1 – Intro to Neuroscience

Question 1

Function of NS:

Answer 1

-allow animal to detect stimuli and respond to changes in the environment
>external (temperature, pressure (pain)
>internal (BP)

Question 2

‘steps’ of the NS:

Answer 2

1. Detect sensation (PNS)
2. Integrate and interpret (CNS)
3. Behavioural response (PNS)

Question 3

Neuron:

Answer 3

-cell body and it’s processes
>axons and dendrites

Question 4

Nerve:

Answer 4

-a bundle of axons within the PNS
>myelinated or unmyelinated

Question 5

Tract:

Answer 5

-bundle of axons within the CNS

Question 6

Ganglion:

Answer 6

-collection of nerve cell bodies forming a gross enlargement OUTSIDE of the CNS
-‘knot’

Question 7

Nucleus:

Answer 7

-collection of cell bodies WITHIN CNS

Question 8

Types of peripheral nerves:

Answer 8

-sensory: afferent (carrying to CNS), dorsal root
-motor: efferent (carrying from CNS), ventral root

Question 9

Peripheral nerve is:

Answer 9

-bundle of axons, both motor and sensory
>sometimes named based on the predominant axon type
»actually contains BOTH fiber types

Question 10

Synapse:

Answer 10

-structure/connection between two neurons that allows the transfer of information

Question 11

Spinal cord:

Answer 11

-neural connection from brain to the peripheral body
*spinal nerves

Question 12

Spinal nerves exit the CNS via:

Answer 12

-intervertebral foramen

Question 13

Spinal nerve sections and numbers in cat and dog:

Answer 13

-cervical: 8
-thoracic: 13
-lumbar: 7
-sacral: 3
-coccygeal: ~5

Question 14

Spinal nerves arise from:

Answer 14

-corresponding spinal segments
-cranial: emerge CRANIAL to corresponding vertebrae
-thoracic: emerge CAUDAL to corresponding vertebrae
*how you get 8 cervical spinal nerves from only 7 cervical vertebrae

Question 15

Spinal segments of cervical and thoracolumbar regions are generally within:

Answer 15

-corresponding vertebrae

Question 16

Sacral spinal segments are within:

Answer 16

-vertebra of L5

Question 17

Functional spinal cord terminates at the:

Answer 17

-L6-7 vertebral junction
>can be one segment more caudally in cats/dogs under 7kgs
>terminates closer to L1 in humans

Question 18

Spinal nerves combine in certain regions to form:

Answer 18

-named nerves of PNS
>C7, C8, T1=radial nerve
>L4, L5, L6=femoral nerve

Question 19

‘Plexus’ or ‘intumescence’:

Answer 19

-regions of emerging spinal nerves that are closely associated
>form a dense, intersecting network of nerves
Ex. brachial plexus/cervical intumescence

Question 20

Where does the spinal cord have enlargements?

Answer 20

-cervical (C6-T2) region
-lumbar (L4-S1) region
*’intumescence’

Question 21

‘intumescence’:

Answer 21

-increase in number of cell bodies required to innervate and control the limbs

Question 22

Where is the greatest amount of white matter (myelinated axons) in the spinal cord?

Answer 22

-cervical region

Question 23

Where is there proportionally more grey matter (neuronal cell bodies) in the spinal cord?

Answer 23

-lumbosacral region

Question 24

Cranial nerves:

Answer 24

-12 paired nerves emerging from brain and brainstem
-not arrange segmentally
-function as sensory and motor to head and neck

Question 25

PNS is divided into:

Answer 25

-sensory
-motor
>somatic and ANS

Question 26

Sensory neuron:

Answer 26

-cell body is in the PNS
-2 axons (one into PNS and CNS)
-info from PNS into CNS (afferent)

Question 27

Motor neuron:

Answer 27

-cell body is in CNS
-info from CNS into PNS (efferent)
-typically just 1 axon
-axonal end plates (synapse on individual muscle fibers)

Question 28

What are some things that are similar between motor and sensory neurons?

Answer 28

-have portions located in PNS with synapses into CNS
-myelinated axons
-long distance transmission of info

Question 29

What are some things that are different between motor and sensory neurons?

Answer 29

-motor neuron cell body is in CNS
-sensory neuron cell body is in PNS
-different embryological origins
-opposite direction of signal transmission

Question 30

Different embryological origins of sensory and motor neurons:

Answer 30

-sensory=neural crest
-motor=neural tube

Question 31

Types of pathways in the PNS:

Answer 31

-somatic
-visceral
*BOTH have sensory and motor components
>sensory are same for both somatic and visceral

Question 32

Somatic:

Answer 32

-conscious sensation
-skeletal muscle
-‘voluntary;
Ex. feeling fingers, walking, etc.

Question 33

Visceral:

Answer 33

-unconscious sensation
-smooth or cardiac muscle
-‘involuntary’
-motor=autonomic (S + PS)
Ex. pupil dilation, heart beating, GI digestion

Question 34

Somatic MOTOR neuron:

Answer 34

-cell body in CNS
-axon into PNS
-telodendrites onto effector organ to cause motion, etc.

Question 35

Visceral MOTOR neuron:

Answer 35

-cell body in CNS
-axon extends into PNS and synapses on autonomic ganglia
-autonomic ganglia has a synapse that goes onto the organ
*not direct synapse (always 2 neurons involved)

Question 36

Preganglionic ganglion fibers in visceral MOTOR neuron:

Answer 36

-ANS: distributed along axis of spinal cord
>don’t find S and PS fibers in the same region

Question 37

Sympathetic NS:

Answer 37

-active
-thoraco-lumber
-adrenergic
-everywhere
-synapses close to CNS
-preganglionic fibers short

Question 38

Parasympathetic NS:

Answer 38

-restorative
-cranio-sacral
-cholinergic
-mainly visceral (organs)
-synapses close to action site
-preganglionic fibers are long