Nervous System

Question 1

What is the name of the cell body of a neuron?

Answer 1

soma

Question 2

What is the function of sensory neurons?

Answer 2

detect changes in external and internal environment (CNS and PNS, light, sound, odours, touch

Question 3

What is the function of motor neurons?

Answer 3

• controls muscle contraction and also gland secretion (CNS and PNS)

Question 4

What is the functions of interneurons?

Answer 4

• lie entirely within the CNS and are involved in cognition (i.e.,perceiving, learning, remembering and executive functioning such as decision making)

Question 5

What is a multipolar neuron?

Answer 5

neuron with one axon and many dendrites attached to its soma

Question 6

what is a bipolar neuron?

Answer 6

neuron with one axon and many dendrites attached to its soma

Question 7

what is a unipolar neuron?

Answer 7

neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the central nervous system.

Question 8

what are astrocytes?

Answer 8

Type of glial cell. The support cells imbetween neurons

Question 9

what do astrocytes do?

Answer 9

• Provide physical support to neurons
• Provide nourishment
• When neurons die they clean up debris and form scar tissue
• Control chemical composition of fluid surrounding neurons

Question 10

what are Oligodendrocytes

Answer 10

cells that support axons and produce myelin sheath, in the CNS - they wrap around several adjacent axons

Question 11

what are nodes of Ranvier?

Answer 11

the parts of neurons not covered by myelin sheaths

Question 12

what are schwann cells?

Answer 12

Found in PNS, single Schwann cell wrapped around the PNS axon (kinda myelin sheath for PNS)

Question 13

What is the name for the weakest part pf the blood-brain barrier?

Answer 13

area postrema

Question 14

where is the area postrema located?

Answer 14

the medulla

Question 15

which neuron plays the inhibitory role in the role of inhibition?

Answer 15

the interneuron

Question 16

what is a membrane potential?

Answer 16

electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell.

Question 17

what is the resting potential of a neuron?

Answer 17

-70mV

Question 18

what is depolarisation?

Answer 18

reduction of negative charge (toward zero) of the membrane potential when we stimulate neuron

Question 19

what is an action potential in a cell?

Answer 19

– brief electrical impulse that provides the basis for conduction of information along an axon

Question 20

what is the threshold of excitation?

Answer 20

The value of the membrane potential that must be reached to produce an action potential

Question 21

what is hyperpolarisation?

Answer 21

– decrease in the membrane potential of a cell

Question 22

summarise a cell action potential cycle

Answer 22

Starts at -70 as this is the baseline.
Reaches the threshold of excitation.
Fully action potential causes massive +ve spike in cell charge
The action +ve cahrge decreases after a peak and they after enters hyperpolarisation dips below -70 briefly before depolarising back to -70.
CHECK SLIDE 21 ON WEEK 2

Question 23

what is electrostatic pressure?

Answer 23

When substances dissolve in water, they split into 2 parts with opposing electrical charge have attraction & repulsion (Na + and Cl− ions)

Question 24

Revisit and draw flow diagram of NaK pump

Answer 24

CHECL SLIDE 21 OF WEEK 2

Question 25

what is the all-or-none law?

Answer 25

– once the action potential begins, it proceeds without decrement to the terminal buttons (it either occurs, or it doesn’t occur)

Question 26

how do you measure speed of conduction?

Answer 26

delay between stimulus and action potential

Question 27

what is the rate law?

Answer 27

variations in the intensity of a stimulus are represented by variations in the rate at which that axon fires

Question 28

what is saltatory conduction?

Answer 28

Conduction of action potentials by myelinated axons. The action potential appears to jump from one node of Ranvier to the next, speeding up signalling.

Question 29

what is the name for the gap between neurons?

Answer 29

synaptic cleft

Question 30

can action potentials jump over the synaptic cleft?

Answer 30

no- that why we have neurotransmitters dummy

Question 31

where are neurotransmitters kept before firing?

Answer 31

in the synaptic vesicles

Question 32

what does lock and key binding mean in regards to nerve impulses?

Answer 32

The membrane of the post-synaptic neuron has chemical-gated ion channels called neuroreceptors. These have specific binding sites for neurotransmitters. The chemical messenger fits the binding site like a lock and key.

Question 33

Is opening transmitter-dependant ion channels direct of indirect?

Answer 33

It can be both indirect = metabotropic direct = ionatropic (go over slide 31/32 of week 2)

Question 34

What is Excitatory Postsynaptic Potential (EPSP)

Answer 34

excitatory depolarization (+ve) of the postsynaptic membrane.

Question 35

What us the Inhibitory Postsynaptic Potential (IPSP)?

Answer 35

inhibitory hyperpolarization (-ve) of the post synaptic membrane.

Question 36

what are the 3 main types of ion channel?

Answer 36

Na+, K+ and Cl-

Question 37

how do neurotransmitters cause hyperpolarisation or depolarisation of the post-synaptic cell?

Answer 37

The neurotransmitters bind to ion channels to cause influx of Na, Cl or K ions to enter the cell.

Question 38

what is neuronal integration?

Answer 38

Process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron.

Question 39

what is temporal summation?

Answer 39

sensory summation that involves the addition of single stimuli over a short period of TIME. (a few small depolarisations that don't meet threshold for excitation can combine together if they arrive at similar times)

Question 40

what is spatial summation?

Answer 40

Spatial summation involves simultaneous signals coming from multiple presynaptic neurons being received by a single postsynaptic neuron.

Question 41

what are glial cells?

Answer 41

glue cells that hold neurons together, split into astrocytes and oligodendrocytes.

Question 42

briefly describe how you study the resting potential of an axon

Answer 42

apply a +ve stimulation to an axon placed in saltwater with 1 electrode in the water and another on the axon & use an oscilloscope/voltmeter to measure the AP

Question 43

which lobe is the motor cortex in?

Answer 43

frontal

Question 44

which lobe is the somatosensory cortex in?

Answer 44

parietal

Question 45

which lobe is the visual cortex in?

Answer 45

occipital

Question 46

which lobe is the auditory cortex in?

Answer 46

temporal