Structures and Functions of the Brain Flashcards
Three main division of the brain and what they each do
Forebrain - controls reasoning
Midbrain - controls “middle-level” functions
Hindbrain- controls basic functions
afferent neurons
sensory neurons
efferent neurons
motor neurons
motor neurons effect the body’s behavior
way to remember afferent versus efferent neurons
SAME
sensory - afferent
motor - efferent
cerebellum location and function
hindbrain little ball
coordinates movement
medulla oblongata location and function
lower part of brainstem
autonomic functions like breathing, heart rate, BP
substantia nigra location and function
lower part of midbrain, upper brainstem
helps coordinate voluntary movements
what brain structure does Parkinson’s affect?
substantia nigra
affects coordinated voluntary movements
thalamus
relays sensory and motor signals
regulates sleep and alertness
hypothalamus
connects the nervous system to the endocrine system
where are the thalamus, hypothalmus, and pituitary gland located?
located in the diencephalan of the forebrain
below the cerebrum
pituitary gland
releases important hormones
*more information in the endocrine flashcards
what is the cerebrum divided into?
cerebral cortex and subcortical structures
what are the subcortical structures?
olfactory bulbs
hippocampus
basal ganglia
olfactory bulbs
subcortical structure
detect odors / smell
hippocampus
subcortical structure
converts short term memory to long term memory
basal ganglia
eye movement, voluntary movement, procedural and habitual learning
generally what does basal ganglia control?
movement and learning
amygdala
episodic memory, attention and emotion
what structure controls emotion?
amygdala
what structure controls flight or fight response?
amygdala
which structures are involved in reward and addiction?
VTA and nucleus accumbens
nucleus accumbens
reward, motivation and learning
receives signals from the VTA
VTA
a cluster of dopaminergic neurons involved in reward
sends signals to VTA
what is the cerebral cortex broken into?
4 lobes
frontal lobe
involved in decision making and “adulting” processes
parietal lobe
sensory processing except vision
occipital lobe
vision
temporal lobe
visual memories and language
Wernicke’s area location and function
located in temporal lobe
language comprehension / understanding
Broca’s area location and function
located in frontal lobe
language production, actually speaking
how does specialization of the brain areas arise?
specific, individualized receptors on neurons
what protects the brain and spinal cord?
CSF
EEG
uses electrical signals to measure neuron’s activity
CT
images static structures of brain with radiation dose
MRI
images soft structures of the brain
PET scan
radiolabeled glucose shows where brain is functioning
measures neuronal activity
when are PET scans commonly used?
to find brain tumors
after strokes and functional changes
fMRI
allows visualization of blood flow
measures both structure and function
cerebrum
the most anterior part of the brain
made up of the cerebral cortex (4 lobes) and subcortical structures
limbic system
a grouping of various structures involved in emotion, memory, and motivation
How can you generally describe the function of the temporal lobe?
involved in meaning making
makes sense that Wernicke’s area for language comprehension is there
lateralization
the tendency of the left and right hemispheres of the brain to specialize in different functions
mesolimbic pathway
the brain’s reward system and relies on dopamine
VTA and nucleus accumbens are part of this pathway
What brain structures help coordinate movement?
cerebellum, substantia nigra, and basal ganglia
pons
a relay station for other signals and controls some autonomic functions
superior colliculus
located in the midbrain
visual reflexes
inferior colliculus
located in the midbrain
auditory reflexes
synaptic ganglia
relay stations for the PNS
junctions between the CNS and target organs
post central gyrus
located in parietal lobe and is primary sensory cortex
pre central gyrus
contains motor cortexes in the frontal lobe
glial cells
provide nutrients, structure, insulation and defense for neurons
astrocytes
glial cells that provide nutrients and create blood brain barrier
provide constant glucose supply
Schwann cells
wrap the PNS neurons in myelin
myelination
prevents cross talk between neurons and speeds up signal transduction
saltatory conduction
action potential moving down the neuron
microglia
glial cells that function like macrophages
CSF
cerebrospinal fluid bathes and buffers CNS cells
ependymal cells
secrete CSF
soma
body of the neuron and contains a nucleus
synaptic cleft
found between two neurons
sodium potassium pump
3 Na+ and 2 K+ in
graded potentials
happen at the post synaptic cleft
most are excitatory
can add up to the threshold potential
What happens when threshold potential is activated?
Na+ channels open
which makes cell more positive and triggers action potential
How does the cell repolarize?
opening up K+ channels and closing Na+ channels
causes K+ to move out and no more Na+ to move in
absolute refractory period
new action potential will not initiate as Na+ channels cannot reopen immediately
relative refractory period
Na+ channels are able to open again, but membrane is still hyperpolarized so it’s hard to accomplish
What causes neurotransmitters to leave the terminal end?
Ca2+ channels open and Ca2+ causes neurotransmitters to leave
acetylcholinesterase
breaks down ester linkages that hold acetylcholine together
What happens to neurotransmitters?
they must be either degraded or reuptaked
What does higher membrane capacitance mean?
more difficult to change membrane potential
What is the insulator in a neuron’s capacitance?
the membrane itself
Difference between small and large neurons
Small neurons are able to change membrane potential easily but are slow
Large neurons are not able to change membrane potential quickly but are fast
How does myelination speed up signals?
increases membrane resistance and decreases capaticance
membrane and cytoplasmic resistance in neurons
higher membrane resistance makes a more effective action potential
higher cytoplasmic resistance makes worse conduction of signal
Nodes of Ranvier
intermittent unmylenated regions that can replenish a signal to full capacity along the axon
