Nervous Integration Flashcards
(41 cards)
How many spinal nerves are there and what is their distribution?
31 pairs of spinal nerves
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal

How are the spinal nerves named?
Cervical nerves named for the vertebra below them
- except for cervical nerve 8 b/c theres only 7 cervical vertebrae
- Cervical nerve 8 exits below C7 and above T1
- Cervical nerve 1 below occiput and abov 1st cervical vertebra
Thoracic, Lumbar, Sacral, and coccygeal nerves are named for the vertebra above them
What composes a typical spinal nerve?

A mixed nerve with efferent and afferent neurons

Contains Connective tissues
- endoneurium
- perineurium
- epineurium
What purpose does insulation serve in a typical spinal nerve?
allows you to disrciminate between sensory input
- one axon per region
- impulse on axon doesn’t stimulate other axons because of insultation
What are dermatomes? What are the dermatomes in the picture?

Every piece of skin has adesignated spinal nerve that innervates it
-except face

What are the cranial nerves and hw many of them are there?
12 pairs of cranial nerves
Motor components
-arise from brainstem gray matter
Sensory components
-arise from ganglia outside brain
What is the cranial nerve mnemonic?

What is the cranial nerve function mnemonic?

Draw the weird cranial nerve picture

What are the essential functions of the nervous system?
- Sense changes in the internal and external environments
- Integrate and interpret incoming sensory information
- Respond, if necessary to environmental changes
What is a sensation?
stimulus sensed and sent to CNS
How is a sensation different from perception?
a perception is a sensation that is also routed to cerebral cortex and you are aware of it
What are the levels sensation?
- spinal (reflex only)
- brainstem (reflex only)
- thalamus (crude perception)
- cerebral cortex (precise perception)
What is sensory modality?
Specific types of receptor based on sense
-eg can’t feel cold with heat receptors
What are the components of sensation?
- Stimulation - stimulus + Receptor
- Transduction - receptor tranduces stimulus to sensory neuron
- Conduction - conduction of nerve impulse
- Translation - synapse in CNS not necessarily consciousness
What are generator potentials?
- stimulation of receptor directly causes depolarization of sensory neuron
- action potential is initiated if the stimulus is a threshold stimulus
- all receptors do this except those for the special senses
What is a Receptor potential?
- receptor cell releases neurotransmitter onto first neuron in pathway
- neurotransmitter will produce depolarization or hyperpolarization of a bipolar neuron
- bipolar neuron is the 1st neuron on pathway to CNS
- can inhibit/excite the 1st neuron
- used by the receptors for the special senses
What is the receptor difference between generator and receptor potentials?
Generator potential
-receptor is dendritic end of sensory neuron
Receptor potential
-receptor is separate cell
How does amplitude of potentials vary?
Amplitude of both types of potentials vary with stimulus intensity
- high amplitude = high frequency of firing in pathway
- low amplitude = low frequency of firing in pathway
more ap/sec that reach CNS are interpreted as more intense
-too strong = pain stimulus
What are the types of recetors based on the location in the body and based on the type of stimulus it detects?
Based on Location in the Body
- interoceptors (visceroceptors)
- exteroceptors
- proprioceptors
Based on Type of Stimulus Detected
- mechanoreceptors
- thermoreceptors
- chemoreceptors
- photoreceptors
- nociceptors
What are the different types of adapting receptors?
Fast-adapting (phasic) receptors
- Adapt very quickly
- Specialized for signaling changes in a particular stimulus
- Pressure, touch, hot, smell
Slow-adapting (tonic) receptors
- Adapt slowly, continuing to initiate impulses as long as stimulus persists
- Pain, body position, cold, chemical composition of blood
What is an afterimage?
after removal of stimulus the receptors are still sending info down signal pathway
What is projection?
each receptor has corresponding neuron in cerebral cortex
Where does adaptation occur?
Most at receptor level but further adaptation ocurs during central processing




