The Nervous System Flashcards
the neuron
dendrites
soma/cell body
axon hillock
axon
myelin
Node of Ranvier
axon terminal- axon collaterals
synapse
dendrites
finger-like projections that have receptors
receive neurotransmitters
axon hillock
where the soma and axon join
action potential starts
myelin
insulation surrounding the axon
allows the electrical signal to travel down smoothly
terminal buttons
vesicles- package of chemical information
neurotransmitters travel between the presynaptic cleft (release zone) and to postsynaptic receptors
Node of Ranvier
exposed axon in between myelin cells
allows cell to interact with the extracellular fluid
glial cells
astrocytes
oligodendrocytes
microglia
astrocytes
help form the blood brain barrier
regulate neurotransmission
oligodendrocytes
create myelin (CNS)
hold the cell in place
microglia
remove cellular waste (phagocytosis)
major part of immune system in CNS
2 types of microglia
M1 and M2
M1
release chemicals that promote inflammation
can damage blood brain barrier
M2
release chemicals that reduce inflammation & promote growth and development of cells
autonomic systems
sympathetic system
parasympathetic system
enteric system
sympathetic system
emergencies, energy expenditure, highly aroused states
increase heart beat, inhibits digestion, open airways
parasympathetic system
relaxed states
decrease heart rate, stimulates digestion, slows respiration
enteric system
controls digestion
gut & brain communicate
autonomic system activation
both sympathetic & parasympathetic systems contain ganglia
neurons in the spinal cord send signals to other (postganglionic) neurons
ganglia
clusters of cell bodies
primary neurotransmitter (NT) of autonomic neurosystem
Acetylcholine (ACh)
other peripheral nerves: the cranial nerves
structures lower in the brain (the medulla)- sends signals to the cranial nerves
cranial nerve
broadly devoted to movement and sensations of the head
vagus nerve (X)
sends & receives signals from the body (heart, liver, lungs, intestines)
primary line of communication between enteric NS & CNS
divisions of the CNS
hindbrain
midbrain
forebrain
hindbrain
myelencephalon
metencephalon
midbrain
mesencephalon
forebrain
diencephalon
telencephalon
medulla
controls the autonomic nervous system (ANS)
breathing, heart rate, vomiting, sneezing, etc.
damage to the medulla=really bad news!
narcotics and depressants inhibit behavior of medulla
mixing (even safe amounts) of different depressants can produce synergistic effects
hypothalamus
maintains homeostasis- endocrine system
motivation (the 4 F’s of survival)
direct influence on the medulla & ANS
hypothalamus regulates
the pituitary gland & pineal gland
both part of the endocrine system
the 4 F’s of survival
feeding, fighting, fleeing, fornicating
thalamus
the landmark that looks like a butt
sensory relay center in the brain
adjacent to: hypothalamus
drugs produce serotonin in the thalamus
basal ganglia
learned motor movements
instrumentally learned behaviors
how to do things automatically
e.g. drive a car, type on a keyboard, inject and IV drug
the limbic system: emotional behaviors
contains many structures that are involved in emotional processing
amygdala is often involved in
fear & aggression
nucleus accumbens
anterior to the amygdala
the brain’s reward center
cerebral cortex (neocortex)
“higher” order functioning
functionally divided
occipital lobe
back of brain
temporal lobe
above your ears
drum keeping temp
auditory processing and speech processing
parietal
explicit planned motor movements
touch
egocentric judgements about space
frontal lobe
front of brain
cerebellum
is the butt
balance
