Lymphatics

Question 1

what are the primary lymph organs

Answer 1

o	Thymus (sits inferior to butterfly shaped thyroid gland)
o	Bone marrow

Question 2

what are primary lymph organs

Answer 2

• Organs where immature lymphocytes acquire the receptors to recognise antigens

Question 3

2 parts of the thymus

Answer 3

cortex + medulla

Question 4

describe the thyme cortex

Answer 4

• Cortex of thymus pack with immature and maturing T cells (thymocytes)
• Approx same size as erythrocyte
o But has nucleus, granular

Question 5

describe the thyme medulla

Answer 5

form groups of keratinised epithelial cells and have debris fragments in lumen

Question 6

difference of thymus corposucles from blood vessels

Answer 6

• Dark pink stain of keretinsed squamous

* Different items inside lumen= not erythrocytes

Question 7

what occurs in bone marrow

Answer 7

• Home of lymphocyte stem cells

* Site of B lymphocyte maturation

Question 8

how is a bone marrow smear different to blood smear

Answer 8

• 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

Question 9

what are secondary lymphoid organs

Answer 9

• Organs where lymphocytes are activated in response to antigens

Question 10

what are the secondary lymphoid organs

Answer 10

• 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

Question 11

what re the palpable lymph nodes

Answer 11

• superficial inguinal nodes

* Deep cervical lymph nodes surrounding the internal jugular vein.

Question 12

histological structure of lymph node

Answer 12

• 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

Question 13

features of medullar sinus (lymphatic channels)

Answer 13

• Lack erythrocytes
• Large lumen
• Valve
• No clear periocytes, no basement membrane
• Something inside staining pink = lymph fluid

Question 14

where is spleen located

Answer 14

left hypochondirum

Question 15

blood vessels in and out of spleen

Answer 15

• Great blood supply from splenic artery

* Splenic vein drains splenic blood to liver.

Question 16

role of spleen

Answer 16

• 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.

Question 17

how to find spleen

Answer 17

• 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

Question 18

what is the red and white pulp in spleen

Answer 18

• Lymphoid tissue= white pulp
• Red pulp= reticulin fibres & capillaries

White pulp looks purple on micrograph (as full of lymphocytes)

Question 19

why is there a gap on top of slpleen

Answer 19

where artery and vein is

Question 20

describe activated lymph

Answer 20

Dark ring (mantle zone= b cells) with lighter centre (germinal centre= b cell activation, expansion)

Question 21

what are PALS

Answer 21

Pariarteriolar Lymphoid Sheath
• Arteriolessurrounded with large numbers of lymphocytes and macro
• Heavy density
• = first line of defense as what seeps outs arteriole attacksby dense

Question 22

TYPES OF malt (Mucosal associated lymphoid tissue )

Answer 22

tonsils, •

GALT= Aggregated lymphoid nodules of ileum + Aggregated lymphoid nodules of appendix

Question 23

difference of spleen and tonsil

Answer 23

o Lot of lymphocytes (purple)= angry secondary follicles
o Little blood
o Different shape
• Clefts allows entry and trap > attack

Question 24

ilium vs appedix

Answer 24

• Entire lumen covered in lymphoid tissue (different to ilium)

Question 25

How are we exposed to pathogens (link to lymph sites)

Answer 25

MALT
Inhaling (// tonsils at tongue + oral cavity)
• Digestion (GALT ilium + appendix)