Neuroscience: Organization of the Nervous System

Question 1

Neuroscience Def’n

Answer 1

Study of function and structure of the nervous system

Question 2

Importance of Understanding Neuroscience

Answer 2

facilitates the clinical decision making process
- helps assessment selection/interpretation
- helps det diagnosis and expectation for prognosis
- helps intervention selection/progression

Question 3

Seven CNS Structures

Answer 3

spinal cord, medulla, pons, midbrain, cerebellum, diencephalon, cerebral hemispheres

Question 4

Spinal cord is responsible for

Answer 4

sensory and motor innervation

Question 5

Descending pathway

Answer 5

motor control from body to brain

Question 6

Ascending pathway

Answer 6

sensory perception from body to brain

Question 7

Brain stem is responsible for

Answer 7

• relaying information from spinal cord to cerebrum and cerebellum
• regulation of vital functions

Question 8

PNS is responsible for

Answer 8

• sending information from body to brain and spinal cord
• sending commands from brain and spinal cord to body parts

Question 9

PNS Subsystems (2)

Answer 9

1. Somatic: functions you manage by thinking about them
2. Autonomic: functions your brain runs w/o thinking of them

Question 10

Autonomic Nervous System

Answer 10

1. Sympathetic: fight or flight
2. Parasympathetic: rest and digest

Question 11

Neurons

Answer 11

specialized for electrical signalling over long distances

Question 12

Neuroglial Cells

Answer 12

supporting cells; not capable of signaling

Question 13

Four component of neurons

Answer 13

dendrites*, cell body/soma, axon, axon terminals

Question 14

Dendrites are responsible for

Answer 14

receiving and transferring electrical messages (impulses) from other cells to the soma (cell body)

Question 15

Importance of dendrites

Answer 15

• more dendrites = more inputs; ability to receive signal/information
• affect neuron’s ability to modify the strength of their connections (plasticity)

Question 16

Cell body

Answer 16

membranes specialized for signaling

Question 17

Axon

Answer 17

aka a nerve fibre
- carries information along long distances, from one part of the neuron to another
- variable (length, myelinated/unmyelinated)

Question 18

Path of Information travelling down the axon

Answer 18

• information is integrated in the cell body (soma)
• information read out at the axon hillock
• information travels along the axon to the axon terminals

Question 19

Synapse

Answer 19

Junction between nerve cells, no physical contact

Question 20

presynaptic/postsynaptic terminal

Answer 20

presynaptic terminal: contain synaptic vesicles
postsynaptic terminal: control the response

Question 21

Interaction btwn Neurons and Neuroglia

Answer 21

provide homeostatic support, protection, and defense to the nervous tissue; support the neurons

Question 22

Neurogliac Cell Function Cont’d

Answer 22

• support synaptic connections, signaling
• maintain ionic milieu of nerve cells
• support the rate of signal propagation
• control uptake of neurotransmitters
• aid neural recovery

Question 23

Myelinating Neuroglial Cells: Oligodendrocytes vs Schwann Cells

Answer 23

Oligodendrocytes
- myelinate the CNS
- myelinate multiple axons
- more widely spaced

Schwann Cells
- myelinate the PNS
- can only myelinate one axon
- closer together

Question 24

Nodes of Ranvier

Answer 24

Space between myelin cells

Question 24

Myelin Function

Answer 24

- allow impulses to travel quickly/efficiently along the neuron - if myelin is damaged, impulses slow down --> demyelinating disease ex. MS

Question 24

Collection of Cell Bodies: CNS vs PNS

Answer 24

CNS: Nuclei PNS: Ganglion

Question 25

Cortex

Answer 25

layers of cell bodies on the surface of the cerebrum and cerebellum

Question 25

Gray Matter

Answer 25

regions of cell bodies in the CNS

Question 26

White Matter

Answer 26

regions of myelinated axons in the CNS

Question 27

Axons travelling in Bundles: CNS vs PNS

Answer 27

CNS: tracts PNS: nerves

Question 28

Neuropil

Answer 28

- Space btwn neurons and glial cell bodies - more density of neuropil = more interconnection in that area; role in cognitive function

Question 29

Afferent Neurons

Answer 29

"arriving" toward spinal cord/brain

Question 30

Efferent Neurons

Answer 30

"exiting" away from brain/spinal cord

Question 31

Interneurons

Answer 31

local circuit neurons, short distance, modulate the response of larger circuits

Question 32

Neural Circuit Interruptions: Diabetes

Answer 32

- Nerve damage via high blood sugar - lose sensation in the bottom of the foot via reduced blood flow - myelin damaged; lose ability to send sensory info to spinal cord - prevent the perception of noxious stimuli

Question 33

Neural Circuit Interruptions: Peripheral Neuropathy

Answer 33

- peripheral nerves damaged - causes weakness, numbness and pain, usually in the hands and feet - prevent the perception of noxious stimuli

Question 34

Neural Circuit Interruptions: Disc Herniation

Answer 34

- displacement of the nucleus pulposus of the IV disc - puts pressure on nerve - pinched nerve may cause pain, numbness, tingling or weakness in the arms or legs