W4 Classification of the Nervous System

Question 1

what are the topographical subdivisions of the nervous system?

Answer 1

central nervous system = brain and spinal cord
peripheral nervous system = cranial and spinal nerves

Question 2

what are the functional subdivisions of the nervous system?

Answer 2

somatic system = voluntary
visceral system = involuntary
- autonomic (sympathetic and
parasympathetic)

Question 3

what are the directional subdivisions of the nervous system?

Answer 3

afferent = towards brain and spinal cord
efferent = away from brain and spinal cord

Question 4

the embryological classification of the brain can be divided into what three regions that the neural tube expands into? what are the subdivisions?

Answer 4

1) the prosencephalon (forebrain)
- telencephalon
- diencephalon
2) the mesencephalon (midbrain)
3) the rhomboencephalon (hindbrain)
- metencephalon
- myelencephalon

Question 5

what are the major derivatives of the telencephalon? what is the lumen?

Answer 5

cerebral cortex, basal nuclei and limbic system, lumen is the lateral ventricle

Question 6

what are the major derivatives of the diencephalon? what is the lumen?

Answer 6

epithalamus, thalamus and hypothalamus, lumen is the third ventricle

Question 7

what are the major derivatives of the mesencephalon? what is the lumen?

Answer 7

tectum (corpora quadrigemina), tegmentum and cerebral peduncles, lumen is the cerebral aqueduct

Question 8

what are the major derivatives of the metencephalon? what is the lumen?

Answer 8

pons and cerebellum, lumen is the rostral part of the fourth ventricle

Question 9

what are the major derivatives of the myelencephalon? what is the lumen?

Answer 9

medulla oblongata, lumen is caudal part of the fourth ventricle

Question 10

what are the major derivatives of the remainder of the neural tube? what is the lumen?

Answer 10

the spinal cord, the lumen is the central canal

Question 11

what does the forebrain do?

Answer 11

receive and integrates sensory information from the nose, eyes and ears (in land dwelling vertebrates - contains highest integrating centres)

Question 12

what does the midbrain do?

Answer 12

coordinates reflex responses to sight and sounds

Question 13

what does the hindbrain do?

Answer 13

relfex control of respiration, blood circulation and other basic tasks in complex vertebrates, coordinates sensory input, motor dexterity and possible mental dexterity

Question 14

the olfactory bulb is part of which part of the brain?

Answer 14

forebrain

Question 15

how did the true CNS firt evolve?

Answer 15

as a bilateral symmetrical body plan - before this animals had nerve nets/rings and simple ganglia

Question 16

where have some nerve nets been retained through evolution?

Answer 16

taking the form of the nerve plexus located in the intestinal wall responsible for propelling digesta

Question 17

the peripheral nervous system contains spinal nerves, cranial nerves and what else?

Answer 17

ganglia (cell bodies) - sensory and autonomic motor

Question 18

in the CNS bundles of neurone axons are called what?

Answer 18

tracts

Question 19

myelination of axons is achieved by what cells in the PNS?

Answer 19

a separate schwann cell

Question 20

myelination of axons is achieved by what cells in the CNS?

Answer 20

arms of myelin-forming oligodendrocyte

Question 21

does myelination slow down or speed up action potential velocity?

Answer 21

speeds up

Question 22

what can afferent also be known as?

Answer 22

ascending within spinal cord or sensory

Question 23

what can efferent also be known as?

Answer 23

descending within spinal cord or motor

Question 24

what is the special afferent in association with?

Answer 24

special senses - taste and small, vision, hearing and balance

Question 25

what does the somatic nervous system do?

Answer 25

voluntary - senses and controls body relative to external environment (touch, pressure, heat, pain, vision, balance)

Question 26

is the somatic or visceral system related to ascending and descending pathways of the CNS?

Answer 26

somatic

Question 27

what does the visceral nervous system do?

Answer 27

senses and maintains the internal environment within permissible limits (receptors in organs and blood vessles, taste and smell, ANS, hypothalamus and hypophysis functions)

Question 28

can nerves have different types of axons?

Answer 28

yes e.g. spinal nerves have afferent and efferent axons or facial nerve (CNVII) has somatic and visceral components