Sem 4 Week 12 Lec 1

Front 1

What happens if there are small structural changes within steroids?

Back 1

Large effects on activity.

Front 2

Steroid hormones produced where?

Back 2

-Adrenal cortex
-ovary
-placenta
-testes
-kidney
-local synthesis in skin,brai,bone.

Front 3

Steroids synthetized from

Back 3

Cholesterol

Front 4

First rate limiting step in steroid synthesis?

Back 4

-Cholesterol-->Pregnenolone

Front 5

How many rings?

Back 5

4

Front 6

Estradiol compared to testosterone has

Back 6

-OH group on A ring

Front 7

What is the common intermediate in the pathway for cortisol and sex hormones prod. ?

Back 7

17-OH progesterone

Front 8

Type of steroid synthetized depends on

Back 8

Enzymes present within cell.

Front 9

How is steroid hormone synthesis acheived?

Back 9

-Cholesterol uptake and transfer within cell(by Star)
-Conversion of cholesterol to pregnenolone

Front 10

5 types of steroids?

Back 10

1) Glucocorticoids
2) Mineralocorticoids
3) Androgens
4) Estrogens
5) Progestagens

Front 11

What are the 3 types of glucocorticoids terms used?

Back 11

-cortisone
-cortisol
-hydrocortisone

Front 12

Cortisone is

Back 12

metabolite of cortisol and biologically inactive.

Front 13

Hydrocortisone is

Back 13

drug for cortisol

Front 14

Cortisol is

Back 14

made by adrenal gland.

Front 15

Cortisol is

Back 15

stress hormone

Front 16

Actions of cortisol:

Back 16

-stimulate glc production in liver
-inhibit glc uptake in muscle
-stimulate protein and fat breakdown
-anti-inflammatory

Front 17

Glucorticoids maintain

Back 17

BP

Front 18

Acute effect of GCS is

Back 18

stress response.

Front 19

Long term effects of GCS are

Back 19

Opposite to the short term effects.

Front 20

GCS regulated by

Back 20

ACTH released from pituitary.

Front 21

How is cortisol released from adrenal cortex?

Back 21

1) Stress acts on hypothalamus which releases CRF
2)CRF acts on pituitary to release ACTH
3)ACTH acts on adrenals to release cortisol.

Front 22

Red striae is due

Back 22

to thinning of subcutaneous tissue.

Front 23

When do you have increased pigmentation of fingers?

Back 23

-In Addisons: increased ACTH which increases activity of melanocytes.

Front 24

Cushings

Back 24

-can be due to ACTH producing tumour of pituitary
-increased adipose tissue
-lemon on stick
-muscle wasting

Front 25

Mineralocorticoids produced in

Back 25

Adrenal cortex

Front 26

Actions of Aldosterone :

Back 26

-Regulation of salt and water balance via Na+ retention
-regulation of serum K+ via K+ loss.

Front 27

Mineralocorticoids regulated by:

Back 27

-Renin/angiotensin
-K+

Front 28

Androgens?

Back 28

-Testosterone
-Dihydrotestosterone(DHT)
-DHEA

Front 29

Precursor of Testosterone and DHT?

Back 29

DHEA

Front 30

Androgens produced where?

Back 30

-Testis
-Ovary
-Adrenal

Front 31

Androgenic effects:-

Back 31

-Control sexual differentiation
-Regulate function in male reproduction

Front 32

Anabolic effects:

Back 32

Promote growth of bone,muscle,prostate.

Front 33

Main androgen?

Back 33

Testosterone

Front 34

Functions of testosterone in men?

Back 34

-Masculinising(androgenic)
-Growth promoting(anabolic)

Front 35

What regulates reproduction in males?

Back 35

Testosterone

Front 36

When is the first burst of testosterone occur?

Back 36

-In utero-dev. of male genitalia

Front 37

Testosterone expressed at

Back 37

Puberty also.

Front 38

At birth,neonates have same levels of testosterone as adult males.

Back 38

True

Front 39

In women,where is aromatase found?

Back 39

Everywhere.

Front 40

Oestradiol is synthetized from

Back 40

Testosterone

Front 41

In ovaries what convert testosterone to oestradiol?

Back 41

Aromatase(nt present in testis)

Front 42

What regulates androgens?

Back 42

LH released from pituitary.

Front 43

Testosterone inhibits its own synthesis if its conc. increases.

Back 43

True

Front 44

What are the oestrogens?

Back 44

-Estradiol,Estriol,Estrone

Front 45

Where are estrogens produced?

Back 45

-Ovary and placenta

Front 46

Functions of estrogens in women:

Back 46

-Regulate sexual development
-Regulate reproductive dev.

Front 47

What happens with congenital adrenal hyperplasia/

Back 47

Precocious puberty.

Front 48

Main estrogen?

Back 48

Estradiol(main female hormone)

Front 49

Functions of estradiol?

Back 49

-feminising function
-effects on body shape,breast development,reproduction.

Front 50

When is estrogenic puberty expressed?

Back 50

Initially in utero and then at puberty.

Front 51

How is estrogens regulated?

Back 51

LH and FSH from pituitary.

Front 52

Oestrogens have both +ve and -ve feedbacks on hypothalamus and pituitary.

Back 52

True

Front 53

What acts on pituitary to release LH and FSH?

Back 53

GnRH ( LHRH)

Front 54

Menopause?

Back 54

-Period stops
-Fractures
-Mood changes
-Change in CV risk

Front 55

Excess cotisol causes?

Back 55

Cushings sundrome

Front 56

Cortisol deficiency?

Back 56

Addisons disease

Front 57

Aldosterone excess?

Back 57

Conn's syndrome

Front 58

Aldosterone deficiency?

Back 58

-Hypotension
-Hyperkalaemia(potentially fatal)

Front 59

Excess testtosterone?

Back 59

-Precocious puberty in males/females

Front 60

Testosterone deficiency?

Back 60

-XY female
-Delayed puberty
-Hypogonadism

Front 61

Excess estradiol?

Back 61

Precocious puberty

Front 62

Estradiol deficiency?

Back 62

-delayed puberty
-hypogonadism
-menopause

Front 63

Steroids circulate in blood in contact with

Back 63

Binding proteins.

Front 64

Binding proteins for testsoterone and oestradiol?

Back 64

-Sex hormone binding globulin(SHBG) (specific,high affinity)

Front 65

Binding protein for cortisol?

Back 65

-Cortisol binding globulin(CBG)(specific, high affinity)

Front 66

Non-specific and low affinity binding proteins for steroids?

Back 66

Albumin

Front 67

Are steroids stored in cells?

Back 67

No,its not stored!!-synthetized when required.

Front 68

Mechanism of steroid action:-

Back 68

-Cross cell mb being lipi soluble
-Enter all cells
-bind to specific receptors.
-receptors dimerise & bind to co-activator proteins.
-receptor complex binds to specific DNA sequences
-Regulate gene expression
-Steroid action is via protein synthesis.

Front 69

On binding of steroid to steroid receptor,there is dissociation of

Back 69

Heat shock proteins

Front 70

Receptor complex bind to

Back 70

Hormone response elements(HRE) on DNA.

Front 71

Steroid receptors?

Back 71

-Hormone dependent transcription
-Steroid action occurs via regulation of responsive genes
-Tissue-specific effects occur via diff. genes.(act via peptide-like mb receptor:non genomic effects)

Front 72

Steroids' clinical uses?

Back 72

-Replacement if inadequate production
-Contraception(estradiol,progesterone,testosterone)
-Anti-inflammatory(cortisol)
-Body building(testosterone)

Front 73

Steroids are

Back 73

Small lipid molecules.

Front 74

Steroid levels in blood are regulated by

Back 74

Rate of steroid synthesis.