Chapter 3 Synapses

Question 1

In 1906, ______physiologically demonstrated that communication between one neuron and he next differs from communication along a single axon. He inferred a specialized gap between neurons and introduced the term synapse to describe it.

Answer 1

Charles Scott Sherington

Question 2

repeats stimuli can have a cumulative effect and can produce a nerve impulse when a single stimuli is too weak. Ex. Pinch dogs paw multiple times.

Answer 2

Temporal Summation

Question 3

synaptic input from several locations can have a cumulative effect and trigger nerve impulses. Ex. Pinch dog in multiple spots

Answer 3

Spatial Summation

Question 4

neuron delivers the synaptic transmission. Calcium must enter the ________in order to evoke the release of the neurotransmitter

Answer 4

Presynaptic Neuron

Question 5

neuron that receives the message

Answer 5

PostSynaptic Neuron

Question 6

Graded potential (variability in action potentials) that decays over time and space
The cumulative effect of ____s are the basis for temporal and spatial summation.
During ______sodium gates open

Answer 6

Excitatory Post Synaptic Potential (EPSP)

Question 7

An ____ occurs when synaptic input opens the gates for positively charged potassium ions to leave the cells or negatively charged chloride ions to ender the cells
Served as an active “brake” that suppresses excitation.
During ____ potassium or chloride gates open.

Answer 7

Inhibitory Postsynaptic Potentials

Question 8

INCREASE the number of action potentials above the spontaneous firing rate.

Answer 8

EPSP

Question 9

DECREASE the number of actions potentials below the spontaneous firing rate.

Answer 9

IPSP

Question 10

German physiologist ____ was the first to convincingly demonstrate that communication across the synapses occurs via chemical means by experimenting with frog’s vagus nerve.

Answer 10

Otto Leowi

Question 11

chemicals that travel across the synapse and allow communication between neurons.

Answer 11

Neurotransmitters

Question 12

tiny spherical packets located in the presynaptic terminal where neurotransmitters are held for release

Answer 12

Vesicle

Question 13

excretion of neurotransmitter from pre-synaptic terminal into the synaptic cleft Triggered by action potentials arriving from the axon

Answer 13

Exocytosis

Question 14

acids containing an amine group (NH2)

Answer 14

Amino Acid

Question 15

chemicals formed by a change in certain amino acids.

Answer 15

Monoamines

Question 16

( a one member family) a chemical similar to an amino acid, except that it includes an N (CH3)3 group instead of an NH2.

Answer 16

Acetylcholine

Question 17

chains of amino acids.

Answer 17

Neuropeptides

Question 18

a category of chemicals including adenosine and several of its derivatives.

Answer 18

Purines

Question 19

a gas release by many small local neurons, _______ is poisonous in large quantities yet many neurons contain the enzyme that enables them to make nitric acid. One special function of nitric oxide relates to blood flow, nitric oxide sends messages to blood in order to now which brain area became more active and also dilates nearby blood vessels therefore increasing blood flow to the brain.

Answer 19

Nitric Oxide

Question 20

Neurons that release serotonin, dopamine, or norepinephrine, contain an enzyme _____that breaks down these transmitters into inactive chemicals

Answer 20

Momoamine Oxide (MAO)

Question 21

o At one type of receptor, neurotransmitters exert i
________corresponding to the brief on/off effects in Sherrington and Eccles study. When the neurotransmitter binds to an ionotropic receptor it twists the receptor enough to open its central channel, which is shaped to let a particular type of ion pass through.

Answer 21

Ionotropic Effects

Question 22

The channels controlled by a neurotransmitter, when a neurotransmitter attaches it open a channel.

Answer 22

Transmitter gated or ligand gatd channels

Question 23

At other receptors, neurotransmitters exert _______ effects by initiating a sequence of metabolic reactions that are slower and longer lasting than ionotropic effects.

Answer 23

Metabotropic Effects

Question 24

a protein coupled to guanosine triphosphate (GTP) an energy-storing molecule, bending the receptor proteins detaches that __________which is then free to take its energy elsewhere in the cell.

Answer 24

G Proteins

Question 25

a kind of neuron that is shaped more like a glia cell releases huge amounts of GABA all at once forming a “cloud: that spreads to large number of neurons in the area, producing widespread inhibition.

Answer 25

Neurogliaform Cell

Question 26

a chemical that is secreted by cells in one part of the body and conveyed by blood to influence other cells, can travel longer distances than neurotransmitters, coordinate long-lasting changed in multiple parts of the body.

Answer 26

Hormones

Question 27

• Composed of chains of amino acids, attach to the membrane receptors where they activate a second messenger within the cells.

Answer 27

Protein Hormones and Peptide Hormones

Question 28

• Attached to the hypothalamus, consists of two distinct glands: Anterior Pituitary and Posterior Pituitary

Answer 28

Pituitary Gland

Question 29

composed of glandular tissue, synthesizes six hormones, although the hypothalamus controls their release. The hypothalamus secretes releasing hormones, which flow through the blood to the ________ pituitary.

Answer 29

Anterior Pituitary

Question 30

composed of neural tissue, can be considered an extension of the hypothalamus. Neurons in the hypothalamus synthesize the hormones oxytocin and vasopressin, which migrate down axons to the posterior pituitary, later the _______ pituitary releases these hormones into the blood.

Answer 30

Posterior Pituitary

Question 31

• Occurs through special membrane proteins called transporters, _______ refers to when the presynaptic neuron takes up most of the neurotransmitter molecules intact and reuses them.

Answer 31

Reuptake

Question 32

• Breaks down the excess into inactive chemicals that cannot stimulate the dopamine receptors. In the prefrontal cortex _______breaks down about half of the released dopamine.

Answer 32

COMT

Question 33

• Receptors that respond to the released transmitter by inhibiting further synthesis and release. They provide negative feedback.

Answer 33

Autoreceptors

Question 34

• At an electrical synapse, the membrane of one neuron comes into direct contact with the membrane of another.

Answer 34

Gap Junction

Question 35

A drug that mimics or increases the neurotransmitter effects

Answer 35

Agonist

Question 36

A drug that blocks a neurotransmitter.

Answer 36

Antagonist

Question 37

A drug has an ____ for a receptor if it binds to it, like a key into a lock; affinities vary from strong to weak.

Answer 37

Affinity

Question 38

o A drugs efficacy is its tendency to activate the receptor. • A Survey of Abused Drugs

Answer 38

Efficacy

Question 39

just as the “first messenger” (the neurotransmitter) carries information to the postsynaptic cells, the second messenger communicates with many areas within a cell. It may open or close ion channels in the membrane or activate a portion of a chromosome.

Answer 39

Second Messanger

Question 40

Name the two pituitary glands

Answer 40

Anterior Pituitary & Posterior Pituitary