PHARMACOLOGY 1 Hormones Or The Adrenal Pituitary And Thyroid Gland

Question 1

Structure of T3 in terms of tyrosine derivatives

Answer 1

MIT+DIT

Question 2

Structure of T4 in terms of tyrosine derivatives

Answer 2

DIT+DIT

Question 3

Which is more potent T3 OR T4

Answer 3

T3
T4 is converted into T3 (prohormone for T3)

Question 4

Where is T3+T4 secreted from and what stimulates it

Answer 4

Thyroid gland
Stimulated by TSH

Question 5

What is the action of T3 and T4
(5 key effects)

Answer 5

• Inc metabolic rate
• Inc metabolism of proteins, lipids and carbohydrates
• stimulates growth and development ie regulation of weight energy levels
• Deveopment and maturation of CNS
• up-regulation of beta adrenoceptors = inc heart rate

Question 6

Target cells of T3&4

Answer 6

LIVER AND KIDNET

Question 7

Calcitonin role
Secreted from?

Answer 7

Produced by parafollicular C cells(Endocrine cells in thyroid)
Reduce plasma calcium ion levels

Question 8

Parathyroid hormone
- produced?
- role?

Answer 8

Inc Ca2+ levels
Secreted by parathyroid gland

Question 9

What is primary hypothyroidism (hashimotos)
What effect on TSH,T3, T4 levels
How to treat

Answer 9

Failure of thyroid gland
Presence of antibodies
Inc TSH - not being used to stimulate thyroid gland to secrete T3&T4 as there is failure of thyroid gland
= dec T3&4
Treatment = levothyroxine (T4)

Question 10

What is secondary hypothyroidism

Answer 10

Pituitary disease

Pituitary stimulated by TRH - thyrotropin releasing hormone

Dec t3 t4
Dec TSH

Question 11

Is a goitre present in primary hypothyroidism

Answer 11

Yes

Question 12

What does a lack of dietary iodine lead to
- t3,t4,TSH levels
Goitre ?

Answer 12

Dec t3 t4 TSH
- as hypothalamus doesn’t produce enough TRH = less TSH from anterior pituitary = less T3&4
Goitre present as body tries to absorb as much iodine from the body as possible
Iodine needed to produce TH

Question 13

What is iodine essential for in thyroid gland

Answer 13

TH production

Question 14

What is primary hyperthyroidism
Levels of t3 t4 TSH
Goitre present

Answer 14

Thyroid gland overactive
Inc t3 t4 TSH
Goitre present

Anti thyroid meds
Beta blockers to reduce side effects - no effect on thyroid hormones

Question 15

What is Graves’ disease

Answer 15

Too many thyroid stimulating immunoglobulins
Cause is unknown
The antibodies stimulate TSI = inhibitory effect

Inc T3 T4
Dec TSH

Goitre present as thyroid overactive and inc amount id TSI (thyroid stimulating immunoglobulins)

Question 16

What does GnRH stimulate (gonadotropin releasing hormone)

Answer 16

LH FSH

Question 17

Effect of LH

Answer 17

Control of menstrual cycle. Triggers the release of an egg from the ovary. LH levels rise before ovulation

Question 18

Effect of FSH

Answer 18

Stimulates growth of eggs in the ovary in woman and control of sperm production in men
Peak before egg is released by ovary

Question 19

Effect of growth hormone

Answer 19

Effect on metabolism and linear growth (skeletal growth)
Metabolism:
- Liver – inc Gluconeogenesis
- Muscle – inc amino acid uptake, inc protein synthesis, dec glucose uptake
- Adipose tissue – inc lipolysis, dec glucose uptake
Promotes growth by stimulating growth factors such as IGF 1&2 which promote soft tissue growth and bone growth

Question 20

Prolactin role

Answer 20

Stimulates mammary glands to produce milk ie lactation and promotes growth and development of the breasts
Inhibits GnHR release to dec fertility – hence why lactation can prevent fertilisation – resources are needed elsewhere rather than the development of a foetus

Question 21

ACTH role

Answer 21

Controls production of cortisol And androgens (growth and reproduction hormones, androgens are a group of sex hormones) – stress hormone

Question 22

What stimulates released of vasopressin and what is its effect

Answer 22

Released upon fall on blood volume or pressure, also stimulated by angiotensin II

Increase in body fluid osmolality

Causes vasoconstriction by binding to V1 receptors
Increases permeability of DCT by binding to V2 receptors = inc re-absorption of water

Stimulates Expression of aquaporins (in DCT and CD (kidney)
Increased water re absorption increases blood pressure and volume.

Question 23

What stimulates release of oxytocin and what is its effect

Answer 23

In women the release is stimulated by sucking and cervical stimulation (parturition)

Female: Stimulates expression of breast milk
And stimulates contraction of uterine smooth muscle
It’s release is via a positive feedback loop

Question 24

Effect if growth hormone deficiency

Answer 24

Deficiency = stunted growth and deficiencies
Excess = accelerated growth and acromegaly Which is where the body develops a glucose intolerance = diabetes
Many non specific symptoms

Question 25

Effect of excess prolactin and its treatment

Answer 25

Excess – hyperprolactinaemia = loss of fertility and libido Treated with dopamine receptor antagonists Radiotherapy/ surgery for tumours (prolactin release is stimulated by dopamine)

Question 26

Cushing’s syndrome effect

Answer 26

Cushing Syndrome – tumour in corticotropic cells of pituitary gland = Increased secretion of ACTH = more cortisol secreted = high blood pressure or bone loss, potentially cause type 2 diabetes

Question 27

Vasopressin deficiency effect

Answer 27

Deficiency = diabetes insipidus (central diabetes) - Large urine volume production - Thirst Symptoms as a result of water loss as there is decreased reabsorption of water Cause of deficiency : lesions in hypothalamus or insensitivity of the kidney to ADH – body doesn’t produce as much

Question 28

Vasopressin excess effect

Answer 28

= SIADH Could be caused by trauma to the brain causing inappropriate release of ADH

Question 29

Oxytocin deficiency cause and effect

Answer 29

Deficiency caused by panhypopituarism - Condition where all pituitary hormones are low low levels linked to autism and depressive symptoms Deficiency also prevents milk ejection reflex for breastfeeding

Question 30

What hormone does dopamine inhibit

Answer 30

Prolactin

Question 31

What hormones does somatostatin inhibit

Answer 31

Insulin Glucagon GH TSH

Question 32

What does TRH stimulate

Answer 32

TSH + prolactin

Question 33

What does CRH stimulate

Answer 33

ACTH

Question 34

What is an endocrine axis ?

Answer 34

The interaction between the hypothalamus, pituitary and peripheral endocrine glands showing feedback regulation

Question 35

Feedback control

Answer 35

Physiological response to the hormone feeds back to the endocrine gland that secreted the hormone- alters secretion rate.

Question 36

. How do steroid hormones create a physiological response?

Answer 36

Increased gene expression/decreased gene expression

Question 37

What is the action of steroid hormones

Answer 37

Steroid hormone binds to intracellular receptor- acts as transcription factor.

Question 38

How is cortsiol protective

Answer 38

Protects the body against damage from over-activation of immune defence mechanisms- at high levels- immunosuppressive/anti-inflammatory effect.

Question 39

How do autocrine cells work?

Answer 39

Substance produced by the cell, enters interstitial fluid and acts on the same cell that made the substance.

Question 40

What are paracrines

Answer 40

Substance made by the cell acts on local cells via interstiial fluid.

Question 41

How do neuroendocrine cells work?

Answer 41

Action potential triggers secretion of neurohormone into the blood- then acts on target cell.

Question 42

What are steroid hormones

Answer 42

Derived from cholesterol Bio synthetic enzymes convert cholesterol to its derivatives (eg cortisol)

Question 43

What is preprohormone

Answer 43

Large precursor molecule- 'pre' signal peptide informs the cell that the molecule needs further processing.

Question 44

Where is preprohormone converted into prohormone

Answer 44

ER

Question 45

What is prohormone

Answer 45

Complete hormone sequence with additional peptide sequences

Question 46

How is prohormone converted to hormone?

Answer 46

Peptide sequences are cleaved by proteolytic enzymes to form hormone

Question 47

How is the final hormone stored and released

Answer 47

In secretory vesicles until endocrine cell is stimulated. Then secreted via exocytosis

Question 48

How are steroid hormones synthesised and released

Answer 48

Bio synthetic enzymes convert cholesterol to hormone and steroid hormones diffuse out of cell due to lipophilicity

Question 49

How do steroid hormones travel around blood

Answer 49

Protein bound

Question 50

Action of peptide hormones

Answer 50

GPCR&tyrosine kinase receptors

Question 51

How does peptide hormone action lead to a physiological response?

Answer 51

Signal transduction- altered activity of enzymes, altered expression of specific proteins.

Question 52

What is the action of steroid hormones

Answer 52

Steroid hormone binds to intracellular receptor- acts as transcription factor. Increased gene expression/decreased gene expression.

Question 53

What is a neuroendocrine reflex?

Answer 53

Input from higher centres ie CNS Axon terminals in hypothalamus

Question 54

How does hormone excess (hypersecretion) occur?

Answer 54

Tumour/immunological factor.

Question 55

How does hyposecretion occur?

Answer 55

Genetic, immunological attack

Question 56

How are endocrine disorders investigated and treated

Answer 56

Stimulation/suppression tests Hormone deficiency - hormone replacement Hormone excess - drugs to block production Decreased target cell responsiveness - drugs to enhance cellular response