Ch 12 - Central Nervous System Flashcards
Regions of the brain
1) Cerebral hemispheres
2) Diencephalon
3) Brain Stem
4) Cerebellum
Anatomy/Physiology of Gray matter
Contains dendrites, cell bodies, & axon terminals
function: all synapses found in gray matter
Anatomy/Physiology of White matter
Contains myelinated axons, mostly in fiber tracts
function: passes “messages” between different areas of gray matter
Distribution of Gray Matter and White Matter in the Brain
Gray matter is peripheral, white matter is central
Outer layer of gray matter is called the cerebral cortex
Distribution of Gray Matter and White Matter in the Brain Stem
Scattered gray matter found within white matter
Distribution of Gray Matter and White Matter in the Spinal Cord
Gray matter in butterfly pattern surrounded by white matter
Central canal found at the center of gray matter
Hollow chambers found in the brain that are filled with CSF and lined with ependymal cells
Ventricles of the brain (4) - all continuous
4 Ventricles of the Brain
- Two Lateral Ventricles - look like rams horns in cerebral hemispheres
- Third Ventricle - found in diencephalon (center of brain, thin, looks like skull laterally
- Fourth Ventricle - found in hindbrain, connected to third ventricle via cerebral aqueduct, continuous with central canal of spinal cord
Ridges and valleys of Cerebral hemispheres
- Gyri - ridges of cerebral hemispheres
- Sulci - shallow grooves
What brain fissure separates the left and right hemispheres
Longitudinal fissure
What brain fissure separates the cerebral hemispheres from the cerebellum
Transverse cerebral fissure
Sulci that separate brain lobes
- Central Sulcus - separates frontal lobe and parietal lobe
- Parieto-occipital sulcus - separates the occipital lobe from the parietal lobe
- Lateral Sulcus - separates the temporal lobe from the fronal & parietal lobes (the insula is deep to the lateral sulcus)
Part of the brain that provides self-awareness, sensation, communication, memory, understanding/learning, and initiation of voluntary movement
Cerebral cortex
The hemispheres of the cerebral cortex are contralateral!!
Functional Areas of the Cerebral Cortex
1) Motor Areas: control voluntary movement
2) Sensory areas: conscious awareness of sensations
3) Association areas: integrate diverse information
Do each hemispheres do the same thing on each side, but for opposite sides of the body?
No!
Ex. Broca’s area - controls speech, usually found in only left hemispheres
Motor Areas of the Cerebral Cortex
1) Primary motor cortex - Allows for conscious control of skilled/precise voluntary movements
2) Premotor cortex
3) Broca’s area
4) Frontal eye field
Ordered from parieto-occipital sulcus anteriorly:
1) Primary motor cortex
2) Premotor cortex
3) Broca’s area & Frontal eye field
(broca’s area is inferior, extends further anteriorly)
Large neurons found in primary motor cortex
Pyramidal Cells - axons of these neurons travel to spinal cord in corticospinal tracts, synapsing with motor neurons
Remember the Motor Homunculus!!!
https://brightspace.binghamton.edu/d2l/le/content/348464/viewContent/1249091/View
Function of Premotor Cortex
1) Helps plan movements by selecting and sequencing basic motor movements into complex tasks - communicating with primary motor cortex
2) Controls voluntary actions that depend on sensory feedback
Part of the body that controls the motor movements involved in speech
Broca’s Area
Part of the body that controls voluntary movement of the eyes
Frontal Eye Field
Sensory Areas of the Cerebral Cortex
1) Primary somatosensory cortex
2) Somatosensory association cortex
3) Visual areas (sight)
4) Auditory areas (hearing)
5) Vestibular cortex (balance/orientation)
6) Olfactory cortex (smell)
7) Gustatory cortex (taste)
8) Visceral sensory area (sensations of internal organs)
Function of the Primary Somatosensory Cortex
recieve information from the general sensory receptors in the skin
Function of the Somatosensory Association Cortex
Integrates sensory input relayed to it via primary somatosensory cortex (produces understanding of what is being felt; size, texture, relationship of its parts)
Ex. reaching into a bag and being able to identify phone vs keys
Visual areas
1) Primary visual cortex - receives visual information that originates on the retina of the eye
2) Visual association area - uses past visual experiences to interpret visual stimuli - allows us to recognize things
The primary visual cortex is the largest corital sensory area
Auditory Areas
1) Primary auditory cortex - interpretation of sound from inner ear as pitch, loudness, and location
2) Auditory association area - permits perception of sound stimulus & stores memories of sounds for referecce
Area that allows for conscious awareness of balance/orientation
Vestibular Cortex
Area that allows conscious awareness of different odors
Primary olfactory cortex
Area that allows conscious awareness of different odors
Primary olfactory cortex
Area that allows conscious awareness of taste stimuli
Gustatory Cortex
Area that allows conscious perception of visceral sensations
(i.e. full stomach or bladder)
Visceral Sensory Area
Definition
Division of Labor of Cortical Functioning
Cerebral Lateralization
* Can cause Cerebral Dominance
Cerebral Dominance of Left side of Brain
Language abilities, math, logic
Ex. left side of the brain is dominant while speaking publicly, memorizing infiormation
Fiber tracts connect the left/right side of the brain - share information almost instantly, allowing complete functional integration
Cerebral Dominance of Right side of Brain
Visual-spatial skills, insight, creativity
Fiber tracts connect the left/right side of the brain - share information almost instantly, allowing complete functional integration
Function and Location of Cerebral White Matter
Deep to cortical gray matter, manages communication in the CNS
Classification of Cerebral White Matter
1) Association fibers - connect different areas of the same hemisphere
2) Commisural fibers - connect corresponding areas of different hemispheres (allow hemispheres to function as a coordinated “team”)
3) Projection fibers - allows sensory information to reach cortex motor output to leave cortex
Part of the Brain that filters out incorrect/inappropriate motor/emotional/cognitive responses
Basal Nuclei (Basal Ganglia)
Structures that make up the Diencephalon
1) Thalamus
2) Hypothalamus
3) Epithalamus
Functions of the Thalamus
Relay sensory information coming to the cerebral cortex - information is “edited” here, impulses with similar functions are grouped together and relayed to appropriate part of the cortex
1) Motor activities
2) Cortical arousal (sleep/wake cycles)
3) Learning
4) Memory
Functions of the Hypothalamus
visceral control center
1) Controls autonomic nervous system - blood pressure, rate/force of heartbeat, digestive tract mobility, pupul size of eye, etc. etc. etc.
2) Initiates physical response to emotion - limbic system involvement (involved in perception of pleasure, fear, rage, sex drive, sleep, etc)
3) Regulates body temperature - “thermostat” - blood pressure changes heat output
4) Regulates food intake - monitors blood nutrient levels
5) Regulates water balance and thirst - conc. of body fluids
6) Regulates sleep-wake cycles - uses daylight-darkness cues from visual pathways
7) Controls endocrine system function - controls secretion of hormones by other glands
