Exam 3 lecture 1 Flashcards
Divide the brain into 3 regions
Hindbrain
Midbrain
forebrain
What are the notable structures in each region of the brain
hindbrain- medulla, pons, cerebellum
Midbrain- Substantia nigra
forebrain- cerebral cortex
-basal ganglia (striatum, globus pallidus, subthalmic nucleus)
-limbic system (hippocampus, amygdala)
- diencephalon (thalamus, hypothalamus)
Functions of medulla
autonomic functions
centers for controlling respiration, cardiac function, vasomotor responses, reflexes (coughing)
functions of pons
It is a “bridge” Relays signals from forebrain to cerebellum
Functions of cerebellum
Governs motor coordinations for producing smooth movements
Pathogenic response of cerebellum
Undergoes neurodegeneration in spinocerebellar ataxias
function of substantia nigra pars compacta
Provides input to basal ganglia. supplies dopamine to striatum
also involved in voluntary motor control
pathogenic response of substantia nigra
Undergoes neurodegeneration in PD (parkinsons disease)
where is striatum located
frontal end of basal ganglia
Function of substantia nigra pars reticulata
relays signals from basal ganglia
function of cortex
Involved in processing and interpreting information
involved in higher level function
basal ganglia function
voluntary motor control and some cognitive functions
limbic system function
Emotions (amygdala), memory (hippocampus)
diencephalon function
Thalamus-
hypothalamus- regulates internal homeostasis and hormonal control through pituitary gland
decisions are made in _________ about how to interpret and act on the incoming sensory information
corticothalamic loops
damage to cortex affects
Movement
speech
personality
Name a disease of the frontal cortex
Schizophrenia
what are the brain structures directly involved in involuntary functions
Hypothalamus and medulla
know structure location of medulla, pons, midbrain, thalamus, cerebellum and cortex for exam
CNS consists of what kind of cells
Neurons and glial cells
name glial cells
Astrocytes
oligodendrocytes
microglia
Role of astrocytes
provide neurons with growth factors, antioxidants
remove excess glutamate
support BBB
Role of oligodendrocyte
Produce myelin sheath that insulates axons
Role of microglia
Provide GF
clear debris (myelin debris) by phagocytes
role in neuroinflammation
Tight junction use
stabilizes BBB
What are dendrites
Finger like protrusions that receive signal and transfer to soma (neuron body)
neurotransmission is triggered by
electrical depolarization of the neuron (influx of Na+ ions)
signal received by dendrites make way to
soma and down to axon
action potentials last
0.2-0.5ms
what is refractory period
Period after action potential (hyperpolarized phase) during which a neuron will not fire again
explain action potential steps
Initial state is negative
Na+ channels open and Na+ flows in and changes charge
K+ channels turn on and K+ gets moved out and become negative
hyperpolarized- overshoot negative
do excitatory depolarization change size (magnitude) or frequency in which they occur
frequency
How do inhibitory signals work
Makes neuron less likely to pass threshold
What is EPSPs
Excitatory post synaptic potential
EPSPs are weak signals that do not clear threshold (subthreshold depolarization)
What is IPSP
inhibitory post synaptic potential
How do IPSPs work
Inhibitory neurotransmitters induce hyperpolarization by allowing Cl- ions to cross membrane
How do IPSPs affect EPSPs
IPSPs can reduce magnitude of subsequent EPSPs
Lifecycle of neurotransmitter (diagram will be on exam)
1.Pre synaptic neuron
2. Neurotransmitter is synthesized
3. packaged into vesicle (store)
4. fusion at membrane due to action potential
5. neurotransmitter is released and it can act on receptor on post synaptic neuron
6. neurotransmitter gets uptaken back into presynaptic neuron through transporter (glutamate can be removed from synapse by astrocyte)
7. degradation of neurotransmitter
