Week 2

Question 1

junction between neurons
- mediates the flow of information


Answer 1

synapse

Question 2

conducting neuron=

Answer 2

presynaptic

Question 3

-receiving neuron=

Answer 3

postsynaptic

Question 4

2 types of synapses:

Answer 4

1. electrical synapse
2. chemical synapse

Question 5

which synapse:

• Least common
• Cytoplasm of adjacent cells connected by gap junctions
• Ions flow directly
• Bidirectional
• Fast (allows heart to contract)
  
  • Abundant in embryonic nervous tissue

Answer 5

electrical synapse

Question 6

which type of synapse

• Releaase of neurotransmitters
• axonalterminal=presynaptic
• receptorregion=postsynaptic
• Neurotransmitter diffuse across synaptic cleft
• One way flow
  
  • Electrical event leads to chemical event

Answer 6

chemical synapse

Question 7

Flow of info at synapse

Answer 7

1. Calcium channels open in the presynaptic neuron and calcium enters the axon terminal
2. Neurotransmitter released into synaptic cleft
3. Neurotransmitters diffuse bind to postsynaptic receptors; this is reversible because they can bind and unbind
4. Ion channels open in the postsynaptic membrane creating a new graded potential

• Excitatory or inhibitory

Question 8

neurotransmitters move across the synapse via

Answer 8

diffusion

Question 9

are neurotransimiteres permanent or reversible

Answer 9

reversible, they can bind and unbind

Question 10

________ is a rate limiting step; neurotransmitters take a bit to release, diffuse, and bind

Answer 10

Synaptic delay

Question 11

what happens to neurotransmitters

Answer 11

1. degraded by enzymes
2. reuptake by astrocytes
   
   1. diffusion out of synapse

Question 12

Modification of neurotransmitters:

Answer 12

1. agonist = enhances NT effect
   * Albuterol asthma inhaler
2. antagonist = blocks NT action
   * Antihistamines block histamine receptor
3. receptor site can be blocked
   * Antipsychotics used to bind to receptor site
4. time in cleft can be prolonged or lessened
   * SSRIs- reuptake inhibitor- stays in the cleft
5. release blocked or enhanced
   * MDMA enhances release of serotonin
6. synthesis stimulated or inhibited
   * Clonidine lowers BP by inhibiting presynaptic NE production

Question 13

-neurotransmitters generate ________ membrane potentials on postsynaptic membranes

Answer 13

GRADED

Question 14

• EPSP – excitatory =

Answer 14

depolarizing

Question 15

• IPSP – inhibitory =

Answer 15

hyperpolarizing

Question 16

• Summation is important for EPSPs or IPSPs

Answer 16

EPSP

Question 17

• Sodium channels open for EPSP or IPSP

Answer 17

EPSP

Question 18

• Reduces AP potential
• Cl- or K+ channels open [Na+ closed]

Answer 18

IPSP

Question 19

-role of the ________ to ‘inhibit’ unnecessary activity

Answer 19

cerebral cortex

Question 20

Summation

Answer 20

-add all the EPSPs and IPSPs together

Question 21

rapid production of EPSPs

• rapid fire from SAME axon terminal
• tons of ESPS all in a row like a machine gun

Answer 21

temporal summation

Question 22

large number of EPSPs

-impulses arrive from MANY axon terminals

Answer 22

spatial summation

Question 23

Structural Neurotransmitters:

Answer 23

1. acetylcholine [ACh]
2. Biogenic amines
3. amino acids
4. neuropeptides
   
   1. novel messgengers

Question 24

Biogenic amines

Answer 24

1. Dopamine- regulates skeletal muscle tone
2. Norepinephrine and epinephrine (adrenaline)- both derived from amino acid tyrosine
3. Indolamines- serotonin, histamine

Question 25

* most common= GABA= inhibitory * glutamate= most common in brain= excitatory * glucine= inhibitory= found in brain stems and spinal cord

Answer 25

Amino acids

Question 26

where is glycine found

Answer 26

brain stem an dspinbal cord

Question 27

3 Novel messengers

Answer 27

1. ATP- excitatory in PNS and CNS 2. Nitric Oxide- produced on demand- vasodilator 3, Carbon Monoxide

Question 28

Types of Circuits

Answer 28

1. diverging 2. converging 3. reverberating (oscillating) 4. parallel after discharge

Question 29

- single neuron stimulates many others * One input, many outputs

Answer 29

1. diverging circuits

Question 30

- many outpours, one input - one neuron stimulated by many others

Answer 30

converging circuti

Question 31

- feedback loop - impulses from distal neurons stimulate proximal neurons repeatedly - short term memory, sleep wake cycles breathing

Answer 31

reverberating (oscillating) circuti

Question 32

-single neuron stimulates group of neurons that then stimulate one neuron

Answer 32

parallel after-discharge circuits

Question 33

left brain logic does what kind of processing

Answer 33

serial

Question 34

- many pathways and many destination - right brain

Answer 34

parallel processing

Question 35

Reflex Arc

Answer 35

1. receptor → activated by a stimulus 2. sensory neuron → AFFERENT 3. interneuron → CNS integration → brain/spinal cord 4. motor neuron → EFFERENT 5. effector [response] → muscle or gland