Lymphatics Flashcards
what are the primary lymph organs
o Thymus (sits inferior to butterfly shaped thyroid gland) o Bone marrow
what are primary lymph organs
• Organs where immature lymphocytes acquire the receptors to recognise antigens
2 parts of the thymus
cortex + medulla
describe the thyme cortex
• Cortex of thymus pack with immature and maturing T cells (thymocytes)
• Approx same size as erythrocyte
o But has nucleus, granular
describe the thyme medulla
form groups of keratinised epithelial cells and have debris fragments in lumen
difference of thymus corposucles from blood vessels
- Dark pink stain of keretinsed squamous
* Different items inside lumen= not erythrocytes
what occurs in bone marrow
- Home of lymphocyte stem cells
* Site of B lymphocyte maturation
how is a bone marrow smear different to blood smear
- Size of RBC
- Lots of Leukocytes
- Some mature RBC (ejected nucleus)
- Large cell > megakaryocyte (produce thrombo)
- Most cells are developing granulocytes and developing erythrocytes.
- Also present are anucleated mature erythrocytes
what are secondary lymphoid organs
• Organs where lymphocytes are activated in response to antigens
what are the secondary lymphoid organs
• Lymph nodes
o Ilium > cecum= ileocecal valve = size change > slows chyme waiting to go into LI
• Spleen
• Mucosa-associated lymphoid tissues (MALT) in tonsils and intestine
what re the palpable lymph nodes
- superficial inguinal nodes
* Deep cervical lymph nodes surrounding the internal jugular vein.
histological structure of lymph node
• Adipose surrounding (white)
• Thick capsule surrounding
• White sub captual sinus (blood comes in)
• Slightly active as have secondary folicules
Group of lymphs already tagged antigen and replicating
features of medullar sinus (lymphatic channels)
- Lack erythrocytes
- Large lumen
- Valve
- No clear periocytes, no basement membrane
- Something inside staining pink = lymph fluid
where is spleen located
left hypochondirum
blood vessels in and out of spleen
- Great blood supply from splenic artery
* Splenic vein drains splenic blood to liver.
role of spleen
- Produces immunological responses against blood-borne antigens.
- Removes particulate matter and aged/defective blood cells, particularly erythrocytes.
- Recycles iron to the bone marrow.
- Haematopoiesis in normal fetus and diseased adults.
how to find spleen
- Pancreas points to spleen
- Spleen vein leads to liver
- Confuse with kidneys (k=retroperitreneal + often covered in fat)
• X ray, deep near ribs, next to right kidney
what is the red and white pulp in spleen
- Lymphoid tissue= white pulp
- Red pulp= reticulin fibres & capillaries
White pulp looks purple on micrograph (as full of lymphocytes)
why is there a gap on top of slpleen
where artery and vein is
describe activated lymph
Dark ring (mantle zone= b cells) with lighter centre (germinal centre= b cell activation, expansion)
what are PALS
Pariarteriolar Lymphoid Sheath
• Arteriolessurrounded with large numbers of lymphocytes and macro
• Heavy density
• = first line of defense as what seeps outs arteriole attacksby dense
TYPES OF malt (Mucosal associated lymphoid tissue )
tonsils, •
GALT= Aggregated lymphoid nodules of ileum + Aggregated lymphoid nodules of appendix
difference of spleen and tonsil
o Lot of lymphocytes (purple)= angry secondary follicles
o Little blood
o Different shape
• Clefts allows entry and trap > attack
ilium vs appedix
• Entire lumen covered in lymphoid tissue (different to ilium)
How are we exposed to pathogens (link to lymph sites)
MALT
Inhaling (// tonsils at tongue + oral cavity)
• Digestion (GALT ilium + appendix)
