Neuron BIOLOGY Flashcards
What are the 3 types of sensory Receptors
Interceptors
Monitor internal systems such as digestive,Respiratory,reproductive
And internal senses taste,pain
Exterioceptors
External sense such as touch,temperature and sight and smell
Proprioceptors
Monitor position and movement
What are the two major efferent systems?
Somatic nervous system
Autonomic nervous system
Where do signals from CNS motor neurons to visceral effectors pass synapses at autonomic ganglia?
Preganglionic and Postganglioc fibers
What is the function of interneurons?
Distribution of sensory information and coordination of motor activity
Also involved in memory,planning and learning
What is the reflex arc?
It us a signal conduction from the cns and involves interneurons,afferent and efferent neurons
Affarent neurons conduct impulses to the Cns
Interneurons carry information and process it
The efferent will conduct impulses from the cns to the effectors(muscles)
What are the five main membrane processes in neural activities?
Resting Potential
Graded Potential
Action Potential
Synaptic activity
Information Processing
What us the the Resting Potential?
It is the transmembrane potential of a resting cell
What is a graded Potential?
Temporary change in a resting potential
What is an action Potential?
It is an electrical impulse
And is produced by a graded potential and moves along the axon to the synapse
What is synaptic activity?
Releases NTS in the presynaptic membrane and produces graded potentials in the postsynaptic membrane
What is information processing?
Response of postsynaptic cell
What is the diffrence in electric charge?
Potential
What is a membrane potential?
It is a diffrence in concentration of ions (outside there’s an excess of positive ions and inside there’s a slight deficit in positively charged ions
What is the magnitude of potential difference between 3 sides of polarized membrane?
Volts or Milivolts
What are the 3 important concepts of a transmembrane potential?
Extracellular fluid and intracellular fluid differ greatly in ionic composition
And cells have a selectively permeable membrane
And membrane permeability varies by ion
What are the passive forces acting across a plasma membrane?
Chemical gradients -
Electrical gradient
Equilibrium potential-the transmembrane potential at which there’s no net movement of a particular ion across a cell membrane
What is the sodium potassium pump?
An active transport mechanism which involves Na and K ions moving in opposite directions
It maintains an imbalance of distribution of positive ions
And the inside becomes slightly more negative than the outside
The pump ejects 3 Na and brings in 2 K into the cell
It serves to stabilize the resting potential
What are local potentials ?
Excitation
When a stimulus triggers the opening of additional Na channels and membrane potential moves towards 0(Depolarization)
Inhibitation
Stimulus triggers opening of K channels increasing membrane potential(hyperpolarisation)
What is the mechanism that produces an action potential?
Stimulus gated Na channels open
Na diffuses into the cell this is called local deploarization.
Threshold potential Then the Na channels open further causing more Na to enter cell
Action potential peaks and then moves back to resting potential and K gates open causing K to move out of cell this is called repolarization
A brief moment if hyperpolarisation occurs
Then causing resting potential to restore
What is the refractory period?
Neuron is incapable of producing another action potential
What is the absolute refractory period?
It is a brief period during which a local area of neurons membrane resists restimulation no matter how strong
What is relative refractory period?
When the membrane is repolarized and restoring resting membrane potential it will respond to only strong stimulus
What are the types of synapses?
Neuromuscular
Neuron and muscle
Neuroglandular
Neuron and gland
What are neuronal pools?
Finctional groups of interconnected neurons with limited input sources and output destinations
May stimulate or depress a part of the brain
What are the 5 patterns of neuronal circuits in neuronal pools?
Divergence-spreads stimulation to many neurons
Convergence -brings input from many sources to single neuron
Serial processing -moves info in a single line
Paraell processing -moves same info along several paths at the same time
Reverberation -positive feedback mechanism
What is Receptor potential?
It is a potential that develops when there is enough stimulus that acts on a receptor
When threshold is reached an AP in sensory neuron axon is triggered
What is adaptation?
A functional characteristic of receptors
Receptor potential Decreases overtime in response to continuous stimulus
Leading to a decreased rate of impulse conduction and Decreases sensation
What is a primary response of sensory receptors?
Have axons that can conduct an AP in response to receptor potential
What is a secondary response of sensory receptors ?
Have no axons and receptor potential produced and no AP but release NTs
