MacDonald

Question 1

What speed do hormones act?

Answer 1

Slow response, low acting

Question 2

Where are hormones produced?

Answer 2

In endocrine glands

Question 3

What are the 3 classes of hormones?

Answer 3

Peptides
Amines
Steriods

Question 4

How do nuclear hormones cross the plasma membrane?

Answer 4

Hydrophobic diffusion

Carrier proteins

Question 5

What type of targets do steroid hormones have?

Answer 5

Nuclear

Question 6

What are the types of steroid hormones?

Answer 6

Glucocorticoids
Mineralocorticoids
Androgens
Oestrogens
Progestogenss

Question 7

What are the 2 vague classifications of steriod hormones?

Answer 7

Adrenal

Gonadal

Question 8

Where are the corticosteroids produced?

Answer 8

Adrenal cortex

Question 9

How are the corticosteroids synthesised?

Answer 9

Dervived from cholesterol via pregenelone by the action of dehydroxylation and dehydrogenation

Question 10

Which enzymes catalyse the synthesis of corticosteroids?

Answer 10

Cytochrome P450s

Question 11

How is the synthesis of corticosteroids stimulated?

Answer 11

7 releasing hormones from hypothalamus
anterior pituitary releases secondary hormone
Adrenal cortex stimulated

Question 12

How many hormones do the adrenal glands produce?

Answer 12

36

Question 13

What are the 3 regions of the adrenal cortex?

Answer 13

Glomerulosa
Fasiculata
Reticularis

Question 14

What class of steroid hormones does the glomerulosa region of the adrenal cortex produce?

Answer 14

mineralocorticoids

Question 15

What region of the adrenal cortex is responsible for the synthesis of glucocorticoids?

Answer 15

Fasiculata

Question 16

What region of the adrenal cortex is responsible for the synthesis of androgens?

Answer 16

reticularis

Question 17

What is the main glucocorticoid?

Answer 17

Cortisol

Question 18

What is the main mineralocorticoid?

Answer 18

Aldosterone

Question 19

What are the main roles of cortisol?

Answer 19

Increase gluconeogenesis
Mobilisation of fatty acids and amino acids
Inhibition of glucose uptake in muscle and adipose tissues

Question 20

How is cortisol released?

Answer 20

Stress
Hypothalamus
CRH
Anterior Pituitary
ATCH
Adrenal gland

Question 21

What are the gonadal steroids?

Answer 21

testosterone

oestrogen

Question 22

Where is testosterone synthesised?

Answer 22

Leydig cells in the testes
Transported by ABP
Activated in Sertolli cells

Question 23

What is the active form of testosterone?

Answer 23

dihydrotestosterone

Question 24

What is the synthesis pathway for steroid hormones?

Answer 24

Cholesterol
Pregenelone
Progesterone
Mineralo/Gluco/testosterone

Question 25

How is oestrogen derived?

Answer 25

From testosterone using aromatase enzyme in ovaries

Question 26

Where is oestrogen produced in post-menopausal women?

Answer 26

Adrenal glands

Question 27

Where is progesterone produced?

Answer 27

in corpus luteum

Question 28

What effects does progesterone have?

Answer 28

Changes in luteral phase of menstrual cycle | A differentiation factor for mammary glands

Question 29

What is the releasing hormone for oestrogen?

Answer 29

FSH

Question 30

What is LH the releasing hormone for?

Answer 30

Progesterone and testosterone

Question 31

What is angiotensin the releasing hormone for?

Answer 31

Aldosterone

Question 32

How are most steroid hormones found?

Answer 32

Inactive forms bound to carrier proteins in blood

Question 33

What structure do steroid receptors have?

Answer 33

Modular transcription factors with | (N)variable-zinc finger-ligand binding

Question 34

What are orphan receptors?

Answer 34

No identified ligand

Question 35

How does ligand binding activate receptors?

Answer 35

Conformational change exposes DBD

Question 36

Are steroid receptors ubiquitous?

Answer 36

No, none in yeast or plants

Question 37

What are the 2 classes of steroid receptors?

Answer 37

``` Classical class 1 RXR class 2 ```

Question 38

How are Class 1 receptors activated?

Answer 38

Release from HSP Migration to nucleus Homodimer TFs bind to inverted repeat

Question 39

What are examples of Class 1 receptors?

Answer 39

Androgens, Corticosteroids Progesterone

Question 40

Where are RXR receptors found?

Answer 40

Constitutively bound to DNA

Question 41

How do RXR receptors bind DNA?

Answer 41

As heterodimers with another TF

Question 42

How are nuclear hormones degraded?

Answer 42

Steroids are hydroxylated/sulphated/glycosylated in liver | Thyroids are de-iodinated

Question 43

How can steroid signalling be switched off?

Answer 43

Absence of stimulus ligand degradation Receptor dissociation

Question 44

How is secretion of cortisol regulated?

Answer 44

Negative feednack to CRH and ATCH

Question 45

What is Addisons disease?

Answer 45

Absence of cortisol

Question 46

What are the symptoms of lack of cortisol?

Answer 46

``` hypotension, darkening of skin, weight loss vomiting salt cravings cardiac arrest in crisis ```

Question 47

How is addisons disease caused?

Answer 47

Autoimmune attack of adrenal glands | Infectious disease

Question 48

What does aldosterone do?

Answer 48

Raise blood volume and blood pressure, Raise Na levels Reduce K levels

Question 49

Where does aldosterone act?

Answer 49

In kidney and small intestine

Question 50

How is aldosterone produced?

Answer 50

Kidney senses stimuli releases renin Conversion of angiotensinogen (liver) to angiotensin 1 angiotensin 1 converted to angiotensin II by ACE Angiotensin releases aldosterone

Question 51

What receptors does aldosterone act on?

Answer 51

glucocorticoid receptors

Question 52

How are cells selective for aldosterone over cortisol?

Answer 52

Cortisol converted to cortisone by 11-β-hydroxysteroid dehydrogenase cortisone lower affinity

Question 53

What gene does aldosterone transcribe?

Answer 53

Na/K pump

Question 54

What is aldosteroidism also known as?

Answer 54

Conn's syndrome

Question 55

What symtpoms does Conn's syndrome have?

Answer 55

High Na/K pumps Hypertension and cardiac failure Depletion of K and muscle weakness

Question 56

What is congenital adrenal hyperplasia?

Answer 56

Absence of mineralocorticoids and overexpression of androgens

Question 57

What is congenital adrenal hyperplasia caused by?

Answer 57

90% caused by mutations of 21-hydrolase enzyme

Question 58

What symptoms does congenital adrenal hyperplasia have?

Answer 58

Lack of corticosteroids Salt wasting Mis-development of the sex characteristics

Question 59

Where does oestrogen bind?

Answer 59

ERE receptor in promoters of 600 genes | AP1 /ER independant pathways

Question 60

What function does oestrogen have?

Answer 60

Proliferation of cells

Question 61

How common is ER receptor overexpression?

Answer 61

70% of breast, ovarian, colon, prostate, endometrial cancers

Question 62

How does ER overexpression cause cancer?

Answer 62

Increased cell proliferation has more spontaneous DNA mutations Metabolism of oestrogen produces genotoxic waste

Question 63

What ER receptor is found in differentiated tissue?

Answer 63

ERα

Question 64

What does tamoxifen do?

Answer 64

Neutralise ER overexpression treats anvoluntary infertility treats gynecomastia

Question 65

Where is vitamin D synthesised?

Answer 65

Skin, Kidney and liver

Question 66

How is Vitamin D transported?

Answer 66

carrier proteins in blood

Question 67

How is vitamin D synthesis stimulated?

Answer 67

By PT gland sensing low Ca Secretes PTH Stimulates liver activation of D3

Question 68

What effects does vitamin D have on a cell?

Answer 68

Binds RXR-LXR receptors Mobilisation of Ca from bone Kidney Ca retention Intestinal calbindin Ca channel

Question 69

What do Vitamin D deficiencies cause?

Answer 69

Ricketts/osteomalacia

Question 70

How can vitamin D deficiencies be caused?

Answer 70

Hereditary mutations of receptor Lack of sunlight Kidney/Liver disease Poor dietary intake of precursor