Lecture 20 Flashcards
What are hormones?
chemical messengers secreted into blood by specialized epithelial cells affecting distant target tissues
What are 5 functions that hormones are responsible for?
metabolism | regulation of internal functions | reproduction | growth | development
What are the classic endocrine tissues called?
glands
What are the 3 things that hormones control?
rates of enzymatic reactions | transport ions/molecules across cell membranes | gene expression
What does the history of hormones tell us?
lack of iodine can cause changes in body
What organ removal is known to change animal behavior?
testes as it contains many hormones
What is organotherapy?
direct injection of hormones
What are pheromones?
ecto-hormones = secreted to the outside environment
Where are neurohormones released from?
neurons
Where are cytokines released from?
immune cells
How much hormone is needed in order to induce a physiological effect?
very low concentrations
What are releasing hormones?
hypothalamic regulating hormones (factors) | releases other hormones
What are eicosanoids?
lipid-derived molecules
What is the hypothalamus?
under the thalamus | regulates hormone levels
Where is the pituitary gland located?
under hypothalamus = communicates with hypothalamus constantly
What does the thalamus act as?
gateway between the brain and body
What must hormones bind to in order to elicit a physiological response?
hormone receptors
What are the 3 ways in which hormone action is terminated?
limit secretion | degradation (removal/inactivation) | terminate activity in target cells
Which part, anterior or posterior, of the pituitary is a true endocrine gland?
anterior pituitary gland
What is the posterior pituitary?
neuronal tissue
What other organs that don’t have the word “gland” are true endocrine glands?
hypothalamus | pancreas | adrenal on kidneys | testes | ovaries
What is a requirement for classic endocrine organs/glands to have?
epithelial structure
What is the thymus gland involved in?
self-defense
What is the main effect of the atrial natriuretic peptide?
increase sodium excretion from water
How are peptide hormones released from parent cell? Is the half-life long or short?
exocytosis | short
How are steroid hormones released from parent cell? Is the half-life long or short?
simple diffusion | long
What are 2 types of amine hormones?
catecholamines | thyroid hormones
How are catecholamines released from parent cell? Is the half-life long or short?
exocytosis | short
How are thyroid hormones released from parent cell? Is the half-life long or short?
transport proteins | long
What are preprohormones?
hormone with a signal sequence and peptide fragments attached to it
What do the peptide fragments and signal sequence prevent the hormone from doing?
prevents hormone from being activated before getting into the circulation | these need to be cleaved for the hormone to be activated
What is the function of the signal sequence on the preprohormone molecule?
guides and directs preprohormone to the ER lumen
What are 2 ways hormones can initiate a signaling cascade within a cell?
hormone+receptor activates GPCR | hormone+receptor = activates tyrosine kinase
How is cAMP made?
adenylate cyclase converts ATP into cAMP
What is the precursor of steroid hormones?
cholesterol
What is cholesterol immediately converted into in the making of most steroid hormones?
DHEA
Since steroid hormones are lipophilic, how are they transported throughout the circulation?
binds to plasma protein carrier
What is the differences between the simple endocrine reflex and multiple pathways of endocrine reflex?
multiple pathway endocrine reflex = more than one stimulus = one result | simple endocrine reflex = one stimulus = one result
What does the stomach have that tell the brain the animal has ate a meal?
stomach has stretch receptors
What are the 3 types of signaling molecules?
neurotransmitters (local/paracrine) | hormones (distant target, not local) | pheromones (excreted to influence other animals)
What are 3 pheromones reviewed in lecture?
CO2 | lactic acid | light
How can the Anophaeles gambiae mosquito find us if they cannot see/sense well?
pheromones | we excrete CO2 (exhaling) and lactic acid (in sweat)
What is CRISPR used for?
modifying specific gene sequence
What are the 2 most important endocrine glands in the body?
pituitary | hypothalamus
What are the 2 neurohormones the posterior pituitary stores and releases? Where are these made?
oxytocin | vasopressin | made in hypothalamus
What is the hormone oxytocin? What organ is it active on/effects?
involved in childbirth and lactation, start out as preprohormone | on gonads
What is the hormone vasopressin? What organ is it active on/effects?
ADH = antidiuretic hormone = prevents body from losing a lot of water, start as preprohormone | on kidneys
What are the 6 hormones that the anterior pituitary makes?
prolactin (PRL) | thyrotropin (TSH) | adrenocorticotropin (ACTH) | growth hormone (GH) | follicle stimulating hormone (FSH) | luteinizing hormone (LH)
What dictates the secretion of the hormones made in the anterior pituitary?
hypothalamus
What is the growth hormone inhibiting hormone (GHIH)?
somatostatin
What does prolactin (PRL) affect?
controls milk production
What does the growth hormone (GH) affect?
affects metabolism in many tissues
What do FSH and LH affect?
affects ovaries and testes
What does the TH affect?
thyroid gland
What does ACTH affect?
adrenal gland
What hormone inhibits the prolactin hormone?
dopamine (PIH)
In the Hypothalamus-Pituitary pathway, what is the short-loop feedback to and from?
from pituitary to hypothalamus
In the Hypothalamus-Pituitary pathway, what is the long-loop feedback to and from?
hormone released by target organ all the up to the pituitary or hypothalamus
