Neuroanatomy Laterization And Localization Flashcards
(33 cards)
How does the skull protect the brain?
bony outer layer, suit of armour, first line of defence, protect direct force of mechanical insult, against potential damage or intrusion
How does the CSF protect brain?
shock absorber, reduce impact of whatever force makes it through the brain itself. Increases buoyancy, decreases pressure of brain stem, cells of nervous system receive nutrients from CSF
How does the Meninges protect brain?
and what are the 3 separate sheaths?
protective covering surrounding tissue of brain
3 separate sheaths
1) PIA MATER
2) ARACHNOID MEMBRANE
3) DURA MATER
space between Pia mater and arachnoid = SUB ARACHNOID SPACE
How does the blood-brain barrier protect the brain?
- supply brain and spinal cord with blood
- allow only some substances to pass in/ out of brain
- capillaries of brain don’t contain GAPS unlike capillary walls elsewhere in the body = selectively permeable
Exception to blood brain barrier?
Area Prostrema: controls vomitting reflex
-allows brain to find toxic substances in blood so body can rid them through vomiting any substance in stomach
What is the cortex made up of? (Latin word bark)
-resembles a shelled walnut with bumps and crevices
-made up of Fissures which are deep crevices and Sulci
if they are shallow
-bumps are called gyri
these serve as divisions of the cortex
what are the primary FISSURES?
1) Longitudinal fissures: separates left and right hemi
2) Central Fissures: separates frontal lobe from parietal lobe of each hemi
3) Lateral Fissures: separates the temporal lobe from frontal and parietal lobe of each hemi
Primary GYRI?
1: Pre and post central Gyri: divide the central fissure (pre in front, and post behind)
What are the 4 primary Lobes and their functions?
1) Frontal Lobes: motor function and personality
2) Parietal Lobes: somatosensation
3) Temporal Lobes: audition and memory
4) Occipital Lobes: vision
What 2 axons map projection areas?
AFFERENT Axons: APPROACH central nervous system from sensory systems into the cortex
EFFERENT Axons: EXIT the CNS from the cortex as they project to the motor systems of brainstem and spinal cord
Afferents role:
carry info from joints and sensory system, skeletal muscles and vice-versa (body organs) towards the CNS
-provide CNS with info about body environment
Efferents role:
carry info from CNS toward the skeletal muscles and vice versa. Enabling the organism to behave in accordance with the incoming info.
What are the 3 projection areas?
- Primary Area
- Secondary Area
- Tertiary or Association Area
Primary sensory projections: what are they arising from and where do they go?
Primary motor projections: what are they arising from and where do they go?
Primary sensory projections= eye, ear, and somatosensory systems
go to: Primary projection areas of corresponding lobes of cortex (occipital, temporal, and parietal)
Primary motor projections= arise from primary motor cortex
go to: spinal cord where connections are made with other neurons that go on to innervate the skeletal muscles of the body
DISTRIBUTED FUNCTION
The observation that some behavioural and psychological functions, particularly complex cognitive functions, require collective input from more than one brain structure to execute.
What are secondary and tertiary areas?
These are adjacent areas that primary areas receive info from. They also appear to have a role in further analysis, integration, and association from the primary areas.
Motor Homunculus
and Sensory Homunculus
1) electrical stimulation of the primary motor cortex reveals a complete motor representation of the body on the precentral gyrus
2) electrical stimulation of primary somatosensory cortex reveals a complete somatosensory representation of the body on the postcentral gyrus which is referred to as the sensory homunculus
what do both the primary cortex and the primary somatosensory cortex have in common?
they devote the largest amount of physical space to those areas of the body with greatest sensitivity and those that require the most precise and complex muscular control
ex/ face and hands are very sensitive to touch
Cerebral Laterality
- There’s a certain amount of specialization regarding the roll of each hemisphere for different psychological and motor functions, and it is not equal.
- left and right hemi specialized with repect to their cognitive and behavioural functions
Longitudinal Fissure
divides the brain in two halves, called left and right cerebral hemi
Corpus callosum
a strip of tissue that facillitates communication between hemispheres
-neural signals pass back and forth
Role of Left Hemisphere
Role of Right Hemisphere
Left Hemisphere- more involved in langauge tasks, reading and pseaking
Right Hemipshere- more involved in processing and recognition of emotion
The division of labour between right and left brained
- origin of colloqualism about whether one is “left or right brained”
- left brain strengths =academic and scientific endevours like writing and math
- right brain strengths= intuitive and arts and fantasy
Define Contralateral organization and the exception
- the organization of the brain and body, such that sensory and motor information to and from the left side of the body is primarly processed by the right side of the brain and vice versa
- ex/ visual input received by sensory field (right side) is processed by the opposite hemisphere (left) and then sends information to right side via corpus callosum
*one exception is for the sense OLFACATION which projects ipsilaterally (ipsi=same) into our frontal lobes. This is like much like the motor organization of our bodies
and eyes sensory info arrives at both sensory fields simultaneously
