H: Immune system

Question 1

Identify

Answer 1

Lymphocyte

Question 2

Identify structures + tissue

Answer 2

Thymus
C: capsule
Cx: cortex
M: medulla
S: interlobular septa

Question 3

Identify tissue + letters + dark blue spots

Answer 3

Medulla of thymus
Dark blue spots: lymphocytes
Ep: epithelial cells
H: Hassal’s corpuscles - keratinised epithelial cells

Question 4

Identify structures + tissue

Answer 4

Tissue =.young cortex of thymus
Dark blue = lymphocytes
Light pink = reticular

Question 5

Identify

Answer 5

Lymph node
C = capsule
S = subcapsular sinus
E = endothelial cells lining sinus
M= macrophages

Question 6

Identify

Answer 6

Lymph node
C = capsule
T = trabeculae
S = subcapsular sinus
Cx = cortex
M = medulla
F = follicles with germinal centres (actively dividing B cells) surrounded by resting B cells.
P = paracortex with T cells
MC = medullary cords - have mature B cells

Question 7

What are the spaces between medullary cords called?

Answer 7

Medullary sinuses

Question 8

Spleen functions

Answer 8

• Removes blood-borne antigens
• Destroys old/defective RBCs, WBCs and platelets
• Site of hematopoiesis in fetus

Question 9

What’s the largest lymphoid organ?

Answer 9

Spleen

Question 10

Function of white and red pulp in spleen?

Answer 10

White = thick sleeves of lymphoid tissue
Red = surrounds white pulp, composed of splenic cords and venous sinuses

Question 11

Identify structures + tissue

Answer 11

Spleen
WP = white pulp
RP = red pulp
C = capsule
T = trabeculae

Question 12

White pulp components in spleen

Answer 12

T cells around arteries
B cells form follicles

Question 13

Red pulp components in spleen

Answer 13

• Splenic sinusoids with macrophages (sinusoid = leaky capillary)
• Splenic cords (sheets of reticular CT)

Question 14

Explain splenic artery division + what surrounds central arteries?

Answer 14

Splenic artery –> central artery –> sheathed capillaries –> blood emptied into red pulp –> re-enters sinusoids –> veins of pulp –> splenic veins

PeriArterial Lymphoid Sheath (PALS) = white pulp that surrounds central arteries

Question 15

Peyer’s patches (location + structure)

Answer 15

Found in distal small intestine wall
Have clusters of lymphoid follicles with germinal centres

Question 16

Identify

Answer 16

Neutrophils

Question 17

Identify

Answer 17

Eosinophils

Question 18

Answer 18

Question 19

Answer 19

Question 20

Answer 20

Question 21

Functions of lymphatics and immune system

Answer 21

• Draining excess interstitial fluid to bloodstream
• Transporting dietary lipids
• Immune responses

Question 22

What are the primary lymphoid tissues + their function?

Answer 22

Thymus: maturation of T lymphocytes
Bone marrow: maturation of B lymphocytes

Question 23

What are the secondary lymphoid tissues?

Answer 23

• Lymph nodes
• Spleen
• Mucosal Associated Lymphoid Tissue (MALT) = tonsils, Peyer’s patches, mucosae of GIT, respiratory and GU tracts

Question 24

Types of lymphocytes

Answer 24

• B lymphocytes
• T lymphocytes (Helper, Cytotoxic, Suppressor, Memory)
• NK cells

Question 25

Where are less and more mature T cells?

Answer 25

Less mature = cortex
More mature = medulla

Question 26

Where are macrophages?

Answer 26

In cortex and medulla

Question 27

Identify tissue + letters

Answer 27

Palatine tonsil
E =epithelium (invaginates tonsils –> crypts)
White spaces = crypts, where pus will accumulate if sick
F = follicles with germinal centres
Cap = Hemi-capsule (antigens contact immune across epithelium)

Question 28

Identify tissue + components

Answer 28

Question 29

Identify tissue + component

Answer 29

Question 30

Identify tissue + component

Answer 30

Peyer’s patch
GC = cluster of lymphoid follicles with germinal centres