Hemolymphatics

Question 1

List Reasons for small lymph nodes.

Answer 1

1. Developmental disorders
2. lack of antigenic stimulation
3. Cachexia/malnutrition
4. Aging/senile atrophy
5. Viral infections

Question 2

Reasons for small lymph nodes: Developmental Disorders

Answer 2

SCID - Severe Compromised Immune Deficiency

Question 3

Reasons for small lymph nodes: Lack of antigenic stimulation

Answer 3

Specific pathogen-free animals

Poorly developed

Question 4

Reasons for small lymph nodes: Cachexia/malnutrition

Answer 4

Mainly decreases in production of T-lymphocytes

Question 5

Reasons for small lymph nodes: Aging/Senile atrophy

Answer 5

generalized depression of immune system with age –> loss of lymphocytes –> lymph node atrophy

Question 6

Reasons for small lymph nodes: Viral Infections

Answer 6

• Destruction of lymphoid tissue
• BVDV
• Canine Distemper Virus

Question 7

List reasons for LARGE lymph nodes.

Answer 7

1. Lymphoid Hyperplasia (normal elargement)
2. Lymphadenitis
3. Neoplasia

Question 8

Reasons for LARGE lymph nodes: Lypmhoid hyperplasia

Answer 8

GENERALIZED: Systemic Inflammatory Disease (Bastard Strangles)
LOCALIZED: Draining regional inflammation; Normal enlargement due to antigenic stimulation of lymph nodes

Question 9

Generalized LN hyperplasia vs. Neoplasia

Answer 9

Hyperplasia: MOTTLED appearance; retention of cortical and medullary architecture; PAINful on palpation

Neoplasia: LOSS of normal architecture; Homogenous white-tan; NON-painful on palpation

Question 10

Why do 15% of dogs with Lymphoma present with Hypercalcemia?

Answer 10

neoplastic lymphocytes secrete analog of PTH (PTHrp)

Question 11

Splenosis

Answer 11

usually secondary to TRAUMATIC RUPTURE:

seeding omentum with multiple lymphoid structures

Question 12

Siderotic plaques

Answer 12

Common in older dogs
IMPORTANT, COMMON, RECOGNIZE!!
Margin of the spleen; Raised white/tan placques
Iron accumulation from previous rupture and healing

Question 13

List reasons for a SMALL spleen.

Answer 13

1. Developmental disorders.
2. Cachexia/malnutrition
3. Aging/senile atrophy
4. Splenic contraction

Question 14

Reason for SMALL spleen: Developmental disorders

Answer 14

Immunodeficiency (SCID)

Question 15

Reason for SMALL spleen: Cachexia/malnutrition

Answer 15

Mainly decreases production of T lymphocyte

Question 16

Reason for SMALL spleen: Aging/senile atrophy

Answer 16

generalized depression of immune system –> loss of lymphocyte –> splenic lymphoid atrophy

Question 17

Reason for SMALL spleen: Splenic contraction

Answer 17

contraction of smooth muscle:

• SNS: “fight or flight”
• Heart failure
• Shock

Question 18

List reasons for a LARGE spleen.

Answer 18

Diffuse:
- Congestion (Bloody Spleen)
- Cellular Infiltration (Meaty Spleen)
Multi-focal

Question 19

Reason for LARGE spleen: Diffuse/Congestion

Answer 19

Barbituates (most common) GUN METAL BLUE
Acute Septicemia (Anthrax and Salmanellosis)

Question 20

Reason for LARGE spleen: Cellular Infiltration/Meaty Spleen

Answer 20

MØ hyperplasia:

• Hemolytic anemia
• Chronic infectious diseases

Neoplasia:

• Lymphoma
• Leukemia

Stored deposits of material:

• Amyloidosis - firm, waxy appearance
• lysozomal storage disease

Question 21

What concentration of bilirubin in the body yields ICTERUS?

Answer 21

2 and higher

Question 22

What species have HEMAL NODES?

Answer 22

RUMINANTS!! > horses > primates

NORMAL FINDING!!

Question 23

What are hemal nodes?

Answer 23

Lymph nodes filled/engorged with RBCs; Normal component of the hemolymphatic system

Normal finding on RUMINANTS > horses > primates

Usually on fascia or omentum

Question 24

Causes of THYMIC ATROPHY

Answer 24

Infectious agents (viruses)
Toxins
Chemotherapeutic agents
Ionizing radiation
Cachexia/malnutrition
Aging

Question 25

Thymic Neoplasia: Thymoma vs. Thymic lymphoma

Answer 25

Thymoma:

• BENIGN
• Epithelial neoplasia
• Dogs with myasthenia gravis or Megaesophagus

Thymic Lymphoma:

• Cats, Cattle > dogs
• YOUNG cattle
• main issue: SPACE OCCUPYING
• T-cell lymphoma

Question 26

Types of Hemolytic Anemia.

Answer 26

Extravascular:
- SPLEEN > liver, bone marrow
Intravascular:
- hemoglobinemia
- hemoglobinuria

Question 27

Spherocytosis

Answer 27

partial phagocytosis of RBC by MØ