Central Nervous System- Spinal Cord

Question 1

central nervous system

Answer 1

brain and spinal cord

Question 2

embryonic development

Answer 2

1. neural plate forms from ectoderm
2. plate invaginates to form neural groove and folds
3. neural fold migrates to form neural crest
4. neural groove becomes neural tube
5. neural tube will form neural structures day 22

Question 3

week 5 of embryonic development

Answer 3

two major flexures form and cause telencephalon and dienccephalon to angle toward brain stem

Question 4

week 13 of embryonic development

Answer 4

cerebral hemispheres develop and grow posterolaterally to enclose diencephalon and rostral brain stem

Question 5

week 26 of embryonic development

Answer 5

growing cerebral hemispheres begin to crease

Question 6

birth of development

Answer 6

brain has developed an adult structure

Question 7

defects of developing fetus caused by?

Answer 7

maternal exposure to teratogens
genetic mutations

Question 8

types of defects in embryonic development

Answer 8

anencephaly
cerebral palsy
spina bifida

Question 9

anencephaly

Answer 9

neural folds fail to fuse (no tube)
cerebrum never develops
fatal

Question 10

cerebral palsy

Answer 10

infection, damage, or lack of oxygen to fetus causes brain damage
poor control of muscles, seizures, mental disability, deafness
3:1000 births

Question 11

spina bifida

Answer 11

incomplete closure of neural tube because lamina/spinous process is missing from vertebrae
folic acid deficiency

Question 12

where does spinal cord develop from?

Answer 12

posterior neural tube

Question 13

basal plate

Answer 13

gives rise to ventral motor neurons
axons to synapses in muscles

Question 14

alar plate

Answer 14

gives rise to dorsal interneurons
connection with dorsal root ganglia

Question 15

neural crest cells

Answer 15

find and form dorsal root ganglion
axons that bring in sensory infromation

Question 16

what does tube becomes in brain?

Answer 16

central canal and ventricles

Question 17

ventricles

Answer 17

hollow chambers filled with CSF
continuous with one another and central canal of spinal cord
connected to subarachnoid space

Question 18

ependymal cells

Answer 18

line cavities and ventricles to circulate CSF

Question 19

types of ventricles

Answer 19

2 lateral ventricles
3rd ventricle in diencephalon
4th ventricle in hindbrain
central canal in spinal cord

Question 20

functions of CSF

Answer 20

buoyancy to CNS organs -97% weight reduction
protects CNS from trauma/blows
nourishes brain
carries chemical signals

Question 21

composition of CSF

Answer 21

watery solution
more specialized extracellular fluid
less proteins
different ionic concentration than plasma
150 mL replaced every 8 hours

Question 22

choroid plexuses

Answer 22

produces CSF at constant rate
cluster of capillaries enclosed by pia mater and ependymal cells
ependymal cells use ion pumps to control composition of CSF, remove wastes and help cleanse CSF
tight junctions

Question 23

blood-brain barrier

Answer 23

helps maintain stable envirnment for brain
tight junctions between capillary endothelia cells
astrocyte feet
separates neurons from some bloodborne substances

Question 24

function of blood brain barrier

Answer 24

• selective barrier
• allow glucose, essential amino acids with facilitated diffusion
• toxins, wastes, and certain drugs excluded
• fat soluble substances can pass (O2, CO2, fats, alcohol, nicotine, anesthetics)

Question 25

two areas where blood brain barrier is absent

Answer 25

vomiting center hypothalamus

Question 26

3 meninges covering CNS

Answer 26

dura mater arachonoid mater pia mater

Question 27

spinal cord

Answer 27

extends from foramen magnum to 1st/2nd lumbar vertebrae two way communication with brain reflex center protected by bones, meninges, CSF

Question 28

epidural space

Answer 28

fatty tissue between vertebrae and dura mater anesthetic injected or CSF taken out

Question 29

dorsal half of spinal cord

Answer 29

sensory roots and ganglia

Question 30

ventral half of spinal cord

Answer 30

motor root

Question 31

how many spinal nerves are present on spinal cord

Answer 31

31 pairs

Question 32

gray matter

Answer 32

cell bodies of neurons located on internal part of spinal cord

Question 33

dorsal horn

Answer 33

interneurons

Question 34

ventral horn

Answer 34

somatic motor neuron cell bodies axons form from ventral root

Question 35

largest ventral horns

Answer 35

cervical and lumbar more muscles to control in this area

Question 36

lateral horn

Answer 36

autonomic motor neurons for visceral organs sends axons out ventral root

Question 37

dorsal root ganglion

Answer 37

cell bodies of dorsal root bringing sensory information in afferent nerves

Question 38

spinal nerve

Answer 38

fusion of dorsal and ventral roots

Question 39

paresthesia- loss of sensation or abnormal sensations, where is injury?

Answer 39

dorsal root regulates sensory information

Question 40

paralysis- loss of motor function, where is injury?

Answer 40

ventral root regulates motor neurons for somatic system

Question 41

flaccid paralysis

Answer 41

severe damage to ventral root or ventral horn cells impulses do not reach muscles, no voluntary/involuntary control muscle atrophy

Question 42

spastic paralysis

Answer 42

upper motor neurons of primary cortex are damaged but spinal motor neurons remain intact muscles not subject to voluntary control but remain healthy longer neurons in brain damaged

Question 43

transection

Answer 43

cross sectioning of spinal cord total motor and sensory loss inferior to cut

Question 44

paraplegia

Answer 44

transection between T1 and L1 lose leg control

Question 45

quadriplegia

Answer 45

transection in cervical region lose control of arms and legs

Question 46

spinal shock

Answer 46

transient loss of function following an injury all reflex activity caudal to lesion is depressed function can return 2-48 hours after injury

Question 47

poliomyelitis

Answer 47

destruction of ventral horn motor neurons by poliovirus muscle atrophy death due to paralysis of respiratory muscles

Question 48

amyotrophic lateral sclerosis ALS

Answer 48

lou gehrig's disease progressive destruction of ventral horn motor neurons and fibers of pyramidal tract loss of ability to speak, swallow, and breathe 5 years then death glutamate excitotoxicity or attack of immune system