Nervous System Flashcards
Central Nervous System (CNS)
Brain and Spinal Chord
Peripheral Nervous System (PNS)
Cranial nerves and Spine nerve roots
Cerebrospinal Fluid (CSF)
Originates in Choroid plexus, baths cell of CNS
Flows through central cerebrospinal canal of spinal cord
Returns to the the brain through veins?
Meninges
3 sheets of connective tissue, covers brain and spinal cord
Dura Mater
Sheet of meninges nearest to bones and inside of skull
Arachnoid
Sheet of Meninges in middle
Pia Mater
Inner CSF filled area
Subarachnoid space
Area between pia mater and arachnoid
Spinal Cord
Cased by vertebrae, runs from skull to L1
Conus Medullaris
Near L1-L2 where the cauda equine begins and Spinal cord ends
Caude Equina
Horses tail
Bundle of spinal nerves encased in NSF that extends from L1-L2 to coccyx
Number of nerve pairs in spine
31, each with two different types of nerves
Sensory Nerves (afferent)
Transmit messages from PNS to the brain
Dorsal root located on posterior of the spine
Dorsal Root Ganglion (DRG)
Bundle of nerves at each level, controls inflow of sensory nerves
Proprioceptors
Transmit info from stretch receptors in muscles and inner ear about position and balance
Nocireceptors
Sensory nerves ending in skin and joints and muscles that detect harmful stimuli
Motor Nerves
Signals from brain to muscles causing them to react
Ventral nerve roots located on anterior side of spine
White matter
Impulse travel rapidly along myelinated nerves
Grey Matter
Contains masses of nerve cells bodies and dendriles, as well as synapses
- posterior grey matter of the spinal cord (dorsal horn) receives input from peripheral nerves via dorsal root ganglia
- afferent nerve pathways
Neurons
Nerve cell comprised of
- cell body (soma)
- dendrites(sends stimuli toward cell body)
- axons (away from cell body)
- cell between axons and neighboring cell/dendrite is called synapse
Autonomic Nerves
Controls autonomic functions that are not under conscious control
Sympathetic nervous system
Responds to immediate danger; increases heart rate and blood pressure
Parasympathetic nervous system
Produces relaxation and calm in digestion
Enteric nervous system
manages digestion
Nerve roots
31 Pairs, exit spinal cord through inter verbal forma
- 8 in cervical spine
- 12 in thoracic spine
- 5 in lumbar spine
Dermatome
Single spinal nerve that covers an area of skin, able to be used to diagnose spine issues
Plexus
Bundle of nerves that control a particular area
Brachial Plexus
Highly organized system of nerve muscles, controls transverse neck, arm control and sensation
Lumbar Plexus
Forms Lumbosacral Plexus
Formed by ventral divisions of first four lumbar nerves (L1-L4) and from contributions of subcostal nerve (T12)
Primary afferent fibers (PAF)
First order of afferent receptors to take in input
Dorsal Root Ganglia
PNS, second order of afferent nerves, extensions into the dorsal horn of the spinal cord
Thalamus
All sensory input minus smell is projected from spinal cord to it before going to cerebral cortex
Acute Pain
Short lived and temporary, easy to pinpoint
Serves a purpose
Most intense at first
Chronic Pain
Begins gradually
Varies in intensity from mild to severe
Can occur sporadically
Has no purpose
