Chapter Eight

Question 1

Identify the divisions of the nervous system

Answer 1

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Question 2

Nervous System: CNS

Answer 2

Brain: Receives and processes sense information, initiates responses, stores memories, generates thoughts, feels emotions
Spinal Cord: Conducts signals from the brain, controls reflexes

Question 3

Nervous System: PNS

Answer 3

Sensory Neurons: Conducts impulses from receptors to the CNS
Motor Neurons: Conducts impulses from the CNS to effectors
(1) Sympathetic Division: Controls voluntary movements
(2) Autonomic Nervous System: Controls involuntary responses
(a) Sympathetic Division: fight or flight
(b) Parasympathetic Division: rest or digest

Question 4

Identify structures that protect the Nervous System

Answer 4

Bone, Meninges, Cerebral Spinal Fluid (CSF), Blood Brain Barrier

Question 5

Structures that protect the Nervous System: Bone

Answer 5

Brain sits inside the skull and the spinal cord is surrounded by vertebrae

Question 6

Structures that protect the Nervous System: Meninges

Answer 6

These tissue surround the brain and spinal cord, acting as a protective lining.

Question 7

Structures that protect the Nervous System: CSF

Answer 7

This fluid helps protect the nerve tissue, keep it healthy, and remove waste products.

Question 8

Structures that protect the Nervous System: Blood Brain Barrier

Answer 8

Relative impermeability of blood vessels supplying the brain acts to further protect the brain by not allowing harmful substances to enter

Question 9

Identify parts of a neuron and functions

Answer 9

SEE IMAGE

Question 10

Identify a function for each glial cells found in the Nervous System: Astrocytes

Answer 10

provide physical support to neurons and clean up debris within the brain

Question 11

Identify a function for each glial cells found in the Nervous System: Ependymal cells

Answer 11

Epithelial lining that influence the direction of flow of cerebrospinal fluid (CSF), bringing nutrients and other substances to neurons and filtering out molecules that may be harmful to the cells

Question 12

Identify a function for each glial cells found in the Nervous System: Microglia

Answer 12

Very small cells of the central nervous system that remove cellular waste and protect against microorganisms.

Question 13

Identify a function for each glial cells found in the Nervous System: Oligodendrocytes

Answer 13

Form an insulating coat known as the myelin sheath for the central nervous system, extending to wrap up to fifty axons at a time

Question 14

Identify a function for each glial cells found in the Nervous System: Schwann Cells

Answer 14

Form an insulating coat known as the myelin sheath for the peripheral nervous system, wrapping one axon at a time.

Question 15

Explain how the resting potential of a neuron is established: Part One (Three Parts)

Answer 15

When the neuronal membrane is at rest, the resting potential is negative due to the accumulation of more sodium ions outside the cell than potassium ions inside the cell

Question 16

Explain how the resting potential of a neuron is established: Part Two

Answer 16

Potassium ions diffuse out of the cell at a much faster rate than sodium ions diffuse into the cell because neurons have many more potassium leakage channels than sodium leakage channels

Question 17

Explain how the resting potential of a neuron is established: Part Three

Answer 17

Sodium-potassium pumps move two potassium ions inside the cell as three sodium ions are pumped out to maintain the negatively-charged membrane inside the cell; this helps maintain the resting potential

Question 18

Action Potential

Answer 18

Resting potential (at -60), Depolarization phase (shoots up to +60, past threshold), Repolarization phase (shoots down), Undershoot (goes past -60, to -80, shows a dip, then goes back to resting potential)

Question 19

Describe how Action Potential is propagated

Answer 19

When the sodium channels are opened, sodium ions rush in; once inside, they cause nearby regions of the neuron to become depolarized by moving laterally through the axon. This, in turn, causes the opening of more voltage-gated sodium channels in those regions. Thus, the sodium channel activation moves in a wave-like fashion: the action potential is propagated down the length of the neuron, from it’s input source at the dendrites, to the cell body, and then down the axon to the synaptic terminals.

Question 20

Grey Mater within Brain and Spinal Cord

Answer 20

Made up of nerve cell bodies. Neurons do not have extended axons. Occupies 40% of the brain. Grey cause of the grey nuclei that comprises the cells. Within grey matter, processing ics concluded. Has no Myelin sheath.

Question 21

White Mater within Brain and Spinal Cord

Answer 21

Made up of fibers. Neurons have extended axons.Fills 60% of the brain. White appearance due to the Myelin. White matter allows communication to and from grey matter areas and between the grey matter and other parts of the body. White matter is myelinated

Question 22

Myotome

Answer 22

group of muscles on one side of the body that are innervated by one spinal nerve. Testing these help doctors locate specific spinal nerve(s) that underlie any loss of movement or physical function you may be experiencing

Question 23

Dermatomes

Answer 23

Helps doctor locate the nerve(s) that give rise to your pain

Question 24

Consequences of a complete sever of the spinal cord above C6

Answer 24

Typically cannot handle activities of daily living

Question 25

Describe how sensory information gets to the brain for processing

Answer 25

In the periphery, the somatosensory system detects various stimuli by sensory receptors. e.g. by mechanoreceptors for tactile sensation and nociceptors for pain sensation. The sensory info is then conveyed to the central nervous system by afferent neurons