Endocrine System Pt. 1 Flashcards
The endocrine system works with the nervous system to ____
Control and coordinate all body functions or to maintain homeostasis
Similar in action like nervous it has messengers (like the neurotransmitters in the nervous) called
hormones
What are hormones made by
endocrine gland cells or modified neurons
T/F Nervous system works quickly but cannot sustain responses for an extended period of time
True
How fast does the endocrine system work
works slowly but can sustain responses for long periods
Where are endocrine glands located
throughout the body
What do endocrine glands secrete and where do they secrete these thing directly to
secrete minute amounts of hormones and goes directly to the bloodstream
What differentiates endocrine glands from exocrine glands
they are ductless glands
Exocrine glands secrete things through ducts
When is an action only produced
Only produces an action when the hormone is bound to their specific receptor either in the cell or on the cell
What happens if the hormone doesn’t fit in the receptor
it won’t bind (acts as a key)
If a cell has a receptor for a specific hormone, it is called
the cell is a target for the hormone
three main groups of hormones
peptides, steroid, monoamine
peptide hormones have chains of what
amino acids (AAs) can be a few or up to >200
are peptides hydrophilic or hydrophobic
hydrophilic (water soluble)
What is the benefit of peptides being hydrophilic
makes it easier to travel in blood
where are the receptors of peptide hormones found
on cell membranes of targets
Steroid hormones are ______ made from
Lipids made from Cholesterol
Since the steroid hormones are made from lipids, are they hydrophilic or hydrophobic
hydrophobic or insoluble in water
since steroids are hydrophobic, what must they do so they can travel through the blood
must bind to a hydrophilic transport protein to move in plasma
hormones attached to a transport protein are called
“bound hormones”
Hormones that are not attached to a transport protein are
“free hormone / unbound”
“free /unbounded” hormones are the only steroid hormones that can what
leave the bloodstream and reach the target cell
where are receptors for steroid hormones found
inside the cell
either in the cytoplasm or nucleus
Lipids make it easier for the steroid hormones to do what
easier to pass through the cell wall
Monoamine hormones are derived from
derived from amino acids and retain an amino group
group gives name
one type of monoamine hormones is catecholamine. what are two catecholamine
epinephrine and norepinephrine
is epi/norepi hydrophilic or hydrophobic
hydrophilic
dissolved in plasma like peptides
where are epi/norepi receptors located
on cell membranes
Another type of monoamine hormones that are not catecholamine is
thyroid hormones
are thyroid hormones hydrophilic or hydrophobic
hydrophobic like steroid hormones
require transport proteins
where are the thyroid hormone receptors found
inside the cell
hormone levels act ___________ or __________ on the gland itself
directly or indirectly
if gland activity is decreased, then there is a high level of circulating hormones. This is considered
negative feedback
If gland activity is increase, then there is lower levels of circulating hormones. This is considered
positive feedback
what type of feedback is most common?
negative feedback
Example of negative feedback
Thyroid stimulating hormone -> Thyroid gland -> thyroid hormone
When circulating thyroid hormone levels drop
* TSH is pumped out of the anterior pituitary
o Acts on the thyroid gland
Increases thyroid hormone productions
* When at selected level
o TSH is anterior pituitary is slowed
Stops working on thyroid gland
How does positive feedback work?
Rising levels of hormone production by a gland feedback and increase hormone production
Positive feedback is less common bc is has a potential to
Potential to lead to a “viscous cycles” of out of control hormone production
what is an example of positive feedback
female estrous cycle
In a non-feedback-related control, hormones from __________ are stimulated by what
Hormones from the adrenal medulla are stimulated by the sympathetic nervous system
