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Flashcards in Endocrinology Deck (659)
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211

Endorphin = 

Endogenous morphine

212

Enkephalin=

Endogenous opioid / Signal peptide

213

Give the steps of ACTH production

  1. Pre-POMC
  2. POMC
  3. ACTH

214

Give the effect of ACTH in the glomerulosa layer

Increases cholesterol-pregnenolone conversion  →

Increasing mineralocorticoid synthesis

215

Synthesis of ACTH is regulated according to the...

Classical feedback principle

216

Long feedback

Involvement of glucocorticoid concentration in ACTH feedback

217

Ultra-short feedback

The inhibiting effect of ACTH on CRF

218

Give the steps of neural impulses causing ACTH secretion

  1. Nerve impulses → Hypothalamus
  2. Impulses are integrated by CRF synthesising cells
  3. Circadian fluctuation of CRF
  4. Determination of ACTH release

219

Title the figure

Regulation of ACTH synthesis

220

Exogenous/endogenous effects

221

  • Serotonin
  • ACh

222

CRF

223

ACTH

224

Neurosecretion

225

Tropic

226

Steroids

227

  • Norepinephrine
  • GABA

228

Circadian rhythm of ACTH

  • Short half-life
  • Conc. is higher in the early morning
  • Lowest at midnight

This is the cause of the fluctuation of glucocorticoid conc. (diurnal rhythm)

229

Annotate the figure

  • ACTH levels increase in early morning hours

230

TSH

  • Gonadotropic peptide hormone
  • Alpha chain: Species specificity
  • Beta chain: Biological specificity

231

What increases TSH levels

  • Thyroid hormones
  • Hypothalmic TRH

232

What decreases TSH levels?

  • Cortisol
  • Dopamine
  • Somatostatin

233

Role of TSH

Stimulation of thyroxine

234

Plasma TSH concentration is increased by...

TRH

235

FSH

  • Increase oestrogen synthesis in the follicle
  • Maturation of the follicle
  • Increased testicular spermatogenesis

236

FSH expression is directed by...

  • GnRH
  • Steroids
  • Inhibin

237

LH

  • Luteinising hormone
  • Located: Leydig cell → Testis / Granulosa cell → Ovary
  • Increases synthesis of androgens in both organs
  • Primary factor initiating ovulation

238

PRL

Prolactin

  • Stimulate mammary gland differentiation
  • Stimulate + maintain milk production
  • Metabolic hormone

 

239

How is PRL stimulated

  • Hypothalamic neuronal activity
  1. Oestrogen inhibits dopamine synthesis
  2. Stimulating PRL production during ovulation

240

Give the effects of PRL

  • Facilitation of lactogenesis
  • Facilitation of galactopoiesis
  • Support of suckling
  • Ovulation in the rat