Cerebral Cortex Flashcards
What is the cerebrum
Cerebral hemispheres and diencephalon
- includes subcortical structures
- basal ganglia
- amygadala
What is the Diencephalon
- center of cerebrum
- thalamus
- hypothalamus
- epithalamus
- subthalamus
Thalamus
What is it?
what are important nuclei in the thalamus and their function?
- relay station
- Relay Nuclei: convey info from the sensory system (except olfactory)
- motor loops from thalamus received info from the basal ganglia or cerebellum to the cortex
- assoication nuclei: process emotional and memory info or integrate different types of sensations
- nonspecific nuclei: regulate consciousness, arousal and attenion
What happens with thalamic lesions
- contralateral sensory loss: interruptions of ascending pathways (proprioception primary)
- thalamic pain syndrome: rare contralateral pain without provocation
- lateral pulsion/pusher syndrome:
Pusher syndrome
- Altered perception of the body’s orientation in relation to gravity
- Active pushing with unaffected side results in tendency to fall toward hemiparetic side
- May resolve about 6 months post CVA
- tend to fall toward hemiparetic side
Hypothalamus
- homeostatsis
- eating behavior
- reproductive and defenseive behaviors
- helps regulate circadian rhythms
- helps with emotional expressions
- regulates endocrine functions: growth, metabolism, reproductive
- activation of sympathetic nervous system
- all carried out by hypothalamic control via regulation of secretions from the pituitary
Epithalamus
- Pineal gland = major structure of the epithalamus; helps regulate circadian rhythm
- influences: pituitary, islet of langerhands (pancreas), Parathyriod, adrenal gland
Subthalamus
- has connections with basal ganglia
- helps with motor control
Subcortical white matter
- Projection fibers
- commissural fibers
- associated fibers
Subcortical white matter
Projection fibers/bundles
- Extend from subcortical structures to the cerebral cortex,
- from cerebral cortex to spinal cord, brainstem, basal ganglia, and thalamus.
- Travel through internal capsule
Subcortical white matter
Association Fibers
- Connect cortical regions within the same hemisphere (gyri or lobes with a cerebral hemisphere)
Subcortical white matter
Commissural Fibers
- Largest Group=Corpus Callosum-links right and left hemispheres (links like structures); other links right and left temporal lobes
Pyramidal cells
- Most common type of cortical neuron—short axons
- Apical dendrite: extends toward the surface of the cortex
- Almost all travel through white matter as projection, commisural, or association fibers.
What is brodmann’s area
- Used to designate cortical locations (types of cells)
- Numbered areas of functional importance (numbered in the order they were studied)
- Variable from brain to brain
- Used by clinicians and researchers for reference purposes
look at flow of cortical information
function of
1. primary sensory cortex
2. secondary sensory cortex
3. assoication cortex
4. motor planning areas
5. primary motor cortex
- primary sensory cortex: Simple sensory discrimination (ntensity vs quality)
- secondary sensory cortex: recognition of sensation
- assoication cortex: goal selection, planning, monitoring, interpretation of sensation, emotions, memory, processing
- motor planning areas: movement compoisition, sequencing
- primary motor cortex: cortical motor output
primary sensory cortex
Primary somatosensory
function/lesion will cause
function:
- discriminates shape, texutre or size of oject
Lesions causes:
- loss of tactile localization and conscious proprioception
Primary sensory cortex
Primary auditory
Function:
- conscious discrimination of loudness and pitch of sounds
Lesions cause:
- loss of localization of sounds
Primary sensory cortex
Primary visual
function:
- distinguishes intensity of light, shape, size and location of objects
Lesions cause:
- homonymous hemianopia
a field loss deficit in the same halves of the visual field of each eye
Primary sensory cortex
Primary vestibular
functions:
- discriminates amoung head positions and head movements
- contributes to perception of vertical
lesions cause:
- change in awareness of head position and movement and perception of vertical,
- lateropulsion
Secondary sensory cortex
Secondary somatosensory cortex
function:
- stereognosis and memory of tactile and spatial environment
Lesions cause:
- astereognosis
Secondary sensory cortex
Secondary visual
- analysis of motion,
- color
- recognition of visual objects
- understanding of visual spatial relationships
- control of visual fixation
Lesions cause:
- visual agnosia or optic ataxia
visual agnosia-Inability to visually recognize objects despite having intact vision
Secondary sensory cortex
Secondary auditory
function:
- classification of sounds
Lesions cause
- auditory agnosia