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Endocrine System: Endocrine System Review
1. Hormones act at specific target organs because these organs contain __________ specific for the hormones.
2. Growth hormone, secreted by the _____ _______ gland, stimulates growth of bones and muscle by activating intermediary proteins called ________________.
3. __________ (hormone) from the anterior pituitary stimulates secretion of cortisol from the ______ ________ (gland). The anterior pituitary consists of _________ tissue.
4. The parafollicular or C-cells of the ____________ gland produce __________, a peptide hormone that lowers plasma calcium levels.
5. Hormones secreted by the pancreatic islets of the pancreas include ___________ from the ? cells and _______________ from the ? cells. Which of these hormones raise blood glucose levels?
6. Specialized muscle cells in the heart produce _________ (hormone), which increases excretion of _______ (electrolyte) by the kidneys.
7. ___________ (hormone) promotes the final conversion of vitamin D to ___________ in the kidney.
8. __________ (hormone) produced by G-cells in the pyloric antrum stimulates _____ secretion in the stomach.
9. One ventral hypothalamic hormone (__________) is essential for the stress response and another (___________) inhibits release of prolactin.
10. ___________ (hormone) is a stimulus for sperm production in the male and maturation of ovarian follicles in the female.
11. ________, secreted by the pineal gland, helps regulate body activities with the light-dark cycle.
12. The zona glomerulosa of the adrenal cortex primarily produces the hormone ___________, which acts on the _________ (organ) to increase ___ (electrolyte) reabsorption.
13. _______ ________ (gland) is a modified sympathetic ganglion producing the amine hormones known as _______________. This category of amine hormones includes both __________ and ______________ (two hormones).
14. The ___________ (organ) produces a steroid hormone called ____________ in the interstitial cells and a peptide hormone called ___________ that inhibits FSH.
15. Large follicles in this gland (__________) contain a protein colloid called ______________ from which the hormones _______ and ______ are made. These hormones regulate many metabolic functions and are important for nervous system development and growth.
16. Nuclei in the ventral hypothalamus produce two hormones that are stored in the posterior pituitary. Name the two nuclei that produce these hormones and name the two hormones, one of which is important for water balance.
Endocrine System: The Hypothalamic–Pituitary Axis
1. The anterior pituitary is composed of __________ tissue. Name the six classic hormones whose functions are well known.
a.
b.
c.
d.
e.
f.
2. TRH, GNRH, CRH etc. are known as ____________ hypothalamic hormones which regulate the function of the _________ pituitary. These hormones are released into capillary beds and carried directly to the pituitary by the __________ ________ ________ located in the __________________.
3. _____________ and ________________, the posterior pituitary hormones are synthesized in the ____________ and _______________ nuclei of the hypothalamus. They are stored in the axon terminals located in the __________ pituitary. Similar to neurotransmitters, an ________ ________ in the neuron causes their release.
4. In negative feedback, the target hormone feeds back to alter the release of the anterior or hypothalamic hormones thus (increasing or decreasing) its own release.
5. Give an example of a hormone that has negative feedback mainly to the anterior pituitary. __________
Give an example of a hormone that has negative feedback to both the anterior pituitary and the ventral hypothalamus. ____________
6. Prolactin is unique in that the main ventral hypothalamic hormone regulating its secretion (___________), inhibits its release.
____________ (hormone) increases prolactin release. Very high levels of this hormone during pregnancy actually block the effect of prolactin on milk production.
7. _________ hormones are necessary for the release of __________ hormone. This is an example of modulation of a hormone by a target hormone of another series.
8. Suckling of an infant causes milk letdown by stimulating what hormone? ____________
Changes in osmolarity detected by chemically sensitive neurons in the hypothalamus will alter what hormone's level? ______________
9. Cortisol release is synchronized by the light/dark cycle and has a 24 hour pattern of secretion known as a _____________ rhythm. Levels are highest at what part of the day? ___________
10. Besides controlling levels of T3 and T4, TSH also promotes __________ of the thyroid gland. T3 and T4 are carried in the blood stream bound to _________ ________ because they are (hydrophilic or lipophilic).
11. T3 and T4 enter the target cells by __________ and bind to receptors located ______________. T3 and T4 are synthesized from ___________ and __________.
12. Which of the following would be symptoms of hypothyroidism also known as ___________?
lethargy or hyperexcitability
high BMR or low BMR
high heart rate or low to normal heart rate
feeling cold or sweating
weight loss or weight gain
13. Lack of dietary iodine would cause (primary or secondary) hypothyroidism and the patient would probably get an iodine-deficient _________.
14. Graves' disease is the most common cause of primary ___________________ . The body secretes _________ __________ ____________, which mimics the action of TSH and thus may cause a ___________ as well as high levels of thyroid hormones.
The Nervous System: Ion Channels
1. What structures in the cell membrane function as ion channels?
2. Ion channels are selective for specific ions. What three characteristics of the ions are important for this selectivity?
a.
b.
c.
3. Channels can be classified as either gated or nongated channels. A sodium channel that is always open would be classified as a/an __________channel.
4. Would sodium ions move into or out of the neuron through these channels?
_______________
5. Voltage-gated potassium channels open at what voltage? __________ mV
6. Acetylcholine (ACh) and GABA are neurotransmitters that open chemically-gated channels. What ions pass into the cell when these channels are activated?
a. ACh: ___________________ _____ ions
b. GABA: ___________________ _____ ions
7. Ion channels are regionally located and functionally unique. List all the areas on the neuron and the type of potential dependent on the following types of ion channels:
Channels Areas on the neuron Type of potential
Nongated
Chemically-gated
Voltage-gated
8. From the quiz, place an “X” by the characteristics of voltage-gated sodium channels.
______ Always open
______ Found along the axon
______ Important for action potential
______ Opened and closed by gates
______ Found on the dendrites and cell bodies
______ Important for resting membrane potential
9. Name two channels (gated or nongated) through which chloride ions could pass into the cell through.
a.
b.
10. a. The Japanese puffer fish contains a deadly toxin (tetrodotoxin). What type
of channels does this toxin block? ___________________ ____________
b. What potential would this toxin block? ___________________ ________
c. What specifically would cause death? ___________________ _________
The Nervous System: Membrane Potential
1. Record the intracellular and extracellular concentrations of the following ions (mM/L):
Intracellular Extracellular
Sodium (Na+)
Potassium (K+)
Chloride (Cl–)
2. Excitable cells, like neurons, are more permeable to ___________ than to ___________.
3. How would the following alterations affect the membrane permeability to K+? Use arrows to indicate the change in permeability.
a. An increase in the number of passive K+ channels ___________
b. Opening of voltage-gated K+ channels ___________
c. Closing of voltage-gated K+ channels ___________
4. a. What acts as a chemical force that pushes K+ out of the cell? ___________
b. What force tends to pull K+ back into the cell? ___________________ __
5. When the two forces listed above are equal and opposite in a cell permeable
only to K+, this is called the ___________________ ______ potential for K+
which is ___________ mV.
6. In an excitable cell, also permeable to Na+ and Cl–, the gradients mentioned
in question 4 would both tend to move Na+ ___________ the cell.
7. Would the gradients in question 4 promote or oppose the movement of Cl– into the cell?
a.
b.
8. Since the neuron is permeable to Na+ as well as K+, the resting membrane
potential is not equal to the equilibrium potential for K+, instead it is
___________ mV.
9. What compensates for the movement (leakage) of Na+ and K+ ions? ______________
10. What will happen to the resting membrane potential of an excitable cell if: (Write pos or neg to indicate which way the membrane potential would change.)
a. ? extracellular fluid concentration of K+ ___________
b. ? extracellular fluid concentration of K+ ___________
c. ? extracellular fluid concentration of Na+ ___________
d. ? number of passive Na+ channels ___________
e. open voltage-gated K+ channels ___________
f. open voltage-gated Na+ channels ___________
The Nervous System: The Action Potential
1. a. The action potential changes the membrane potential from _______
mV (resting) to _______ mV and back again to the resting membrane
potential.
b. This results from a change in membrane permeability first to _______
then to _______ due to the opening of what type of ion channels?
___________________ __________________
2. a. Where is the density of voltage-gated Na+ channels the greatest?
__________________
b. What areas of the neuron generate signals that open these voltage-gated
channels? ___________________ ___________________ ____
c. Opening of these channels causes the membrane to
__________________ (voltage change).
3. a. If the membrane reaches the trigger point, known as
__________________, what electrical potential will be generated?
___________________ ___________________ ____
b. During the depolarization phase, voltage-gated __________ channels open
and _______ enters the cell.
4. What are the two processes that stop the potential from rising above +30 mV?
a.
b.
5. a. The opening of voltage-gated K+ channels cause the membrane to
___________________ __.
b. Does K+ move into or out of the cell? __________________
c. If the membrane potential becomes more negative than –70 mV, this is
called _________.
d. This potential is caused by what characteristic of K+ permeability?
_____________________________
_____________
6. a. After an action potential, the neuron cannot generate another action
potential because _______ channels are inactived. This period is called the
___________________ ____ period.
b. During the ___________________ ___ period, the cell can generate
another action potential but only if the membrane is ___________ (more or
less) depolarized.
7. a. Conduction velocity along the axon is increased by what two characteristics?
1. ___________________ _____________
2. ___________________ _____________
b. Conduction along a myelinated axon is called
___________________ _______ conduction.
8. a. Name the disease whose symptoms include loss of vision and increasing
muscle weakness: ___________________ _______(from the quiz section)
b. What does this disease destroy? ___________________ _____________
c. How does this stop an action potential?
The Nervous System II: Ion Channels
1. List four neurotransmitters that bind to ion channels, these neurotransmitters
are called ___________________ ________-acting neurotransmitters.
a.
b.
c.
d.
2. a. The binding of ACh opens ion channels in the dendrites or cell body that
permits both _______ and ____________ to move through them.
b. Which ion would move into the cell? ______________ out of the cell?
______________
c. Which ion has the greatest electrochemical gradient? ______________
d. The net movement of these two ions would do what to the cell?
_________________
e. This would be called an ___________________ __________
postsynaptic potential, or ___________________ _.
3. a. An inhibitory postsynaptic potential (IPSP) causes a neuron to
___________________ .
b. An example of a neurotransmitter that causes an IPSP is ______________.
c. What type of ions move into the cell in response to this neurotransmitter?
______________.
4. a. Norepinephrine binds to a receptor that is separate from the ion channel.
This is known as a/an ___________________ ___________ - acting
neurotransmitter.
b. Norepinephrine is known as the ___________________ ________ messenger.
c. The receptor is coupled to the ion channel by a ___________________ .
5. a. This activates an enzyme which induces the production of a
_____________ messenger.
b. An intracellular enzyme is activated and ___________________ _ the ion channel.
c. As a result of this sequence of events, what channels are closed?
___________________ _
d. What does this do to the neuron? ___________________ ___________
6. Name three neurotransmitters that can only act indirectly.
a.
b.
c.
7. Which of the four neurotransmitters mentioned in question 1 can also act indirectly?
a.
b.
c.
8. Which one of the four neurotransmitters mentioned in question 1 can
only act directly? ___________________ ___
The Nervous System II: Synaptic Transmission
1. What channels in the presynaptic neuron open up in response to an action
potential? ___________________ _____
2. The presence of what ion inside the cell causes the synaptic vesicles to
fuse with the membrane? ________
3. a. What is the name for the chemicals stored in the synaptic vesicles?
____________
b. What do these chemicals diffuse across? ___________________ ______
c. Where do these chemicals bind to receptors? ___________________ ___
4. What type of gated channels do these chemicals open? ________________
5. Name two ways these chemicals can be removed from the synaptic cleft.
a.
b.
6. The response on the postsynaptic cell depends on two factors:
a.
b.
7. Name the two types of cholinergic receptors and indicate where these are found.
Type Found
excitatory:
inhibitory:
8. Indicate where the following three adrenergic receptors are found:
?1
?1
?2
9. Autonomic nerves innervate what three things?
10. The most common excitatory neurotransmitter in the CNS is
________________.
11. Two major inhibitory neurotransmitters in the CNS are:
a.
b.
12. Name a drug that alters synaptic transmission in the following ways:
a. blocks the action of the neurotransmitter at the postsynaptic membrane
__________________.
b. blocks the reuptake of the neurotransmitter at the presynaptic membrane
________________.
c. blocks the release of the neurotransmitter ___________________ and
___________________ .
The Nervous System II: Synaptic Potentials and Cellular Integration
1. Enhanced postsynaptic potentials are due to increased _______ entering the
terminal as a result of ___________________ _________________.
2. Presynaptic inhibition is due to decreased _______ entering the terminal as
a result of ___________________ _________________.
3. a. Synaptic potentials are also known as ______________ potentials.
b. They _____________ as they travel away from the synapse.
4. a. Increasing the number of action potentials on an axon in a given period
of time would cause ___________________ _______ summation.
b. Increasing the number of synapses from different neurons would cause
__________________ summation.
5. The magnitude of the EPSPs may be reduced (thus affecting their ability to
generate and their action potential) by adding ___________________ ____
potentials, or ___________________ _s.
6. Inhibitory synapses would have the maximum effect if located where?
___________________________
7. From the quiz, how many impulses did it take to cause an action potential:
a. From the axon the furthest away from the cell body? ___________
b. From the axon located on the cell body? ___________
8. Pulses from how many neurons were required to stimulate the postsynaptic
neuron? _________________
9. Compare action potentials and synaptic potentials:
Action Potential Synaptic Potential
Function
Depolarization/
hyperpolarizations
Magnitude
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