L3 - Neuronal structure and function

Question 1

What are the basic properties of neurons?

Answer 1

Cell membrane

Nucleus: contains DNA, the genetic blueprint for cell structure and function

Organelles + machinery for translating genetic code for proteins

Metabolic machinery: enables glucose oxidation to provide energy

Question 2

What are dendrites + what is it specialised for?

Answer 2

network of fine processes from the cell body

specialised for receiving signals

Question 3

What are synapses?

Answer 3

connection between 2 neurones

Question 4

What is the axon hillock?

Answer 4

site of action potential generation

Question 5

What is the axon + what is it specialised for?

Answer 5

elongated neural process

specialised for rapid signal transmission over long distances

Question 6

What is myelination?

Answer 6

fatty sheath around axons

Question 7

What is differential permeability?

Answer 7

The neuronal cell membrane allows certain ions to pass through more easily than others, which creates an uneven charge distribution.

This difference is the membrane potential

Question 8

What is the resting membrane potential of neurones?

Answer 8

-70mV

Question 9

What is polarisation + what causes it?

Answer 9

Where there is a difference n electrical charge between the inside + outside of the cell

This difference in charge creates a voltage, which is called membrane potential

Question 10

What are the contributing ions in membrane potential?

Answer 10

Sodium (NA+)
Potassium (K+)
Chloride (Cl-)
Negatively charged proteins (A-)

Question 11

What is depolatisation?

Answer 11

increase in NA+ permeability making the membrane potential less negative

Question 12

What is hyperpolarisation?

Answer 12

increase in Cl- permeability makes the membrane potential more negative

Question 13

What is signal integration?

Answer 13

when a neuron combines multiple incoming signals to determine its overall response

Question 14

What are the 2 synaptic inputs?

Answer 14

Excitatory Postsynaptic Potentials (EPSPs)

Inhibitory Postsynaptic Potentials (IPSPs)

Question 15

What do Excitatory Postsynaptic Potentials (EPSPs) do?

Answer 15

they depolarise the neuron, making the. inside of the cell less negative + closer to the threshold for generating an action potential

Question 16

What do Inhibitory Postsynaptic Potentials (IPSPs) do?

Answer 16

they hyperpolarize the neuron, making the. inside of the cell less negative + closer to the threshold for generating an action potential

Question 17

What is spatial sumation?

Answer 17

when multiple synaptic inputs from different locations on the neuron’s dendrites + cell body occur simultaneously + their combined effects can add together

if enough EPSPs combine they can bring the neuron to the threshold for firing an action potential

Question 18

What is temporal summation?

Answer 18

when multiple synaptic inputs occur in rapid succession at the same synapse, their effects can add over time

if these inputs are close enough in time, they can collectively bring the neuron to the threshold

Question 19

What is the all-or-none phenomenon in regards to action potential?

Answer 19

an action potential is always the same size and does’t decay over distance

Question 20

what is action potential mediated by?

Answer 20

rapid changes in membrane permeability to Na+ and K+

Question 21

What are the components of a synapse?

Answer 21

Synaptic vesicles - contains neurotransmitters

postsynaptic receptors - bind neurotransmitters

neurotransmitter reuptake sites - remove neurotransmitters from the synaptic cleft

Question 22

What is the process for neurotransmitters to be released?

Answer 22

they’re combined near the release ste

stores until required

released into the synaptic cleft in response to action potential

bind to receptors on the postsynaptic membrane

Question 23

What are the 6 examples of neurotransmitters?

Answer 23

AMINO ACIDS:
Glutamate: excitatory
GABA: inhibitory

MONOAMINES:
Dopamine: excitatory and inhibitory
Noradrenaline: excitatory and inhibitory
Serotonin: excitatory and inhibitory

OTHERS:
Acetylcholine: excitatory and inhibitory

Question 24

what affects membrane potentials?

Answer 24

Local anesthetics

Question 25

what affects synthesis?

Answer 25

L-DOPA enhances dopamine synthesis for Parkinson’s treatment

Question 26

what interacts with receptors

Answer 26

Dopamine receptor antagonists for Sz

Question 27

what affects reuptake?

Answer 27

SSRIs for depression