Lymphatics

Question 0

Postcapillary venule location

Answer 0

deep cortex of lymph node

Question 1

Postcapillary venules

Answer 1

allow lymphocytes to leave blood stream and re-enter lymph node

Question 2

postcapillary venule endothelium

Answer 2

“high” or tall endothelium

Question 3

Blood supply of lymph node

Answer 3

enters/leaves at hilus. vessels use trabeculae for distribution & eventually enter parenchyma of node

Question 4

Pig Lymph nodes

Answer 4

reversal of cortex & medulla

Question 5

Birds & lymph nodes

Answer 5

birds do NOT have lymph nodes

Question 6

Hemal Node location

Answer 6

widely distributed in ruminants & pigs

Question 7

Hemal Node Microscopically

Answer 7

• has nodules throughout, blood, and a capsule.

- does NOT have cortex/medulla, epithelium.

Question 8

Tonsil types

Answer 8

Palantine, Pharyngeal, Lingual

Question 9

Palantine & Lingual Tonsil characteristic feature

Answer 9

nonkeratinized stratified squamous epithelium

Question 10

Pharengeal Tonsil Characteristic Feature

Answer 10

ciliated pseudostratified columnar epithelium

Question 11

Tonsilar Crypts

Answer 11

• invaginations of epithelium & LP into substance of tonsil

- not ALL tonsils have them

Question 12

Tonsil Stromal Elements

Answer 12

Capsule (incomplete CCT at base w/o epithelium)

Septa (strands of CCT inwards from capsule, can connect to LP [has reticular ct. and CCT])

Question 13

Reticular CT in tonils

Answer 13

throughout tonsil as part of stroma

Question 14

Thymus locations

Answer 14

thoracic to cranial depending on species

Question 15

Thymus microscopic appearance

Answer 15

• lobules each with cortex & medulla continuous across them
• thymic corpuscles
• capsule
• no lymph nodules

Question 16

Thymic Corpuscles

Answer 16

• made of degenerating Epithelial-Reticular Cells
• only in medulla
• may aid in t-cell differentiation

Question 17

Epithelial-reticular cells job

Answer 17

help isolate t-cells from medulla and rest of body

Question 18

Blood-Thymus Barrier

Answer 18

• located only in cortex

- separates t-cells from blood to protect them from Ag while they’re maturing.

Question 19

Components of Blood-Thymus Barrier

Answer 19

1. Endothelial Cell
2. Endothelial Cell Basal Lamina
3. Some Ct & macrophages
4. Epithelial-Reticular Cell Basal Lamina
5. Epithelial-Reticular Cell Cytoplasm

Question 20

Thymus Funtions

Answer 20

1. Development & proliferation of T-cells
2. Populates other organs with T-cells
3. Humoral Factors made here

Question 21

Effects of Thymectomy

Answer 21

depends on animal’s age.

-young = compromised adaptive immunity

Question 22

Thymus does NOT

Answer 22

filter lymph or blood

Question 23

Spleen

Answer 23

largest lymphoid organ

Question 24

Spleen's job

Answer 24

filters blood

Question 25

Spleen's microscopic appearance

Answer 25

- lymph nodules throughout, blood in red pulp, contains nodular arterioles. - NO cortex/medulla, or epithelium

Question 26

Spleen stroma

Answer 26

Capsule: thick with smooth muscle. Trabeculae Reticular CT throughout spleen

Question 27

White Pulp

Answer 27

- splenic nodules - B-cells in secondary nodules - PALS - nodular arterioles

Question 28

PALS

Answer 28

Periarterial Sheaths of Lymphocytes

Question 29

PALS contain

Answer 29

T-cells

Question 30

PALS do this..

Answer 30

interconnect nodules (b-cells)

Question 31

Red Pulp

Answer 31

most of parenchyma of spleen

Question 32

Red Pulp contains.

Answer 32

``` splenic sinusoids (endothelium) splenic cords ```

Question 33

splenic sinusoid

Answer 33

special type of capillary | can't see them when there's blood in the spleen

Question 34

splenic cord

Answer 34

between sinusoids & contains all elements of circulating blood

Question 35

Spleen's blood supply

Answer 35

splenic a. -> trabecular aa. -> central aa. -> penicillar aa. ->splenic sinusoids -> pulp vv. -> trabecular vv. -> cranial mesenteric v. -> portal v.

Question 36

Spleen functions

Answer 36

- early hematocytopoietic - blood filtration - blood storage (RBCs & platelets) - small role in immunity

Question 37

Cloacal Bursa

Answer 37

in birds only

Question 38

ID features of Cloacal Bursa

Answer 38

simple columnar or pseudostratified columnar epithelium | smooth mm. on outer wall

Question 39

Cloacal Bursa Microscopic features

Answer 39

simple columnar or pseudostratified columnar epithelium, LP of CCT, elongated lymph follicles, cortex/medulla per follicle, smooth mm. in outer wall

Question 40

Cloacal Bursa Function

Answer 40

B-cell proliferation & differentiation site in BIRDS

Question 41

Peyer's Patches

Answer 41

aggregations of lymph nodules in lower S.I., cecum, ascending colon

Question 42

Deep Cortex/Paracortical Zone of Lymph Nodes

Answer 42

contains T-cells & postcapillary venules where lymphocytes leave blood stream to re-enter lymph nodes

Question 43

Lymph node medulla's characteristic arrangement

Answer 43

trabeculae-sinus-cord

Question 44

Medullary cords

Answer 44

irregular columns of lymphatic tissue separated by lymph sinuses

Question 45

Lymph node capsule

Answer 45

fibromuscular with CCT & small bit of smooth mm.

Question 46

General Functions of Lymphatic System

Answer 46

- filtration of lymph/blood | - immunity

Question 47

What makes up sheathed arterioles in the spleen?

Answer 47

reticular cells & macrophages

Question 48

What tissue type predominates in sheep/ruminant spleens?

Answer 48

smooth m.

Question 49

In the thymus, what accounts for the difference in staining affinity between cortex & medulla?

Answer 49

the medulla has lower cell density & has more ER cells present. the cortex has higher cell density

Question 50

What is the mammalian functional equivalent to the cloacal bursa?

Answer 50

bone marrow