Neuro/Endocrinology and Hormones Flashcards Preview

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Flashcards in Neuro/Endocrinology and Hormones Deck (52)
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1

How do water soluble hormones trnasport in the blood and what is their half-life?

Circulate freely in blood

The shortest half-life

  • Catecholamines: seconds
  • Protein/peptides: minutes

2

How to lipid and thyroid hormones transport around body and what are their half lives?

Reversibly bind to blood bourne transport proteins.

Steroid/thryoid hormones half life = hours

3

Are intracellular recpetors of cell membrane receptors faster? 

Cell membrance receptors

 

4

Brief description of intracellular receptor and action?

  1. Diffuses across membrane
  2. Bind lipid soluble hormone
  3. Hormone-receptor complex binds to DNA sites
  4. Gene activation/deactivation
  5. Cell response

5

Where are the intracellular receptors for steroids?

Cytoplasm and nucleus

6

Where are the intracellular receptors for thyroid hormones?

Nucelus and mitochondria

7

Brief description of events in FSHR G Protein-coupled receptor and signal transduction

  1. FSH bind to receptor-> G Prot activated (GTP replaced GDP)
  2. Active G Prot activates adenylate cyclase
  3. Adenylate cyclase converts ATP to PPi + cAMP (2nd messenger)
  4. cAMP acts on behalf of FSH
  5. cAMP changes activity of protein kinase A (PKA) enzyme
  6. PKA phosphorylates target proteins and induces cell response

 

8

What does a target cell response depend on?

receptor affinity

number of receptors

hormone (ligand) concentration

receptor up and down regulation

9

What are 3 ways to terminate a hormonal signal (not positive or negative feedback)

- receptor desensitisation

-receptor canalisation (endocytosis)

- second messenger degradation

10

What nuclei from the hypothalamus release neurohormones  in the primary capillary plexus in the hypophyseal portal system?

Paraventricular

Medial pre-optic

Arcuate

11

Which nuclei from the hypothalamus have their axons in the hypothalamo hypophyseal tract releasing neurotransmitter in the posterior pituitary?

Paraventricular nucleus

Supra-optic nucleus

12

How does the anterior pituititary develop?

Evagination of the oropharynx ectoderm toward the brain, “Rathke’s pouch”

Rathke’s pouch gives rise to:

o pars distalis

o pars intermedia

o pars tuberalis

13

How does the posterior pituitary develop?

derived from a downgrowth of the neuroectoderm of brain floor

 

 proximal part – infundibulum & distal part – pars nervosa

14

The adrenal cortex secretes ___ Hormones

Corticosteroid

15

What does the zona glomerulosa secrete?

Mineralcorticoids: aldosterone

 

16

What does the Zona fasciculata secrete?

Glucocorticoids: cortisol

17

What doesthe Zona reticularis secrete?

Sex steroids

18

What does the adrenal medulla secrete?

Catecholamines

 

19

What 'weak' androgens does the zona reticularis secrete?

Androstenedione

dehydroepiandrosterone (DEHA)

Small amount oestrogen

20

What would hypersecretion in the zona reticularis cause?

Androgenital syndrome

21

Where is kispeptin 1 made in humans?

Infundibulum

22

Where are Kisspeptin receptor found?

On GnRH-containing neurons in hypothalamic median eminence

23

What is the molecular type for hypothalamic neurohormones?

Peptides

24

What is the moecular type of FSH?

Glycoprotein

25

What is the molecular type of LH

glycoprotein

26

What is the source of LH and FSH in the anterior pituitary?

Pars distalis, gonadotrope cells

27

What is the molecular type of prolactin?

Protein

28

What is the source of prolactin in the anterior pituitar?

Pars distalis, lactotrope/mammotrope cells

29

What are the target tissues of prolactin?

Breasts, uterus and thymus

30

What is the molecular type for Adrenocorticotrophic hormone?

Protein