Physiology Ex 1 - Immune System Flashcards Preview

Fall 2015 > Physiology Ex 1 - Immune System > Flashcards

Flashcards in Physiology Ex 1 - Immune System Deck (60)
1

Where are all leukocytes (immune system cells) formed?

Bone marrow

2

Where do T-Lymphocytes mature?

Thymus

3

Where do B-Lymphocytes mature?

Bone Marrow and Liver

4

What do T-Lymphocytes mature into?

Cytotoxic T-Cells (mostly CD8)

for cellular immunity

5

What do B-Lymphocytes mature into?

Plasma cells ->

igG

igA

igM

igE

igD

for humoral immunity

6

What are the functions of the lymphatic system and vessels?

Fluid Balance

Fat Absorption

Defense

7

What system removes fluid gained by tissues?

Lymphatic system

8

Where does the lymphatic system return excess fluid to the cardiovascular system?

The large subclavian veins of the thorax

9

What is an imbalance where more capillary filtration than lymph drainage called?

Edema

10

Do lymphatic vessels have valves?

Yes

11

What do lymph nodes do?

Filter lymph

12

Name the 5 lymphatic trunks

Jugular

Subclavian

Bronchomediastinal

Intestinal

Lumbar

13

Name the 2 lymphatic ducts

Right

Thoracic

They empty into the large veins in the thorax

14

What happens to the 20L of fluid that filters out of the capillaries to the tissues every day?

17 L is reabsorbed by the capillaries

3 L is returned to the blood via the lymphatic vessels

15

What type of an imbalance causes edema?

Imbalace of fluid homeostasis:

  • increased secretion of fluid into interstitium
  • impared removal of interstitial fluid

16

Which factors can cause edema?

1 - Increased hydrostatic pressure

2 - Reduced oncotic pressure (pressure by albumin pulling water into circulatory system - low serum protein)

3 - Lymphatic obstruction

4 - Impaired circulation

5 - Sodium retention

6 - Inflammation

17

What two parts do lymph nodes consist of?

Cortex

Medulla

18

Post surgery damage due to removal of lymph nodes can cause?

Edema

19

Where are lymphatic nodules found?

Loose connective tissue of the following systems:

Digestive (Peyer's patches)

Respiratory

Reproductive

Urinary

20

Lymphatic tissue consists mainly of?

Lymphocytes

21

What is lymphoid tissue?

Collection of lymphoid cells:

B-lymphocytes

T-lymphocytes

Macrophages & Dentritic cells

Other immune & connective tissue cells

22

What are tonsils?

Lymphatic nodules located in nasopharynx and oral cavity

23

Name the 3 tonsil groups

Palatine

Pharyngeal (adenoids)

Lingual

24

What are the functions of the spleen?

Filters blood and removes defective RBC's

Lymphoid tissue detects and responds to foreign substances

Limited reservoir for blood

25

List the steps in T-Cell Maturation

Stem cells -> (in bone marrow) Immature Thymocytes (TCR-,CD4-,CD8-) -> (in thymus) Thymocytes (TCR+, CD4+, CD8+) -> (in thymus: positive and negative selection) MHC II: Helper T Cells (TCR+, CD4+), MHC I: Cytotoxic T cells (TCR+,CD8+)

26

What is positive selection of T-Lymphocytes

lymphocytes that bind to MHC complex will be stimulated to survive and mature to CD4 or CD8 cells

27

What is negative seelction of T-Lymphocytes?

T-Lymphocytes that react to self-antigens on the MHC complex will undergo apoptosis

28

What is the TCR?

The T cell receptor, a heterodimeric transmembrane protein on the surface of T lymphocytes (T cells)

29

What does the TCR do?

Recognizes antigens bound to MHC molecules. Lymphocytes with TCRs that can bind to MHC are stimulated to survive (positive selection)

30

What is CD8?

A transmembrane glycoprotein on the surface of cytotoxic T cells and NK cells. Important for cell mediated immmunity

31

Which MHC complex does CD8 bind to?

I

and produces memory T-cells

32

What do cytotoxic T cells do?

lyse virus-infected cells, tumor cells, and tissue transplants

They also produce cytokines, which promote phagocytosis and inflammation

33

What is CD4?

A glycoprotein on the surface of helper T cells, regulatory T cells, monocytes, macrophages, and dendritic cells

Its intracellular portion activates tyrosine kinase- lck, which is involved in the signaling cascade of an activated T cell and plays a role in activating humoral immunity

34

What is immunity?

The ability to resist damage from foreign substances:

  • Microorganisms
  • Parasites
  • Viruses
  • Harmful chemicals
  • Tumor cells

35

What are the 3 types of innate or nonspecific resistance?

- Mechanical mechanisms, which prevent entry or remove microbes (epidermis and mucous membranes)

- Chemical mediators which promote cell lyses, phagocytocis and inflammation

- Cells: involved in phagocytosis and production of chemicals

36

Where are the mechanical mechanisms of innate immune mechanisms found?

skin

tears

saliva

mucous membranes

mucus

37

Which are the chemical mediators of innate immune mechanisms?

Acid

Lysozymes

Complement

Inteferons (prevent viral replication)

Prostaglandins & leukotrienes

Pyrogens

Others

38

Which are the cells involved in innate immune?

  • White blood cells via chemotaxis and phagocytosis
  • Neutrophils - phagocytic and first cells to enter infected tissue
  • Macrophages
  • Basophils and mast cells (promote inflammation)
  • Eosinophils (Modify inflammation response, attack parasitic worms)
  • NK cells (lyse tumor and virus infected cells)

39

What is the complement?

A group of 20 proteins that circulate in the blood. They become activeated in cascade form by antibodies or an alternate pathway. They insert into the plasma membrane of the attacked cell causing lysis.

40

What is meant by specificity in an adaptive or specific immunity?

The ability of immune ceslls to recognize and generate a response agains a particular substance (pathogen or antigen)

41

What is meant by Memory in adaptive or specific immunity?

The ability to remember previous encounters with a particular substance and response rapidly during later exposure to the substance

42

Which are the 2 types of adaptive or specific immunity?

Cell-Mediated Immunity

and

Humoral Immunity

43

What stimulates adaptive immunity?

Antigens: Foreign (not produced by the body) and Self-Antigens (normal body components)

Haptens: small molecules that combine with other molecules to produce an immune response

44

Which cells are responsible for humoral or antibody mediated adaptive immunity?

B cells

45

Which cellls mediate cell-mediated adaptive immunity?

Cytotoxic T cells (TCR+, CD8+)

46

What are primary lymphatic organs?

Where lymphocytes mature into functional cells (red bone marrow, thymus)

47

What are secondary lymphatic organs?

Where lymphocytes produce an immune response

48

What is the B-Cell maturation flowchart?

Stem cells -> (in bone marrow) Pro-B cells (lg-) -> (gene rearrangement) Pre-B cells (lg-) -> Immature B cells (igM+ igD-) -> (light chain rearrangement) Mature B cells (igM+ igD+) -> (selection & migration to lymphoid tissue) Mature B cells (igM+ igD+)

49

Why do immunoglobin genes in B-lymphocytes undergo mutation and rearrangements as the cell matures?

It allows production of antibodies with higher affinity for the antigen

50

What is an antigen?

A molecule that binds to the antigen binding site of an antibody, B cell, or T cell

51

What are mature antibody producing cells called?

Plasma cells

52

What protein is produced by B lymphocytes?

Immunoglobulin

53

What do B lymphocytes become?

B lymphocyte -> Plasma cell -> Antibody

54

What is the Fab or Fab2 fragment of the lg molecule used for?

To avoid the activities of the Fc region (compliment activation, etc)

55

What is produced when the lg gene is fused with the gene of another protein?

A unique fusion protein

56

Which are the actions of antibodies?

  • Antigen inactivation
  • Antigen aggregation
  • Complement activation
  • Inflammatory cell activation
  • Opsonization - enhances phagocytosis

57

Where are Class I MHC molecules found?

On the surface of all nucleated cells

58

What are cells that display foreign antigens on their Class I MHC destroyed by?

Cytotoxic T cells (CD8)

59

What are cells without Class I MHC destroyed by?

NK cells

60

Name the parts of the lymphatic system

  • Lymphatic capillaries (become lymphatic vessels)
  • Lymphatic nodes
  • Lymphatic trunks
  • Lymphatic ducts