nervous system Flashcards
what are the 3 general anatomical features of the brain
cerebrum, cerebellum, brain stem
what provides nutrients and cushion to the CNS
CSF
what does the diencephalon consist of and what are the respective components functions
thalamus = relay station for sensory and motor info
hypothalamus = regulates internal environment of the body
what does the metencephalon consist of and what are the components respective functions
cerebellum = balance, coordination, fine tuning of mvmt
pons = info flow to and flow cerebrum
what does the myelencephalon consist of and what are the components respective functions
medulla oblongata = vital reflexes e.g heart rate, breathing and salivation
what does the mesencephalon consist of and what are these regions respective functions
tectum (roof) = visual
tegmentum (floor) = auditory
cerebral peduncles = connect cortex + pons to cerebellum / connect cortex to spinal cord
what are the functional divisions of the NS
autonomic NS, somatic NS, enteric NS, sensory NS (afferent > PNS nerve endings to CNS), motor NS (efferent > CNS to PNS effectors), integrative (interneurons that combine sensory and motor info)
what are the functional properties of neurons
conductive (generate AP), excitable (respond to stimuli), secretory (neurotransmitters)
what is axoplasmic transport and what are the two types of it
it is transport of material b/w the axon terminal and soma. the types are anterograde (towards the terminals) and retrograde (towards the soma)
what are the functional and structural classifications of neurons
sensory/afferent (unipolar and pseudounipolar)
motor/efferent and interneurons (multipolar)
special senses (bipolar)
what are the different types of glial cells in the CNS/PNS
microglia (CNS)
astrocytes (CNS)
ependymal cells (CNS)
satellite cells (PNS)
schwann cells (PNS)
oligodendrocytes (CNS)
describe structure and function of microglia
defence cells, involved in inflammation
describe the structure and function of astrocytes
star shaped, provide structural support, comprise BBB, absorb and recycle NT
describe the structure and function of satellite cells
astrocyte like, support and protect nerves, control extracellular environment
describe the structure and function of ependymal cells
epithelial-like cells, produce CSF, involved in CSF circulation
describe the structure and function of oligodendrocytes
produce myelin, wraps processes around axons, (they are not regenerative)
describe the structure and function of schwann cells
repair and regenerate damaged nerves, myelin production, conduction of signals
what are the components of the BBB
endothelial cells (tight junctions)
pericytes
basement membrane
astrocytes (podocytes)
what is the significance of the BBB
protector of the CNS, regulate transport, mediator of communication, selectively permeable membrane
What are the components of the membrane that contribute to the membrane potential
Plasma membrane, ions, ion channels, cytosol / extracellular fluid
Explain how excitatory neurotransmitters work
Excitatory NT (e.g glutamate) binds to post synaptic receptor
Ligand gated Na+ channels open
Influx of positive ions
Becomes more positive
Closer to threshold
Increases likelihood of AP in post synaptic neuron
Explain how inhibitory NT works
Inhibitory NT (e.g GABA) binds to post synaptic receptor
Ligand gated Cl- ion channels open
Influx of negative ions
More negative
Further from threshold
Reduces the likelihood of AP in post synaptic neuron
Ionotropic receptors
Open and close in response to NT binding at ligand gated receptors
FASTER
Metabotropic NT
G coupled receptors senses ligand binding > activates secondary messengers > activates other effector proteins > cascading signals in cell
SLOWER
What are the two major branches of NT
Amino acid
Classical Amine
What are the types of amino acid NT
Glutamate (+)
GABA (-)
What are the types of classical amine NT
Norepinephrine (concentration and body temp)
Epinephrine (mental alertness, increased cardiac output)
Dopamine (euphoria)
Serotonin (mood, appetite)
Acetylcholine (two types: nicotinic which is ionotropic and muscarinic which is metabotropic)
What are the two types of graded potentials
EPSP and IPSP
Explain what EPSP is
Local changes (short distance) in the membrane potential of the post synaptic neuron that makes it more likely to fire an AP
Can summate > spatial summation and temporal summation
Explain what IPSP is
Local changes (short distance) in the membrane potential of the post synaptic neuron which makes it less likely to fire an AP
