steroids

Question 1

Types of steroid hormones

Answer 1

mineralcorticoids (aldosterone), glucocoticoids ( cortisol) Sex hormones (androgens and estrogens)

Question 2

Zones of the adrenal cortex

Answer 2

1. outermost - Z. Glomerulosa - minerals
2. zona fasciulata - cortisol
3. Z. reticularis - formation of DHEA

Question 3

Describe the hypothalamic pituitary adrenal axis

Answer 3

Hypothalamus secretes Corticotropin releasing hormone which stimulates ACTH from anterior pituitary

Question 4

What is androstendione

Answer 4

it is the precursor for the androgens and estrogens

Question 5

Enzymes involved in formation of steroid hormones

Answer 5

1. CYTp450 SCC
2. 3 b hydroxy steroid DH
3. 17 (alpha) OH
4. 21 OH
5. 11 B OH

Question 6

Mechanism for LH and FSH

Answer 6

G protein coupled - adenylate cyclase

Question 7

which pathway do growth hormones use?

Answer 7

Jack Stat - associated with TYR K

Question 8

Effects of growth hormone

Answer 8

1) increase lipolysis
2) protein synthesis
3) Increase glucose

Has direct effects on tissues and indirect effects due to the liver producing IGF-1 which acts on tissues too.

Question 9

what causes prolactin to be produces

Answer 9

1. The absence of dopamine (prolactin inhibitory hormone)

2. Thyrotropin releasing hormone from hypothalamus (prolactin releasing hormone

Question 10

which molecules are agonists

Answer 10

Angiotensin and vasopression

Question 11

What decreases ca

Answer 11

calcitonin which is produced by Parafollicular (c cells) of thyroid G

Question 12

what increases ca

Answer 12

1. vitamin D3 and parathyroid hormone

Question 13

Actions of parathyroid

Answer 13

-Bones -osteoclasts
Kidneys - absorb more ca
- Small intestine - reabsorb more can but u need vitamin D3

Question 14

What is the role of the kidney in regards to calcium

Answer 14

it activates vitamin D into its more active form (Calcitriol) also is involved in reabsorbing more ca if ca levels are low

Question 15

Pro-opiomelacortin

Answer 15

a Precursor polypeptide made in pituitary which will give rise to polypeptide hormones such as ACTH.

Question 16

Which carbons do you start hydroxylating for aldosterone and cortisol

Answer 16

C- 17

A- 21

Question 17

Structure of thyroid gland

Answer 17

1 unit is called a follicle, cells are called follicular cells and lumen has colloid

Question 18

which enzyme changes the oxidation state of iodine

Answer 18

Thryoid peroxidase (from I- to 0)

Question 19

How do t3 and t4 get to their target cell

Answer 19

immunoglobulin binding protein

Question 20

which pumps/channels are involved in thyroid hormones?

Answer 20

1. NA/I symporter

2. NA/K pump

Question 21

Differences between T4 and T3

Answer 21

t4 can only be made by the thyroid gland, but t3 can come straight from t4 by deiodination using deiodonase (selenium). T3 can also come from the thyroid gland. T3 is the biologically active form- every cell only has receptors t3. t4 is produced in majority!

Question 22

Functions of t3/4

Answer 22

• uncouplers - free oxidation UCP thermogenin
• increase metabolic rate
• increase HR

Question 23

Hyperthyroidism

Answer 23

• Fast HR
• Sweating
• lose weight
• restless
• graves disease can be cause by hyperthyroidism, bulging eyes

treatment: Carbimazole

Question 24

relationship between t3/4 and insulin

Answer 24

antagonists because they increase glucose levels.

Question 25

Thyroid hormes and DNA

Answer 25

Thyroid hormone receptor is a type of nuclear receptor that is activated by binding a thyroid hormone. TRs are transcription factors which are typically associated with retinoic acid receptors forming heterodimers.