neuroanatomy
the study of the parts and function of neurons
neuron
individual nerve cell
dendrites
Rootlike parts of the cell that stretch out from the cell body; grow to make synaptic connections with other neurons.
cell body
cell's life support center, contains nucleus
axon
passes message away from the cell body to other neurons, muscles, or glands
myelin sheath
protection over axon, similar to protection over headphone wiring. Enables faster transmission speed
multiple sclerosis
damage to myelin sheath; communication is disrupted between brain and body: can result in pain, fatigue, and more
terminal buttons
final stops for neurotransmitters before going to the synapse
neurotransmitters
chemical messages that travel the synaptic gap
synapse
microscopic space between two neurons
receptor sites
specific part of the dendrites that receives information
threshold
the level of stimulation required to trigger a neural impulse
action potential
a brief electrical charge that travels down an axon
all or none principle
the law that the neuron either fires at 100% or not at all
why do we feel or experience things more intensely?
because more neurons are firing rather than a stronger action potential
neural firing
neurons communicating with one another via electrical impulses and neurotransmitters
excitatory neurotransmitters
excite the next cell into firing (encourages)
inhibitory neurotransmitters
blocks some type of action
acetylcholine (ACh)
neurotransmitter that controls muscle action, learning, memory
malfunction of acetylcholine (ACh)
ACh neuron deteriorate causing Alzheimer's
dopamine
neurotransmitter: movement, learning, attention, emotion
malfunction of dopamine
too much --> schizophrenia too little --> tremors, parkinson's
endorphins
neurotransmitter : pain control, pleasure
malfunction of endorphins
use of opiate drugs suppresses natural supply
serotonin
mood, hunger, sleep, body arousal
malfunction of serotonin
too little leads to depression
GABA
blocks nerve impulses (inhibitory), helps controls fear/anxiety
malfunction of GABA
seizures, tremors, insomnia
glutamate
sends signals between nerve cells (excitatory), memory
malfunctions of glutamate
too much --> over stimulation --> migraines/seizures
norepinephrine
alertness, body arousal
malfunction of norepinephrine
too little --> depression
afferent neurons
take info from the sense to the brain
efferent neurons
take info from the brain to the rest of the body
central nervous system (CNS)
main division of the brain, brain and spinal cord, all the nerves housed within bone (vertebrae and skull)
spinal cord
a bundle of nerves that run through the center of the spine, transmits info from the rest of the body to the brain
peripheral nervous system
all nerves in the body that aren't encased in bone
somatic nervous system
controls voluntary muscle movements
autonomic nervous system?
controls automatic body functions and our reaction to stress (fight or flight)
somatic and autonomic
what are the two categories in the peripheral nervous system?
sympathetic nervous system
response to something scary/stressful, carries messages to control systems that direct the body's response to stress
examples of the sympathetic nervous system being activated
heart rate, shaky hands, adrenaline, breath speeds up, pupils dilate, slows digestion
parasympathetic nervous system
carries messages to the stress response system that causes our bodies to slow down after a stress response
accidents
things that happen miraculously and lead to case studies
lesions
removal or destruction of certain parts of the brain example: brain tumor that needs to be removed
electroencephalogram (EEG)
detects brain waves, examines what type of waves the brain produces during different stages of consciousness
EEG used for?
sleep studies to identify different stages of sleep and dreaming
CAT Scan
a sophisticated x-ray using cameras that rotate around the brain and combine photos into a 3D pictures of the brain's structure
what does a CAT scan show you?
a doctor could view a tumor, but couldn't get info on how active parts of the brain are
Magnetic resonance imaging (MRI)
gives pictures, but with more detail, shows density and location of brain material
Position Emission Tomography
shows researchers what parts of the brain are most active during certain tasks
Functional MRI (fMRI)
details of brain structure with information about blood flow in the brain
hindbrain
the structures in the top of the spinal cord, life support system, controls basic survival functions Includes: pons, medulla, cerebellum
medulla
controls blood pressure, heart rate, breathing
where is the medulla located?
above spinal cord
pons
connects hindbrain with midbrain and forebrain, controls facial expressions and sleep controls (ponzzz)
cerebellum
coordinates habitual muscle movements and balance (tracking something with your eyes) Translates to: little brain
where is the cerebellum located?
underside of the brain
what is the midbrain?
coordinates habitual muscle movements with sensory information (keeps eyes on text if head turns)
where is the midbrain located
above spinal cord, below forebrain
what is the reticular formation?
in the midbrain, netlike collection of cells througout the midbrain, controls general body arousal and attention focusing
what happens if the reticular formation doesn't work
deep coma
what is the forebrain
controls thoughts and reason
what is the thalamus?
receives 4 of 5 sensory signals up spinal cord, then sends them to correct areas in the rest of the forebrain
where is the thalamus located?
top of brainstem
what is the hypothalamus?
controls body temp, sex drive, hunger, thirst, and endocrine system-- maintains homeostasus
where is the hypothalamus?
tiny and right below the thalamus
what is the amygdala?
agression, fear, emotion
where is the amygdala located?
end of each hippocampal arm
what is the hippocampus?
memory system- processed here, then sent to other location in cerebral cortex permanently
What is anterograde amnesia?
inability to form new memories
What is retrograde amnesia?
Inability to remember events that occurred before the incidence of trauma or the onset of the disease that caused the amnesia
what is the limbic system?
emotion and memory
what is in the limbic system?
hypothalamus, amygdala, hippocampus
what does the left hemisphere of the brain do?
controls language, speech, math, time, recognition in letters, words, numbers
what does the ride side of the brain do?
facial recognition, inferences, context, perceiving/expressing emotion, spatial ability, creativity
what is brain lateralization?
specialization of function in each hemisphere
What is the corpus callosum?
a broad band of nerve fibers joining the two hemispheres of the brain
what are the lobes?
frontal, parietal, occipital, temporal
what is the association area?
any part of the cerebral cortex that doesn't receive sensory info or control muscle movements, controls judgment and humor
what are the frontal lobes?
prefrontal cortex- predicts consequences, pursues goals, maintains emotional control, engages in abstract thought
what is Broca's area?
controls muscles responsible for speech production
what can damage to the broca's area result in?
difficulty in getting words out
what is Wernicke's area?
interprets written and spoken speech
what could damage to the Wernicke's area do?
affect the ability to understand language, and makes sentences nonsensical
what is the motor cortex?
sends signals to our muscles, controls voluntary movements
where is the motor cortex located?
thin vertical strip at the back of the frontal lobe, top controls bottom of body and vice versa
what are the parietal lobes?
receives sensory input for touch and body position
where are the parietal lobes located?
portion of the cerebral cortex lying at the top of the head and toward the rear, top controls bottom of the body and vice versa
what is the sensory cortex?
receives information about touch sensation
Where is the sensory cortex located?
right behind motor cortex
what are the occipital lobes?
interprets messages from eyes (in the visual cortex)
Where are the occipital lobes located?
very rear of brain
what are the temporal lobes?
process sounds from ears
where are the temporal lobes located?
above ears (temples)
what is brain plasticity?
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience (resilience)
what happens to brain plasticity as you age?
brain becomes significantly less plastic
what is the endocrine system?
system of glands that secrete hormones to affect biological processes in our bodies
what are the adrenal glands?
produce adrenaline, signals body to prepare for fight/flight
What are monozygotic twins?
identical twins