Lymphoid Tissue

Question 1

Immunity

Innate immune system

Answer 1

Retains phagocytic system which can defend without memory

Question 2

Innate immunity

Barriers against invasion

Answer 2

Skin, mucose, stomach acid, antibacterial agents etc

Question 3

Adaptive Immunity

Reaction

Answer 3

Slower, but flexible and specific.

Question 4

Lymphoid Organs

Primary lymphoid organs

Answer 4

Where lymphocytes are produced and matured - bone marrow and thymus.

Question 5

Lymphocyte types

B Lymphocytes

Answer 5

Produce antibodies

Question 6

Lymphocyte development and fate

Produced

Answer 6

Stem cells in bone marrow

Question 7

Thymus

Size changes

Answer 7

Increases from birth to puberty and then regresses to almost nothing

Question 8

Thymus

Answer 8

Question 9

T Cells in the Thymus

2% Surviving cortex

Answer 9

Enter medulla and presented with “self” antigens.

Question 10

T Cells

Answer 10

Question 11

Lymphatic System Provides for:

Drainage

Answer 11

Of lymph into vascular system

Question 12

Lymph vessels

Answer 12

Question 13

Lymph Nodes

What are they?

Found where?

Answer 13

Encapsulated, highly organised structures interposed along larger lymph vessels

Found in clusters in areas such as the neck, axillae and groin

Question 14

What is this?

Answer 14

Lymph node

Question 15

Secondary Lymphoid Organs

Secondary follicles

Paracortical region of a lymph node

Answer 15

Have germinal centre which stains less intensely.

Populated by T cells. Notice unual lining of high endothelial vessels (V) in this region

Question 16

MALT

Answer 16

Represents a substantial amount of lymphoid tissue within the body

Question 17

What is this?

Answer 17

Section throguh the palatine tonsil (MALT)

Question 18

What is this?

Answer 18

Peyers patch. Aggregations of lympoid tissue found associated with the mucosa in the small intestine. Germinal centre in this case. (MALT/GALT)

Question 19

Spleen

Functions

Answer 19

Prodcues an immune response against blood-bourne antigens Removes particulate matter and old blood cellsProduces blood cells during foetal life.

Question 20

Spleen

White pulp

Red pulp

Answer 20

Made up of either T cells or B cells.

Mostly blood filled capillaries which are open, with discontinuous endothelium and sinuses.

Question 21

What is this?

Answer 21

Spleen

Question 22

Spleen

Alternative types of white pulp

Answer 22

Question 23

Red Pulp of the Spleen

Answer 23

Question 24

Vasculature of the Spleen

Red blood cells

Answer 24

Must leave through capillaries, passing through the parenchyma, finding their way back into venous sinuses through small spaces.

Question 25

**_Immunity_** Adaptive immune system

Answer 25

Based on presence of trillions of lymphocytes

Question 26

**_Innate immunity_** Phagocytes

Answer 26

Macrophages and neutrophils

Question 27

**_Innate immunity_** Complement

Answer 27

Cascade of plasma proteins that forms an enzyme system defending against bacteria

Question 28

**_Innate immunity_** Extracellular killers

Answer 28

Natural killer lymphocyes and eosinophils

Question 29

**_Adaptive Immunity_** Major role

Answer 29

Destruction

Question 30

**_Adaptive Immunity_** Autoimmune disease

Answer 30

Can be caused if the system fails to distinguish self from non-self.

Question 31

**_Lymphoid Organs_** Secondary lymphoid organs

Answer 31

Sites where lymphocytes migrate to and aggregate in large numbers. Spleen, lymph nodes and lymph nodules found assiciated with epithelia in GI tract, respiratory tract and skin.

Question 32

**_Lymphocyte types_** T Lymphocytes

Answer 32

Participate in cellular immunity and found in three types at least

Question 33

**_Lymphocyte types_** Natural Killer cells

Answer 33

Kill virus infected cells and some tumour cells.

Question 34

**_Lymphocyte development and fate_** B cells

Answer 34

Remain in marrow to continue development (most eliminated)

Question 35

**_Lymphocyte development and fate_** T Cells

Answer 35

Migrate to thymus to be educated (most eiliminated)

Question 36

**_Lymphocyte development and fate_** Fate

Answer 36

Secondary lymphoid organs, transferring between these via the bloodstream.

Question 37

**_Thymus_** Lobes

Answer 37

Two lobes, each divided into lobules by septa. These septa have a lot of epithelial cells which is odd.

Question 38

**_T Cells in the Thymus_** Any activated cells

Answer 38

Destroyed.

Question 39

**_T Cells in the Thymus_** Successful cells

Answer 39

Enter blood vessels

Question 40

**_T Cells in the Thymus_** Hassall's corpuscles

Answer 40

Shown to be source of activation factors

Question 41

**_Lymphatic System Provides for:_** Survaillence

Answer 41

Of tissue for signs of antigens from foreign invaders

Question 42

**_Lymphatic System Provides for:_** Delivery

Answer 42

1. Of absorbed fats from small intestine into vascular system via lymphatic vessels in villi of small intestine (lacteals)

Question 43

**_Vasculature of the Spleen_** Old cells

Answer 43

Cannot deform and will lyse and be phagocytosed by macrophages associated with the wall of the sinuses