Lecture 13: Hormone Synthesis, Regulation of Hormone Secretion, and Hormone Receptors Flashcards
Most hormones are synthesized in and excreted by
Glands
Some molecules can be both
Neurotransmitters and hormones
Dynamic equilibrium definiton
As changes occur, body works to maintain uniform conditions
What are the 3 mechanisms to restore and maintain homeostasis
Receptor, control center, effector
What mechanism of homeostasis receives info about changes
Receptor
What mechanism of homeostasis receives and processes info
Control center
What mechanism of homeostasis responds to commands of CC by opposing or enhancing stimulus
Effector
What kind of loops does homeostasis use?
Negative feedback
Define negative feedback loop broadly
System that is going to act in a way to reverse direction of change
Does positive feedback result in homeostasis?
No
Positive feedback ______ change in variable
amplifies
Name the four hormone signaling pathways
Endocrine/telecrine, neurocrine, autocrine, paracrine
Hormone signaling pathway that travels long distances via blood to target tissue
Endocrine/telecrine
Hormone signaling pathway that is secreted by neuron in blood
Neurocrine
Hormone signaling pathway that exerts effects on itself or very close identical cells
Autocrine
Hormone signaling pathway that has close target cells, diffusing through interstitial fluid, does not go in blood
Paracrine
T/F: Paracrine signaling pathways travel through blood
False
Name the 4 hormone classifications
Peptides and proteins; steroids, amines; eicosanoids
Hormone classification who’s structure differs across species, structure can effect speed at which works
Peptides and proteins
Peptides and proteins are synthesized from
Amino acids
Hormone classification who’s structure is conserved across species for most and is synthesized from cholesterol
Steroids
Which hormone classification is synthesized from cholesterol?
Steroids
What hormone classification is synthesized from tyrosine?
Amines
What hormone classification is synthesized from fatty acids?
Eicosanoids
Examples of peptide/protein hormones
Insulin, growth factors, growth hormone, parathyroid hormone, thyroid-stimulating hormone, antidiuretic hormone
What allows similar peptide hormones to act on multiple receptors?
Structures of peptide hormones can be very similar and only differ be a side chain
Growth factor hormone can act on
Insulin receptors
Steps in synthesis of peptide and protein hormones:
____ is transcribed and travels to ______
mRNA; cytoplasm
Steps in synthesis of peptide and protein hormones:
1. mRNA is transcribed and travels to cytoplasm.
2. Message is _______ on _____
translated; ribosome
Steps in synthesis of peptide and protein hormones:
1. mRNA is transcribed and travels to cytoplasm.
2. Message is translated on ribosome.
3. Product is ________, now transferred to ______.
prehormone; ER
Prehormone bigger or smaller than final hormone?
Bigger
Steps in synthesis of peptide and protein hormones:
1. mRNA is transcribed and travels to cytoplasm.
2. Message is translated on ribosome.
3. Product is prehormone, now transferred to ER.
4. _________ degraded in ER.
Signal peptide
Steps in synthesis of peptide and protein hormones:
1. mRNA is transcribed and travels to cytoplasm.
2. Message is translated on ribosome.
3. Product is prehormone, now transferred to ER.
4. Signal peptide degraded in ER - results in ______, now transferred to ____.
Prohormone; Golgi
Prohormone is packaged into
Secretory granule
When endocrine cell stimulated,
granule contents (containing hormone) released
Catecholamines are synthesized using
Tyrosine
Epinephrine, norepinephrine, and dopamine are
Catecholamines
Thyroid hormones are synthesizes from
Tyrosine and iodide
Thyroglobulin is used for
Thyroid hormone secretion
Cortistol, aldosterone, androgens, estrogen, Vitamin D are examples of
Steroid hormones
Steroid hormones are stored or created when needed?
Created when needed
Prostaglandins have ______ actions
Paracrine
Synthesized using arachidonic acids
Prostaglandins
Regulation of hormone secretion involves which mechanisms?
Neural mechanisms and feedback mechanisms
Which is more common in regulation of hormone secretion, neural mechanisms or feedback mechanisms?
Feedback mechanisms
Hormone from target tissue feeds back to original release point, such as pituitary or hypothalamus
Long feedback loop
Negative feedback from pituitary to hypothalamus
Short feedback loop
Hypothalamic hormone inhibits own secretion
Ultra-short
