the neuroendocrine system

Question 1

describe the different types of signalling

Answer 1

1. synaptic (fast, individual postsynaptic cells, neuron specific, neurotransmitters)
2. paracrine
3. endocrine (slower, target populations of cells, endocrine cells and neurons, hormones and neuropeptides)

Question 2

What are hormones?

Answer 2

Signalling molecules that bind to selective
receptors

Question 3

Describe the difference between hydophilic and hydrophobic hormones

Answer 3

-hydrophilic hormones are stored in vesicles, like neurotransmitters.
They are secreted to the bloodstream for transport to the target cell.
-hydrophobic hormones are synthesised and released through diffusion, like endocannabinoids. For long range transport in the blood, their hydrophobic moieties are shielded by a carrier protein

Question 4

Why do you need carrier proteins for hydrophobic hormones?

Answer 4

For long range transport

Question 5

Where do hydrophilic hormones bind to receptors?

Answer 5

the plasma membrane

Question 6

what type of hormone would affect the CNS
more and why?

Answer 6

the lipophylic hormones, because they can cross the bbb

Question 7

What hormones can cross the bbb?

Answer 7

steroid hormones

Question 8

What is the bbb?

Answer 8

The blood brain barrier is a filter between the
bloodstream and the central nervous system.

Question 9

What is the importance of a feedbackloop?

Answer 9

feedback mechanisms help to maintain homeostasis

Question 10

Where is the hypothalumus located?

Answer 10

It is located just above the optic chiasm
and the pituitary.

Question 11

What are the functions of the hypothalumus?

Answer 11

Maintains homeostasis:
* blood pressure
* metabolism
* body temperature
regulates:
* stress response
* mating behaviour
* circadian rhythms

Question 12

Which hormones are released by the posterior pituitary?

Answer 12

oxytocin and vasopressin

Question 13

What is oxytocin?

Answer 13

The love hormone, regulates affection and lactation. Bonding with offspring

Question 14

What is vasopressin?

Answer 14

A hormone to regulate blood pressure

Question 15

What happens in the posterior pituitary?

Answer 15

The hypothalamus releases neuropeptides from the posterior pituitary. The cells are produced in the hypothalamus.

Question 16

What happens in the anterior pituitary?

Answer 16

The anterior pituitary is a endocrine gland releasing several homones

Question 17

By which neurons are the hormones transported from the hypothalamus to the posterior pituitary?

Answer 17

These are transported from the paraventricular nucleus trough the neurosecretory neurons to the posterior pituitary

Question 18

Explain the HPA axis

Answer 18

• CRH hormone is released in the hypothalamus
• This hormone is recognized in the pituitary and this will release ACTH
• this hormone is expelled into the bloodstream
• The adrenal gland will then secrete glucocorticoids (cortisol)
  this leads to the stress response

Question 19

what do you expect to happen to your immune
system after the Neurosciences and Medical
Pharmacology exam? (higher stresslevels)

Answer 19

Your HPA axis will be less active. Cortisol levels will decrease. As well as, ACTH. Less suppression of your immune system. You are more probable to feel ill after this period of stress as your immune system catches up.

Question 20

name the 2 kind of cortisol receptors?

Answer 20

Mineralocorticoid receptor (MR)
* high affinity
* mainly expressed in the limbic system
* affects hippocampal plasticity
Glucocorticoid receptor (GR)
* low affinity
* expressed in many cell types
* regulates gene transcription

Question 21

Name the different zones of the adrenal gland from outside to inside

Answer 21

• zona glomerulosa
• zona fasciculata
• zona reticularis
  -adrenal medulla

Question 22

What is the function of the cortex of the adrenal gland?

Answer 22

cortex: the outer layer of the
gland, secreting glucocorticoids
(cortisol/corticosterone) upon
ACTH stimulation in de HPA axis.

Question 23

What is the function of the medulla of the adrenal gland?

Answer 23

medulla: core of the adrenal
gland containing specialized
sympathetic nerve cells:
chromaffin cells. These secrete
adrenalin and noradrenalin as
part of the sympathetic nervous
response.

Question 24

What does SAM stand for?

Answer 24

Sympathetic adrenal medulla axis

Question 25

What is the difference between the SAM and the HPA axis

Answer 25

The SAM axis is fast and the HPA takes much more time.

Question 26

When you have a short stressor will the HPA also be triggered?

Answer 26

Yes, it will

Question 27

describe the thyroid endocrine system feedback loop

Answer 27

• TRH thytone-releasing hormone is released in the hypothalamus
• this will release thyroid- stimulating hormone in the pituitary gland
• this will release t4 and t3 in the thyroid
  -then they will be bound to TBG and TTR and released into the bloodstream

Question 28

what are the functions of the thyroid endocrine system?

Answer 28

-increase metabolism
* increases activity of the sympathetic nervous
system
* bone growth
* neuronal development
(neuron migration,
myelination)

Question 29

To what can a defect in the thyroid gland result?

Answer 29

congenital hypothyroidism (defect of thyroid gland) can lead to growth impairment and intellectual disability. Included in the Dutch neonatal screening program (hielprik)

Question 30

What is the difference between a monogamous and a promiscuous rat?

Answer 30

The distribution of oxytocin and vasopressin receptors is different in these two species of vole