Thymus And Lymph Node

Question 1

What is the Thymus?

Answer 1

This is an organ responsible for the production and maturation of immune cells.

Question 2

Which cells make up the main component of the thymus?

Answer 2

T- Lymphocytes

Question 3

What are the other components of the thymus?

Answer 3

3rd pair of pharyngeal pouches, Dense in the cortex, Loose in the medulla- Hassall corpuscles.

Question 4

What is the overall function of the Thymus?

Answer 4

Development of self tolerance to antigens

Question 5

What is hyperplasia?

Answer 5

This refers to the enlargement of a tissue and or organ due to an increase in cell production.

Question 6

What is agenesis?

Answer 6

The failure of a particular organ or tissue to develop during embryonic growth.

Question 7

What is Hypoplasia?

Answer 7

The incomplete development of an organ/tissue, lack of cell growth.

Question 8

What is Neoplasia?

Answer 8

This is the uncontrolled, abnormal growth of a tissue or cells in the body.

Question 9

What is Atrophy?

Answer 9

Arrested development or loss in matter of cells/ tissues resulting in a decrease in size. Due to degradation.

Question 10

What are the developmental pathologies of the thymus?

Answer 10

Agenesis and Hypoplasia

Question 11

What are the acquired pathologies of the thymus?

Answer 11

Atrophy, Neoplasia and Hyperplasia.

Question 12

Agenesis vis Hypoplasia

Answer 12

Agenesis is the failure of an organ/tissue (absence) to be developed while Hypoplasia refers to the underdevelopment of an organ or tissue.

Question 13

Causes of Thymic Atrophy?

Answer 13

Age, Malnutrition, Stress, Terminal illness, Cytotoxic drugs (cancer drugs)

Question 14

What thymic hyperplasia linked to?

Answer 14

Myasthenia Gravis, Graves’ disease, Addison disease, Lupus, Scleroderma and Rheumatoid Arthritis.

Question 15

What is Myasthenia Gravis?

Answer 15

This is a neuromuscular disorder causing weakness in muscles due to the damage of receptors resulting in defective signal transmission.

Question 16

What are some thymic Neoplasms?

Answer 16

Thymomas (epithelial) , Lymphomas (Lymphoid)

Question 17

What is Lymphadenopathy?

Answer 17

Lymph node enlargement

Question 18

What are some causes of Lymphadenopathy?

Answer 18

Acute and Chronic Reactive Hyperplasia as well as Neoplasia

Question 19

What happens overall in reactive hyperplasia?

Answer 19

Antigen processing by macrophages, activation of resting lymphocytes, morphological changes such as size, cytoplasm etc… secretion of cytokines, recruitment of other cells, elimination of a pathogen.

Question 20

What triggers reactive hyperplasia?

Answer 20

Foreign material, cell debris as well as microbes.

Question 21

Features of Acute reactive hyperplasia?..

Answer 21

It is usually microbial and where there is direct drainage of the infection it can be seen in the tonsils, Inguinal? And Enteric as well as Generalized - Viral infections, Bacteraemia and septicaemia.

Question 22

Effects of Acute Reactive Hyperplasia on a general/gross level?

Answer 22

Painful and tender, on the gross level can be red-grey its capsule is intact with perinodal extension

Question 23

What are the microscopic effects/morphology of the lymph nodes during acute reactive hyperplasia?

Answer 23

Follicular Hyperplasia, Sinusoidal Congestion, Polymorphs something about necrosis unclear.??