Neural Conduction And Synaptic Transmission

Front 1

________________ are narrow spaces between adjacent cells that are bridged by fine, tubular cytoplasm-filled protein channels called _____________.

Back 1

Gap junctions; connexins

Front 2

______________ and _____________ are two mechanisms of terminating synaptic messages.

Back 2

Reuptake; enzymatic degradation

Front 3

______________ is the more common of the two deactivating mechanisms.

Back 3

Reuptake

Front 4

Any molecule that binds to another is referred to as its ____________.

Back 4

Ligand

Front 5

_____________ receptors are associated with ligand-activated ion channels and ___________ receptors are associated with signal proteins and G-proteins.

Back 5

Ionotropic; metabotropic

Front 6

_______________ are short amino acid chains comprising between 3 and 36 amino acids; in effect, they are short proteins.

Back 6

Neuropeptides

Front 7

There are two basic categories of neurotransmitter molecules: ________ and _________.

Back 7

Small; large

Front 8

Small-molecule neurotransmitters are typically synthesized in the cytoplasm of the terminal button and packaged in ___________________ by the button's _____________.

Back 8

Synaptic vesicles; Golgi complex

Front 9

It was once believed that each neuron synthesizes and releases only one neurotransmitter, but we now know that many neurons contain two neurotransmitters - a situation referred to as ______________.

Back 9

Coexistence

Front 10

________________ is the process of neurotransmitter release.

Back 10

Exocytosis

Front 11

Amino acids are the neurotransmitters in the vast majority of ____________ acting, directed synapses.

Back 11

Fast

Front 12

Name the four amino acids which are widely recognized neurotransmitters.

Back 12

GABA; glutamate; aspartate, glycine

Front 13

In contrast to the amino acid neurotransmitters, the ___________ are small-molecule neurotransmitters with slower, more diffuse effects; they belong to one of two categories: __________ or indolamines.

Back 13

Monoamines; catecholamines

Front 14

Tremor-at-rest is a symptom of _____________.

Back 14

Parkinson's Disease

Front 15

Microelectrodes are required to record a neuron's resting ____________.

Back 15

Potential

Front 16

The ____________ is about -70mv.

Back 16

Resting potential

Front 17

In its resting state, a neuron is said to be _________________.

Back 17

Polarized

Front 18

Two factors pressure Na+ ions to enter resting neurons; random ____________ and electrostatic pressure.

Back 18

Motion

Front 19

In the resting state, there is a greater concentration of Na+ ions _________ the neuron than __________ the neuron.

Back 19

Outside; inside

Front 20

Natrium is Latin for ____________.

Back 20

Sodium

Front 21

Ions pass through neuron membranes via specialized pores called _____________.

Back 21

Ion channels

Front 22

From their studies, Hodgkin and Huxley inferred the existence of _______________ in neural membranes, the first neural transporters to be discovered.

Back 22

Sodium-potassium pumps

Front 23

Neurotransmitters typically have one of two effects on postsynaptic neurons: they either depolarize them or ________________ them.

Back 23

Hyperpolarize

Front 24

Neurons integrate postsynaptic potentials in two ways: through spatial summation and through ___________ summation.

Back 24

Temporal

Front 25

Unlike postsynaptic potentials, which are graded, action potentials are ____________ responses.

Back 25

All-or-none

Front 26

An action potential is elicited when the depolarization of the neuron reaches its _________________.

Back 26

Threshold of excitation