1: Topographic Anatomy of the Brain and Spinal Cord Flashcards Preview

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Flashcards in 1: Topographic Anatomy of the Brain and Spinal Cord Deck (150):
1

Spinal cord enlargements: where are they, and why are they present?

Enlargements are at cervical and lumbar segments

Cervical contain nerves supplying the arms, lumbar the legs

2

Conus medullaris

The lowest tapering portion of the spinal cord

3

Filum terminale interna

The continuation of the pia mater from the end of the conus medullaris

4

Cauda equina

The lumbar and sacral nerve roots arising from the conus medullaris

5

What are the dorsolateral and ventrolateral sulci?

Small grooves on the dorsolateral and ventrolateral portions of the spinal cord

Located at the point of exit of the nerve roots

6

Briefly describe the anterior median sulcus, dorsal median sulus, and dorsal intermediate sulcus

All help divide the spinal cord into three basic divisions (dorsal, lateral, and ventral funiculi)

AMS: anterior spinal artery runs here

DMS: very small sulcus

DIS: between the DMS and dorsolateral sulcus, a sulcus only present in the upper part of the spinal cord because it separates the fibers from the legs (medial) from those of the arms (lateral)

7

Dorsal funiculus: where is it and what is it?

Between dorsal median sulcus and dorsolateral sulcus

Almost exclusively contains the dorsal columns: ascending tract that conveys vibratory sense, well-localized touch, and joint position sense

8

Lateral funiculus: where is it and (brief) what does it do?

Between dorsolateral and ventrolateral sulci

Contains contralateral corticospinal and spinothalamic tracts

Damage -> weakness

9

Ventral funiculus: where is it?

Between ventrolateral and anterior median sulci

10

Distinguish the ventral horn from the dorsal horn

Ventral horn protrudes forward, dorsal protrudes back

Ventral is motor, dorsal is sensory

11

Briefly, what is the substantia gelatinosa?

A term for the most posterior portion of the dorsal horn

12

What is this structure?

Pons

13

What is this structure?

What does it do?

What emanates from it?

What is the effect of damage to this structure?

Middle cerebellar peduncle

Large white matter tract connecting the basal pons to cerebellum

The trigeminal nerve emerges from the junction of the basal pons with the middle cerebellar peduncle.

Incoordination (cerebellum functions to coordinate skilled movements)

14

Where is the medulla?

Portion of the brainstem from the spinal cord to the pons

15

What is the midbrain?

The portion of the brainstem extending rostally form the pons

16

What is this structure?

What does it contain?

Inferior olive (inferior olivary nucleus)

Contains a motor nucleus connected to the contralateral cerebellum

17

What is the post olivary sulcus and what does it contain?

What is the preolivary sulcus and what does it contain?

Post.: groove located dorsal to the protuberance of the inferior olive; CN IX and CN X nerve filaments emerge from here

Pre.: groove located ventral to protuberance of the inferior olive; CN XII filaments emerge from here

18

What is this structure?

What does it contain?

Brief description of purpose

Medullary pyramids

Bundles of fibers from cerebral cortex extending down to spinal cord (corticospinal neurons)

Critically important for voluntary movements (especially skilled)

19

What is this structure?

What does it contain?

Pyramidal decussation (crossing of fibers)

Comprise the descending motor tract in the lateral funiculus of the cord

20

What is this structure?

What is its function?

CN VI - Abducens nerve

Lateral eye movement

21

What is this structure?

What is its function?

CN VII - Facial nerve

Movement of muscles of facial expression

22

What is this structure?

What is its function?

CN VIII - Vestibulocochlear nerve

Hearing and inner ear balance

23

What is the acoustic tubercle?

Portions of CN VIII that wrap around the inferior cerebellar peduncle

24

What is this structure?

What is its function?

CN V - Trigeminal Nerve

Facial sensations and jaw movements

25

What is this structure?
What is its function?

Cerebral peduncle (crus cerebri): prominent bands of fibers on either side of the interpeduncular fossa (peduncle means "stalk")

The primary fiber bundles that connect the cerebral cortex to the brainstem.

Allows the cortex to control the contralateral side of the body and head

26

What is this structure?

What is its function?

From where is it emanating?

CN III - Oculomotor nerve

Opening the eye, controlling many eye muscles, constricting the pupil

Found in the interpeduncular fossa: the depression in between the cerebral peduncle; contains the posterior perforated substance where branches of the basilar artery enter the midbrain

27

Name this structure.

Optic chiasm: location where the right and left optic nerves meet and form the optic tracts

28

Name this structure.

Olfactory tract

29

Name this structure.

Optic tract

30

Name this structure.

Pituitary stalk (infundibulum): part of the hypothalamus that is funnel-shaped; at the narrow part of the funnel is the stalk of the pituitary gland.

31

Name this structure.

Mamillary bodies: prominences on the ventral side of the hypothalamus that are part of the limbic system

Demarcate the junction between the midbrain and diencephalon

32

Name this structure.

Cerebellar flocculus: the small piece of cerebellum that lies in the area between the ventral pons and cerebellum

Flocculus = "a small tuft or mass"

Part of the flocculonodular lobe

33

Name this structure.

Cerebellar hemisphere: one of the two lateral portions of the cerebellum, separated by the vermis

34

Name this structure.

Cerebellar tonsil: the most inferior part of the cerebellum that lies just superior to the foramen magnum

35

Fill in the following structures related to the cerebellum:

The majority of the cerebellum consists of small folds, called ________

A deep division (___________) separates the anterior lobe of the cerebellum from the posterior.

There are two easily identified divisions to the cerebellum. The __________ is in the midline, while the lateral portions are termed the __________.

There are also two small lobes that are situated between the cerebellum and medulla, the ________ laterally and the _________ in the midline.

The majority of the cerebellum consists of small folds, called folia.

A deep division (primary fissure) separates the anterior lobe of the cerebellum from the posterior.

There are two easily identified divisions to the cerebellum. The vermis is in the midline, while the lateral portions are termed the hemispheres.

There are also two small lobes that are situated between the cerebellum and medulla, the flocculus laterally and the nodulus in the midline.

36

What is this structure?

Inferior cerebellar peduncle (aka restifom body): white matter tract connecting the medulla to the cerebellum

Forms part of the wall of the 4th ventricle

37

What is this structure?

Superior cerebellar peduncle (aka brachium conjunctivum): white matter tract connecting the midbrain to the cerebellum

38

What is this structure? What is it separating?

4th ventricle

Separates cerebellum from dorsal brain stem

39

Fill in the blank:

CSF leaves the fourth ventricle to the subarachnoid space through openings caudal to the cerebellum, the lateral __________________ and the midline ______________________

Lateral foramina of Luschka

Midline foramen of Magendie

40

What is the obex?

The caudal-most point of the 4th ventricle

41

What is this structure?

Gracile tubercle: prominence immediately lateral to the midline over the gracile nucleus

Continuous with the fasciculus gracilis inferiorly

42

What is this structure?

Cuneate tubercle: prominence lateral to the gracile tubercle over the cuneate nucleus

Continuous with the fasciculus cuneatus inferiorly

43

What is this structure?

Facial colliculus: prominence over the facial nerve as it does its “U-turn” around the abducens nucleus inside the pons

44

What is this structure?

Vestribular trigone: area lateral to the sulcus limitans that marks the position of the underlying vestibular nuclei

45

What is this structure?

Sulcus limitans: vertical groove on either side of the median sulcus

Marks the embryologic division between the alar and basal plates, which in the adult, separates motor and sensory nuclei (the motor nuclei are medial to the sulcus, sensory lateral).

46

Define corpora quadrigemina.

The four bumps on the dorsal surface of the midbrain (two inferior colliculi, two superior colliculi)

47

What is this structure?

What is its function?

Inferior colliculus: the “midbrain auditory center”; receives just about all the information from the cochlear nuclei (some directly and some indirectly) and integrates it

Neurons from the inferior colliculus project to the medial geniculate body, which is the thalamic relay for auditory information

48

What is this structure?

What is its function?

Superior colliculus: receives information directly from the retina (first-order neurons in the optic tract project to superior colliculus as well as other locations)

Involved in coordinating movements of the head and eyes

49

What are the brachium of the inferior colliculi and brachium of the superior colliculi?

Small ridges running laterally from the inferior/superior colliculi, respectively, on the lateral side of the midbrain

Superior: connects the superior colliculus to the lateral geniculate body; it passes superior to the medial geniculate body in its course

Inferior: conveys neurons from the inferior colliculus to the medial geniculate body

50

What is this structure?

Hypoglossal trigone: prominence over the hypoglossal nucleus (near the midline)

51

What is this structure?

Vagal trigone: prominence over the dorsal motor nucleus of CN X located immediately lateral to the hypoglossal trigone

The dorsal motor nucleus contains cell bodies of preganglionic parasympathetic neurons.

52

What is this structure?

CN XI - Accessory nerve

53

What is this structure?

Cerebral peduncle

54

What is this structure?

Dorsal median sulcus

55

What is this structure?

CN VII - Facial nerve

56

What is this structure?

Fasiculus cuneatus

57

What is this structure?

Fasiculus gracilis

58

What is this structure?

CN XII - Hypoglossal nerve

59

What is this structure?

Lateral funiculus

60

What is this structure?

Middle cerebellar peduncle

61

What is this structure?

CN V - Trigeminal nerve

62

What is this structure?

CN IV - Trochlear nerve

63

What are these structures?

CN X - Vagus and CN IX - glossopharyngeal nerves

64

What is this structure?

CN VIII - Vestibulocochlear nerve

65

What is this structure? What is its function?

Thalamus: a large nuclear mass, a site of relay of many of the inputs to and from the cerebral cortex

Most of the information (sensory and motor feedback information) that is required by the cerebral cortex passes through the thalamus

Makes up the bulk of the lateral walls of the third ventricle

66

What is this structure?

What is its function?

Hypothalamus: involved in endocrine regulation, regulation of feeding, autonomic regulation, regulation of sexual behaviors, thermoregulation, and fluid/electrolyte homeostasis

67

What is the lamina terminalis?

On the rostral side of the infundibulum

The most rostral portion of the embyologic nervous system, where the anterior neuropore closed

Forms the rostral border of the hypothalamus

68

What is this structure?

Pineal gland (makes up most of the epithalamus): part of the diencephalon that is located rostral to the superior colliculi

Produces melatonin (associated with circadian rhythms) as well as other hormones that seem to influence gonadal development.

69

What are the habenular nuclei?

Tiny swellings anterior to the pineal gland

Thought to be involved in integration of olfactory, sensory and visceral information

70

What is this structure?
What is its function?

Medial geniculate nucleus

Chief site of relay of auditory information from the inferior colliculus (via the brachium of the inferior colliculus) to the cerebral cortex

71

What is this structure?

What is its function?

Lateral geniculate nucleus

Receives information from the superior colliculus related to head/eye coordination

72

What is this structure?

Anterior commisurea tract that connects the two temporal lobes found at the dorsal (superior) aspect of the lamina terminalis.

73

What is this structure?

Rostrum of corpus callosum

74

What is this structure?

Thalamic adhesion

75

What is this structure?

Genu of corpus callosum

76

What is this structure?

Septum pellucidum: a thin membrane that separates the two lateral ventricles

77

What is this structure?

Interventricular foramen (of Monroe): an opening inferior to the fornix by which spinal fluid can pass from the lateral ventricle to the third ventricle

78

What is this structure?

Fornix: a thickening at the inferiormost portion of the septum pellucidum; a C-shaped tract that follows the lateral ventricle

Extends between the hippocampus and the hypothalamus

 

79

What is this structure?

Body of corpus callosum: a collection of fibers that connects the two cerebral hemispheres

80

What is this structure?

Choroid plexus: rough and irregular tissue extending through the foramen of Monroe into the lateral ventricle

Responsible for production of CSF

81

What is this structure?

Parieto-occipital sulcus: sulcus the separates the parietal and occipital lobes

82

What is this structure?

Splenium of corpus callosum

83

What is this structure?

Tectum: the “roof” or dorsal part of the midbrain containing the corpora quadrigemina

84

What is this structure?

Calcarine sulcus: sulcus within the occipital lobe that merges with the parieto-occipital sulcus

The gyri surrounding this sulcus are part of the visual cortex

85

What is this structure?

Primary fissure: the fissure that separates the anterior lobe of the cerebellum from the posterior lobe

Found on the part of the cerebellum that is covered by the overlying cerebral hemispheres, thus it is best seen in a midsagittal view

86

What is this structure?

Vermis: midline portion of the cerebellum that gets it name from the fact that it resembles a worm

Functionally part of the spinocerebellum

87

What is this structure?

Pons

88

What is this structure?

Medulla

89

What is this structure?

Cingulate gyrus: the C-shaped gyrus that follows the dorsal aspect of the corpus callosum

90

What is this structure?

Optic chiasm

91

What is this structure?

Pituitary gland: an endocrine gland that is suspended from the hypothalamus, but is not technically part of it

92

What is the hypothalamic sulcus?

The hypothalamic sulcus is a groove in lateral wall of third ventricle, marking the boundary between the thalamus and hypothalamus

93

What is the stria medullaris thalami?

A ridge running from anterior to posterior along the wall of the third ventricle

Contains afferent neurons traveling from the amygdala to the habenula

 

Meets the habenula at its posterior end

94

What is this structure?

Lateral (Sylvian) fissure: fissure on the lateral aspect of the cerebrum that separates the temporal lobe from the frontal/parietal lobes

When the lateral fissure is opened, the insula can be seen.

95

What is this structure?

Central sulcus: sulcus in the coronal plane that separates the frontal and parietal lobes

96

What is this structure?

Occipital lobe

97

What is this structure?

Frontal lobe

98

What structure is this?

Temporal lobe

99

What is this structure?

Parietal lobe

100

What is this structure?

Precentral gyrus (primary motor cortex): controls movement of face and extremities

101

What is this structure?

Postcentral gyrus (primary somatosensory cortex): termination of many somatic sensory fibers coming from thalamus

102

What is this structure?

Transverse gyri (of Heschl): primary auditory cortex

Run into the lateral fissure on the dorsal aspect of the temporal lobe

103

What is this structure?

Insula (aka isle of Reil): group of small gyri located within the lateral fissure

Associated with visceral functions.

104

What is this structure?

What is its function?

Premotor cortex: planning and initiating movement

105

What is this structure?

What is its function?

Dorsolateral prefrontal cortex: executive functions such as working memory, planning, problem solving, reasoning and organizing

106

What is this structure?

What is its function?

Orbitomedial prefrontal cortex: impulse control, personality, reactivity to the surroundings and mood

107

What is this structure?

What is its function?

Broca's area: the motor language area

108

What is this structure?

What is its function?

Somatosensory association cortex: interpret what a somatic sensory signal is

109

Where are the areas that are involved in attention and visuospatial function (knowing how things can go together and where things are in relation to one another)?

In the posterior parts of the parietal lobes

110

What is this structure?

What is its function?

Auditory association area: involved in interpreting sound

111

What is this structure?

What is its function?

Wernicke's area: involved in interpreting language

112

What is this structure?

What is its function?

Parahippocampal gyrus: along with hippocampus, critical for short-term memory (minutes to hours)

the most medial gyrus on the ventral aspect of the temporal lobe

113

What is this structure? Why is it there?

Uncus: a medial swelling on the rostral end of the parahippocampal gyrus

Present because the amygdala is deep to the cortex in its location (amygdala is responsible for emotional learning, particularly responses to fear and anxiety)

114

What is this structure?

What is its function?

Visual association area: involved in interpreting aspects of what you are seeing

115

What is the caudate nucleus?

Where is it located?

What is its function?

A large ridge running posterior to anterior, paralleling the lateral ventricle

Location: lateral to the thalamus in the floor of the lateral ventricle

Function: part of the basal ganglia, mostly involved in regulating motor function and cerebral cortical excitability

116

What is the stria terminalis?

What is its function?

A thin band in the groove between the thalamus and caudate nucleus

117

What is this structure?

Primary visual cortex

118

What is this structure?

What is its function?

Primary auditory cortex (on the transverse gyri [of Heschl])

119

Dura mater

120

falx cerebri

Fold of dura that extends between the cerebral hemispheres

Occupies the longitudinal fissure

Contains the superior sagittal sinus in its superior edge, inferior sagittal sinus in its inferior edge, and the straight sinus at its junction with the tentorium cerebelli.

121

tentorium cerebelli

horizontal fold of dura between the cerebral hemispheres and cerebellum; contains the transverse sinus in its lateral edge, and the superior petrosal sinus where it meets the petrous ridge.

122

falx cerebelli

small fold of dura between the two halves of the cerebellum (stops at vermis); contains the occipital sinus.

123

arachnoid mater

the middle layer of connective tissue that surrounds the brain; its consistency resembles a spider web, although it is water-tight.

124

pia mater

innermost layer of connective tissue surrounding the brain; it is firmly attached to the surface of the brain and cannot be separated from it.

125

subarachnoid space

space between the arachnoid and pia mater that contains cerebrospinal fluid; large blood vessels of the brain travel within this space.

126

vertebral artery

one of the two sources of arterial blood to the brain

arises from the subclavian artery, travels superiorly in the neck and enters the cranial cavity through the foramen magnum

the right and left vertebral arteries merge to form the basilar artery

Important branches to remember are the posterior inferior cerebellar artery (PICA), and the anterior and posterior spinal arteries.

127

basilar artery

artery that travels on the ventral surface of the pons

several important branches of the basilar are the anterior inferior cerebellar artery (AICA) and superior cerebellar

terminates by dividing into the two posterior cerebral arteries

128

posterior perforated substance

area in the interpeduncular fossa penetrated by small vessels that arise from the terminal region of the basilar artery

129

internal carotid artery

the other source of arterial blood to the brain (besides the vertebral arteries)

arises from the common carotid artery in the neck and enters the cranial cavity through the carotid canal

gives off the posterior communicating and anterior choroidal arteries

terminates by dividing into the anterior cerebral (ACA) and middle cerebral (MCA) arteries.

130

anterior choroidal artery

arises from the internal carotid near where it bifurcates into anterior and middle cerebral

travels in a dorsal direction following the optic tract.

131

posterior communicating artery

branch of the internal carotid that connects to the posterior cerebral artery, thus helping to form the cerebral arterial circle.

132

anterior perforated substance

area lateral to the optic chiasm, punctured by small vessels that branch from the anterior and middle cerebral arteries and supply deep areas of the brain.

133

anterior communicating artery

small artery that connects the two anterior cerebral arteries

134

Define tegmentum.

a synonym for the ventral portion of the midbrain (i.e. the area ventral to the cerebral aqueduct)

135

Which cranial nerves emerge from the medullary-pontine junction?

Abducens nerve

Facial nerve

Vestibulocochlear nerve

136

tuber cinereum

area between the mammillary bodies and infundibulum; has a swelling called the median eminence

137

olfactory sulcus

the sulcus normally “covered” by the olfactory bulb/tract

separates the straight gyrus from the orbital frontal gyri

The olfactory tract ends by dividing into medial and lateral stria.

138

orbital frontal gyri

gyri on the lateral aspect of the olfactory sulcus

139

What is this structure?

Gyrus rectus (aka straight gyrus): gyrus on the medial aspect of the olfactory sulcus

140

collateral sulcus

sulcus on the lateral aspect of the parahippocampal gyrus that separates this gyrus from the remainder of the temporal lobe

141

posterolateral fissure

Sulcus between the flocculus and the posterior lobe of the cerebellum (specifically the tonsillar part of the posterior lobe)

Caudal to the flocculus

142

vellum

name for the membranous dorsal wall of the 4th ventricle

the area rostral to the core of the cerebellum is called the superior medullary vellum, while the area caudal to the core of the cerebellum is the inferior medullary vellum.

143

posterior commissure

marks the junction of the midbrain and diencephalon dorsally (not technically part of either area)

It is a white matter tract that contains axons involved in the pupillary light reflex

Commissure = a tract that crosses the midline

144

What is this structure?

Angular gyrus: one of the two gyri associated with the caudal part of the lateral fissure

145

What is this structure?

Supramarginal gyrus: one of the two gyri associated with the caudal part of the lateral fissure 

146

subcallosal region

gyrus ventral to the rostrum of the corpus callosum.

147

pulvinar

the most posterior part of the thalamus that has the geniculate bodies on its surface

148

lateral ventricle

large C-shaped space in the brain that contains cerebrospinal fluid (CSF)

There are two lateral ventricles – one in each cerebral hemisphere

The floor of the lateral ventricle (ventral surface) is primarily in contact with the thalamus, while the lateral wall of the lateral ventricle is in contact with the caudate nucleus

149

striae medullares

Transverse fibers that separate the facial colliculus and hypoglossal trigone

These neurons are second order neurons in the auditory pathway, part of the posterior acoustic stria (a pathway that leads to the lateral lemniscus) that stays close to the surface

150

cerebral aqueduct (aqueduct of Sylvius)

narrow channel within the midbrain that connects the third and fourth ventricles