lecture 16

Question 1

Responses of lymph nodes to injury

• atrophy
• hyperplasia
• inflammation

Answer 1

response of lymph nodes to injury
-atrophy; toxins, drugs, viruses, radiation, malnutrition
its a failure to replenish lymphocytes from the bone marrow
-hyperplasia
Lymphoid tissue (immun system)
in response to antigenic stimulation, ab production (B cells) and cell mediated immunity (T cell)
Cells of monocyte- macrophage system, also part of the 1st line of defence against noxious agent, sinus macrophage replicate and increase no. and additional monocytes and neutrophils arrive in the blood
-Inflammation; acute micro abscesses and abscess formation
chronic; abscesses, granulomas and fibrosis

Question 2

List the reasons for small lymph nodes (3)

Answer 2

responses for small lymph nodes 
-congenital disorders
primary immunodeficiency disease eg. LN hypoplasia 
-lack of antigenic stimulation 
eg. specific pathogen free animals
e.g small popliteal LN in neonates 
-atrophy 
toxins, drugs radiation, viral infections, malnutrition/cachexia

Question 3

What is Lymphadenopathy and what causes

Answer 3

Lymphadenopathy (large lymph node) causes

• hyperplasia
• lymphadenititis
• Neoplasia

Question 4

Explain hyperplasia for lymphadenopathy

Answer 4

Lymphadenopathy; hyperplasia
types
-Lymphoid hyperplasia
-monocyte-macrophage hyperplasia
occurs as a response of antigenic stimulation
its a reactive lymph node
B cells will proliferate and become plasma cells which produce ab and they will migrate to the cortex

Question 5

Explain lymphadenitis for lymphadenopathy

Answer 5

Lymphadenopathy; lymphadenitis 
acute or chronic of inflammation of LN 
can be primary or secondary
inflammation of lymph node 
acute lymphadenitis usually to drainage from inflammatory lesion @ distant site egg mammary LN drain gin mastitis

Question 6

Explain Neoplasia or lymphadenopathy

Answer 6

Neoplasia

can be primary or secondary

Question 7

Explain what acute suppurative lymphadenitis is

Answer 7

Acute suppurative lymphadenitis
caused by progeny bacteria like strangles in horses
lots of neutrophils followed by macrophages
may rupture

Question 8

List the types of chronic lymphadenitis

Answer 8

Chronic lymphadenitis can be chronic suppurative, granulomatous (focal or diffuse) or mixed (micro abscess plus fibrosis)

Question 9

For Chronic suppurative lymphadenitis discuss morphology

• usually hosts
• when it occurs
• what is causes

Answer 9

Chronic suppurative lymphadenitis
caseous lymphadenitis (cheesy gland)
present in sheeps and goats
follows wound infection, draining to regional LN
can become encapsulated
-chronic lesions can have onion skin (necrosis and encapsulation)
causes ulcerative lymphangitis

Question 10

For Chronic focal granulomatous lymphadenitis state
where it go to and where it ends up
what does it cause

Answer 10

Chronic focal granulomatous lymphadenitis
starts in regional of lymph nodes and can disseminate throughout the whole body
cause multiple caveating granulomas
-coalesce occupy the whole LN
central areas of necrosis surrounded by large macrophages and langhan’s giant cells

Question 11

For lymphadenopathy discuss neoplasia

Answer 11

lymphadenopathy discuss neoplasia 
primary or secondary (metastatic)
both appear grossly similar 
architecture can be obliterated by neoplastic cells 
can have a cut surface, plan, bulgy 
primary tumour is very common eg lymphoma 
secondary tumours; 
-carcinomas 
-malignant melanoma 
-mast cell tumour