Chapter 7 The Nervous System

Question 1

Name the two divisions of the nervous system

Answer 1

CNS

PNS

Question 2

What does the CNS stand for and what does it involve

Answer 2

Central nervous system

Brain and spinal cord

Question 3

What does the PNS stand for and what does it involve

Answer 3

Peripheral nervous system

Cranial and spinal nerves

Question 4

What controls the skeletal muscles

Answer 4

Somatic nervous system

Question 5

What controls the smooth/cardiac muscle

Answer 5

Autonomic nervous system

Question 6

What system is known as rest and digest

Answer 6

Parasympathetic nervous system

Question 7

What system is known as fight or flight

Answer 7

Sympathetic nervous system

Question 8

How can a neuron communicate

Answer 8

electrical signals

Chemical messengers = neurotransmitters

Question 9

What are Glial cells

Answer 9

supporting cells that help neurons to function

Question 10

What receives information from other neurons

Answer 10

dendrites

Question 11

Where do action potentials generally occur

Answer 11

in the axons

Question 12

Where do action potentials specifically occur in myelinated axons

Answer 12

node of ravier

Question 13

What is the percentage of neurons and glial cells in the CNS

Answer 13

50% neurons

50% glial

Question 14

Where are glial cells found and give an example

Answer 14

surrounding the axon and dendrites

Schwann cells (PNS)

Question 15

What do Schwann cells form in the PNS

Answer 15

Myelin around the axon

Question 16

What causes myelin to form around the CNS axon

Answer 16

Oligodendrocytes

Question 17

What does the afferent neuron do

Answer 17

Takes information away from tissue and organs to the CNS

Known as sensory

Question 18

What does the efferent neuron do

Answer 18

Take information away from the CNS to effector cells

Known as motor

Question 19

What system is a muscle contraction an example of

Answer 19

Somatic

Question 20

What does a interneuron do

Answer 20

Connects neurons within the CNS

Question 21

What is a ganglion

Answer 21

Grouping of neuron cell bodies located outside the CNS

Question 22

What is Ohm’s Law

Answer 22

I = V/R

I = Current
V = electrical potential
R = resistance

Question 23

What is current

Answer 23

movement of electrical charge

Question 24

What is resistance

Answer 24

hindrance of electrical charge movement

Question 25

What is the unit of electrical potential

Answer 25

Volts (V)

Question 26

What is the difference between Insulators and Conductors

Answer 26

Insulators = materials with high electrical resistance Conductors = opposite

Question 27

What is Potential difference

Answer 27

Difference in charge between 2 points

Question 28

What is the resting membrane potential of a neuron

Answer 28

- 70 mV

Question 29

What happens in the sodium potassium pump

Answer 29

3 molecules of Na move out | 2 molecules of K move in

Question 30

What are leak channels

Answer 30

always opened

Question 31

What are gated channels

Answer 31

only open to certain substances

Question 32

What happens to the membrane potential in Depolarisation

Answer 32

becomes less negative From -70 to -55

Question 33

What happens to the membrane potential in Hyperpolarisation

Answer 33

becomes more negative

Question 34

Explain the steps of Depolarisation

Answer 34

Neurotransmitter binds to receptor Causes Na to move into neuron making membrane potential less negative Once it reaches threshold potential of -55 voltage gated Na channels, Na rushes in. This causes an all or none sequence and subsequently an action potential occurs

Question 35

What is repolarisation

Answer 35

the return to resting membrane potential

Question 36

What is Ion Gating

Answer 36

the opening and closing of membrane ion channels due to charges/permability/polarisation

Question 37

Explain the steps of Repolarisation

Answer 37

``` Membrane potential reaches +30 mV Na channels become inactive K voltage gated channels open K exits out Membrane potential becomes more negative ```

Question 38

Explain the steps of Hyperpolarisation

Answer 38

Sodium potassium pump moves Na out and K in Cl- channels open and enter neuron This causes membrane potential to become more negative than resting Depolarisation then occurs

Question 39

What is a refractory period

Answer 39

Period where an action potential cannot occur

Question 40

What is propagation

Answer 40

the one way travel of a electrical signal due to the refractory period

Question 41

What is a salatory conduction

Answer 41

action potentials jump from one node of ranvier to another

Question 42

What is a synapse

Answer 42

junction beween neurons or another cell

Question 43

What is the difference between Presynaptic and Postsynaptic

Answer 43

Pre is when the neuron sends a message to another neuron Post is when a neuron receives a message from the Pre

Question 44

Name the two types of synaptic transmission

Answer 44

``` Chemical = neurotransmitter Electrical = current flow ```

Question 45

Explain how neurotransmitters are released

Answer 45

Action potential reaches terminal Voltage gated Ca channels open Ca diffuses in and binds to sensor protein in vesicles containing the neurotransmitter Exocytosis of vesicle occurs and the release of neurotransmitter

Question 46

Graded potentials can be...

Answer 46

Excitatory - depolarisation through Na or Ca entry Inhibitory - hyperpolarisation through Cl entry

Question 47

Excitation can be referred to as....

Answer 47

EPSP = excitatory postsynaptic potential

Question 48

Inhibitory can be referred to as....

Answer 48

IPSP = inhibitory postsynaptic potential

Question 49

Name two neurotransmitters

Answer 49

Acetylcholine Catecholamines

Question 50

Name the two types of neurotransmitting receptors

Answer 50

Nicotinic receptors Muscarinic receptors

Question 51

What is involved with the Nicotinic receptor

Answer 51

Brain Autonomic nervous system Skeletal muscle fibers

Question 52

What is involved with the Muscarinic receptor

Answer 52

Smooth muscle cardiac muscle some glands

Question 53

Give some example of a Catecholamine

Answer 53

Epinephrine = adrenaline

Question 54

Characteristics of catecholamines

Answer 54

based on tyrosine Adrenergic neuron releases catecholamines Adrenergic receptors Cause mood, movement and blood pressure regulation

Question 55

What is Divergence

Answer 55

one neuron synapses with multiple other neurons

Question 56

What is Convergence

Answer 56

Multiple axons synapse onto a single neuron

Question 57

What is Spatial summation

Answer 57

When signals from converging presynaptic axons summate onto a postsynaptic neuron

Question 58

What is temporal summation

Answer 58

When multiple signals from one presynaptic axon summate onto a postsynaptic neuron