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Flashcards in CNS Deck (156)
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1
Q

What are the two parts of the CNS?

A

brain and spinal cord

2
Q

evolution of a CNS with an elaboration of the anterior end of the CNS along with an increase in the number of neurons in the head

A

cephalization

3
Q

a thickening of the surface ectoderm along the dorsal midline of the embryo that eventually becomes the CNS

A

neural plate

4
Q

the invagination of the neural plate

A

neural groove

5
Q

the superior edges of the neural folds come together to turn the neural groove into this

A

neural tube

6
Q

What does the neural tube do shortly after it forms?

A

detaches from the ectoderm and sinks to a deeper position

7
Q

small groups of neural fold cells migrate between the surface ectoderm and the neural tube to form this

A

neural crest

8
Q

What will the cells of the neural crest eventually become?

A

ganglia

9
Q

Give the simple and the complex name for the three primary brain vesicles

A
  1. prosencephalon - forebrain
  2. mesencephalon - midbrain
  3. rhombencephalon - hindbrain
10
Q

meaning of encephalo

A

brain

11
Q

swellings of the anterior end of the neural tube

A

primary brain vesicles

12
Q

what the primary brain vesicles divide to become

A

secondary brain vesicles

13
Q

What does the forebrain divide into?

A

telencephalon - endbrain

diencephalon - interbrain

14
Q

What does the hindbrain divide into?

A

metencephalon - afterbrain

mesencephalon - spinal brain

15
Q

What does the telencephalon become

A

cerebral hemispheres

16
Q

What 4 things does the diencephalon form?

A
  1. thalamus
  2. hypothalamus
  3. epithalamus
  4. retina
17
Q

What does the metencephalon divide to form?

A
  1. pons

2. cerebellum

18
Q

What does the myelencephalon form?

A

medulla oblongata

19
Q

What three structures are considered the brain stem?

A
  1. midbrain
  2. pons
  3. medulla oblongata
20
Q

What does the mesencephalon become?

A

midbrain

21
Q

What does the cavity of the neural tube enlarge to form?

A

brain ventricles

22
Q

Why does the brain need to flex and fold?

A

not enough room in the skull

23
Q

What are the two major flexures?

A

midbrain flexure

cervical flexure

24
Q

What are the foldings of the cerebral surface called? What is their purpose?

A

convolutions - increase SA for more neurons

25
Q

What is the outer layer of gray matter on both the cerebrum and cerebellum?

A

cortex -

26
Q

What happens to the gray and white matter as you proceed down the spinal cord?

A

switch places - spinal cord has gray interior and white exterior

27
Q

What fills the brain ventricles?

A

CSF - cerebrospinal fluid

28
Q

What lines the brain ventricles and circulates the CSF?

A

ependymal cells (neuroglia)

29
Q

What are the paired C shaped cavities that fill the cerebral hemispheres?

A

lateral ventricles

30
Q

What thin membrane separates the anterior horns of the lateral ventricles?

A

septum pellucidum

31
Q

What connects the lateral ventricles to the third ventricle?

A

interventricular foramina

32
Q

Where is the third ventricle?

A

diencephalon

33
Q

What connects the third and fourth ventricles?

A

cerebral aqueduct

34
Q

Where is the cerebral aqueduct?

A

midbrain

35
Q

Where is the fourth ventricle?

A

dorsal to the pons and superior medulla

36
Q

What cavity runs through the spinal cord and connects to the fourth ventricle?

A

central canal

37
Q

What are the openings in the fourth ventricle that connect to the subarachnoid space around the brain?

A

2 lateral apertures and a median aperture

38
Q

What portion of the brain accounts for 83% of the total brain mass?

A

cerebral hemispheres

39
Q

What are the ridges on the cerebral surface?

A

gyri/gyrus

40
Q

What are the shallow grooves on the cerebral surface?

A

sulci/sulcus

41
Q

What are the deep grooves on the brain surface?

A

fissures

42
Q

What fissure separates the cerebral hemispheres?

A

longitudinal fissure

43
Q

What fissure separates the cerebral hemispheres from the cerebellum?

A

transverse cerebral fissure

44
Q

What are the 5 major lobes of the brain?

A
frontal
temporal
parietal
occipital
insula
45
Q

What sulcus separates the frontal and parietal lobes?

A

central sulcus

46
Q

What gyrus is in front of the central sulcus? What is its function?

A

precentral gyrus - primary motor cortex

47
Q

What gyrus is behind the central sulcus? What is its function?

A

postcentral gyrus - primary somatosensory cortex

48
Q

What sulcus separates the parietal and occipital lobes?

A

parieto-occipital sulcus

49
Q

What sulcus separates the parietal and frontal lobes?

A

lateral sulcus

50
Q

What lobe is an “island” of cortex hidden beneath the temporal, parietal, and frontal lobes?

A

insula

51
Q

What are the pieces of gray matter buried inside the white matter of the brain? (2 terms)

A

basal nuclei (or historically basal ganglia)

52
Q

the depressions in the skull where the brain fits - name the three, and say what part of the brain is in each.

A

cranial fossa

  1. anterior - frontal lobes
  2. middle - temporal
  3. posterior - brain stem and cerebellum
53
Q

What is gray matter? How thick is it? What do the convolutions do for it?

A

neuron cell bodies dendrites, glia, and blood vessels - 2-4mm - surface area is tripled by convolutions

54
Q

What is white matter? What is its function?

A

myelinated axons bundled into tracts - that communicate between different parts of the brain

55
Q

What type of imaging technique allows us to see maximal metabolic activity of the brain?

A

PET scan

56
Q

What type of imaging technique shows blood flow in the brain?

A

functional MRI

57
Q

In general, which hemisphere controls the sensory and motor functions of which side of the body?

A

opposite - contralateral

58
Q

What is the term for the understanding that the two hemispheres are specialized for certain functions?

A

lateralization

59
Q

Do the functional areas of the brain work independently of one another? Explain.

A

NO! Most conscious behavior involves the entire cortex

60
Q

What are the large neurons in the primary motor cortex? What are their descending tracts called? (2 terms)

A

pyramidal cells - form pyramidal tracts also called corticospinal tracts

61
Q

the representation of the entire body as a “little man” on the primary motor cortex
- the same thing on the primary somatosensory cortex

A

motor homunculi

somatosensory homunculi

62
Q

mapping of the body in CNS structures

A

somatotopy

63
Q

Where is the premotor cortex, and what is it responsible for?

A

anterior to the primary motor cortex - learned, repetitious motor skills and planning movements

64
Q

the motor speech area is called what? Where is it located? What does it do?

A

Broca’s area - anterior to the premotor cortex - controls speech planning and production

65
Q

What is unusual about Broca’s area?

A

usually only on one side of brain

66
Q

Where is the frontal eye field, and what does it do?

A

above Broca’s area - controls voluntary eye movements

67
Q

What is the term for the ability of a person to discriminate what portion of the body is being stimulated?

A

spatial discrimination

68
Q

What two portions of the somatosensory homunculus are represented by the largest areas?

A

lips and fingertips

69
Q

Where is the somatosensory association area, and what is its function?

A

just posterior to the primary somatosensory cortex - to integrate sensory information and understand what you are sensing

70
Q

Where is the primary visual cortex, and what is its function?

A

extreme tip of occipital lobe (calcarine sulcus) - sight

71
Q

Where is the visual association area, and what is its function

A

surrounding the primary visual cortex - recognize what is seen

72
Q

Where is the primary auditory cortex, and what is its function?

A

superior margin of temporal lobe - hearing

73
Q

Where is the auditory association area, and what is its function?

A

posterior to the primary auditory cortex - interpret sounds

74
Q

Where is the olfactory cortex, and what is its function?

A

medial part of temporal lobe called the piriform lobe - smell

75
Q

What is the olfactory cortex part of?

A

rhinencephalon (primitive brain)

76
Q

Through evolution, the new functions of the rhinencephalon include what? What do we call this system?

A

memory and emotions - limbic system

77
Q

Where is the gustatory cortex, and what is its function?

A

insula - taste

78
Q

Where is the visceral sensory area, and what is its function?

A

insula - posterior to taste region - sense organs (full or upset stomach, full bladder…)

79
Q

Where is the vestibular cortex, and what is its function?

A

posterior part of insula and adjacent parietal lobe - equilibrium

80
Q

What do we call areas that receive input from multiple senses and send outputs to multiple areas?

A

multimodal association areas

81
Q

What is the purpose of multimodal association areas?

A

give meaning, tie to previous experience, store as a memory

82
Q

What are the three parts of the multimodal association areas, and what is the function of each?

A
  1. anterior association area - also known as the prefrontal cortex - most complicated region - intellect, cognition, recall and personality
  2. posterior association area - recognizing patterns and faces, locating us in space, and making a coherent whole of our senses
  3. limbic association area - emotions and memory
83
Q

What are the parts of the limbic association area?

A

cingulate gyrus, parahippocampal gyrus, and hippocampus

84
Q

Which of the multimodal association areas is the last to develop, and what is the significance of this?

A

prefrontal cortex - abstract ideas, judgment, reasoning, persistence and planning all develop slowly and depend on feedback from the social environment

85
Q

What happens with tumors or lesions in the anterior association area?

A

mental and personality disorders - loss of normal social restraints

86
Q

What happens with tumors or lesions in the posterior association area?

A

won’t wash or dress part of body because don’t recognize it as self

87
Q

What does the term cerebral dominance refer to?

A

the side dominant for language

88
Q

In 90% of people, what does the left brain control?

A

language, math and logic

89
Q

In 90% of people, what does the right brain control?

A

creativity, intuition, emotion

90
Q

Most people with left cerebral dominance dominantly use what hand?

A

right

91
Q

a reading disorder where otherwise intelligent people reverse letters and words - How is it related to cerebral dominance?

A

dyslexia - thought to be a processing disorder in one hemisphere

92
Q

What are the three types of white matter tracts in the brain, and what is their function?

A
  1. commissural - connect corresponding gray areas of the two hemispheres for coordinated function
  2. association fibers - connect different parts of the same hemisphere (short and long)
  3. projection fibers - tie the cortex to the rest of the nervous system - ascending and descending
93
Q

What is the largest commissure?

A

corpus callosum

94
Q

projection fibers that form a compact band of white matter tracts between the thalamus and some of the basal nuclei - what are the fibers called as they radiate out to the cortex?

A

internal capsule - corona radiata

95
Q

Name the 3 major bodies that make up the basal nuclei. What are they all called together? Why are they called this?

A

caudate nucleus, globus pallidus, and putamen - corpus striatum (look striped)

96
Q

The putamen and globus pallidus are collectively called what?

A

lentiform nucleus

97
Q

What is the function of the basal nuclei?

A

unsure - regulate attention and cognition, start and stop movements, monitor movement intensity

98
Q

Disorders of the basal nuclei controlling movement are linked to what two diseases?

A

Parkinson’s and Huntington’s

99
Q

What is the thalamus? What is the function of the thalamus?

A

a collection of specialized nuclei - relay station for information coming in to the cerebral cortex - sorts, edits, and groups similar

100
Q

Where is the hypothalamus, and what are its functions (7)?

A

below the thalamus - contains many nuclei that serve to control the viscera

  1. autonomic control center
  2. center for emotional responses - limbic system
  3. body temperature control
  4. regulates food intake
  5. regulates water balance and thirst - antidiuretic hormone
  6. regulates sleep/wake cycles - suprachiasmatic nucleus
  7. controls the endocrine system by controlling the anterior pituitary
101
Q

What are the tiny, paired nuclei that extend from the hypothalamus, and what is their function?

A

mammillary bodies - olfactory relay station

102
Q

What important gland connects to the hypothalamus? What is the stalk of tissue connecting the two structures?

A

pituitary - infundibulum

103
Q

What happens when the pituitary doesn’t function?

A

body wasting/obesity, sleep disorders, dehydration, emotional imbalances, failure to thrive

104
Q

Where is the epithalamus?

A

most dorsal part of diencephalon

105
Q

What is the gland that extends from the back of the epithalamus, and what does it do?

A

pineal gland - secretes melatonin

106
Q

What is the function of melatonin?

A

induce sleep and antioxidant

107
Q

The brain stem is similar histologically to the spinal cord with what major exception?

A

gray matter nuclei embedded in white matter

108
Q

What is the function of the brain stem?

A

survival functions

10 or 12 cranial nerves root here

109
Q

What does the term peduncle mean? What are the cerebral peduncles?

A

little feet - two vertical columns of white matter tracts above the pons

110
Q

What is the corpora quadrigemina? How does the corpora quadrigemina get its name?

A

nuclei that protrude from the dorsal midbrain - 4 domes - quadruplets

111
Q

What is the periaqueductal gray matter, and what is its function?

A

gray matter around cerebral aqueduct - pain suppression, link between fear perceiving area (amygdala) and fight or flight response, contains nuclei for oculomotor and trochlear nerves

112
Q

What is the fear-perceiving center called?

A

amygdala

113
Q

What are the parts of the quadrigemina and their functions?

A

superior colliculi - visual reflex center for tracking

inferior colliculi - auditory relay and startle reflex

114
Q

What is the substantia nigra? Where is it located? What is its function?

A

nuclei in side of midbrain - makes dopamine

115
Q

Why is the substantia nigra so dark?

A

accumulated melanin

116
Q

What is the purpose of the melanin in the substantia nigra?

A

precursor to dopamine production

117
Q

What is the ultimate cause of Parkinson’s disease?

A

degeneration of dopamine producing neurons in substantia nigra

118
Q

What is the red nucleus? Where is it located? What is its function?

A

gray matter deep to substantia nigra in the reticular formation that function as a relay for some motor neurons

119
Q

Why is the red nucleus red?

A

blood supply and iron pigment

120
Q

What is the meaning of the word pons? Why does it have this name?

A

bridge - conduction tracts between midbrain and medulla

121
Q

What are the numerous nuclei in the pons called, and what is their function?

A

pontine nuclei - connect motor cortex and cerebellum, serve as part of reticular formation, maintain normal breathing rhythm

122
Q

the middle portion of the brain stem, anterior bulge

A

pons

123
Q

the most inferior part of the brain stem

A

medulla oblongata

124
Q

What are the longitudinal ridges on the medulla called? What is their function?

A

pyramids - corticospinal tracts (descending)

125
Q

the crossing of the corticospinal tracts or pyramids at the junction between the medulla and spinal cord - What does this explain?

A

decussation of the pyramids - explains why right side of brain controls left side of body and left brain controls right body

126
Q

oval swellings lateral to the pyramids that contain nuclei that relay sensory information about the stretch of muscles and joints

A

olives

127
Q

a measure of the electrical activity of the brain using electrodes

A

EEG - electroencephalogram

128
Q

patterns of electrical activity in an EEG

A

brain waves

129
Q

What generates brain waves?

A

synaptic activity

130
Q

How are brain waves measured?

A

Hertz - Hz

131
Q

What is a Hertz?

A

1 wave or cycle per second

132
Q

What is amplitude?

A

the height of a wave or the depth of a trough

133
Q

Name, and describe the four major patterns of brain waves.

A
  1. alpha - 80=-13 HZ, regular and rhythmic, low amplitude, calm and relaxed state of wakefulness
  2. beta - 14-30 Hz, rhythmic but not as regular, higher frequency, mentally alert and concentrating
  3. theta - 4-7 Hz, irregular, common in children, uncommon in awake adults
  4. delta - 4HZ or less, high amplitude, deep sleep, under anesthesia, may indicate brain damage in awake adults
134
Q

brain waves that are 4HZ or less, high amplitude, deep sleep, under anesthesia, may indicate brain damage in awake adults

A

delta

135
Q

brain waves that are 80=-13 HZ, regular and rhythmic, low amplitude, calm and relaxed state of wakefulness

A

alpha

136
Q

brain waves that are 14-30 Hz, rhythmic but not as regular, higher frequency, mentally alert and concentrating

A

beta

137
Q

brain waves that are 4-7 Hz, irregular, common in children, uncommon in awake adults

A

theta

138
Q

What four factors can change brain waves?

A

age, stimulation, disease, chemical state

139
Q

What are EEGs useful at diagnosing?

A

epilepsy, sleep disorders, brain function

140
Q

a flat EEG is clinical evidence of what?

A

brain death

141
Q

a flood of electrical activity that interferes with brain function

A

epilepsy - seizure

142
Q

List 5 things that can cause seizures.

A

trauma, stroke, infection, high fever, tumors, genetic factors

143
Q

What are the two main kinds, and how are they different?

A
  1. absence (petit mal) - goes blank for a few seconds where not everyone will notice
  2. tonic-clonic (Grand mal) - intense convulsions
144
Q

What sometimes precedes a seizure, and how can it be helpful?

A

aura - light, smell, or taste hallucination that allows the person to lie down

145
Q

What is a difference after the absence or tonic-clonic seizures?

A

tonic clonic seizures leave the person disoriented

146
Q

What can control epilepsy?

A

anticonvulsive drugs or vagus nerve stimulator

147
Q

What 3 factors indicate consciousness?

A
  1. ability to initiate movement
  2. perception of sensation
  3. higher mental functioning
148
Q

What are the 4 degrees of consciousness?

A
  1. alert
  2. drowsy (lethargy)
  3. stupor
  4. coma
149
Q

a brief loss of consciousness (2 terms)

A

fainting or syncope

150
Q

How is sleep different from a coma?

A

Sleeping people use almost as much oxygen as people who are awake, and they can be aroused by stimulation.

151
Q

Give 5 things that can cause a coma.

A
  1. blow to the head
  2. tumor
  3. infection
  4. metabolic disturbance - hypoglycemia
    5, overdose
  5. liver or kidney failure
152
Q

What are the two major types of sleep?

A

REM and non-REM

153
Q

What happens during the first part of our sleep?

A

brain waves decline, respiration, blood pressure and heart rate decline

154
Q

What happens when we are in REM sleep?

A

alpha waves appear, digestion is inhibited, BP, respiratory rate,and heart rate increase, use more oxygen than when awake, dream

155
Q

When do most nightmares and night terrors happen?

A

NREM stages 3-4

156
Q

our alternating sleep and wake cycles reflect a natural 24 hour cycle called what?

A

circadian rhythm