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