Nervous System General Flashcards
(50 cards)
Name the 3 functions of the nervous system
Sensory - detection and input - what gives you info
Integrative - processing, storing, analyzing of sensory info
- decision making
- what to do once you get the information
Motor - output portion
Name the Types of nervous tissue
Neurons
Neurolglia
What are neuralgia and what is their function?
Non neuronal cells that:
Nourish, support and protect neurons in CNS and PNS
Maintain homeostasis
Form myelin
What are the parts to a nerve cell?
Dendrite
Cell body
Axon
What is the structure and function of dendrite?
Structure: single or multiple tree like extensions off of cell body
contain lots of receptor sites to receive chemical information from other cells
Function: input potion of neuron
What is the structure and function of an axon?
Structure:
One single thin cylindrical extension off cell body
Axon terminals:end of axon that divides into many fine processes
Synaptic end bulb: swollen end of some axon terminals
Some axon are myelinated
Function: output portion of the neuron
What is myelin?
A multilayered protein and fat covering that speeds up AP conduction.
Actions coated in myelin are called ‘myelinated’ axons
What is a stimulus?
Any change in the environment (internal or external) that is strong enough to stimulate an action potential (AP)
What is an Action Potential?
An electrical signal that travels along the cell membrane of a neuron.
APs can travel at various speeds
How do neurons respond to a stimulus?
They convert it to an action potential (AP)
Nervous system can be organised into what? And what do they consist of?
Central nervous system : brain and spinal cord
Peripheral nervous system: all nervous tissue outside of CNS
What is the structure and function of cell body?
aka soma
contain nucleus and organelles,
Function: Where cell processes take place ie. Protein synthesis
What is the size and shape of neurons?
Neurons vary in size and shape
What are the three structural classifications of neurons? And how are they distinguished?
Unipolar: one process off cell body
bipolar: 2 processes off cell body
multipolar: multiple processes off cell body
What is the structure of a multipolar neuron?
Where is it found?
One axon, multiple dendrites
Most in the brain and spinal cord, all motor neurons
What is the structure of a bipolar neuron?
Where is it found?
One main dendrite, one main axon (not many)
For special senses, ie sight, hearing
What is the structure of a unipolar neuron?
Where is it found?
Single axon. Cell body divides the axon into two parts: periphery process and central process
Peripheral axon has sensory receptors
Central axon has axon terminals
So… Peripheral process conducts AP from dendrites towards cell body, where it is passed to central process and then move away from cell body and enter CNS
All sensory neurons in the PNS
What is the most common type of sensory neuron?
Pain, touch, temperature, taste, proprioception, visceral organ activity
What are the three functional classifications of neurons?
And what is this classification referring to?
Sensory
Integrative
Motor
Referring to which direction the AP is conducted with respect to the CNS
What are sensory neurons also known as? How would you structurally classify sensory neurons?
Afferent neurons.
Unipolar
Describe sensory neurons structure and their role
Contain either sensory receptors at the dendritic ends OR are located just after sensory receptors on other cells
Once activated by stimulus, AP forms and propagates (continues, keeps going) along the axon and is conveyed into CNS via sensory neurons
Sensory neurons travel together in spinal and cranial nerves on a sensory pathway
What are motor neurons also know as?
What are they structurally classified as?
Efferent neurons
Multipolar
Describe motor neurons role
Action potential propagates away from CNS to effectors via motor neurons (efferent)
What are the effectors?
The cells and organs being effected (ie muscle fibres, glands)
