lymph

Question 1

Describe the flow of lymph

Answer 1

Lymphatic capillaries –> lymphatic vessels –> thoracic duct –> left subclavian vein
Right lymphatic duct –> right subclavian vein

Question 2

Name the primary lymphoid tissues

Answer 2

B cells:
Bone marrow, Bursa of Fabricius (birds), Peyer’s patches (ruminants)
T cells:
Thymus

Question 3

Name the secondary lymphoid tissues

Answer 3

Lymph nodes, spleen, MALT & Peyer’s patches

Question 4

Describe structure of lymphatic capillaries

Answer 4

Small & thin walled
Single layer of epithelial cells
Valves to prevent backflow

Question 5

Describe structure of lymphatic vessels

Answer 5

Tunica intima (inner endothelial layer)
Tunica media (middle layer of smooth muscle)
Tunica externa (outer layer of connective tissue)
Valves to prevent backflow

Question 6

Describe structure of chyle cistern

Answer 6

Sac-like structure in abdominal cavity
Collection point for lymph

Question 7

Describe structure of Thoracic duct

Answer 7

Largest lymphatic vessel
Begins at chyle cistern & runs upwards into left subclavian vein
Collects lymph from left side of head, neck, thorax, left upper limb & entire lower body

Question 8

Describe structure of right lymphatic duct

Answer 8

Smaller duct
Drains lymph from right side of head, neck & thorax & right upper limb
Empties into right subclavian vein

Question 9

What are the functions of the lymphatic system

Answer 9

Fluid balance, transportation of fats & immune defence