Bales: Sagittal Brain and Cerebral topography and vessels (3/5)

Question 1

What 2 symptoms can a pineal gland tumor cause and why?

Answer 1

1. upward gaze palsy (inability of both eyes to look upward) from the compression of the midbrain tectum containing eye control and reflex nuclei
2. hydrocephalus from the compression of the tectum closing off the cerebral aqueduct

Question 2

What are the general properties of nuclei?

Answer 2

1. one or more afferents from other nuclei
2. one or more efferents from other nuclei
3. can have sub nuclei (ex left or right)
4. function to relay, modulated or change signals

Question 3

What are the afferent and efferent pathways of the habenula?

Answer 3

afferent: stria medullaris carries limbic info from regions anterior of the thalamus to the habenula
efferent: habenulo-interpenduncular tract to the interpeduncular nucleus

Question 4

What does the central sulcus divide?

Answer 4

The frontal and parietal lobes

Question 5

What happens to the brain’s structure in neurodegenerative diseases?

Answer 5

The gray matter is degenerated causing a widening of the sulci

Question 6

Where is the primary motor cortex? What Brodman’s area is it? What does the homunculus look like?

Answer 6

precentral gyrus (BA 4)
(homunculus=headless guy standing on the cingulate gyrus bending over holding his head by the hair (makes sense when you see the pic))

Question 7

What is the primary sensory cortex?

Answer 7

post central gyrus (BA 3 (rostral), 2 (caudal), and 1).

homunculus is similar to motor but with larger face and genitals on the medial surface

Question 8

where are the supplementary and premotor areas? what is their function?

Answer 8

Posteriormost superior and middle frontal gyri are the supplementary and premotor areas (BA6) for planning limb and body movements

Question 9

Where is BA located and what does BA 8 do?

Answer 9

Posteriormost superior and middle frontal gyri are the supplementary and premotor areas (BA6) for planning limb and body movements

Question 10

What are the 3 parts of the inferior frontal gyrus?

What is the significance of these areas?

Answer 10

posterior to anterior:
pars opercularis (BA44)
pars triangularis (BA45)
pars orbitalis (close to the orbit)

BA 44+45=Broca’s area ==> directs speech production

Question 11

What is the prefrontal cortex involved in?

Answer 11

higher functions (thinking, cognition, personality)

Question 12

Where is BA 22? What is its function?

Answer 12

Superior temporal gyrus

It is the secondary auditory cortex

the posterior part of BA22 is Wernicke’s area

Question 13

What part of the parietal lobe do the sulci on the sides of the superior temporal gyrus lead to?

What is the function of these 2 areas?

Answer 13

the top of the lateral fissure is capped by the supramarginal gyrus (BA 40)

the angular gyrus (BA39) caps the superior temporal sulcus

Question 14

Where are the transverse temporal gyri and the planum temporal located? What are their functions?

Answer 14

Transverse temporal gyri (Heschl’s; BA 41,42) are located on the superior aspect of the temporal lobe (floor lateral fissure)–> seen if the frontal and parietal lobes are removed

BA41=primary auditory cortex (surrounded by BA22–> secondary auditory cortex)

Planum temporale, posterior to Heschl’s gyri, is involved in language processing

Question 15

Where is the insular gyri located?

Answer 15

on the floor of the lateral fissure. covered by the frontal, parietal and temporal operculum

Question 16

How many gyri commonly make up the insular lobe?

Answer 16

3 short insular gyri (anterior) and 2 long insular gyri (posterior)

Question 17

What is the limen insulae?

Answer 17

Where the insula connects to other gray matter at its inferior angle

Question 18

What is the limbic lobe composed of?

Answer 18

The cingulate gyrus and parahippocampal gyrus.

these are connected by a narrow isthmus

Question 19

Where is precuneus?

Answer 19

it is the parietal lobe between the marginal rams and the parietal-occipital sulcus (seen in sagittal view)

Question 20

What divides the occipital lobe? What BA is this region and what is its function?

Answer 20

the calcarine sulcus divides the cuneus (superior) and the lingual gyrus (inferior)

BA 17 surrounds the calcarine sulcus and is the primary visual area.

Question 21

What other BAs surround BA 17? What are their functions?

Answer 21

BA 18 and 19 surround BA 17 in a mirror image in sagittal view) and are the secondary visual association cortex

they form concentric strips of the whole occipital region with 17 at the end and 18 and 19 moving anteriorly

Question 22

What lobes make up the inferior surface of the brain?

Answer 22

Frontal lobe: orbital gyri and gyrus rectus (adjacent to the longitudinal fissure) (separated by the olfactory sulcus and bulb)

Temporal lobe (from medial–> lateral): parahippocampal gyrus, occipitotemporal gyrus and inferior temporal gyrus. The lingual gyrus is posterior to the parahippocampal gyrus

Question 23

What are the 2 BAs on the parahippocampal gyrus?

Answer 23

BA 28 and the uncus (BA 34) which projects medially at the anterior end

involved in primary olfactory and limbic association

Question 24

What is lissencephaly?

Answer 24

An abnormally smooth brain with fewer gyri

Question 25

What is pachygyria?

Answer 25

thick, fewer than normal gyri

Question 26

Where does the anterior cerebral artery run?

Answer 26

wraps dorsally around the corpus callosum in the longitudinal fissure

Supplies medial surface and corpus callosum as far as parieto-occipital sulcus

Branches extend out of the longitudinal fissure onto the lateral surface

branches into the callosomargial branch and the pericallosal branch at the genu

Question 27

What areas does the ACA supply blood to?

Answer 27

corpus callosum, cingulate gyrus, superior frontal gyrus, and the paracentral lobule

Question 28

What areas does the middle cerebral artery supply?

Answer 28

most of the lateral hemisphere including insula, opercular, auditory cortex and motor and sensory areas for upper limb and face

Question 29

What are border zones? Why are they more susceptible to infarction?

Answer 29

Regions between cerebral artery terminal watersheds are called “border zones”.

More susceptible to infarction due to smallness of vessels and minimal anastomoses.

Question 30

Where does the PCA run? What does the PCA supply blood to?

Answer 30

PCA courses posteriorly between the cerebrum and cerebellum

Supplies medial & inferior temporal lobe, medial & lateral occipital lobes

Question 31

What vein drains the deep brain?

Answer 31

the great cerebral vein (of Galen) –> straight sinus