el fin Flashcards
Threshold of a neuron is
voltage at which the inflow of sodium ions causes reversal of the resting potential.
An neuronal circuit in which one presynaptic neuron stimulates a group of neurons, each of which then synapses with a common postsynaptic cell is a:
Parallel after discharge
Following injury to a peripheral neuron, chromatolysis occurs, which is:
breakup of the Nissl bodies.
The nerve that stimulates the diaphragm to contract arises from which plexus:
cervical plexus.
Spinal nerves emerge from the vertebral column via:
intervertabral foramina
the threshold of a given neuron varies considerably depending on local conditions.
true or false
True
spinothalamic tract carry what information
sensory impulses regarding temperature, pain, itch and tickle.
AKA anterolateral
corticospinal tracts stimulate what
Voluntary muscle movement
Trigeminothalamic pathway involved in
tactile, thermal and pain from face, nasal cavity, oral cavity and teeth
Facial to thalamus and cortex
Which pathway is involved most in voluntary mvement
Corticospinal
- Lateral corticospinal - distal muscles of limbs: precise movements of hands and feet (eg. Play piano)
- Limbs and trunk - Anterior corticospinal – muscles of trunk and proximal limbs
- Corticobulbar tract – muscles of head
Disease attacking the corticospinal pathway
ALS
motor area of cortex is attacked and UMN’s and LMN’s
- Corticalspinal track Aren’t sending info to LMN (also can have LMN problems)
- No cognitive detrement
Brain needs such high amount of blood flow bc
the movement of the blood stimulates the growth the neuronal cytoplasmic extensions.
Part of the pons
a) Pontine Nuclei
- Respiratory control
- Voluntary muscle control
b) Vestibular Nuclei - Involved in equilibrium (along w/ medulla) c) Pneumotaxic Area inhibits respiration – prevents overinflation d) Apneustic Area Stimulates respiration
- Nuclei for 4 pairs of cranial nerves (V, VI, VII, VIII )
Degree of muscle stretch monitered by
Muscle spindle
Muscle spindle vs GTO
Muscle spindle moniters muscle length, contracting if it gets too long
GTO moniters force on muscle, causing it to relax if force is too great
what is a receptor potential
receptor potential only facilitates signal transduction or stimulates inward current flow.
Selectivity of a receptor
Receptors respond weakly or not at all to anything BUT their corresponding stimuli
Receptor potentials and generator potentials
Receptors always occur from receptors producing APs, generator potneitals seem to be tied to general senses
What kind of receptor would sense equlibrium
Mechano
Intrafusal fibers stimulated by? Extrafusal?
Intra - Gamma motor neurons
Extra - Alpha motor neurons
The cell bodies of first-order neurons in the posterior column-medial lemniscus pathway to the cortex are located in the:
posterior root ganglia of spinal nerves
Reason for visceral pain = referred pain
sensory neurons for both visceral pain and surface structures enter the same segment of the spinal cord, and surface sensations are better localized by the brain.
What are olfactory hairs
cilia projecting from the dendrites of first-order neurons.
The auditory (Eustachian) tube connects the:
Middle ear and nasopharynx