Exam 4 Part V

Question 1

cerebellum and excitatory inputs

Answer 1

2 excitatory inputs: They 1st cause excitation of deep Cbl nuclei by collaterals. Then cause excitation of Purkinje cells and inhibition on deep nuclei.

Question 2

Planning function and the cerebellum

Answer 2

. In an area of the cerebellum, one can record activity of the next action to be performed, at the same time as the current action is going on. This area of the cerebellum is concerned with what will be happening next in a series of movements. Normally one has the ability to progress smoothly from one motion to the next. This ability is impaired in cerebellar damage, particularly in fast movements.

Question 3

Timing functions

Answer 3

With cerebellar damage, complex movements such as running, talking and writing are disrupted and uncoordinated.

Question 4

In general, Cbl important for using

Answer 4

In general, Cbl important for using spatiotemporal relationships in sensory info., for learned, unconscious, complicated movements

Question 5

Cerebellar lesions cause

Answer 5

Cerebellar lesions cause abnormal movements ipsilateral to the lesion.

Question 6

Removal of much of the cerebellar cortex doesn’t cause much detectable, lasting deficit. Must have removal of the

Answer 6

Must have removal of the deep nuclei additionally in order to see serious and permanent damage.

Question 7

Dysmetria –

Answer 7

Dysmetria – can’t predict how far movement will go and so overshoot to mark. past–pointing, because normally dependent on that inhibitory damping.

Question 8

Ataxia-

Answer 8

Ataxia- incoordination, e.g., wide gait

Question 9

failure of progression

Answer 9

If one doesn’t know how long it takes for each movement & where the parts will be at a given time, one can lose parts of the body particularly during rapid motions

Question 10

dysdiadochokinesia.

Answer 10

– jumbled – difficulty performing rapid alternating movements: dysdiadochokinesia.

Question 11

Intention tremor –

Answer 11

Intention tremor – jerky during voluntary movement, failure to damp, e.g., Cbl nystagmus (attempts to fixate to the side)

Question 12

Hypotonia –

Answer 12

loss of facilitation from tonic discharge of deep nuclei to increase muscles tone

Question 13

Primary sensory areas: This map is determined by

Answer 13

electrical stimulation in awake epileptics who are having brain surgery to decrease the tendency for convulsions to spread.

Question 14

l° somatosensory – parietal: .

Answer 14

l° somatosensory – parietal: uncomplicated sensations: tingling, numbness, mild electric feeling; localized; also some motor responses.

Question 15

1° visual cortex – occipital:

Answer 15

1° visual cortex – occipital: flashes of light, bright lines, colors or other simple sights – localized to area of visual field

Question 16

1° auditory – temporal:

Answer 16

1° auditory – temporal: simple sound (nothing complicated) as weak or loud high or low frequency, some other simple characteristics. Like squeak or undulation never speech. (Can one localize in space sound from l cortical cell? Yes! )

Question 17

In general, without the primary sensory areas in the cortex,

Answer 17

the person’s ability to analyze sensory signals is greatly impaired. The primary sensory cortex is the first place in the cortex where sensory signals go.

Question 18

Sensory association areas,

Answer 18

The general function of sensory association areas or secondary sensory areas is to provide a higher level of interpretation of sensory experiences. Damage results in an inability to do further analysis.

Question 19

Damage in temporal lobe below and behind primary auditory area in dominant hemisphere. (L for most people hemisphere for language) –

Answer 19

loses ability to understand spoken words & other auditory experiences.

Question 20

Destruction of visual association areas on the occipital lobe in the dominant hemisphere

Answer 20

. e.g. word blindness = inability to recognize meaning of written words one form of dyslexia.

Question 21

Somatosensory association area in the parietal lobe: damage results in the person losing

Answer 21

Somatosensory association area in the parietal lobe: damage results in the person losing perception of the location of the parts of his/her body. The person may exhibit sensory neglect. Important part of body if it gets lost is the hand, e.g., hand skills impaired because of lack of sensory component)

Question 22

All these sensory association areas meet one another in an area called

Answer 22

All these sensory association areas meet one another in an area called Wernicke’s area. It is particularly highly developed in the dominant side of the brain.

Question 23

Wernicke’s is also called

Answer 23

It is also called general interpretation area, Gnostic area or 3rd degree association area.

Question 24

Damage to Wernicke’s area:

Answer 24

The person might hear perfectly well & recognize words but might not be able to organize words into a coherent thought.

Question 25

Can even read words on a page but may not recognize the thought that is conveyed =

Answer 25

sensory aphasia (Damage to Broca’s = motor aphasia).

Question 26

In most people, one hemisphere is

Answer 26

physically larger than the other at birth. Speech & motor control areas tend to be much more highly developed on one side than another.

Question 27

Often L

Answer 27

Often L - -sequential-analytical --details - -“makes all pieces fit into current world-view” - -language, list-making etc.

Question 28

Often R

Answer 28

Often R --visual-spatial, includes face recogn. --global pattern --“hypothesis testing & paradigm shift” --music, emotion etc.

Question 29

What might the “other” (right) hemisphere be doing?

Answer 29

- -recognition of faces (representational) | - -emotional processing? If a certain area is destroyed, the person’s emotional tone may be all wrong

Question 30

music

Answer 30

more controlled on the right, some separation between control for music & for speech and & motor patterns: Actress who had a stroke (Patricia Neal) had no speech but could sing words in a song.

Question 31

--dyslexics more often

Answer 31

--dyslexics more often R-brain default

Question 32

In front of the motor areas, the areas that are removed in “frontal lobotomy.”

Answer 32

In front of the motor areas, the areas that are removed in “frontal lobotomy.” In general the person can still perform IQ tests with prefrontal lobotomy (relatively preserved).

Question 33

Prefrontal areas:

Answer 33

Prefrontal areas: “Elaboration of thought,” increase in depth & abstraction of thought. Rehearsing allows one to remember & plan.

Question 34

B. Memory: One important area is the

Answer 34

B. Memory: One important area is the hippocampus, a medial part of the temporal lobe

Question 35

bilateral lesions of the hippocampus or of some other parts of the temporal lobe, the person may be unable to

Answer 35

ilateral lesions of the hippocampus or of some other parts of the temporal lobe, the person may be unable to put new information from short– to long–term memory.

Question 36

Stimulation of the temporal lobe including the hippocampus:

Answer 36

Stimulation of the temporal lobe including the hippocampus: one sometimes gets complicated sequential memories.

Question 37

Stress can kill off cells needed for conversion to

Answer 37

Stress can kill off cells needed for conversion to long-term memory. Stress increases cortisol. These hippocampal cells have the highest concentration of cortisol receptors. These cells are particularly prevented from using glucose and they starve.

Question 38

The presence of an RAS is inferred from the fact that

Answer 38

The presence of an RAS is inferred from the fact that diffuse electrical stimulation in the midbrain and pons RF causes immediate activation of the cerebral cortex. The animal goes instantly from being asleep to being awake.

Question 39

Function of midbrain RAS:

Answer 39

Preventing the connection from the upper midbrain to the cerebrum causes the cerebrum to become inactive = coma. Cutting the brainstem at the mid-pons → upwards, thus preventing upward connections from the pons, causes the cerebrum to become active. It remains active indefinitely as if continuously awake. An area below the mid-pons can inhibit the midbrain RAS.

Question 40

Therefore, midbrain and upper pons

Answer 40

Therefore, midbrain and upper pons RF: activation. Brainstem below the midlevel pons: can inhibit the activating system and cause sleep.

Question 41

Stimuli from the cerebrum down:

Answer 41

Stimuli from the cerebrum down: mainly into the mesencephalic RF from all over in the cerebrum, but particularly from the motor cortex: Importance of moving around to keep awake.