Lymphoid System Flashcards Preview

Histology > Lymphoid System > Flashcards

Flashcards in Lymphoid System Deck (58):
1

Adaptive immune system

Fights off foreign antigen material introduced from the air, ingestion, and breaks in the skin
Specific
Consists of lymphocytes and APCs

2

Innate immune system

Inflammatory reaction
Quick
Granulocytes
Neutrophils - phagocytic
Molecules that guide immune cells
Nonspecific

3

What are the molecules that guide immune cells?

Cytokines and lymphokines

4

What are the four terms used to describe the inflammatory reaction?

Heat, redness, swelling, and pain


Calor, rubor, tubor, and dolor

5

Lymphocytes consist of _______ and _______.

B cells; T cells

6

What are the organs of the lymphoid system that house and develop mature lymphocytes?

Thymus gland
Peyer's patches
Tonsils
Lymph nodes
Spleen

7

B cells

Originate from the bm
Independent of the thymus
Humoral response
Found in blood, ECF, lymph
Produce Abs

8

T cells

Originate in the bm
Dependent on the thymus for further development
Cell mediated immune response

9

B cells differentiate into _______ and _______.

plasma cells; memory cells

10

Plasma cells

APCs differentiated from B cells
Have surface receptors

11

Memory cells

Differentiated from B cells
Has a "memory" that recognizes antigen that has already been introduced to the body
Programmed to act when antigen is present

12

Immunoglobulins or Abs have 5 categories, called _______, _______, _______, _______, and _______.

IgA; IgD; IgE; IgM; IgG

13

IgA

Immunoglobulin A
Produced by many exocrine glands (mucus-producing cells), saliva, and milk

14

IgE

Immunoglobulin E
Interacts with mast cells that release histamine a upon interaction with IgE

15

IgM

Immunoglobulin M
Small amount
Activates the complement system

16

IgG

Immunoglobulin G
Penetrates placenta and immobilizes fetus
Most abundant

17

APCs are _______ that are a part of the _______ immunity.

macrophages; adaptive

18

MHC I

Major histocompatibility complex
A group of proteins on all cells
Each cell takes fragments of its proteins and attaches them go MHC I complex which is used to recognize and distinguish self from non self
Recognized by CD8+ cytotoxic T cells

19

Lymphoid system

Consists of APCs and effector cells

20

Perforins

Small peptides released by cytotoxic T cells
Attach to infected cells and polymerize, forming perforations in the cell
Causes cell contents to leak out and the cell dies

21

T cells are divided into _______ and _______.

T helper cells; cytotoxic T cells

22

T helper cells recognize MHC class _______ protein and function to _______.

II; mobilize B cells

23

T helper cells have _______ protein and cytotoxic T cells have _______ protein.

CD4; CD8

24

HIV is so deadly because it attacks _______ cells, therefore inhibiting _______ and _______ cells, which are responsible for the immune responses.

CD4; B; cytotoxic T

25

APCs phagocytize foreign material, digest it, and attach it to _______, which tells the immune cells (B and cytotoxic T cells) that it is infected.

MHC II

26

HLA

Human leukocyte receptor
Comparable to MHC molecules, but in human cells

27

There are two forms of lymphatic organization, _______ and _______.

diffuse lymphoid tissue; lymphatic nodules

28

Lymphatic nodules

Lymphatic cells are condensed into nodules

29

What are the lymphoid organs?

Lymph nodes, bone marrow, thymus, tonsils. and spleen

30

Thymus

Encapsulated, lobate gland found in the mediastinum, anterior to the heart
Begins growing at birth and reaches max at puberty
Guides development of and forms T cells
Produces hormone-like substance called thymosin

31

As a person ages, the thymus gland shrinks due to _______.

fat envolution

32

Thymosin

Hormone-like substance produced by the thymus
Directs development of T cells

33

The thymus gland is composed of a _______ and a _______.

cortex; medulla

34

The cortex of the thymus gland is composed of _______.

many lymphocytes

35

The medulla of the thymus gland is composed of _______.

few lymphocytes and many thymoepithelial cells (TECs)

36

What is the distinguishing factor of the medulla of the thymus?

Hassall's corpuscles - clusters of thymoepithelial cells (TECs)

37

Hassall's corpuscles

Distinguishing feature of the medulla of the thymus gland
Clusters of TECs that produce cytokines for the differentiation of T cells and the mobilization on lymphocytes

38

MALT

Mucosa associated lymphoid tissue
Fund in the lining of GI, urinary, and respiratory tracts
Nodular arrangement of lymphocytes
See an unencapsulated basophilic mass of cells

39

When lymphocytes are active due to immune stress, it is common to see _______ of the nodule arrangements of these cells.

a lighter-staining center

40

Tonsils

Lymphoid tissue arranged in encapsulated aggregations of nodules
Line of defense against antigenic material taken in through the mouth

41

What are the three kinds of tonsils and how many are there of each?

3 kinds: palatine tonsils (2), lingual tonsils (2), and pharyngeal tonsil (1) aka adenoid tonsil

42

Palatine tonsils

Tonsils found at the back of the throat on either side of the glossopharyngeal arch
Harbor streptococcus
Commonly removed
Encapsulated aggregation of lymphatic nodules with crypt

43

Lingual tonsils

Tonsils found at the back of the tongue (dorsal)
Similar arrangement to that of palatine tonsils
Covered with stratified squamous epithelium
Presence of a crypt
Smaller than palatine tonsils

44

Pharyngeal tonsil

Aka adenoid
Single, large tonsil of the upper wall of the nasopharynx
Similar arrangement to other tonsils with two exceptions

45

The covering of the palatine and lingual tonsils are made up of _______ cells?

stratified squamous epithelium

46

What are the two distinguishing factors of palatine tonsils?

1. Stratified squamous epithelium covering
2. presence of a crypt

47

What two things about the arrangement of the adenoid makes it different from the other tonsils?

1. Covering is made up of pseudo stratified columnar epithelium instead of stratified squamous epithelium
2. No crypt

48

Peyer's patches

Aggregation of lymphocytes forming nodules
Commonly found in the ileum and the gut
Makes contact with the contents of the lumen

49

Lymph nodes

Aggregations of lymphatic tissue encapsulated in dense, fibrous CT that function to filter lymph
Form chains
Two major chains bilaterally from the neck to the groin

50

What is the major cell type of the lymph nodes?

Lymphocytes

51

Lymph goes back to the _______ blood flow in the neck where the _______ come together and it becomes _______ again

venous; subclavian vein and jugular; plasma

52

Spleen

Largest lymph organ
Located in the UL quadrant above the stomach
Functions to filter both blood AND lymph
Encapsulated in dense, fibrous CT
Consists of white and red pulp

53

What is the only lymphatic organ with two functions? What are they?

The spleen.
1. Filter blood
2. Filter lymph

54

White pulp of the spleen

20% of the spleen
Aka splenic nodule
Made up of lymphocytes

55

Red pulp of the spleen

Highly vascularized cords of cells
Everything in between the white pulp

56

Cords of Billroth

Cords of the red pulp of the spleen
Responsible for hemocatheresis - saves reusable parts

57

Hemocatheresis

Removal of old RBCs

58

What is the distinguishing feature of the spleen?

Each white pulp has its own follicular arteriole