Cerebral Cortex Flashcards
How many layers of cortex are there?
6
What layer is superficial and which is deep?
1 is superficial and 6 is deep
Which cells are the most abundant in the cerebral cortex?
Pyramidal
Is the auditory cortex organized in frequency strips?
Yes
And has columns of binaural dominance
Are cells either excited by stimuli in both ears (EE) or excited by stimuli in one and inhibited by stimuli in the other (EI)?
Yes
What are commissural fibers?
Fibers to other hemisphere
What are association fibers?
Fibers to different lobe in same hemisphere
What is an example of an association fiber?
Arcuate fasciculus
What are projection fibers?
Fibers from the thalamus (corona radiata)
What two things could happen with a lesion in the cortex?
Loss of function (negative sign)
Appearance of behaviors not normally present (positive sign)
What could happen if S1 was damaged?
Deficits in position sense
Can’t tell where limb is
Astrognosis
What is asterognosis?
Inability to identify an object by feel
Does damage to the right side of S1 result in lack of spatial aspect of sensory input for the left side of the body?
Yes
Often results in hemineglect syndrome
What is hemineglect?
Lack of appreciation of spatial aspects of sensory input to left side of body
What might happen with a person with hemineglect?
They might only shave the right side of their face and may only draw the right side of an image
What does the frontal and prefrontal cortex control?
Motor planning, cognitive and emotional activities
Regulate affect associated with sensations (happy, sad, friendly, disagreeable)
What happens when someone has a lesion in the frontal lobe?
Patient is less excitable (flat affect)
Less creative
Apathetic
Impaired consecutive planning
Inability to maintain order of events
Difficult shifting between activities
Loss of self control
Disinhibited social behavior
What might happen when someone has a lesion in M1?
Contralateral paresis (weakness)
Increased deep tendon reflex
Positive babinski
What might happen when someone has a lesion in the premotor cortex?
Increased tone and resistance to passive movements
What is wernicke’s aphasia?
spoken and written words are not meaningful
What is broca’s aphasia?
Production of speech is impaired
What is agnosia?
Inability to recognize an object or interpret sensory stimuli
Can agnosia be for multiple senses?
Yes, tactile, visual, and auditory
What is apraxia?
Interference with planning and performing skilled and complex movements
What side is the planum temporale usually bigger?
Left
Which hemisphere is favored for the development of speech and language?
Left
Is there also lateralization for mood (prefrontal cortex)?
Yes
Left plays a role in happy feelings
Right plays a role in negative feelings
Which side of the brain is dominant for language, speech writing, calculation, and complex reasoning?
Left
Which side of the brain is dominant for spatial construction, creative acts, and facial recognition?
Right
Can an object felt in the left hand be identified verbally?
No because left hemisphere is used to say words
Why is function lateralized?
May increase our intelligence
Probably provides more efficient function
What type of injury has a better prognosis for recovery?
Supratentorial
What happens with a supratentorial lesion?
Slow and stepwise progression
Displacement of supratentorial structures through tentorial notch
What happens with a infratentorial lesion?
Dramatic symptoms associated with cranial nerves (vertigo, nausea, deafness, facial paralysis)
What is a period of abnormal, hyperactive, and synchronized neural firing in the cortex?
Seizure
What is a seizure that is only initiated by a small part of the brain?
Partial
What is a seizure that involves the entire brain?
General
What are absence seizures?
Loss of awareness without loss of muscle tone
What are normal seizures called?
Tonic-clonic
What seizures only happen in young children?
Febrile
What causes seizures?
Many causes
Related to cortical damage
