Endocrine Control Overview Flashcards
A hormone is a blood-borne chemical mediator that is released from ….. glands that acts on distance target cells
endocrine
hormones have …..(one/multiple)…targets and functions
multiple
rate of secretion of some hormones varies over time, following a ….. pattern
cyclical
…. signals act on the same cell that secreted them.
…. signals are secreted by one cell and diffuse to adjacent cells.
Autocrine
Paracrine
hydrophobic hormones tend to be lipid …..
lipophilic hormones tend to be hydro….
lipophilic
hydrophobic
….. are chemicals released by neurons into blood for action at distance targets
neurohormones (neurocrines)
3 major groups/source glands of neurocrines?
1, anterior and 2. posterior pituitary of hypothalamus
3. catecholamines (made by modified adrenal medulla neurons)
…. hormones are those that cause the stimulation of another downstream hormone.
Tropic.
(also tends to have names that end in -tropin,
ie thyrotropin, corticotropin, ACTH)
… hormones tend to stimulate growth and development
Trophic
The …… pathway involves a stimulus acting on a sensory neuron receptor, releasing neurotransmitter on a CNS integrating centre, then ….. neuron releasing NT on a target cell, eliciting a response.
Simple neural reflex.
Efferent.
The Neurohormone reflex pathway involves a stimulus acting on a sensory neuron receptor, releasing NT on a CNS integrating centre, then efferent neuron release ……. into the …… where it effects target cell(s), eliciting a response.
Neurohormone.
Blood stream/circulation/systemically/blood vessel.
The …… pathway involves a stimulus acting on a sensory neuron receptor, releasing NT onto a CNS integrating centre, then release NT or NH (neurohormone) onto a set or series of endocrine cell(s) and blood vessel(s), causing release of classic hormone onto a target cell, eliciting a response.
neuroendocrine reflex pathway.
The ….. pathway involves a stimulus on to an endocrine cell, causing release of hormone in the blood stream, effecting a target cell, eliciting a response.
simple endocrine reflex
Peptide hormones are made in advance, stored in [……..], released from parent cell via [….cytosis], transported in blood by [……..], exhibit [hydro…] and [lipo…] properties, have a [short/long] half life, and have receptors located on [….].
secretory vesicles.
exocytosis.
being dissolved in plasma
hydrophilic, lipophobic
Short.
cell membranes.
Steroid hormones are made on demand from precursors, released from parent cell via [……], exhibit [lipo…] and [hydro…] properties, transported in blood by [….], [short/long] half-life, with receptors located on […., ……., and…..]
Simple diffusion.
Lipophilic and Hydrophobic
Carrier proteins.
Long.
Cytoplasm, nucleus, and cell membrane.
Compare & contrast the amine subtypes: catecholamines vs thyroid hormones
Both made in advance and stored in secretory vesicles.
Catecholamines:
- Short half life
- Cell membrane receptor
- activate second messenger systems
- released via exociytosis
- hydrophilic (lipophobic)
- modify existing proteins
Thyroid:
- long half life
- nucleus receptor
- activate genes
- hydrophobic (lipophilic)
- induce new proteins synthesis
[…..] is the parent compound for all steroid hormones
cholesterol
[…..] is the parent compound for amine hormones
tyrosine
Both peptides and catecholamines bind to a [….] receptor and generate a [….. …..] signal
surface
second-messenger
Both [….] and [….] hormones bind nuclear or cytoplasmic receptors, causing altered gene expression and production of new proteins
steroid and thyroid hormones
the plasma concentration of free, biologically active hormones which can interact with its target cells to produce a physiologic response depends on what 4 factors?
- rate of secretion by endocrine gland major factor*
- rate of metabolic activation (some hormones)
- extend of binding to lipophilic hormones (lipid hormones)
- rate of metabolic inactivation and excretion
steroid hormones are removed via the process of [….] and excreted in the [….]
conjugation
urine (and bile)
peptide hormones are removed via the process of [….]
receptor mediated endocytosis (recycled)
[….] regulation described a hormonal regulation where a first hormone cannot exert effect without the presence of a second hormone
permissive regulation.
ex. cortisol and adrenaline
