1
The Brain
NEUROIMAGING TECHNIQUES:
MRI, CT scan, and fMRI focus on brain structure
PET scan and fMRI focus on function of the brain
EEG((electroencephalogram)) records electrical waves sweeping across the brain's surface – useful for
studying seizures and sleep
PET ((position emission tomography)) scan shows which parts of the brain are active while the brain
performs a given task – does this by tracing where a radioactive form of glucose goes
MRI ((magnetic resonance imaging)) makes images from signals produced by brain tissue after magnets
align the spin of atoms
fMRI reveals brain activity and function – also shows changes in the level of oxygen blood flow in the
brain
BRAIN HIERARCHY:
recently developed structures sit on the top of structures of the past
core: breathing and heart rate
newer systems: complex functions like thinking, reasoning, emotions
AREAS OF THE BRAIN AND THEIR FUNCTIONS:
hindbrain: brainstem and cerebellum
◦ coordinates the body
midbrain: the limbic system
◦ manages emotions, and connects thought to body
◦ sensory portion of midbrain has centers for hearing and seeing
◦ involved in vision and hearing, so has sensory and motor neurons
◦ its motor neurons control eye movement
forebrain: cerebral cortex ((outer covering))
◦ integrates information
◦ parts are cerebrum, limbic system, thalamus, hypothalamus
CEREBRAL CORTEX:
◦ outer covering of two hemispheres of the brain
◦ highest level of the brain
◦ responsible for most complex aspects of perception, emotion, movement, and thought
◦ ultimate control and information-processing center 2
The Brain
CORPUS CALLOSUM:
◦ axon fibres connecting the two cerebral hemispheres
OCCIPITAL LOBE:
◦ visual information
◦ vision signals are processed here
PARIETAL LOBE:
◦ information about touch
◦ sensations like pressure, pain, touch, temperature
◦ has somatosensory cortex
◦ attention and mental operations; manages input from multiple senses
◦ performs spatial and mathematical reasoning
◦ monitors the sensation of movement
TEMPORAL LOBE:
◦ hearing, language; auditory information is sent here; manages sensory input related to sound,
which helps the understand of spoken words
◦ has auditory cortex and Wernicke's area ((left hemisphere))
◦ memory, perception, emotion
◦ gives you the ability to recognize specific faces
FRONTAL LOBE:
◦ planning, judgement, memory, reasoning, abstract thinking, movement
◦ inhibition of impulses
◦ active in use of working memory and the processing of new memories
◦ includes motor cortex and Broca's area ((left hemisphere, language))
◦ motor functions, speech, emotions, creative thinking
LESS COMPLEX BRAIN STRUCTURES:
BRAINSTEM:
MEDULLA:
◦ responsible for autonomic functions like breathing and heart rate
((giraffe structure))
PONS:
◦ its neurons regulate sleep; involved in dreaming
◦ its motor neurons control muscles and glands of the face and neck
◦ helps control respiration, vital functions ((swallowing, bladder function, hearing,
equilibrium, taste, eye movement, facial expressions, facial sensation and posture))
◦ acts as a bridge between higher and lower levels of the nervous system
◦ helps coordinate automatic and unconscious movements 3
The Brain
DAMAGE TO THE BRAIN STEM CAN RESULT IN DEATH
RETICULAR ACTIVATING SYSTEM ((RAS)):
◦ extends from brain stem; arouses cortex and screens incoming information
◦ reticular formation
◦ filters incoming sensory information
◦ nerve network in the brainstem
◦ enables alertness, from coma to wide awake
◦ regulates sleep, wakefulness, and levels of arousal
THALAMUS:
◦ "sensory switchboard" or "router"
More
Less
