anatomy of the nervous system

Question 1

which division of the nervous system is the CNS

Answer 1

spine (spinal cord) and skull (brain)

Question 2

which division of the nervous system is the PNS

Answer 2

outside of the skill and spine

Question 3

somatic nervous system

Answer 3

the part of the PNS that interacts with the external environment

Question 4

autonomic nervous system

Answer 4

the part of the peripheral nervous system that regulates the body’s internal environment

Question 5

afferent nerves

Answer 5

carry sensory signals from skin/muscles to CNS (arrive)

Question 6

efferent nerves

Answer 6

carry motor signals from CNS (exit) to internal organs

Question 7

sympathetic nerves

Answer 7

autonomic motor nerves that project from the CNS in the lumbar (small of back) and thoracic regions of the spinal cord

Question 8

parasympathetic nerves

Answer 8

autonomic motor nerves that project from the brain and sacral (lower back) region of the spinal cord

Question 9

similarity between sympathetic and parasympathetic nerves

Answer 9

both are two-stage neural paths: project from CNS and go only part of the way to target organs before they synapse on other neurons (second stage neurons) that carry the signal the rest of the way

Question 10

difference between sympathetic and parasympathetic nerves

Answer 10

sympathetic neurons project from CNS synapse on second-stage neurons at a substantial distance from their target organs

parasympathetic neurons project from the CNS synapse near their target organs on short second-stage neurons

Question 11

functions of sympathetic and parasympathetic systems

Answer 11

1. S = stimulate and mobilize energy resources in threatening situations, P = conserve energy
2. each autonomic target organ received opposing S&P input and its activity is controlled by relative levels of S and P activity
3. S changes = psychological arousal, P changes indicate psychological relaxation

Question 12

cranial nerves

Answer 12

12 pairs of nerves that project from the brain (other nerves of PNS project from the spinal cord)

Question 13

what is the longest cranial nerve

Answer 13

vagus nerve (contais motor and sensory fibres traveling to and from the gut)

Question 14

what are the three meninges and their functions

Answer 14

the three meninges protect the brain and spinal cord

dura mater menix = outer membrane

arachnoid membrane = fine, spider-web-like membrane

pia mater = innermost menix which adheres to the surface of the CNS

Question 15

subarachnoid space

Answer 15

located between the arachnoid membrane and pia mater

contains many large blood vessels and cerebrospinal fluid

Question 16

cerebrospinal fluid (CSF)

Answer 16

fills the subarachnoid space, central canal of spinal cord, and cerebral ventricles of the brain

supports and cushions the brain for protection

Question 17

central canal

Answer 17

small central channel that runs the length of the spinal cord

Question 18

cerebral ventricles

Answer 18

four large internal chambers of the brain (two lateral ventricles, third ventricle, fourth ventricle)

Question 19

choroid plexuses

Answer 19

network of capillaries that protrude the ventricles from the pia mater

produces cerebrospinal fluid

Question 20

dural sinus

Answer 20

large blood-filled spaces which run through the dura mater

absorb excess CSF from subarachnoid space and drain into jugular veins of the neck

Question 21

cerebral aqueduct

Answer 21

connects third and fourth ventricles in the brain

Question 22

blood-brain barrier

Answer 22

special structure of cerebral blood vessels = cells of blood vessel walls are tightly packed forming a barrier

blocks molecules (eg. proteins/large molecules) and toxc substances from the blood into the brain