Term
| The cortex contains the following specialized areas: |
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Definition
1. Motor areas and corticofugal pathways (i.e., the corticospinal, corticobulbar and corticopontine tracts).
2. Sensory integration centers for vision, audition, somatic sensation, taste and smell.
3. Higher cognitive function areas for speech, thought, memory, and planning. |
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Term
| The gray matter can be divided in to how many layers? |
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Definition
Layer I – Molecular Layer
Layer II – External Granular Layer
Layer III – External Pyramidal Layer
Layer IV – Internal Granular Layer
Layer V – Internal Pyramidal layer
Layer VI – Multiform layer |
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Term
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Definition
| Parallel to the cortical surface. They terminate within the gray matter providing cortico-cortical connections with-in layers. |
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Term
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Definition
| At right angle to the cortical surface. They terminate with the gray matter, between layers, but also project out of the cortex becoming projection, association, and commiural fibers of the white matter. |
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Term
| Functionally specialized areas are... |
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Definition
| Vertical columns clustered together. Then grouped together into functionally and anatomically distinct lobes or cortices |
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Term
| Association fibers are... |
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Definition
| From other regions within the same hemisphere |
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Term
| Commissural fibers are... |
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Definition
| From regions in the contralateral hemisphere |
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Term
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Definition
| From the thalamus (thalamocortical projections |
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Term
| negative signs are considered |
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Definition
| Loss of function (such as paralysis) |
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Term
| positive signs are considered... |
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Definition
Abnormal function (such as a hallucination)
Appearance of behaviors not previously present |
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Term
| Primary Somatosensory Cortex |
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Definition
– receives sensory information
a. Primary somatosensory cortex (Brodmann's areas 1,2,3 of the parietal lobe; the post-central gyrus), contains somatotopic representation of the body (sensory homunculus)
b. Receives input from the thalamus regarding discriminative general senses as well as pain and temperature sense from the body and face.
c. Electrical stimulation of the somatosensory cortex causes numbness and tingling.
d. A lesion of the somatosensory cortex produces deficits in discrimitive touch and position sense (Hemi anesthesia on the side of the body opposite to the cortex) |
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Term
| Somatosensory Association Cortex |
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Definition
-complex analysis of sensory information
a. Brodmann's areas 5, 7, 40 (superior parietal lobule and supramarginal gyrus)
b. Used for perception of shape, size, texture and identification of objects by feel (stereognosis)
c. Lesion of the non-dominant (usually the right) cortex causes no disturbance of language because in most people, language function is located in the left hemisphere, but does cause a lack of appreciation of spatial aspects of all sensory input from the left side of the body, called hemineglect syndrome (often left hemineglect syndrome), which has the following characteristics:
i. Lack of appreciation of spatial aspects of all sensory input from the left side of the body (yet somatic sensations are intact).
ii. Denial that the left side of the body belongs to the patient.
iii. Patients with left hemineglect syndrome may shave only the right side of the face or dress only the right side of the body, or draw the right side of an image. |
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Term
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Definition
a. This is the termination of the retinogeniculostriate pathway (optic radiations)
b. This area fuses the inputs from both eyes into one image.
c. Analyzes the visual world with respect to orientation of visual stimuli, with special attention paid to lines and edges of images.
Distingushes size, shape and location of an object. |
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Term
| Visual Association Cortex |
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Definition
a. Essential for comprehension of a visual image.
b. Mediates slow pursuit (tracking) movements of the eyes through connections with the superior colliculus of the midbrain tectum and cranial nerve nuclei of the extraocular muscles.
c. Mediates vergence eye movements (e.g., convergence and divergence when focusing near & far, respectively).
d. Mediates conjugate eye movements
Motion and color of object |
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Term
| Auditory Association Cortex |
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Definition
a. Important in the interpretation of sounds.
b. Lesion to area 22 makes spoken language difficult to understand.
Association of sounds |
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Term
| The Primary Olfactory Cortex |
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Definition
| a. Projects to the hypothalamus, hippocampus, amygdala, thalamus, and orbitofrontal olfactory area of the cortex |
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Term
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Definition
| inability to recognize an object; inability to interpret and recognize sensory stimuli |
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Term
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Definition
| the inability to recognize faces |
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Term
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Definition
| inability to recognize familiar sounds and words |
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Term
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Definition
-precentral gyrus
B. Contains somatotopic representation of the body for motor function (motor homunculus) with disproportionate representation of the areas for the hand, face and tongue
C. A lesion in the motor cortex produces:
a. contralateral paresis
b. increased deep tendon reflexes
c. positive Babinski sign |
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Term
| Premotor cortex and Frontal Eye Fields |
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Definition
B. Receives input from the cerebellum and is involved in the production of externally referenced movements
C. Stimulation produces postural or tonic movements, and contralateral eye movements and head movements (connections to ocular motor nuclei)
D. Lesion produces hypertonus and increased resistance to passive movements |
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Term
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Definition
Discrimination of loudness and pitch.
Loss of localization of sound. Can still hear because you have two ears. |
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Term
| Supplemental motor cortex |
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Definition
. Receives input from the basal ganglia and is involved in the production of internally referenced movements.
Initiation of planning, orientation of planning |
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Term
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Definition
Most people this represents the speech area in the left hemisphere.
C. Connected to Wernikes area by the arcuate fasciulus
D. Broca'a aphasia or expressive aphasia (lesion in area 44): Normal comprehension of language; expression of speech is difficult and crudely articulated; muscles involved in speech are not damaged; patients can express memorized words correctly. |
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Term
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Definition
| a disorder of sensory integration interfering with the ability to plan and perform skilled and complex movements. Lesions causing apraxia can be in a variety of cortical areas. |
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Term
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Definition
| loss of ability to carry out spontaneous movement |
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Term
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Definition
| inability to carry out movement on command due to inability to remember the command |
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Term
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Definition
| inability to perform complicated motor tasks |
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Term
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Definition
| inability to demonstrate use of objects (e.g., tools placed in a patient's hand). |
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Term
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Definition
| inability to perform facial-oral movements on command (e.g., lick the lips). This is the most common apraxia |
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Term
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Definition
| All activities (motor, cognitive or emotional) are planned in the frontal lobe |
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Term
| Prefrontal lobotomy or lesions of the frontal lobe may result in the following: |
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Definition
a. the patient becomes less excitable (flat affect)
b. patient is less creative, with little or no drive or goal direction (apathy)
c. there is impairment of consecutive planning
d. inability to maintain serial relationships of events
e. difficulty shifting from one mental activity to another
f. loss of self-control
g. disinhibited social behavior
h. euphoria
i. loss of bowel and bladder control (response ranges from surprise/embarrassment to indifference to being incontinent)
j. disinhbition of certain behaviors resulting in sucking, grasping and groping (the mechanisms for these behaviors lie in the parietal lobe, and are normally inhibited by neurons of the pre-frontal cortex).
k. The surgical frontal lobotomy may be used for relief of intractable pain, where the pain is still present, but it does not bother the patient anymore. |
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Term
| Limbic Association Cortex |
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Definition
. Involved in the regulation of emotions, mood, affect, and memory
C. Electrical stimulation of this area elicits recall of things seen or heard (e.g., music from the past) (closely associated with the olfactory cortex).
D. A tumor or stroke here may cause visual or auditory hallucinations. Sights and sounds are vivid in the mind. |
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Term
| Parietotemporal Association Cortex |
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Definition
A. Involved in sensory integration, problems solving, speech, and spatial processing.
B. Interpretation and Integration of sensations are localized here
C. Can be considered tertiary sensory association areas
D. Wernicke's Area (only in one hemisphere, usually left)
i. Wernicke's area is represented by Brodmann's areas 39, 40, and posterior area 22; part visual, part somatosensory and part auditory, respectively.
ii. Wernicke's interconnected to Broca’s area by association fibers called the arcuate fasciculus
iii. Wernicke's aphasia or receptive aphasia (lesion in areas 39, 40, posterior 22): Auditory and visual systems are not impaired, but spoken and written words are devoid of meaningful content. Key words are omitted and replaced by non-meaningful related or even unrelated words. |
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Term
| 1. Anatomically, the two hemispheres of the human cerebrum appear to be fairly symmetrical except... |
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Definition
| is the planum temporale (an area located on the upper surface of the temporal lobe and including Wernicke's speech area) which tends to be larger in the left hemisphere |
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Term
| Functions of the dominant hemisphere |
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Definition
a. Language
b. Skilled motor formulation (aka. Praxis)
c. Arithmetic: analytical skills
d. Sequential processing |
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Term
| Functions of the non-dominant hemisphere |
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Definition
a. Prosody (emotion, tone and rhythm of voice)
b. Visual-spatial analysis and spatial attention
c. Arithmetic: spatial skills
d. Spatial orientation and processing |
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Term
| What is know as the "switchboard" for the brain? |
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Definition
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Term
T or F
Nearly all inputs to the cerebrum first synapse on neurons in the thalamus |
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Definition
| True, These inputs (axons and synapses) arise from many areas of the CNS and convey information regarding sensation, motor/movement, emotions, memory, arousal/consciousness, and attention. |
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Term
| the internal medullary lamina |
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Definition
| a Y shaped white matter structure the seperates the medial, lateral and anterior nuclei. |
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Term
Anterior or Posterior Pituitary?
The hypothalamus and pituitary form a portal system
The hypothalamus secretes hormones which either stimulate or inhibit pituitary hormones
The pituitary secretes 6 hormones |
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Definition
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Term
| What are the 6 hormones secreted by the anterior pituitary gland? |
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Definition
GH (growth hormone)
o Causes liver, kidneys and other organs to produce growth factors that promote increased bone growth
TSH (thyroid stimulating hormone)
o Stimulates the thyroid gland to produce thyroxine (T$) and triiodothyronine (T3)
ACTH (adrenocorticotropic hormone)
o Stimulates adrenal cortex to produce corticospteriod hormones, especially cortisol
FSH (follicle-stimulating hormone)
o Along with LH regulate menstrual cycle and oogenesis in women and regulate testicular hormones and spermatogeneisis in men
LH (luteinizing hormone)
o Along with FSH regulate menstrual cycle and oogenesis in women and regulate testicular hormones and spermatogeneisis in men
PRL (prolactin)
o Promotes milk production |
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Term
Anterior or Posterior Pituitary?
oHypothalamus and pituitary form a neurosecretory system, i.e.:
oCell bodies in the hypothalamus
oAxons terminate on capillaries in the pituitary
opituitary only stores hormones and releases them into the blood – it does not synthesize hormones!!! |
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Definition
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Term
| What are the hormones secreted by the Posterior pituitary gland? |
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Definition
Vasopressin (AKA: antidiuretic hormone-ADH)
o enhances water retention by the kidneys
Oxytocin
o stimulates contraction of uterine smooth muscle during birth; promotes ejection of milk |
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Term
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Definition
Functions:
Autonomic Nervous System
Sympathetic and Parasympathetic
Limbic
Connections with the hippocampal formation, amygdala, and thalamic nuclei
Endocrine and Homeostatic
Hypothalamic hormones control the release of anterior pituitary hormones
Release hormones into the posterior pituitary
Other Functions:
Regulation of Circadian rhythms/sleep
o Suprachiasmatic nucleus
Appetite/Thirst
o Lateral Hypothalamus
o Ventromedial nucleus
Thermoregulation
o Anterior nucleus
o Posterior nucleus |
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Definition
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Definition
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Definition
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Term
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Definition
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Term
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Definition
| Parrahippocampal gyrus – hippocampus – fornix – mammillary bodies (part of hypothalamus) – thalamus – cyngulate gyrus – parahippocampal gyrus. Then back around again. |
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Term
| Stria terminalis & ventral amygdalofugal pathway |
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Definition
o Axons forming reciprocal connections between the amygdala to the hypothalamus
o These circuits connect emotional and homeostatic centers |
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Term
| Damage to components of the limbic system causes profound dysfunctions including: |
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Definition
-Memory loss (retrograde and enterograde amnesias – (HM)
-Olfactory dysfunction (loss and/or hallucinations)
-Emotional disturbances (anxiety, rage, fearlessness, etc.)
-Autonomic and homeostatic dysfunctions
-Personality changes
-Changes in sexual and grooming behaviors
-Seizures |
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