Week 5: Recorded Lectures

Question 1

What is membrane potential?

Answer 1

The difference in electric potential between the interior and exterior of a biological cell

Question 2

What creates an electrochemical gradient in a cell?

Answer 2

The presence of ions inside and outside the cell

Question 3

Charge of inside cell

Answer 3

Negative

Question 4

Charge of outside cell

Answer 4

Positive

Question 5

How is membrane potential measured?

Answer 5

• As voltage
• Expressed as inside relative to outside the cell

Question 6

Polarized cell

Answer 6

A cell with any electrical gradient (not 0mV)

Question 7

Depolarization

Answer 7

Less polarized than at rest

Question 8

Hyperpolarization

Answer 8

More polarized than at rest

Question 9

Repolarization

Answer 9

Returns towards its resting potential

Question 10

Dendrites

Answer 10

Branched extensions of a neuron that receive signals from other neurons

Question 11

Where do changes in cell potentials occur?

Answer 11

The dendrites

Question 12

Agonists

Answer 12

• substances that bind to receptors and activate them
• Make it more likely that a neuron will reach its threshold membrane potential

Question 13

Antagonists

Answer 13

• substances that bind to receptors but block them
• make it less likely that a neuron will reach its threshold membrane potential

Question 14

Action Potential

Answer 14

• brief electrical impulse that travels down a neuron
• allows for the rapid transmission of electrical signals along neurons

Question 15

The nature of the action potential: step 1

Answer 15

• Resting state
• at rest, most ion channels are closed

Question 16

The nature of the action potential: step 2

Answer 16

• Depolarization
• some signals cause some Na channels to open
• initiates a slow depolarization

Question 17

The nature of the action potential: step 3

Answer 17

• Rising phase of the action potential
• When depolarization reaches a certain point, Na channels open, this triggers a massive depolarization

Question 18

The nature of the action potential: step 4

Answer 18

• Falling phase of the action potential
• Na channels close
• K channels open

Question 19

The nature of the action potential: step 5

Answer 19

• Undershoot
• Repolarization continues past the resting potential
• This is quickly corrected

Question 20

Multipolar interneurons

Answer 20

connect neurons together

Question 21

Motor neuron

Answer 21

carries signals to muscles

Question 22

Sensory neuron

Answer 22

Controls feelings

Question 23

Synapse

Answer 23

gap between two neurons where communication occurs

Question 24

Presynaptic events

Answer 24

• Action potential
• Presynaptic membrane
• Exocytosis of neurotransmitter

Question 25

Neurotransmitters

Answer 25

- Each neuron produces and releases one major neurotransmitter

Question 26

Postsynaptic events

Answer 26

- Neurotransmitter binding - Receptor activation - Signal transduction

Question 27

Acetylcholinesterase (AChE)

Answer 27

Stops signaling between neuron and muscle

Question 28

Central nervous system (CNS)

Answer 28

consists of brain and spinal cord

Question 29

Peripheral nervous system (PNS)

Answer 29

ranial nerves, ganglia outside CNS, spinal nerves

Question 30

Forebrain

Answer 30

collects sensory information

Question 31

Midbrain

Answer 31

interpreter; helps hindbrain decide what to do

Question 32

Hindbrain

Answer 32

control of movement

Question 33

Pineal gland

Answer 33

processes info about day length

Question 34

Hypothalamus

Answer 34

collection of neurons that receives and sends signals

Question 35

Where is short term memory stored?

Answer 35

The hippocampus

Question 36

Where is long term memory stored?

Answer 36

The cerebral cortex

Question 37

Enteric division

Answer 37

controls digestion and gut function independently of the brain

Question 38

Parasympathetic divisions

Answer 38

- Rest and digest - slows heart

Question 39

Sympathetic divisions

Answer 39

- fight or flight - speeds the heart and increases contractile strength

Question 40

Plasticity

Answer 40

ability of neurons to change their connections and functions in response to stimuli