Histology: Thymus & Peripheral Lymphoid System (8.1)

Question 1

Lymphocytes:

Answer 1

B & T cells

Question 2

Lymphocytes are formed in:

Answer 2

primary lymphoid organs

Question 3

Primary lymphoid organs (2):

Answer 3

thymus & bone marrow

Question 4

Naive mature lymphocytes are activated in:

Answer 4

secondary lymphoid organs & tissues

Question 5

Secondary lymphoid organs (3):

Answer 5

lymph nodes, spleen, MALT

Question 6

MALT:

Answer 6

TIPU (tonsils, Intestine/Peyer’s patches/appendix, Pulmonary/bronchiolar, Urinary/reproductive tract

Question 7

Lymphocytes are derived from:

Answer 7

hematopoietic stem cell (HSC)

Question 8

Dense packing of immature T cells (thymocytes):

Answer 8

cortex of thymus

Question 9

Does not stain as intensely because there are fewer thymocytes and more framework or stromal cells:

Answer 9

central medullary

Question 10

Intense eosinophilic structures in medulla of thymus:

Answer 10

Hassal’s bodies/corpuscles (collections of epithelial cells)

Question 11

Thymus changes with age:

Answer 11

thymic involution

Question 12

Chromosomal deletion disorder (chromosome 22q11.2 deletion syndrome) that results in poor development of several body systems, including thymic aplasia (a congenital absence of the thymus):

Answer 12

DiGeorge syndrome

Question 13

DiGeorge syndrome is a type of:

Answer 13

severe combined immunodeficiency (SCID)

Question 14

DiGeorge syndrome (a SCID) is often but not always characterized by:

Answer 14

cellular (T-cell) deficiency

Question 15

Flow lymphatic system:

Answer 15

lymph capillary —> lymph node —> lymph trunk —> lymph duct

Question 16

Injured or blocked lymphatic systems results in:

Answer 16

lymphedema

Question 17

Environment where T and B cells encounter antigen:

Answer 17

lymph nodes

Question 18

Site of plasma cell differentiation and antibody production:

Answer 18

lymph nodes

Question 19

Most abundant location of lymph nodes:

Answer 19

axilla, groin (inguinal), along major vessels (neck, thorax, abdomen)

Question 20

Lymph node structure:

Answer 20

dense connective tissue capsule

Question 21

Afferent lymphatics enters on ___ side of lymph node:

Answer 21

convex

Question 22

Efferent lymphatics enters on ___ side of lymph node:

Answer 22

concave

Question 23

___ fibers in cortex serve as scaffolding and create niche for cells carry out their function:

Answer 23

reticular (type III collagen), stained with silver

Question 24

B cell zone/follicle of lymph nodes:

Answer 24

cortex (outer)

Question 25

T cell zone of lymph nodes:

Answer 25

paracortex (middle)

Question 26

Cords and sinuses of lymph nodes:

Answer 26

medulla (inner)

Question 27

Entry point for most lymphocytes into lymph nodes:

Answer 27

HEV (paracortex)

Question 28

Antigen activated B cells within the follicle start dividing (proliferating) and elicit a ___ reaction:

Answer 28

germinal center

Question 29

After germinal center reaction, follicle is now:

Answer 29

secondary follicle

Question 30

Contains antigen activated, proliferating  B cells that can differentiate to plasma cells or memory B cells:

Answer 30

lighter staining center of secondary follicle

Question 31

Assist B cell maturation in the germinal center:

Answer 31

T helper cells

Question 32

B and T cells that haven’t encountered their antigen are pushed to:

Answer 32

mantel zone (periphery)

Question 33

Highly proliferative B cells (plus their CD4+ T helper cells) that are undergoing somatic hypermutation:

Answer 33

Dark zone of germinal center

Question 34

B cells that have undergone somatic hypermutation to test their receptor binding and competition for interaction with antigen specific T cells:

Answer 34

light zone of germinal center

Question 35

Plasma cells leave the germinal center and migrate to:

Answer 35

medullary cord or bone marrow

Question 36

___ may remain in lymph node or recirculate:

Answer 36

Memory B cells

Question 37

Contains most of body’s lymphocytes:

Answer 37

GALT (gut associated)

Question 38

Tonsils covered with stratified squamous epithelium:

Answer 38

lingual, palatine

Question 39

Tonsils covered with pseudostratified columnar ciliated epithelium:

Answer 39

pharyngeal

Question 40

Covered by simple columnar epithelium with M cells:

Answer 40

Peyer patches

Question 41

Diffuse lymphoid tissue of lung:

Answer 41

BALT

Question 42

Largest single accumulation of lymphocytes:

Answer 42

spleen

Question 43

Organ responsible for defense against blood-borne antigens:

Answer 43

spleen

Question 44

Critical for removal of encapulated bacteria:

Answer 44

spleen

Question 45

Removal of senescent erythrocytes:

Answer 45

spleen

Question 46

Storage of platelets:

Answer 46

spleen

Question 47

Red pulp of spleen is responsible for:

Answer 47

blood filtration

Question 48

White pulp of spleen is responsible for:

Answer 48

immune responses

Question 49

Splenic cords and splenic sinusoids are location in:

Answer 49

red pulp of spleen

Question 50

Decline of immunity in elderly due to:

Answer 50

reducing size of thymus (and thus maturation of T cells)

Question 51

Blocks infections and eliminates extracellular microbes:

Answer 51

humoral immunity (adaptive)

Question 52

Elimination of phagocytose microbes:

Answer 52

cell-mediated immunity (adaptive)


Question 53

Kill infected cells and eliminated reservoirs of infection:

Answer 53

cell-mediated immunity (adaptive)

Question 54

B-lymphocytes are part of ___ immunity (adaptive):

Answer 54

humoral

Question 55

T-lymphocytes are part of ___ immunity (adaptive):

Answer 55

cell-mediated

Question 56

T-cells primarily make up this white pulp structure in the spleen:

Answer 56

PALS (Periarteriolar lymphoid sheath)

Question 57

Endothelial cells in splenic sinusoids:

Answer 57

stave

Question 58

Abbreviated name for lymphoid tissue found in and near the wall of the intestinal tract:

Answer 58

GALT

Question 59

Tonsils are covered by:

Answer 59

epithelium

Question 60

All leukocytes are derived from:

Answer 60

hematopoietic stem cell

Question 61

Medullary sinus in a lymph node drains into:

Answer 61

efferent lymph vessel

Question 62

Resident monocyte becomes ___ after it migrates to tissue:

Answer 62

macrophage

Question 63

Lymphatic organ that initiates an immune response to lymph-borne antigens:

Answer 63

lymph node

Question 64

Cells that form intracellular pocket to allow antigen from gut lumen to enter lymphatic system:

Answer 64

microfold

Question 65

Lymphatic tissue found on the back wall of the nasopharynx:

Answer 65

adenoid

Question 66

Dome-like aggregates of lymphocytes make up prominent gut mucosa associated lymphoid tissues:

Answer 66

Peyer’s patches

Question 67

Reticular fibers are made of:

Answer 67

Collagen

Question 68

Encapsulated, primary lymphatic organ:

Answer 68

thymus

Question 69

Medullary cords in lymph nodes are formed by T, B, and ___ cells:

Answer 69

plasma