Thyroid, Parathyroid, Pancreas

Question 1

Thyroxine

Answer 1

T3 and T4 combined

Question 2

TSH (via cAMP) stimulates the following events…

Answer 2

stimulates all steps of making and releasing T3 and T4

1. synthesis of thyroglobulin –> once synthesize, stored in colloid
2. uptake of Iodide; oxidation to iodine (on basal surface)
3. iodination of thyroglobulin to MIT or DIT
4. formation of T3 and T4
5. endocytosis and degradation of T3 and T4
6. release of free T3/T4 on basal surface

Question 3

Parathyroid

Answer 3

chief cells = PTH … smaller and darker staining

oxyphils = large, very eosinophilic, filled with mitochondria
–> larger and lighter staining
adipocytes

Question 4

Graves disease

Answer 4

hyperthyroidism caused by a diffuse, hyperplastic goiter

autoimmune disease that produces TSH receptor-stimulating autoantibodies

symptoms:

• eye bulging
• heat intolerance
• irritability
• weight loss in presence of good appetite

bind to receptor to tweak it do bind to caMP and start T3, T4 overproduce

Question 5

secondary hyperthyroidism

Answer 5

relatively uncommon….caused by a TSH adenoma i

Question 6

Hashimoto Thyroiditis (HT)

Answer 6

most common cause of goiterous hypothyroidism

autoimmune disease that produces
= thyroid peroxidase autoantibodies –> therefore T3 and T4 production is shut down

clinical
= goiter and hypothyroidism

Question 7

primary hypothyroidism

Answer 7

TSH receptor autoantibodies

low bp, low HR, low RR, reduced body temperature, and myxedema

Question 8

secondary hypothyroidism

Answer 8

uncommon compared to primary

deficiency in anterior pituitary so low TSH secretion or hypothalamus with low TRF secretion

Question 9

primary hypoparathyroidism

Answer 9

(-) PTH secretion

bones are very dense

spastic muscle contraction, convulsions, tetany, death

Question 10

pseudo-hypoparathyroidism

Answer 10

rare

abnormal PTH receptors leading to hypocalcemia although there are high PTH levels

Question 11

primary hyper-parathyroidism

Answer 11

usually hyper secreting tumor of chief cells

thinning of bones

deposits of bone in soft tissues

over production of PTH

Question 12

malignant tumors all over body may secrete what peptide

Answer 12

PTHrp

leading to hypercalcemia

Question 13

Type I diabetes hisology

Answer 13

autoantibodies and lymphocytic infiltration leading to destruction of beta cells

reduced number of beta cells

WBCs infiltartion for destruction of beta cell (autoimmune)

can see large, dark staining nuclei of WBCs

loss of clear pancreatic islets structure

Question 14

type II diabetes histology

Answer 14

amyloid deposition in islets can also reduce number of beta cells

sometimes reduced beta cells, sometimes not

clear loss of cellularity usually present in pancreatic islet

looks fibrotic

Question 15

primary hyperaldosteronism

Answer 15

elevated aldosterone commonly caused by aldosterone secreting adenoma (Conn Syndrome)

excess cells in glomerulosa

Question 16

Pheochromoctyoma

Answer 16

catecholamine producing tumor (both epi and NE) of the adreanl medulla

tumor = more cells, so adreanl medulla will grow and produce more

Question 17

neuroblastoma

Answer 17

neoplasm containing primitive neruoblasts

40% occur in adrenal medull

Question 18

vascularity of adrenal gland

Answer 18

arterial supply comes through capsule with long and short arteries

short - filter through cortex to medulla (venous blood by the time it reaches medulla)

long = run directyl to medulla and bypass cortex

drained into medullary vein