Intro to Endocrine System

Question 1

Synthesis/Secretion of Protein and Peptide Hormones

Answer 1

1. DNA –> mRNA w/in nucleus (transcription)
2. mRNA –> Preprohormone w/in ribosomes (Translation)
3. Preprohormone –> Prohormone w/in ER
4. Prohormone –> Hormone w/in Golgia
5. Hormone packaged in secretory vesicles

Question 2

Synthesis/Secretion of Steroid hormones

Answer 2

• All produced as derivates of cholesterol and are synthesized w/in adrenal cortex, corpus luteum & placenta
• Lipid soluble and therefore not stored

Question 3

Synthesis/Secretion of Amine hormones

Answer 3

• All synthesized from Tyrosine
• Catecholamines are synthesized in the cytosol and secretory granules and act through cell membrane associated receptors (Dopamine, NE, Epinephrine)
• Thyroid hormones are synthesized in the thyroid gland and stored as thryoglobulins in thyroid follicles. Able to cross cell membranes of target tissue and act through nuclear receptors

Question 4

Which hormones elicit downstream signaling via the actions of: Adenylyl cyclase pathway (Gs)

Answer 4

• ACTH
• LH
• FSH
• TSH
• Glucagon

Question 5

Which hormones elicit downstream signaling via the actions of: PLC pathway (Gq)

Answer 5

• GnRH
• TRH
• GHRH
• Oxytocin

Question 6

Which hormones elicit downstream signaling via the actions of: Guanylyl cyclase

Answer 6

• ANP –> activates cGMP kinases

- Nitric Oxide –> relaxation of vascular smooth muscle

Question 7

Which hormones elicit downstream signaling via the actions of: Tyrosine kinases

Answer 7

• Receptor tyrosine kinases –> nerve growth factor (NGF) and insulin
• Tyrosine kinase-associated receptors –> Growth hormones (GH)