L20 - Nervous System Anatomy Flashcards
What are the divisions of the nervous sytem?
- central nervous system (CNS)
- peripheral nervous syrem (PNS)
What parts include the CNS?
- brain
- spinal cord
What parts include the PNS?
Nerves in the rest of the body
What is the simple sequence in the nervous system?
- afferent from periphery (sensory)
- to NS
- efferent back to periphery
What is the periphery?
Everything outside NS
What are the different types of NS?
- somatic - somatic motor (muscles under voluntary control, consicous)
- autonomic - visceral motor (subconscious movement)
What are the different regions of the spinal nerves?
- cervical
- thoracic
- lumbar
- sacral
What are the different inputs to the CNS?
- touch and visceral input
- sight
- sound
- smell
- taste
What are the different touch and visceral inputs?
- mechanoceptors (touch)
- proprioceptors
- nociceptors (pain)
- thermoceptors (temp/heat)
- chemoceptors (chemicals)
What are the different part in the cross section of spinal cord?
- grey matter
- white matter
- dorsal root
- dorsal root ganglion
- dorsal root ganglion cell
- vental rool
- sensory neuron
- sensory receptor
What part of the spinal cord does the input go into?
The dorsal part
What is the sequence of steps for the input from the sensory receptor go into the spinal cord (monosynaptic reflex)?
- sensory receptor
- dorsal root ganglion cell
- dorsal root
- input goes in through dorsal side
- gray matter
What are the sequence of steps after the input reaches the spinal cord (monosynaptic reflex)?
- input goes out through ventral side
- ventral root
- spinal nerve
- muscle
What is an examples of the monosynaptic spinal reflex?
Muscle stretch
What are the sequence of steps in the muscle stretch?
- tendon of quadriceps hit = stretches
- proprioceptors in the muscle spindle detect stretch of tendon
- send signal through dorsal side
- alpha motorneuron causes quadriceps to contract
What is a reflex arc?
Movement/action that doesn’t need consicous control
What are the sequence of steps in the reflex arc?
- receptor
- afferent fibre
- integrative centre (spinal cord, integrates input from periphery)
- efferent fibre
- effector
What are responses?
Movement/action that involves the brain
What are the sequence of steps in a response?
- receptor
- afferent fibre
- integrative centre (spinal cord, integrates input from periphery)
- goes to brain
- provides input back
- efferent fibre
- effector
What are the different parts of the spinal cord projections
- dorsal columns
- dorsal horn
- ventral horn
- zone of lissaur
- substantia gelatinosa
- dorsal root
- ventral root
What are the sequence of steps in the ascending pathways - dorsal column - medial lemniscal pathway?
- large dorsal root axons
- dorsal column (in the spinal cord)
- dorsal column nuclei
- medial lemniscus (in the medulla)
Crosses over - thalamus
- somatosensory cortex
What are the sequence of steps in the asecnding pathways - spinothalamic pathway?
- small dorsal root axons
- dorsal column (in the spinal cord)
- spinothalamic tract (straight through medulla to thalamus)
- somatosensory cortex
What senses go through the dorsal column - medial lemiscal pathway?
- touch
- vibration
- two-point discrimination
- proprioception
What senses go through the spinothalamic pathway?
- pain
- temperature
- some touch
What are the sequence of steps in a descending pathway?
- PAG - midbrain
- raphe nuclei (in the medulla)
- dorsal horn (in the spinal cord
What are the cranial nerves?
Sensory
- olfactory
- optic
-glossopharyngeal
Somatic motor
- trochlear
- abducens
- oculomotor
Visceral motor
- vaguus
What are glial cells?
Non neuronal cells within the NS
- oligoendrocytes
- astrocytes
What are the functions of glial cells?
- support
- insulation
- buffering and scavenging
- guide developing neurones
- immune response
- blood brain barrier
What are the covering of the CNS?
- dura matter
- subdural space
- arachnoid membrane
- subarachnoid space
- pia mater
- artery
- brain
What is cerebrospinal flluid (CSF)?
Fluid that flows through ventricles and around the subarachnoid space
- produced by choroid plexus
- aq solution of Nacl + glucose (120ml)
What are the functions and clinical significance of CSF?
- buoyancy & cushioning
- compensation of changes in brain vol
- diagnosis: lumbar puncture
- drug delivery
- hydrocephalus
What are the different parts of the blood-brain barrier?
- astrocyte
- basement membrane
- endothelial cells
- lumen of blood vessel
- tight junction
