Intro + Synapses Flashcards
- functional classification of NS
- comprised of what
Somatic sensory & autonomic (symp & para symp)
- Anatomical classification of the nervous system
- what’s each comprised of
CNS (brain & spinal cord) & PNS (spinal & cranial nerves)
function of somatic sensory NS
- comprised of CNS & PNS
- voluntary motor (muscles) & afferent info
function of autonomic NS (general)
motor control to cardiac & smooth muscle
sensory info from organs
what are the embryological subunits of the brain
what do they turn into
forebrain = cerebrum & diencephalon
midbrain = midbrain
hindbrain = pons & medulla
spinal cord
what are the parts of the diencephalon
thalamus & hypothalamus (also an epi & subthalamus)
who’s nickname is “bulb”?
medulla
define rostral
towards nose (rostral, like nostril)
define caudal
towards tail
define symptom
felt by the patient
define sign
discovered, observed, evaluated by a clinician
where is the junction between PNS & CNS?
where spinal nerves enter & leave spinal cord /cranial nerves enter & leave brainstem
gray type I synapse (chemical synpase)
=asymmetrical dense material on postsynaptic but not pre synaptic cleft is 30nm wide synaptic vesicles are round and large synaptic region is 1-2um long
usually ACh = excitatory
Gray type II (chemical synapse)
=symmetrical dense, thin material on both pre & post cleft = 20nm wide vesicles = oval, flattened, or variable in shape region less than 1um long
-usually GABA = inhibitory
postsynaptic element of CNS? Of PNS?
CNS = dendrite or axon PNS = skeletal muscle or gland
what does the shape of the seminal vesicle indicate?
type of NT it carries
round = excitatory
flattened = inhibitory
what causes inhibition/excitation?
the specific receptor the NT binds to
where are bigenic amines and amino acid NT’s synthesized?
in the axon terminal - axon gets these materials from the cell body
what happens in the cell during excitation/inhibition?
an action potential causes ligand-gated channels to open and ions rush into the cell
excitatory = Na+ in = depolarization
inhibitory = Cl- in = hyperpolarization
do post-synaptic cells release NTs?
No way! only pre … post have the receptors, duh
**this allows unidirectional motion of chemical synapses
define quantum; where is it; what are it’s implications?
a fixed amount of NT inside a synaptic vesicle
the amount of NT released depends on the number of vesicles that fuse to the presynaptic membrane —> which is dependent on Ca2+
What NT is effected in Parkinson’s? What are the results?
Dopamine in the substantia nigra of the midbrain –> causes SN neurons to die
Results in resting tremor & inability to properly control movements
What causes Bipolar Disorder? What helps it?
caused by imbalances in phosphatidyl inositol (PI)-linked NT systems
lithium carbonate helps to stabilize the turnover rate
What causes Alzheimers? What NT is affected?
Degeneration of neurons in the basal forebrain nuclei, loss of cerebral cortex and hippocampus synapses & presence of neurofibrillary tangles & senile plaques.
ACh releasing neurons are affected
What is Myasthenia gravis? what does it cause? treatments?
autoimmune disorder: Immune system breaks down the acetylcholine receptor —> destruction of NMJ
results in fluctuating muscle weakness, fatigue, ptosis
treatment: symptomatic = take acetylcholinesterase inhibitors
immunosuppresive = immune modulating treatments
What is botulism? symptoms? what NT is affected?
paralytic disease caused by a nerve toxin
Blurred & double vision, difficulty swallowing, dry mouth, autonomic paralysis, widespread weakness
prevents the release of ACh vesicles
Medical (PT related) uses of botox
repetitive neck spasms, excessive sweating, overactive bladder and sometimes crossed eye
Effects of denervation
no contractile forces can be distributed –> atrophy
muscle fiber types change & get fibrous/fatty –> contractures
define motor unit
a motor neuron & the muscle fibers it inneravtes
Functions & examples of Directly gated receptor
- recognized and bind to the chemical transmitter 2. creat a pore in the membrane for ions to flow
skeletal muscle ACh receptors
how many ACh have to bind the the alpha receptor for a conformation change to take place?
2
Nicotinic receptor responsibilities
found in the NMJ, autonomic ganglia & some areas of CNS
muscle actions: maintain muscle tone — receptor site for muscle relaxants
between neurons: involved in cognitive function, learning, memory, arousal, reward, motor control & analgesia
muscarinic receptors responsibility
involved in physiological functions including HR & force of contraction of smooth muscle
act upon the PNS
