NEURO
Brain consists of the cerebrum, cerebellum, diencephalon (thalamus &
hypothalamus) and brain stem
Cerebral cortex: outer layer of nerve cell bodies the “grey matter” is the center for
highest function with 2 hemispheres and 4 lobes
Left Hemisphere: language, speech, reading and writing, math and verbal
communication
Right Hemisphere: visual spatial skills, expressing emotion, concentration and
attention, sense of direction
Lobes structure and function
Frontal: motor cortex
o Voluntary movement- L/R controls opposite side
o Broca’s area (speech), talking and writing
o Influences emotion, intellect, reasoning ability, judgement & behavior
Parietal: sensory cortex
o Touch, pain, temperature, shapes and 2-point discrimination
Temporal: auditory cortex
o Receives/interprets impulses from the ear
o Wernicke’s area- interprets auditory stimuli
Occipital lobe: visual receptor center
o Influence reading understanding
o Visual receptor center
Structure & Function
Brainstem:
o Midbrain- relay center for ear and eye reflexes
o Pons- links cerebellum to cerebrum & midbrain to medulla
o Medulla Oblongata- controls and regulates respiratory function,
HR/force & BP
Cerebellum:
o Behind brain stem and under the cerebrum, 2 hemispheres
o Coordination and smoothing of voluntary movements, maintenance of
equilibrium, muscle tone
Spinal cord:
o Consists of dorsal & ventral columns, grey matter
o White matter (myelinated axons) surrounds grey matter
o Ascending (sensory) carry impulses from body to parietal lobe
o Descending (motor) carry impulses from fontal lobe to muscles for
voluntary movement; responsible for simple reflex activity, reflex arc
Structure & Function: Neural Pathways
Sensory (afferent)
, o Spinothalamic tract- pain, temp., crude & light touch
o Posterior (dorsal) columns- position, vibration, finely local touch
stereognosis, graphesthesia
Motor (efferent)
o Corticospinal or pyramidal tract- skilled purposeful movement (writing)
o Extrapyramidal tracts (outside pyramidal tract)- maintenance of
muscle tone, body control
Sensory impulses travel to the spinal cord, takes 1 to 2 routes. Thalamus
fibers synapse with a sensory neuron then to the sensory cortex for
interpretation
Pyramidal tract motor nerve fibers- in the motor cortex, travels to the
medulla, crosses over to the opposite side, pass down in the lateral columns
of spinal cord
Lower motor neurons in the spinal cord send impulses to muscles to produce
voluntary movements
Extrapyramidal tract motor neurons travel from frontal lobe to the pons to
cross over to the opposite side and down spinal cord- connect with lower
motor neurons that conduct impulses to the muscles
Peripheral Nervous System
All nerve fibers OUTSIDE the brain and spinal cord: somatic and autonomic
o Somatic fibers- carry CNS impulses to voluntary skeletal muscle and
mediates conscious or voluntary activities
o Autonomic fibers- carry CNS impulses to smooth, involuntary
muscles (in heart and glands), mediates unconscious or involuntary
activities
Spinal nerves: 31 pairs names for the region of the spine from which they exit
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Sensory (afferent) & Motor (efferent)
Exit the spinal cord in orderly ladder, and each nerve innervates an area in
the skin (dermatome)
Dermatomal Map
Dermatome- a skin area supplied mainly from 1 spinal cord segment through
a certain spinal nerve
The dermatomes overlap, and if one is severed most sensations can be
transmitted by the adjacent nerves
Autonomic Nervous System
Both cranial and spinal nerves from the CNS to the involuntary smooth
muscles of the heart and glands
o Sympathetic NS (fight or flight) activated during stress
Decreased gastric secretions, bronchiole dilation, inc. pulse and
pupil dilation
Brain consists of the cerebrum, cerebellum, diencephalon (thalamus &
hypothalamus) and brain stem
Cerebral cortex: outer layer of nerve cell bodies the “grey matter” is the center for
highest function with 2 hemispheres and 4 lobes
Left Hemisphere: language, speech, reading and writing, math and verbal
communication
Right Hemisphere: visual spatial skills, expressing emotion, concentration and
attention, sense of direction
Lobes structure and function
Frontal: motor cortex
o Voluntary movement- L/R controls opposite side
o Broca’s area (speech), talking and writing
o Influences emotion, intellect, reasoning ability, judgement & behavior
Parietal: sensory cortex
o Touch, pain, temperature, shapes and 2-point discrimination
Temporal: auditory cortex
o Receives/interprets impulses from the ear
o Wernicke’s area- interprets auditory stimuli
Occipital lobe: visual receptor center
o Influence reading understanding
o Visual receptor center
Structure & Function
Brainstem:
o Midbrain- relay center for ear and eye reflexes
o Pons- links cerebellum to cerebrum & midbrain to medulla
o Medulla Oblongata- controls and regulates respiratory function,
HR/force & BP
Cerebellum:
o Behind brain stem and under the cerebrum, 2 hemispheres
o Coordination and smoothing of voluntary movements, maintenance of
equilibrium, muscle tone
Spinal cord:
o Consists of dorsal & ventral columns, grey matter
o White matter (myelinated axons) surrounds grey matter
o Ascending (sensory) carry impulses from body to parietal lobe
o Descending (motor) carry impulses from fontal lobe to muscles for
voluntary movement; responsible for simple reflex activity, reflex arc
Structure & Function: Neural Pathways
Sensory (afferent)
, o Spinothalamic tract- pain, temp., crude & light touch
o Posterior (dorsal) columns- position, vibration, finely local touch
stereognosis, graphesthesia
Motor (efferent)
o Corticospinal or pyramidal tract- skilled purposeful movement (writing)
o Extrapyramidal tracts (outside pyramidal tract)- maintenance of
muscle tone, body control
Sensory impulses travel to the spinal cord, takes 1 to 2 routes. Thalamus
fibers synapse with a sensory neuron then to the sensory cortex for
interpretation
Pyramidal tract motor nerve fibers- in the motor cortex, travels to the
medulla, crosses over to the opposite side, pass down in the lateral columns
of spinal cord
Lower motor neurons in the spinal cord send impulses to muscles to produce
voluntary movements
Extrapyramidal tract motor neurons travel from frontal lobe to the pons to
cross over to the opposite side and down spinal cord- connect with lower
motor neurons that conduct impulses to the muscles
Peripheral Nervous System
All nerve fibers OUTSIDE the brain and spinal cord: somatic and autonomic
o Somatic fibers- carry CNS impulses to voluntary skeletal muscle and
mediates conscious or voluntary activities
o Autonomic fibers- carry CNS impulses to smooth, involuntary
muscles (in heart and glands), mediates unconscious or involuntary
activities
Spinal nerves: 31 pairs names for the region of the spine from which they exit
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Sensory (afferent) & Motor (efferent)
Exit the spinal cord in orderly ladder, and each nerve innervates an area in
the skin (dermatome)
Dermatomal Map
Dermatome- a skin area supplied mainly from 1 spinal cord segment through
a certain spinal nerve
The dermatomes overlap, and if one is severed most sensations can be
transmitted by the adjacent nerves
Autonomic Nervous System
Both cranial and spinal nerves from the CNS to the involuntary smooth
muscles of the heart and glands
o Sympathetic NS (fight or flight) activated during stress
Decreased gastric secretions, bronchiole dilation, inc. pulse and
pupil dilation
