Diffusion
The movement of molecules from one location to another across a membrane
Net flux always proceeds from higher to lower concentrations
What is the direction of Diffusion?
1. Temperature
2. Mass of molecule
3. Surface area
4. Medium
What factors influence the magnitude of Diffusion?
increase net flux
Diffusion:
The higher temperatures will increase speed of molecules, which..
slower net flux
Diffusion:
The larger the molecule, the slower the speed. Which leads to...
greater net flux
The greater the space available for diffusion....
slower net flux
Diffusion:
The denser the medium...
Have no effect
Increasing the amount of ATP used in facilitated diffusion would ____________ movement of molecules across the cell membrane
Resting Membrane Potential
If Na+/K+ ATPase pumps were increased, which of the following would be most affected?
Increase
If the reuptake of neurotransmitter at the synaptic cleft was decreased, the signal strength would __________.
Increased Heart rate
If you were to administer a muscarinic receptor antagonist, like atropine, to a patient for irritable bowl syndrome, which additional effects would you expect to see?
4. A and B are incorrect statements regarding hormones
Which of the following statements is Incorrect regarding hormones? 1. Hormones will be secreted by a discrete group of cells derived from connective tissue.
2. Hormones will be secreted into the blood at high concentrations to be transported to a distant
Oxygen, carbon dioxide, fatty acids, and steroid hormones
Nonpolar molecules that diffuse rapidly through the lipid portions of membranes
Polar molecules and hydrophilic
What does not diffuse readily through the membranes
Binding and conformational shifts
Transporters do not move as many molecules as channels do because
Transporters
What can be saturated and reaches a maximum
>Ion permeability
>Charges of ions that are moving
>Ion distribution across the cell membrane
Which of the follow factors, if changed would alter the resting membrane potential?
Signal transmission zone
Which of the following neuronal zones is the site of electrical to chemical signal conversion?
Sodium or calcium
According to the Goldman equation, which of the following ions would depolarize a neuron?
Potassium or chloride
According to the Goldman equation, which of the following ions would hyperpolarize a neuron?
>Leakage of ions
>Cytoplasmic electrical resistance
>Electrical membrane properties
Which of the following factors may cause a decrement (decrease) in electric current spreading across the cell body of a neuron?
Opening of sodium channels
Which of the following is responsible for depolarizing the membrane?
Opening of potassium channels
Which of the following is responsible for repolarizing the membrane?
Sodium-potassium ATPase pump
Which of the following is responsible for correcting hyperpolarization of the membrane?
Not effect
Decreasing energy availability would ___________ the rate of repolarization.
Decrease
Decreasing the number of positively charged ions entering the cell would ___________ the rate of depolarization.
Decrease
Decreasing the number of positively charged ions exiting the cell would ___________ the rate of repolarization.
Decrease (make more positive)
Decreasing energy availability would ___________ the mV (millivoltage) of the resting membrane potential.
Absolute
Depolarization and repolarization phases will coincide with __________ refractory period.
Relative
The hyperpolarization phase will coincide with __________ refractory period.
Not effect
Increasing the uptake of a neurotransmitter from the synaptic cleft will _________ neurotransmitter binding on the presynaptic cell.
Decrease
Increasing the uptake of a neurotransmitter from the synaptic cleft will _________ neurotransmitter binding on the postsynaptic cell.
Increase
Increasing the calcium concentration around the presynaptic cell would __________ neurotransmitter release.
Depolarizing
An excitatory postsynaptic potential will cause a _________ event on the postsynaptic cell.
Hyperpolarizing
An inhibitory postsynaptic potential will cause a _________ event on the postsynaptic cell.
Signal Reception Zone (Dendrites and the cell body)
Receives incoming signals
1. Signal Reception Zone (Dendrites and the cell body)
2. Signal Integration Zone (Axon Hillock) 3. Signal Conduction Zone (Axon)
4. Signal Transmission Zone (Collaterals)
What are the four neural zones?
Signal Integration Zone (Axon Hillock)
Where the cell body meets the axon
Transporters
_________________ are specific for their ligand
Facilitated diffusion
What uses a concentration gradient?
Primary active transport
What directly uses ATP?
Secondary active transport
The use of an electrochemical gradient across a membrane to drive the process is present in _______________
Signal conduction zone (axon)
Neurons wrapped in a myelin sheath transmit the electrical signal
Signal transmission zone (collaterals)
Swelling at axon terminus where comes in close contact with the target cell; does not touch
Resting (unstimulated) cell membrane
In a ________________, it has the potential to conduct electrical signal or action potential
Resting Membrane Potential
Has a deficit of positive ions on the inside of the cell, so Cells are more (-) charged inside than outside
3; 2
In a Sodium-potassium pump, _______ sodium ions are pumped out of the cell, and _______ potassium ions pumped into the cell
Energy
The resting membrane potential requires ________ to maintain equilibrium
Depolarization
Na+ ; Membrane potential becomes less negative; Either positively charged ions enter the cell or negatively charged ions leaving the cell.
Repolarization
K+ ; Returns to the normal resting membrane potential; Either negatively charged ions enter the cell or positively charged ions leaving the cell
Hyperpolarization
Become more negative; Either negatively charged ions entering the cell or positively charged cells leaving
Spatial summation
Interaction of graded potentials from different receptors will "meet" at the axon hillock
Temporal summation
Interaction of graded potentials that occur at slightly different times at the axon hillock
Preganglionic neuron and Postganglionic neuron (Autonomic ganglia)
What are the 2 neurons of the Autonomic Nervous System?
Parasympathetic and Sympathetic
What are the 2 divisions of the Autonomic Nervous System?
Parasympathetic
>Controls routine maintenance or "housekeeping" functions when the body is at rest, "rest and digest"
>Digestion and waste motility
Sympathetic
>Controls "fight or flight" response
>Increases heart rate, vasoconstriction, respiration, pupil dilation and cell metabolism
>Decreases non-essential functions like digestion and waste motility
1. Cell bodies of preganglionic sympathetic and parasympathetic neurons are located in different regions of the CNS.
2. Locations of the ganglia differ
3. Differing relationship between the preganglionic and postganglionic neurons
What are the three anatomical differences of between the 2 divisions of the Autonomic Nervous System?
Agonist
A ligand that binds to a receptor and it activates the receptor.
Antagonist
A ligand that binds to a receptor and it does not activate the receptor
Neurotransmitter availability
>Availability of precursor molecules
>Activity of rate-limiting enzyme
Synaptic Signal Strength: Presynaptic Factors
>Neurotransmitter availability
>Axon terminal membrane potential (AP firing frequency, duration of AP train)
>Axon terminal calcium concentration
Synaptic Signal Strength : Neurotransmitter Release
Removal of unbound transmitter
Removal of unbound transmitter
>Diffusion away from cleft
>Enzymatic transformation into inactive substances
>Reuptake pumps
Excitable (excitatory postsynaptic potential or EPSP)
depolarizing event on postsynaptic cell membrane
Inhibitory (inhibitory postsynaptic potential or IPSP)
hyperpolarizing event on postsynaptic cell membrane
Electrical potential status
> Excitable (excitatory postsynaptic potential or EPSP)
> Inhibitory (inhibitory postsynaptic potential or IPSP)
>
Synaptic Signal Strength: Postsynaptic Factors
>Electrical potential status
>Up or down regulation of receptors (density)
>Desensitization of receptors (property)
Oxytocin
Which of the following would NOT be produced by the anterior pituitary?
A. Prolactin
B. Oxytocin
C. Growth hormone
D. Follicle stimulating hormone
E. Luteinizing hormone
growth hormone
Tropic hormones control the secretion of other hormones, what hormone is not trophic?
Decrease
As a pharmacist it is your responsibility to dispense the proper medication & one of your patients is diagnosed with polyuria(frequent urination). vasopressin would ____ urine production.