CNS Unit 12 Flashcards
What are the 4 basis categories of function with the Limbic System?
“HOME”
- Homeostasis ; Hypothalamus
- Olfaction ; Olfactory cortex
- Memory ; Hippocampal formation
- Emotion ; Amygdala
Limbic System
What is the Function of Septal Nuclei? What would happen if there was a lesion here?
This is involved in pleasure center; moderate memory; responsible for desire to eat
- Lesions associated with anorexia, nervosa and gluttony
Limbic System
What is the function of the Thalamus? What would happen if there was a lesion here?
This deals with emotional response to sensation
- Korsakoff’s Syndrome: is caused by alcoholism or Vitamin B1 deficiency
Limbic System
What is the Function of the Hypothalamus? What would happen if there was a lesion here?
Mediates autonomic response to emotion - blushing ; Special nuclei modulates opposing function of the hypothalamus
- Lesions can cause Anorexia, Bulimia
Limbic Lobe
What would happen if there was a lesion to Pariaqueductal Gray (of brainstem)?
This leads to indifference to pain
Limbic System
With the Olfactory Cortex, what is the function of Rhinencephalon?
- Smell
-Odors of external environment
-Sensation to taste
With the Olfactory Cortex, what are secondary Olfactory areas?
- Anterior Entorhinal Cortex: Memory
- Orbitofrontal Olfactory Area: Smell discrimination
What is the Function of the Amygdala? What would a lesion here cause?
Function:
- Emotion
- Autonomic
- Neuroendocrine
Lesion:
- Flat affect
- Hypersexuality
- Disinhibited behavior
Where does the Amygala recieve input and take out the output?
Input:
- Sensory systems
- Mediodorsal thalamus
- Lat., Med. Hypothalamus
- Septal area
- Periaqueductal Gray
Output:
- Stria terminalis
- Ventral Amygdalofugal
Limbic System: Hippocampal Formation
What are the 2 regions for Memory Formation?
- Medial Temporal Lobe:
-Hippocampal Formation
-Parahippocampal Gyrus - Medial Diencephalic
-Mediodorsal and anterior thalamic nuclei
-Mammillary Bodies
-Diencephalic nuclei
What are the Classifications of Different Types of Cortex?
- Primary Motor or Sensory Cortex
- Unimodal Association Cortex: These deal with association that is modality specific
- Heteromodal Association Cortex
- Limbic Cortex
What is Cerebral Lateralization?
This is when certain functions tend to be lateralized or specialized in one hemisphere versus another
- Hemishperic Specialization eliminated the delay of long callosul transmission
Ex:
- Handedness: 90% of the population is right handed
- Language: L hemisphere is dominate for 95% of right handers adn 60-70% of left handers
- Perception: R hemisphere
This is not apparent until 3 to 4 years of age
With Cerebral Organization, which higher order functioning cortex will you find posteriorly? Whats the function?
- Posterior Parietal and Temporal Association Cortex
- This deals more with interpreting perceptual data and assigning meaning to sensory information
With Cerebral Organization, which higher order functioning cortex will you find anteriorly? Whats the function?
- Frontal Association Cortex (Prefrontal cortex)
- This deals more with planning, control, execution of actions
What are the Functions of the Dominant Hemisphere?
Usually Left Hemisphere
- Language
- Skilled Motor Formulation (Praxis)
- Musical Ability: sequential and analytical skills in trained musicians
- Arithmetic: Sequential and analytical calculating skills
- Sense of Direction: following a set of written directions in sequence
What are the Functions of the Non-Dominant Hemisphere?
Usually Right Hemisphere
- Prosody (emotion conveyed by tone of voice)
- Visual-spatial analysis and spatial attention
- Musical Ability: In untrained musicians, and for complex musical pieces in trained musicians
- Arithmetic: Ability to estimate quantity and to correctly line up columns of numbers on the page
- Sense of direction: Finding one’s way by overall sense of spatial orientation
L Hemisphere
How is information transferred between Broca’s Area and Wernicke’s Area?
By the Subcortical white matter pathway called the Arcuate Fasciculus
Sounds converted to words in Wernicke’s; and Words converted to sounds in Broca’s
What other areas work with Broca’s Area?
Other Anterior Areas, for higher-order motor aspects of speech forumlation and planning
- Premotor and Supplementary Motor Cortex (B.A 6)
- Prefronal Cortex (B.A 8, 9,10, 46,47)
This is where we get syntax or grammatical structure
Syntax: The arrangement of words and phrases to create well-formed sentences in a language
What other areas work with Wernicke’s Area?
More Posterior Areas, for language comprehension
- Inferior Temporal Language Area (B.A 37)
- Angular Gyrus (B.A 39); this is important for written gyrus
- Supramarginal Gyrus (B.A 40)
This is more about lexicon and its very important in mapping sounds to meaning
What is Aphasia?
- A defect in language processing
- Dysfunction of the Dominant cerebral hemisphere (typcially left)
- Spoken and written language is affected
What is Broca’s Aphasia?
AKA Non-Fluent Aphasia/Expressive Aphasia/Motor Aphasia/Anterior Aphasia
- Damage to Broca’s Area (B.A 44, 45)
- Most common lesion due to L MCA Superior Division Infarct
- Decreased fluency in language
- Naming difficulties
- Repetition is impaired
- Comprehension is INTACT
What ae Common Associated Features of Broca’s Aphasia?
- Dysarthria
- Right Hemiparesis
- Frustration
- Depression
- Sometimes apraxia on non-paretic left side
What is Wernicke’s Aphasia?
AKA Fluent Aphasia/Receptive Aphasia/Sensory Aphasia/Posterior Aphasia
- Damage to Wernicke’s Area (B.A 22) in dominant temporoparietal lobes
- Most common lesion due to L MCA Inferior Divisions Infarct
- Fluent speech, but its empty, its meaningless with nonsensical paraphasic error
- Naming difficulties
- Repetition is impaired
- Impaired Comprehension
What are Common Associated Features with Wernicke’s Aphasia?
- Contralateral Visual Field Cut (Optic Radiation Involvement)
- Patient unaware of their deficits
- Angry or paranoid behavior
- Apraxia may be present but difficult to diagnose
