Hormones

Question 1

Organise the words paracrine/ endocrine/ autocrine in ascending distance of action

Answer 1

Autocrine, paracrine, endocrine

Question 2

How does the hypothalamus interact with the anterior pituitary?

Answer 2

Hypophyseal portal system

Ant blood

Question 3

What does corticotropin-releasing hormone CRH cause the release of from the anterior pituitary?

Answer 3

Adrenocorticotropic hormone ACTH

Question 4

What happens when prolactin inhibitory hormone PIH is no longer released from the hypothalamus?

Answer 4

Anterior pituitary secretes prolactin

Question 5

Which are the tropic hormones released from anterior pituitary?

Answer 5

M FLAT stimulate other endocrine glands like adrenal gland/ gonads
MSH (melanocyte stim horm to prod melanin)/ FSH/ LSH/ ACTH/ TSH

Question 6

Which are the direct hormones released from anterior pituitary?

Answer 6

PEG stimulate a part of the body directly

Prolactin/ Endorphins/ GH

Question 7

How does the hypothalamus interact with the posterior pituitary?

Answer 7

Nervous stimulation causes release of hormones produced by hypothalamus but stored in posterior pituitary
(Ant blood)

Question 8

Hormones released by the posterior pituitary?

Answer 8

ADH (vasopressin)

Oxytocin

Question 9

What does TROPHIN mean?

Answer 9

Nourishing/ stimulating

e.g. Corticotrophin

Question 10

What does TROPIN mean?

Answer 10

Stimulating effect of a hormone/ other substance on a target organ/ system
e.g. Somatotropin/ Gonadotropin/ Thyrotropin

Question 11

What has an inhibitory effect on growth hormone?

Answer 11

Somatostatin (SS)

Question 12

What has an inhibitory effect on prolactin?

Answer 12

Dopamine (DA)

Question 13

Which hormones affect growth and how?

Answer 13

Growth hormone - lack inhibits growth
Thyroxine - lack inhibits growth
Cortisol - excess inhibits growth
Insulin - excess stimulates growth

Question 14

Does GH have a role in foetal development and normal growth from birth to 2yrs?

Answer 14

No

Question 15

Does GH exert an effect on neurons?

Answer 15

No but almost all other cell type

Main targets: bone and muscle

Question 16

How does GH decrease fat deposits?

Answer 16

Decreases adipose tissue glucose uptake

Increase lipolysis

Question 17

How does GH increase muscle mass?

Answer 17

Decreases muscle glucose uptake
Stimulates aa uptake/ protein synthesis
Inhibits protein breakdown

Question 18

How does GH stimulate Insulin-like growth Factor production?

Answer 18

Increases gluconeogenesis in liver

Decreases protein synthesis

Question 19

How does GH protect agains hypoglycaemia?

Answer 19

It is glucose sparing with anti-nsulin action

Question 20

Which growth factor is responsible for skeletal growth (cartilage formation and bone deposition – lengthening and thickening)?

Answer 20

IGF-1

Question 21

Which growth factor is responsible for soft tissue growth (protein synthesis and cell proliferation/ hyperplasia and hypertrophy)?

Answer 21

IGF-2

Question 22

When do bones not respond to GH?

Answer 22

After growth plates have fused

Question 23

Describe the somatopause phenomenon

Answer 23

Decrease in lean body mass
Decline in bone mineral density
Increase in body fat
Sleep disturbance

Question 24

What occurs when there’s excess of GH causing Gigantism?

Usually result of pituitary tumour secreting GH

Answer 24

Abnormally high linear growth due to excessive action of IGF-1 while the epiphyseal growth plates are open during (children)
Normal body proportions as soft tissues are also affected

Question 25

What occurs when there's excess of GH causing Acromegaly?

Answer 25

``` Increased growth hormone later in life after fusion of epiphyses course facial features enlarged hands and feet protruding jaw and separation of teeth enlarged tongue and thickened lips deep voice cardiomegaly diabetes ```

Question 26

If primary surgery on pituitary tumours fail to induce complete remission, how is GH excess treated?

Answer 26

Somatostatin analogues | Dopamine analogues GH receptor antagonists

Question 27

What's the cause of pituitary dwarfism? | not the only cause of dwarfism

Answer 27

GH insufficiency in childhood

Question 28

Characteristics of pituitary dwarfism

Answer 28

Slow growth rate below 3rd centile on age/height or bone chart Normal body proportions Poor muscle development, excess subcutaneous fat

Question 29

What is GH insufficiency in adults characterised by?

Answer 29

No major symptoms

Question 30

Effect of GH on cartilage and bone before growth plates have fused?

Answer 30

Increase chondrocyte mitosis and matrix production

Question 31

Effect of dihydrotestosterone

Answer 31

Embryo life - differentiation of penis, scrotum and prostate | Later in life - contributes to male balding, prostate growth and sebaceous gland activity

Question 32

What are gehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione?

Answer 32

Testosterone precursors converted to testosterone in peripheral tissues

Question 33

What is the primary source of testosterone in men and women?

Answer 33

Men - Testes | Women - Adrenal glands

Question 34

Where are androgens produced in women?

Answer 34

Ovaries, adrenal glands and fat cells

Question 35

What is adrenal cortex hyper function and its treatment?

Answer 35

Excessive production of adrenal androgens Overproduction of ACTH = masculinisation/ virilization (Acne, hirsutism, irregular periods, breast shrinkage, low voice, typical male muscle development) Treatment: ACTH antagonist e.g. Cyproterone acetate/ Ethinyl estradiol

Question 36

What is hirsutism?

Answer 36

Excessive hair growth in women

Question 37

Production and storage of sperm

Answer 37

Produced in testis Formation in seminiferous tubule Stored in seminal vesicles

Question 38

What dihydrotestosterone (dht), androstenedione or to oestradiol?

Answer 38

Testosterone converted into them

Question 39

What does FSH do in men?

Answer 39

FSH stimulates the sertoli cells to produce androgen binding protein (binds to testosterone) and facilitate sperm development

Question 40

What does LH do in men?

Answer 40

LH stimulates the leydig cells to secrete testosterone

Question 41

What do sertoli cells do?

Answer 41

Create seminiferous tubules Nourish germ cells and support spermatogenesis Convert testosterone to DHT or oestradiol Secrete INHIBIN (Inhibits FSH production)

Question 42

What converts testosterone to estradiol and androstenedione to estrone? And where is it widely distributed?

Answer 42

Aromatase | Adipose tissue

Question 43

What is important for spermatogenesis and contributes to male heterosexualty?

Answer 43

Estradiol

Question 44

What causes serum testosterone concentration and the sperm count are below normal and the serum LH and FSH concentrations are above normal?

Answer 44

Primary hypogonadism

Question 45

What is there a problem with in secondary hypogonadism?

Answer 45

Hypothalamus or the pituitary gland

Question 46

What syndrome causes an extra copy of the X chromosome, testicles smaller than normal, low production of testosterone, reduced muscle mass, reduced body and facial hair, enlarged breast tissue and produce little or no sperm?

Answer 46

Klinefelter syndrome

Question 47

What are the following signs of? Lower IQ than siblings/ tall/ poor muscle tone/ reduced secondary sexual characteristics/ gynaecomastia/ small testes/ infertility

Answer 47

Klinefelter syndrome

Question 48

What is the autosomal recessive sex-limited condition resulting in the inability to convert testosterone to the more physiologically active dihydrotestosterone (DHT)?

Answer 48

5-alpha-reductase deficiency (5-ARD)

Question 49

What syndrome is caused by a mutation of androgen receptor and affects the normal development of a child's genitals and reproductive organs so that the child born is genetically male, but their genitals may appear to be female/ somewhere between? (very rare condition)

Answer 49

Androgen insensitivity syndrome (AIS)

Question 50

What is addison's disease?

Answer 50

Chronic hypoadrenalism that caused adrenal cortex hypo function