Nervous System Flashcards
Brain is protected by
the skull
Spinal cord is protected by
the backbone
Brain and spinal cord are bathed in
cerebrospinal fluid, CSF
2 types of cortical cells
- projections neurons (pyramidal cells)
- local interneurons
Projections neurons are
excitatory
Local interneurons are
inhibitory (GABA)
5 components of a neuron
- cell body
- dentrites
- axon
- myelin sheath
- synaptic terminals
Nodes of Ranvier are
where voltage gated ion channels are activated
Membrane is impermeable for
charged ions
Equation that takes into consideration one type of ion
Nerst Equation
Equilibrium resting potential of membrane
- 70mV
Action potential
+55 mV
When the neuron is at rest the resting potential is mainly governed by
the potassium equilibrium potential
The equation that takes into consideration all ions and their permeability is
Goldman Equation
Goldman Equation terms are:
- ion concentration, ion permeability, temperature, gas constant and faraday’s constant
at resting membrane potential, voltage gated channels are
closed
there is potassium current flowing outwards during
the refractory period
the patch clamp experiment measures the current in
a single ion channel
4 characteristics of electrical synapse
1 - usually bidirectional
2 - in gap-junction channels
3 - virtually no synaptic delay
4 - there is cytoplasmic continuity between pre and postsynaptic cells
3 characteristics of chemical synapse
1 - unidirectional
2 - needs a chemical transmitter - neurotransmitter
3 - there is a delay (1-5 ms)
The action potential reaches the presynaptic terminal and the depolarization of the terminal opens
calcium channels which causes vesicle fusion and transmitter release
Binding to the postsynaptic receptor channels opens
the channels which causes a sodium influx
2 types of chemical synapes
1 - glutamatergic (excitatory)
2 - GABAergic (inhibitory)
system that samples information about the state of our muscular skeletal system or postural changes
proprioceptive system
Identify the three steps involved in hearing and their anatomical structures
sound collection - auricle in the outer ear
sound transmission - external auditory meatus, ear bones
sound transduction - cochlea in the inner ear
how is the appropriated pressure maintained in the middle ear?
by the Eustachian tube
Three compartments of the cochlea
scala vestibuli, scala media, scala tympani
at the distal end of the basilar membrane, the membrane is
broad and flaccid, more sensible to low frequencies oscillations
at the proximal end of the basilar membrane, the membrane is
stiffer and more sensible to high frequency sound frequencies
the vestibular system monitors both
linear and angular accelerations of the head and the body
system that detects linear acceleration
utricle and saccule
system that detects angular acceleration
semi-circular canals
photo-receptor that is highly light sensible
rod
photo-receptor that is less sensible but enables colour vision
cones
receptors of pain
nociceptors
receptors sensitive to pressure and touch
merkel disk receptors
receptors that detect gross pressure changes
Pacinian corpuscles
receptors sensible so shape and textural changes
Meissner’s corpuscles
Which fibres of muscle spindles induce flexion?
Afferent fibres
muscle spindles are most sensible to
changes in length of the muscle
tendon organ are most sensible to
changes in muscle tension
muscle spindles are a type of
proprioceptor
reciprocal innervation is based on
flexor excitation and extensor inhibition
eye movement that makes a fast change in the focal point
saccadic system
eye movement that maintains objects in their focal point
smooth pursuit system
eye movement that changes perspective-focal point
vergence system
eye movement that copes with movements of people and stabilizes the eyes
vestibulo-ocular system
compensatory eye movements induced by the visual system
optokinetic system
TMS stands for
Transcranial Magnetic Stimulation
information from skin receptors is transmitted to the brain through …. cells
dorsal root ganglion
Three mechanism for neural processing:
- convergent excitation
- surround inhibition
- lateral inhibition
