Endocrine and Biochemistry Flashcards Preview

Uworld Journal COPY > Endocrine and Biochemistry > Flashcards

Flashcards in Endocrine and Biochemistry Deck (87)
Loading flashcards...
1

Mechanism of potassium iodide =

Competitively inhibits the uptake of radioactive iodine into follicular cells. Increased iodine also decreases release of T4/T3 due to the Wolff Chaikoff Effect.

2

Function of smooth ER = (3)

-produces steroids and phospholipids (contains the appropriate enzymes)
-acts as the sarcoplasmic reticulum for striated muscles
-detoxification of drugs

3

What medication can be given to men who are suffering from gynecomastia?

SERM - inhibits ER in breast tissue

4

Hypoketotic hypoglycemia in a young kid after a long period of fasting is most likely a deficiency in _

FA beta-oxidation

Most likely it is inhibition of acyl CoA dehydrogenase enzyme.
Will not be able to oxidize FA for energy and cannot produce ketone bodies

5

Superior thyroid artery and vein travel with _ nerve

external branch of the superior laryngeal nerve

-innervates the cricothyroid muscle

6

Inferior thyroid artery and vein travel with _ nerve

recurrent laryngeal nerve

7

Gene from Albright Hereditary Osteodystrophy is inherited from mother/father

mother - due to imprinting of father's genes
AD

defective Gs alpha subunit in the PTH receptor = pseudohypoparathyroidism - end organ resistance to PTH

presentation:
-serum= low Ca, high P, high PTH
-shortened 4th/5th digits
-short stature

8

Conn syndrome =

Primary adrenal adenoma

increased aldo
decreased renin

9

Addison's disease =

Primary adrenal insufficiency

decreased aldo
decreased cortisol

10

Metyrapone stimulation test

Blocks the last step of cortisol synthesis (11DOC -> cortisol)

Helps dx adrenal insufficiency

11

11-beta hydroxylase deficiency findings

female genitalia =

-decreased aldo
-increased 11-DOC (not salt wasting)
-increased BP
-decreased renin
-increased androstenedione

female genitalia are ambiguous (due to increased androstenedione)

12

21 hydroxylase deficiency findings

female genitalia =
male genitalia =

-decreased aldo (salt wasting)
-decreased BP
-increased renin
-increased 17-hydroxyprogesterone
-increased androstenedione

female genitalia are ambiguous (due to increased androstenedione)
male genitalia is normal and they are identified later due to salt wasting

13

17-alpha hydroxylase deficiency findings

female vs male genitalia

-increased aldo (not salt wasting)
-increased BP
-decreased androstenedione

females - born with normal genitalia but will not have secondary sex characteristics
males - born undervirilized or with female external genital (due to decreased androstenedione)

14

Insulin independent glucose uptake locations (6)

-Brain
-RBC
-Intestine
-Cornea
-Kidney
-Liver

15

MEN 1

-Pituitary adenoma (prolactin or GH)
-Pancreas endocrine tumor (Zollinger-Ellison (gastrinoma), Insulinoma, VIPoma, Glucagonoma)
-Parathyroid adenomas

mutation in MEN1 gene - menin tumor suppressor protein

16

MEN2A

-Parathyroid hyperplasia
-Thyroid medullary carcinoma (C cell tumor - secrete calcitonin)
-Pheochromocytoma

mutation in RET gene - receptor tyrosine kinase
affects cells of neural crest origin!

17

MEN2B

-Thyroid medullary carcinoma (C cell tumor - secretes calcitonin)
-Pheochromocytoma
-Muosal neuroma (oral/intestinal ganglioneuromatosis)

mutation in RET gene - receptor tyrosine kinase
associated with marfanoid habitus

18

Hashimoto thyroiditis associated HLA subtype =

HLA-DR5, DR3

19

Diabetes Mellitus Type 1 associated HLA subtype =

HLA-DR4
HLA-DR3

20

Vitamin _ deficiency -> hemolytic anemia, acanthocytosis, posterior column or spinocerebellar tract demyelination

Vitamin E deficiency

21

Niacin is derived from _ and requires what two cofactors?

Derived from tryptophan

Cofactors = B2 (riboflavin), B6 (pyridoxine)

Niacin is B3
Requires B2, B6
(6/2=3)

22

Elfin facies + intellectual disability with well developed verbal skills + hypercalcemia =

Williams Syndrome - microdeletion of long arm Chr 7 (includes elastin gene)

Hypercalcemia is due to increased vitamin D sensitivity

23

Myotnia + Cataracts + Testicular atrophy + CTG repeat =

myotonic dystropy type 1

mutation in the DMPK gene -> abnormal myotonin protein kinase

24

Cancers associated with Li Fraumeni Syndrome (4)

-Sarcoma
-Breast
-Leukemia
-Adrenal gland

25

Cross linking of elastin is done by _ enzyme

lysyl oxidase with copper cofactor required

this is the same enzyme that crosslinks collagen fibrils

26

Mutation in ATP7A + brittle, kinky hair + growth retardation =

Menke disease

-decreased copper absorption which leads to a decreased collagen and elastin synthesis

27

Coarse facial features + clouded corneas + limited joint movements + increased plasma lysosomal enzymes + child

I cell disease - inhibits N-acetylglycosaminyl-1-phosphotransferase enzyme

Results in the failure of the golgi to add a mannose-6-phosphate to glycoproteins that are supposed to be degraded in the lysosome

28

Ribosomes: prokaryotic vs eukaryotic

-80s
-70s

-80s = 40s+60s -> eukaryotes

-70s = 30s+50s -> prokaryotes

eukaryotes - even numbers
prokaryotes - odd numbers

29

tRNA thymine + pseudouracil + cytosine sequence is used for

tRNA-ribosome binding

30

tRNA dihydrouracil residue is used for

tRNA recognition of the correct aminoacyl tRNA synthetase