Objectives:

I. Immune system

Be able to identify (based on morphology and organ location) the various cells of the immune system:

1. B-lymphocytes (plasma cells)

2. T-lymphocytes (T-helper; T-cytotoxic; Natural Killer cells)

3. Macrophages

4. Others (Dendritic cells, Neutrophil, Mast cell

II. Thymus

A. Be able to recognize the anatomical features of the thymus:

B. Describe pattern of blood flow within the thymus from the corticomedullary arteries through the cortex and medulla and back to the corticomedullary veins.

C. Define the relationship of the thymus to lymphocytes that originate in bone marrow and to lymphocytes which populate lymph nodes and unencapsulated lymphatic tissue.

III. GALT and MALT

A. Identify non-encapsulated aggregates of lymphatic tissues (e.g., Peyer's patches, palatine and nasopharyngeal tonsils) present in the mammalian body.

B. Correlate the function of tonsils with their location in the body.

IV. Lymph node

A. Describe the architecture of a lymph node in the following terms: cortex, medulla, capsule, trabeculae, and reticular connective tissue.

B. Describe the flow of lymph through a lymph node from afferent lymph vessels to the efferent lymph vessel incorporating structures such as the subcapsular sinus, cortical lymph sinusoid, and medullary lymph sinusoids.

C. Define the lymph (lymphatic) nodule and germinal center (identify these structures on your slides).

D. Describe the route of recirculation of lymphocytes from blood to lymph within the lymph node.

V. Spleen

A. Describe the cellular and fibrous connective tissue elements present in the capsule and trabeculae of the spleen.

B. Describe the morphologic and functional differences between red and white pulp.

C. Identify the following vascular components of the spleen and explain the route of blood flow through the spleen:

1. splenic artery

2. trabecular artery

3. artery (arteriole) of the white pulp

4. Artery of the red pulp (a.k.a. pulp arteriole)

5. sheathed capillaries

6. splenic (venous) sinuses or venules

7. trabecular vein

8. splenic vein

Slides:

#73            Bovine hyoid bone

#79            Thymus

#76            Palatine tonsil

#80            Nasopharyngeal tonsil

#74            Lymph node

#29            lymph Node - Silver stain

#75            Mesenteric node

#77            Spleen