Chapter 12
The postsynaptic potential immediately follows the binding of neurotransmitter molecules that can ______.
Be both excitatory and inhibitory
A synapse is a junction _______.
Between a neuron and another cell
A _____ is best described as a channel that is usually closed that open in response to binding a neurotransmitter and that when open, allow a specific type of ion to diffuse across the plasma membrane.
Chemically gated channel
The tots length of the axon is called the _______ segment.
Conductive
Place the events of synaptic transmission from earliest to latest
1. Action potential reaches synaptic knob 2. Voltage gated calcium channels open 3. Calcium enters the synaptic knob 4. Calcium triggers exocytosis of vesicles 5. Neurotransmitter diffuses across synaptic cleft 6. Neurotransmitter binds to postsynaptic receptors
Place the events of an EPSP in order
1. Exciting neurotransmitter binds to chemically gated cation channel 2. More Na+ enters the postsynaptic cell than K+ leaves 3. The inside of the cell becomes more positive 4. The local current of Na+ becomes weaker as it moves towards the axon hillock
Place the events of a chloride-based IPSP in order from earliest to latest.
1. Inhibitory neurotransmitter binds to postsynaptic chemically gated chloride channels 2. Chloride moves from outside the cell to the inside. 3. The inside of the postsynaptic cell becomes more negative 4. The local chloride current becomes weaker as it moves away from the neurotransmitter binding site.
Match the location with the larger concentration or ions.
Extracellular - Sodium Intracellular - organic ions
______ neurons are most common.
Multipolar
Synapses occur where axons contact which of the following?
Muscle cells, gland cells, and other neurons
Which of the following pumps can you find in the plasma membrane?
Na+, K+, Ca2+
The ability to alter a response of neurons to neurotransmitters is known as ______.
Neuromodulation
The flow of _____ ion is the most common cause of depolarization.
Sodium
Which of the following ions have leak channels on the plasma membrane?
Sodium (Na+) and potassium (K+)
A change in membrane potential insufficient to cause potential is known as a _______ _______.
Subthreshold value
Which of the following are true of neurolemmocytes?
They are also called Schwann cells They create the myelin sheath in the PNS
Vesicles involved in retrograde transport are moving ______ the cell body.
Toward
______ are unique channels in that they have three states; resting, activation, and inactivation.
Voltage gated channels
The "I" in IPSP stands for ______, meaning that the potential makes the inside of the postsynaptic cell more _______.
Inhibitory, negative
If you were moving across a neurons membrane from the receptive segment towards the transmission e segment, in the ______ is where you would first encounter large numbers of voltage gated Na+ and K+ channels.
Initial segment
The _______ division of the nervous system is subdivided into the sympathetic and the parasympathetic divisions.
autonomic
The plasma membrane of an axon is called the ______.
axolemma
A soma is another name for the _____.
cell body
Dendrites branch off of the _______.
cell body
The tissues that receive nerve impulses from motor neurons are called _______.
effectors
The electrochemical gradient is formed from a combination of the _____ gradient and the _____ gradient.
electrical and chemical
Oligodendrocytes create the ______ sheath in the central nervous system.
myelin
Voltage is measure of relative _______ energy.
potential
during ______ ______ an axon is either incapable of generating an action potential or requires a larger than normal stimulus
refractory period
A return of the membrane potential towards the resting membrane potential immediately following depolarization is called _____.
repolarization
Relative difference in charge across the plasma membrane of a resting neuron is known as the ______ ______ _______.
resting membrane potential
Interneurons facilitate communication between ____ neurons and ____ neurons
sensory and motor
Neurons integrate multiple synaptic inputs by the process of _______.
summation
The junction between an axon and another cell is called a ______.
synapse
if several EPSPs occur at a synapse over a shot period of time, they undergo ______ at the initial segment
temporal summation
Pseudounipolar is another name for a _____ neuron.
unipolar
most afferent neurons are classified functionally as __________
unipolar
Which of the following are structural classifications of neurons?
unipolar, bipolar, multipolar
Which two are divisions of the sensory nervous system?
visceral division, somatic division
_____ is an acronym which is used to describe a postsynaptic graded potential in which the membrane becomes more negative on the inside.
IPSP
What must happen in order for a chemical signal to change the membrane potential of a neuron?
- There must be a change in the number of open ion channels - There must be a change in ion flow across the membrane
"An action potential either happens or it doesn't." This statement could also be called ______.
All-or-none law
Neurons are classified _______ depending kn the direction the nerve impulse travels.
Functionally
The components of the somatic sensory division are:
Hearing, taste, joints and muscles
The neurons in the retina of the eye are _____.
bipolar
