the what type of immune cells?

Answer 12

Any type of immune cells

Question 13

Lymphocytes refer mainly to ___ and ___ cells of the ____ immune system.

Answer 13

B and T cells; adaptive immune system

Question 14

What is the third type of lymphocyte, and why is it not usually grouped in with B and T cells?

Answer 14

Natural killer cells. They are usually not included with leukocytes because they are part of the innate immune sys., while B and T cells are part of the adaptive immune sys.

Question 15

What is the largest type of blood vessel?

Answer 15

Artery

Question 16

How do leukocytes circulate around the body?

Answer 16

They travel through the vascular and lymphatic systems

Question 17

What does the vascular system circulate throughout the body?

Answer 17

blood

Question 18

What does the lymphatic system circulate throughout the body?

Answer 18

lymph

Question 19

A small pre-B cell that is ready to leave the bone marrow uses what receptor to signal its release?

Answer 19

IgM

Question 20

What does a small pre-B cell undergo to be released to the peripheral lymphoid organs?

Answer 20

Alternative splicing

Question 21

Some pre-B cells will start to express _____ receptors with the same specificity as those with IgM

Answer 21

IgD

Question 22

Where do naive B cells mainly hang out in the secondary lymphoid tissue?

Answer 22

in primary lymphoid follicles

Question 23

How do naive B cells enter the spleen?

Answer 23

through blood

Question 24

How do naive B cells enter the lymph nodes?

Answer 24

through the lymphatic system

Question 25

Primary lymphoid follicles contain what type of cells?

Answer 25

Follicular dendritic cells

Question 26

Follicular dendritic cells only capture antigens that are brought in by ______.

Answer 26

lymph

Question 27

What are the GALT lymphoid organs?

Answer 27

Peyer's patches, tonsils, and appendix

Question 28

What synthesis do the GALT lymphoid organs participate in?

Answer 28

IgA synthesis

Question 29

What are _ important functions of the lymph system for immune response?

Answer 29

- maintain fluid balance in the body by draining excess fluid from tissues - absorb dietary fats from the intestines, - filtering out harmful substances - producing white blood cells to fight infection

Question 30

Lymphocytes circulate between lymph and blood under the direction of _____ and ______.

Answer 30

Addressins (adhesion molecules) and chemokines

Question 31

What are other terms for lymphocyte circulation?

Answer 31

Lymphocyte homing Lymphocyte trafficking (These are terms used to describe what carries lymphocytes to different areas)

Question 32

About what percent of nucleated cells in the *blood* are **lymphocytes**?

Answer 32

About 30%

Question 33

About what percent of nucleated cells in lymphatics are lymphocytes?

Answer 33

Over 99%

Question 34

How/when is lymph formed?

Answer 34

When fluid leaves the capillaries and goes to the interstitial space. It bathes tissues (????), and is collected in lymphatic vessels.