lecture 16

Question 1

what are the functions of the cerebrum?

Answer 1

conciousness, memeory, perception, skilled movements

Question 2

what are gyri? sulci? fissures?

Answer 2

gyri: folds
sulci: grooves
fissures: deep grooves

Question 3

what are the cerebral lobes?

Answer 3

frontal, parietal, occipital, temporal, insula, limbic

Question 4

what is contained in the frontal lobes?

Answer 4

motor areas, CN I

Question 5

what is contained in the parietal lobes?

Answer 5

somatosensory areas

Question 6

what is contained in the occipital lobe?

Answer 6

visual areas

Question 7

what is contained in the temporal lobes?

Answer 7

auditory areas

Question 8

describe the insula?

Answer 8

maintains homeostasis by processing visceral sensations, taste, and ANS functions
-hidden by frontal, parietal, and temporal lobes

Question 9

describe the limbic lobes?

Answer 9

• drives emotions, memory
• cingulate gyrus and parahippocampal gyrus
• encircles telencephalon and diencephalon junction

Question 10

what are key components of the cerebral hemispheres?

Answer 10

• lateral ventricles
• corpus striatum
• white matter
• some limbic structures
• cerebral cortex
• CN I

Question 11

the lateral ventricles are a landmark for what?

Answer 11

the study of brain sections

Question 12

several regions of gray matter protrude into the lateral ventricles, what are they?

Answer 12

• caudate nucleus
• thalamus and interthalamic adhesion
• hippocampus

Question 13

what is the caudate nucleus?

Answer 13

• functions in movement, memory, learning, reward, motivation, etc.
• forms lateral wall of body and anterior horn of lateral ventricles
• forms roof of interior horn

Question 14

what is the thalamus?

Answer 14

• relays motor and sensory information to the cerebral cortex
• forms floor of body of lateral ventricles

Question 15

what is the hippocampus?

Answer 15

• functions in learning and memory

- forms floor and medial wall of inferior horn of lateral ventricles

Question 16

what is the corpus striatum?

Answer 16

collective name for caudate and lentiform nuclei

Question 17

is the corpus striatum composed of white or gray matter?

Answer 17

gray

Question 18

what is the corpus striatum a part of?

Answer 18

basal ganglia

Question 19

why is it called the corpus “striatum”?

Answer 19

because it appears striated due to the bridges of gray matter than connect nuclei

Question 20

what are the functions of the corpus striatum?

Answer 20

motor control and learning

Question 21

the corpus striatum is divided into two parts, what are they?

Answer 21

neostriatum and paleostriatum

Question 22

describe the neostriatum

Answer 22

• primary receiver (output info only goes to other basal nuclei)
• further divided into ventral striatum and dorsal striatum

Question 23

describe the ventral neostriatum

Answer 23

• input from the limbic system, hippocampus and amygdala

- consists of nucleus accumbens and olfactory tubercle

Question 24

where is nucleus accumbens? whats its function?

Answer 24

• in basal forebrain

- possible function in reward system

Question 25

where is the olfactory tubercle? whats its function?

Answer 25

- near olfactory tract | - possible function in reward system and locomotion

Question 26

describe the dorsal neostriatum

Answer 26

- fibres from cortex, substantia nigra and thalamus enter basal ganglia here - consists of caudate and putamen

Question 27

describe the caudate

Answer 27

- input: cortical association areas - projects to prefrontal areas - functions in cognition - superior to putamen

Question 28

describe the putamen

Answer 28

- input: motor and somatosensory areas - projects to motor, pre-motor, and supplementary motor areas - functions in movement and learning - deep to insula

Question 29

describe the paleostriatum

Answer 29

- input: neostriatum - outpur: motor related areas - consists of: globus pallidus

Question 30

describe the globus pallidus

Answer 30

divided into globus pallidus externa (gpe) and globus pallidus interna (gpi)

Question 31

do gpe and gpi have the same inputs? outputs?

Answer 31

similar inputs, different outputs

Question 32

what separates gpe and gpi?

Answer 32

medial medullary lamina (white matter)

Question 33

what is the lentiform nucleus?

Answer 33

anatomical groupung composed of the putamen and the globus pallidus

Question 34

the corpus striatum has many surrounding structures, what are they?

Answer 34

- thalamus (medial to globus pallidus) - white matter (internal capsule, external capsule, extreme capsule) (internal capsule divides caudate and putamen) - claustrum (btwn external and extreme capsules) - insula lobe

Question 35

what is white matter in the cerebral hemispheres?

Answer 35

myelinated axon nerve fibers

Question 36

what are the types of white matter in the cerebral hemispheres?

Answer 36

- association fibers - commisural fibers - projection fibers

Question 37

describe association fibers

Answer 37

- paired | - 2 types: short or long

Question 38

describe short association fibers

Answer 38

connect adjacent gyri (are located in the same lobe in the same hemisphere)

Question 39

describe long association fibers

Answer 39

connect cerebral lobes (are located in different lobes in the same hemisphere)

Question 40

can short fibers travel bidirectionally? can long?

Answer 40

short: no long: yes

Question 41

do short fibers have a distinct entry or exit? do long?

Answer 41

short: yes long: no

Question 42

list 4 long association fibers*

Answer 42

- cingulum (cingulate fasciculus) - uncinate fasciculus - superior longitudinal fasciculus - inferior longitudinal fasciculus

Question 43

describe the cingulate fasciculus*

Answer 43

connects frontal lobe, parietal lobe and parahippocampal gyrus

Question 44

describe the uncinate fasciculus*

Answer 44

connects inferior frontal lobe and anterior temporal lobe

Question 45

describe the superior longitudinal fasciculus*

Answer 45

connects frontal lobe, parietal lobe and occipital lobe

Question 46

describe the inferior longitudinal fasciculus*

Answer 46

connects temporal and occipital lobe

Question 47

describe commisural fibers

Answer 47

- connect equivalent regions btwn hemispheres | - not paired

Question 48

list the two main commissural fibers

Answer 48

- corpus callosum | - commisure of the fornix

Question 49

describe the corpus callosum

Answer 49

- connects the two cerebral hemispheres | - C shape: curves anteriorly towards olfactory tract, and posteriorly towards the temporal lobe

Question 50

what are the components of the corpus callosum?

Answer 50

- rostrum (tip of C) - genu (like head) - body - splenium (bottom of C)

Question 51

what are the forceps minor?

Answer 51

- frontal fiber bundle of corpus callosum | - crosses midline at genu

Question 52

what are the forceps major?

Answer 52

- occipital fiber bundle of corpus callosum | - crosses midline at splenium

Question 53

describe the commissure of the fornix

Answer 53

- connects hippocampus to mammillary bodies (aka hippocampal commissure) - formed by left and right cura od Fornix

Question 54

what is the anterior commissure?

Answer 54

- anterior portion of commissure of Fornix | - connects olfactory regions

Question 55

what is the posterior commissure?

Answer 55

- posterior portion of commissure of Fornix | - connects visual nuclei

Question 56

describe projection fibers

Answer 56

- ascending and descending fibers interconnecting the cortex, thalamus, basal nuclei and brainstem - composed of internal capsule and corona radiata

Question 57

describe the internal capsule

Answer 57

- composed of anterior limb, genu and posterior limb - communication pathway btwn brainstem and cortex - separates caudate nucleus and thalamus from putamen and globus pallidus

Question 58

describe the corona radiata

Answer 58

white matter tract that connects motor and sensory nerve pathways of the brainstem and cerebral cortex

Question 59

what are the ascending projection fibers?

Answer 59

thalamocortical

Question 60

what are the descending projection fibers?

Answer 60

frontopontine, corticobulbar, corticospinal

Question 61

what are the key limbic structures?

Answer 61

``` outer arc: -cingulate gyrus -parahippocampal gyrus inner arc: -hippocampus other: -subcallosal gyrus -amygdala -anterior thalamus ```