Lymphatic Organs

Question	Answer
Location of the thymus	Just above the heart
Gross structure of thymus	2 lobes
2 Main Areas of Thymus	Cortex & medulla
Location of Positive Selection	Cortico-Medullary Junction
Positive Selection	Cortical Epithelial cells select T-Cell that can bind to them
Effect of cortex on T-cells	Lose B cell function and gain CD4 & 8 markers
T-cell specialisation	They lose either CD4/CD8 markers
Purpose of Negative Slection	Prevent autoimmune disorders
Negative Selection	T-cells with high affinity for cortico-medullary junction cells are destroyed
Thymus defects	Cause autoimmune disorders
Location of Spleen	Left of abdomen
White pulp of spleen	Lymphocytes/immune surveillance
Red pulp of Spleen	Destruction of aged erythrocytes
Detection of aged erythrocytes	Aged R.B.C's are inflexible and cannot pass through microcapillaric system
Debris and pathogens in spleen	Removed by microphages
Only Lymphatic Tissue	Lymphatic Nodules (NOT NODES)
Lymphatic Tissue	Not surrounded by capsule
Lymphatic Nodules- Mouth	Tonsils
Lymphatic Nodules- Intestines	Appendix
Lymphatic Nodules- Respiratory Tract	Mucosa associated lymphatic tissue
Cells contained by lymphatic nodules	B-cells

Resource summary

	Created by gina_evans0312 about 11 years ago