Cerebral Hemispheres

Question 1

Where are pyramidal cells located?

Answer 1

In the cortex (spanning on edge from white to gray matter)

Question 2

Where are upper motor neurons located?

Answer 2

Cell bodies in CNS, end up in CNS - generate EPSPs on lower motor neurons and interneurons

Question 3

Where are lower motor neurons located?

Answer 3

Cell bodies in CNS, and end up in PNS

Question 4

What are the three parts of the internal capsule and what is its significance?

Answer 4

Posterior limb, genu, anterior limb
The primary motor cortex sends axons through post. limb so lesions in this area result in contralateral hemiparesis or hemiplegia - severe weakness that can recover

Question 5

Aphasia

Answer 5

A defect in language processing caused by brain lesions; develop as consequence of lesions in the dominant cerebral hemisphere; most cases are caused by stroke, head injury, cerebral tumors or degenerative dementia (alzheimer’s)

Question 6

Expressive aphasia

Answer 6

Broca’s aphasia - problem in formulation of speech

Question 7

Receptive aphasia

Answer 7

Wernicke’s aphasia - form of auditory agnosia in which the patient fails to recognize or comprehend the meaning of known words - “word deafness”

Question 8

Apraxia

Answer 8

Inability to carry out a motor action in response to a verbal recent in the absence of paralysis/paresis, comprehension deficit, etc. generally associated with (left) dominant cerebral hemisphere

Question 9

Agnosia

Answer 9

Inability to understand or recognize the significance of sensory stimuli, although sensory pathways (primary sensory context) are intact.
-Lesion related to cortical association areas (somesthetic, visual, auditory)

Question 10

Tactile agnosia

Answer 10

Patient can’t correlate surface texture, shape, size, etc. and compare with previous experience.
-Parietal association cortex lesions

Question 11

Visual agnosia

Answer 11

Inability to recognize objects and patient fails to relate present to past visual experiences. Patient fails to recognize what is seen and appreciate significance.
-Visual association cortex lesions

Question 12

Auditory agnosia

Answer 12

Condition where patient with unimpaired hearing fails to recognize or appreciate meaning with a perceived sound
-Auditory association cortex lesions

Question 13

Anosognosia

Answer 13

A loss of disease awareness

-Parietal lobule

Question 14

Prosopangnosia

Answer 14

“face blindness” ability to recognize faces is impaired, while other aspects of visual processing and intellectual functioning remain intact.
-Involves lesions affecting the underside of the occipital lobes

Question 15

What is the motor homunculus?

Answer 15

It is pre-central gyrus - contains the map of the body from sacral to cervical

Question 16

What is the sensory homunculus?

Answer 16

It is post-central gyrus

Question 17

What is the limbic lobe? What are its parts?

Answer 17

“Physiological lobe” -
Anterior part - emotional behavior & homeostasis
Posterior part - cortical process of learning and memory (consolidation of memories)
-Septal or subcallosal area, isthmus of the cingulate gyrus, parahippocampal gyrus and hippocampal formation

Question 18

What does the frontal lobe do?

Answer 18

“executive” - responsible for initiating the motor/behavioral responses to the information collected

Question 19

What does the parietal/occipital lobe do?

Answer 19

“where” -shape, form, texture, color, moving or not moving

-Connects with prefrontal cortex and temporal/occipital cortex to tell events that are occurring

Question 20

What does the temporal/occipital lobe do?

Answer 20

“what” - connects parietal/occipital cortex, prefrontal cortex, orbitofrontal cortex, hippocampus (memory) and amygdala (emotion) to tell what is occurring