Functional Neuroanatomy- (Lecture 2) Flashcards
CNS
Central Nervous System
encased by bone, contains brain and spinal cord
PNS
Peripheral Nervous System
isn’t encased by skull or spine, carries info to and from the CNS
afferent nerves
travel INTO the CNS from the periphery
efferent nerves
leave the CNS for the periphery (Exit)
somatic nervous system
- contains sensory nerves (afferents) and motor nerves (efferents)
- voluntary nervous system
autonomic nervous system
- regulates respiration, heart rate, digestion (all involuntary),
- contains the sympathetic and parasympathetic nervous system (both efferent)
similarities in sympathetic vs. parasympathetic
all are efferent, all contain second stage neurons
sympathetic nervous system properties
thoracic and lumbar
- “fight or flight”
- second stage neurons are far from the target organ
parasympathetic nervous system properties
cranial and sacral
- “rest and restore”
- second stage neurons are near the target organ
cranial nerves
12 types
- part of PNS
- numbered in sequence from front of brain to back of the brain
- location of the nerves for senses well known
spinal chord
- base of brain
- extension of the medulla, all the way down to the small of the back, stops before the vertebrae of the back end, then have nerve roots on the spinal cord
spinal nerves
contain axons for sensory and motor
dorsal spinal nerves
- sensory (input)
- sensory info from stimulus is sent to dorsal nerve then to dorsal horn which sends the info to the brain for processing
ventral spinal nerves
motor (output)
-carry motor commands from the brain to the muscle
protections for the brain (3)
- armor (skull and vertebrae)
- meninges
- CSF
meninges
- contain dura mater
- arachnoid membrane
- sub-arachnoid space (cushion)
- pia mater
CSF
cushion against trauma
ventricular system
spinal fluid travels throughout the ventricular system to help wash out metabolic waste through the blood brain barrier
dorsal ventricule axis
- top to bottom
medial lateral axis
- in reference to midline, medial is near the midline (toward the spine), lateral is out or toward periphery
anterior posterior axis
- anterior is in front
3 coordinate system (planes):
- dorsal/ventral
- medial/lateral
- anterior/posterior
3 types of planes for sectioning
- horizontal
- sagittal
- coronal
horizontal plane
top of head to bottom of head
sagittal plane
down the center, both halves
coronal plane
front of head to back
development process of neural tube
ectoderm forms a plate, plate curves in and folds until it backs the neural tube neural canal forms, neural canal forms into neural tube with 3 interconnected swellings (ventricles) that develop into the 3 major sections of the brain
3 original parts of the brain
- forebrain
- midbrain
- hindbrain
forebrain –>
- telencephalon
- diencephalon
midbrain –>
-mesencephalon
hindbrain –>
- metencephalon
- mylencephalon
causal hindbrain
“oldest part”
- mylencephalon (medulla)
- control of central life processes, heart and respiratory system, breathing,
- damage to this part of the brain could result in death
rostral hindbrain
- metencephalon (pons, cerebellum)
- sleep and arousal, control consciousness
- pons (pathway)
- cerebellum (motor coordination and balance)
midbrain
mesencephalon
- tectum (roof) helps guide orientations to sights and sounds,
- tegmentum basal ganglia and limbic system help initiation and control of movement
basal forebrain
- diencephalon
- contains thalamus (relay station) which contains synapses from many sensory input
- hypothalamus (base of brain) which controls autonomic (for Fs)
dorsal forebrain
telencephalon
contains limbic system involved in motivation, interconnected structures for learning, memory, and emotional senses (limbic cortex, amygdala, hippocampus, fornix, mammillary bodies)
amygdala
emotional responses such as fear, aggression, stress
hippocampus
- memory consolidation
- spatial/directional
fornix
hippocampus –> thalamus
basal ganglia
series of 4 things: (causae, putamen, globus pallidus),
-commands –> motor actions, planned motor movements and motor control
cerebral cortex
- most expansive and most growing during development
- it is a layer of tissue only a few mm wide that contains loves of protrusions and bumps
cerebral cortex function
important for higher level processes, thought, memory, attention, perceptual awareness, language, consciousness
grey matter
layers of cell bodies
white matter
axons of those cell bodies, cell axons that travel between brain structures (corpus callosum)
neo-cortex area
contains 6 layers of cells, each layer consists of a different cell type, some layers receive more information, some layers send more information
cortex organization
2 hemispheres, 4 lobes, 52 cortical areas
primary cortex area
1st part of cortex that receives info from the sensory stimuli
association areas
secondary areas that receive the info 2nd and organize sensory data to make it into a more meaningful signal
mammalian brain facts
size of brain is proportional to body size, cortical development varies dramatically between species, can be 2 square meters if spread flat
structural approaches to studying the brain
- histology
- computed tomography (CT or CAT)
- magnetic resonance imaging (MRI)
functional approaches to studying the brain
- neuropsychology (disease, damage)
- electroencephalogram (EEG)
- position emission tomography (PET)
- functional MRI (fMRI)
- behavioral neuroscience (animal models),
histology
- direct manipulation and staining of tissue
- cellular and molecular analyses
- can only be down post-mortem
computed tomography (CT or CAT)
- series of X-ray images
- scan living brain
- low resolution
- radiation exposure is a downside
- obvious brain pathology can be seen
- not too specific
magnetic resonance imagine (MRI)
- measuring waves
- use electromagnetic fields to image atom (hydrogen density)
- scan living brain
- high resolution
- no radiation
- expensive
clinical neuropsychology
analyzes cognitive changes after brain damage, determines critical region
-downside: no control to brain damage, most rely on case studies, small sample size, hard to make a “control” so you don’t know exactly what is damaged
EEG (electroencephalogram)
- measures electrical potentials from scalp
- activity in living brain, high temporal resolution, surface (cortical) tissue only
- correlate behavior/cognitive process and activity, only good for neo-cortex type studies
PET (positron emission tomography)
detect decay of injected radioactive substance (glucose)
- measure activity in living brain
- detect metabolic/chemical changes in living brain low resolution
- exposure to radioactive substance,
functional fMRI (fMRI)
- use electromagnetic fields to image blood flow (hemoglobin)
- detect metabolic needs of living brain
- indirect measure of activity
- high resolution
- very expensive
- correlation between activity and behavioral/cognitive processes
