Week 3 Quiz

Question 1

what are the directional terms and how do they differ between species?

Answer 1

superior/inferior and anterior/posterior remains the same across species
for animals that move horizontally and the human brain dorsal = superior, ventral = inferior and rostral = towards the head/caudal = towards the tail
for the human spinal cord and brain stem dorsal = posterior and ventral = anterior

Question 2

what are the three planes of section?

Answer 2

coronal: separates the brain into front and back halves
sagittal: separates the brain into left and right halves
axial/horizontal/transverse: separates the brain into upper and lower halves

Question 3

what is holoprosencephaly?

Answer 3

when the brain does not divide into two halves, results in a cyclops like eye and fused brain

Question 4

what are the anatomic lobes of the brain?

Answer 4

frontal: forehead area of brain
parietal: top middle of the brain
occipital: back section of the brain
temporal: sides of the brain

Question 5

what are the functional lobes of the brain?

Answer 5

insula and limbic lobes (seen above the corpus callosum on a sagittal slice)

Question 6

what are the poles of the cerebrum?

Answer 6

frontal pole: front most tip of the frontal lobe, behind where forehead would be
temporal pole: front most tip of the temporal lobe, underneath frontal lobe
occipital pole: bottom tip of the occipital lobe
(diagram on L3S11)

Question 7

what are the boundaries between the lobes?

Answer 7

central sulcus: lies on top of the brain, separates the frontal and parietal lobes
lateral sulcus: lies on the side of the brain, separates the frontal and parietal lobes from the temporal lobe
preoccipital notch: lies on the back of the brain, notch on the bottom of the brain that separates the parietal and temporal lobes from the occipital lobe
(diagram on L3S11)

Question 8

what are the major sulci seen from the outside of the brain?

Answer 8

precentral sulcus: lies in front of the central sulcus
central sulcus: runs perpendicular to the temporal lobe, bisects temporal lobe
postcentral sulcus: lies behind the central sulcus
superior temporal sulci: lies underneath the lateral sulcus
interior temporal sulci: lies below the superior temporal sulci
(diagram on L3S12)

Question 9

what are the major sulci seen from a sagittal slice of brain?

Answer 9

cingulate sulcus: upper boundary of the limbic lobe, first sulcus above corpus callosum
callosal sulcus: upper boundary of the corpus callosum that separates it from the cortex
parietooccipital sulcus: separates the top of the occipital lobe from the bottom of the parietal lobe
(diagram on L3S12)

Question 10

what do the folds of the insula look like?

Answer 10

usually consists of three short gyri towards the frontal lobe and two long gyri towards the temporal lobe
(diagram on L3S13)

Question 11

what are the major frontal lobe gyri and what do they contain?

Answer 11

superior frontal gyri: lie along the midline of the two hemispheres on the frontal lobe
middle frontal gyri: lie below the superior frontal gyri on the frontal lobe
inferior frontal gyri: lie below the middle frontal gyri, lowest set of gyri on the frontal lobe just above the temporal lobe
precentral sulcus and gyrus: runs diagonal along the back of the ends of the superior, middle, and inferior frontal gyri, bisects the temporal lobe
orbital gyri: seen from a sagittal brain slice, lies in the area below the frontal lobe and above the temporal lobe
contain motor areas
(diagram on L3S14)

Question 12

what are the major parietal lobe gyri and what do they contain?

Answer 12

postcentral sulcus and gyrus: lies behind the precentral gyrus
superior parietal lobule: lies along the midline of the brain, behind the postcentral gyrus and in front of the occipital lobe
supramarginal gyrus: lies behind the postcentral gyrus, along the top border of the temporal lobe
angular gyrus: lies behind the supramarginal gyrus but in front of the occipital lobe
contains somato-sensory areas
(diagram on L3S15)

Question 13

what are the major temporal lobe gyri and what do they contain?

Answer 13

superior temporal gyri: lie at the top of the temporal lobe, below the parietal and frontal lobes
middle temporal gyri: lies below the superior temporal gyri on temporal lobe
inferior temporal gyri: lies at the bottom of the temporal lobe, below the middle temporal gyri, can be seen from a sagittal slice as well
occipitotemporal gyrus: seen on sagittal brain slice, first major section of the temporal lobe, lies above the interior temporal gyrus
contains auditory areas
(diagram on L3S16)

Question 14

what are the major occipital lobe gyri and what do they contain?

Answer 14

lateral occipital gyri: gyri that lie on the occipital lobe
cuneus: can be seen on a sagittal slice, upper-most section of the occipital lobe
lingual gyrus: can be seen on a sagittal slice, lie below the cuneus, the middle section of the occipital lobe
contains visual areas
(diagram on L3S17)

Question 15

what are the major limbic lobe gyri and what do they contain?

Answer 15

cingulate sulcus and gyrus: as seen on a sagittal slice, the area above the corpus callosum that designates the limbic lobe
uncus: as seen on a sagittal slice, small gyrus on the temporal lobe that sits closest to inner ventricle
parahippocampal gyrus: gyrus that lies below the uncus, makes up the temporal lobe
contains emotion and memory areas
(diagram on L3S18)

Question 16

what forms the diacephalon and brain stem?

Answer 16

as seen from a sagittal slice
thalamus: head of the seahorse containing the “eye” part of the diencephalon
hypothalamus: nose of the seahorse, makes up the other half of the diencephalon
midbrain: neck of the seahorse above the mass but below the thalamus, part of brainstem
basal pons: large mass below the neck of the seahorse, part of brainstem
medulla: long section below the pons, part of the brainstem
(diagram on L3S20)

Question 17

what two cranial nerves do not attach to the brainstem?

Answer 17

CN I: olfactory nerve
CN II: optic nerve

Question 18

what are the subdivisions of the cerebrum?

Answer 18

diencephalon and cerebral hemispheres (made up of cerebral cortex (lobes), basal ganglia, hippocampus, and amygdala)

Question 19

how is somatosensory information relayed?

Answer 19

1 degree afferent neurons in the skin send signal to 2 degree neuron in ventral horn, which transmits up to either 3 degree neuron in the thalamus to be relayed elsewhere or to the cerebellum

Question 20

contralateral vs ipsilateral?

Answer 20

contralateral: information crosses the midline to reach the other hemisphere
ipsilateral: information remains on the same side of the midline

Question 21

how do somatosensory pathways travel?

Answer 21

somatosensory pathways cross the midline and travel to the cerebral cortex (contralateral) after passing through the thalamus

Question 22

how do primary motor neurons travel?

Answer 22

primary motor neurons at higher levels of CNS (like in the cortex) affect activity of lower order neurons (like in the muscle), fibers from cortex cross the midline, fibers from cerebellum cross the midline twice

Question 23

what are the embryonic origins of the meninges?

Answer 23

spinal cord meninges originate from the somite mesoderm, brainstem meninges originate from the cephalic mesoderm, and the forebrain meninges originate from the neural crest

Question 24

what are the three meningeal layers?

Answer 24

dura mater at the top, then arachnoid, then pia mater with the arachnoid and pia mater being part of the leptomeninges
(diagram on L4S5)

Question 25

what are the two potential spaces?

Answer 25

epidural: area between the dura and skull subdural: area between the dura and the arachnoid layer (diagram on L4S7)

Question 26

what are the dural septa and what do they do?

Answer 26

dural septa separate differential intracranial compartments and include the falx cerebri (which lies between the two hemispheres of the cortex) and the tentorium cerebelli (which lies between the two hemispheres of the cerebellum), both of which are separated by the tentorial notch (diagram on L4S10)

Question 27

where do the venous sinuses in the dura mater lie on the base of the skull?

Answer 27

falx cerebri: sinus that lies in the center of the frontal lobe sigmoid sinus: S-shaped sinus that lies on either side of the occipital lobe transverse sinus: sinus that lies along the skull in the occipital lobe, connects the end of the sigmoid sinus and the confluence of sinuses confluence of the sinuses: deep sinus in the center of the occipital lobe along the skull, transverse sinus leads into confluence straight sinus: thinner sinus that extends off of the confluence of sinuses towards the center of the skull (diagram on L4S13)

Question 28

where do the venous sinuses in the dura mater lie on the back of the brain?

Answer 28

superior sagittal sinus: sinus that lies between the two hemispheres transverse sinus: sinus that lies between the cerebellum and the back of the cortex sigmoid sinus: sinus that lies on the bottom of the cerebellum, continuation of the transverse sinus around the cerebellum jugular bulb: bulb that lies on the back of the cerebellum that lies at the end of the sigmoid sinus (diagram on L4S14)

Question 29

how does CSF move through the brain?

Answer 29

CSF -> arachnoid villi in subarachnoid space -> dural sinuses (cerebral venous drainage also happens here) -> jugular veins CSF moves through either through large vacuoles in endothelial cells that line the outside of the arachnoid villi or through channels between cells (diagram on L4S15 & 21)

Question 30

what are the major cranial cisterns?

Answer 30

arachnoid lining stretches over the CNS to form cisterns (large spaces filled with CSF) interpeduncular cistern: lies at the bottom on the skull between the two hemispheres, between temporal lobes cisterna magna: lies underneath the cerebellum behind the spinal cord chiasmatic cistern: lies in the mouth of the seahorse pontine cistern: lies along the front side of the spinal cord on the chest of the seahorse (diagram on L4S17-18)

Question 31

what is the anatomy of the spine?

Answer 31

vertebral canal called the epidural venous plexus lies between the vertebra and the spinal cord, spinal cord also has dura, arachnoid, and pia meninges (diagram on L4S25 & 26)

Question 32

what happens when bleeding occurs in potential meningeal spaces?

Answer 32

epidural hematomas can form if blood pools between cortex and skull, chronic subdural hematomas can surround entire hemisphere but still cannot cross midline