NUR 221
UNIT 1: CHAPTER 35 INDEPENDENT REVIEW
Neurological System
CNS: brain and spinal cord
PNS: cranial nerves, spinal nerves + ANS
★ ANS divided into sympathetic and parasympathetic systems
Neuroglial Cells
★ “Glue” cells, hold neurons together and provide support, nutrition, and protection-
have ability to multiple, making them a common source for tumor growth in the brain
and spinal cord > other cells:
○ Astrocytes: structure and support, responsible in the blood-brain barrier
○ Ependymal: line ventricles of the brain and central canal of the spinal cord,
assist in production of CSF & protect brain from foreign materials that might
enter through the bloodstream
○ Microglial: phagocytic when they encounter inflammation or debris, defense
○ Oligodendrocytes: form myelin sheath, aid in impulses
○ Schwann: forms myelin sheath that cover axons in the PNS
Neurons
★ Afferent Neurons: detect sensory stimuli from sensory nerve endings and transmit to
CNS
★ Efferent Neurons: transmit messages from the brain back to the muscles or glands
that respond and are considered motor nerves
★ Interneurons: in the CNS, integrate incoming and outgoing messages, process and
store information, and make decisions about the body’s response to the stimuli
Conduction of Nerve Impulses
★ Action potential facilitates transmission of information from presynaptic neuron to a
receptor by the action of the sodium-potassium pump which creates changes in
electrical balance between outside and inside the cell
○ Na+ resides extracellularly and K+ intracellularly
○ At rest, the cell has a negative charge inside and a positive charge outside
○ When the cell receives stimuli, sodium channels are opened, potassium
channel also opens slowly
○ Sodium channel opens= positively charged sodium enters the cell= cell
becomes positive= depolarization
○ Repolarization occurs when sodium channels close and potassium is fully
open, allowing potassium to leave the cell= return to negative charge inside
the cell or “resting”
, NUR 221
UNIT 1: CHAPTER 35 INDEPENDENT REVIEW
Central Nervous System: The Brain
Divided into three parts:
1. Cerebrum
2. Cerebellum
3. Brainstem
Cerebrum
★ Largest portion, thin layer of gray matter
★ Majority is white matter containing myelinated nerve fibers
★ Longitudinal fissure divides into R&L hemispheres which are connected by the corpus
callosum= band of thick fibers that facilitates communication between the
hemispheres
★ Folds= gyri
★ Grooves= sulci
★ Divided into four different lobes:
○ Frontal: Motor cortex, voluntary movement; Broca’s expressive speech
center—dominant hemisphere; personality; behaviors: social, sexual, judgment,
and problem solving
○ Parietal: Sensation interpretation and perception; spatial relationships such
as body position; integration of sensory input, especially visual input
○ Temporal: Auditory sensation and perception; long-term memory; Wernicke’s
receptive speech center
○ Occipital: Process visual information; perception of color and shapes
★ Thalamus: relay center for sensory impulses= pain, temperature, taste, smell,
hearing, equilibrium, vision, touch
★ Basal Ganglia: regulate movement by sending information back and forth through
the thalamus to the cerebral cortex, balance of excitatory (cerebellum) and inhibitory
(basal ganglia) to operate properly, issues with basal ganglia result in movement
disorders= parkinson’s
★ Hypothalamus: regulator for ANS and sends signals to brainstem, regulating HR +
BP, also regulates metabolism, reproduction, growth, and stress responses by
secreting hormones that control the anterior pituitary, other functions=
thermoregulation, regulation of food and water intake, sleep, memory, and emotional
behavior
★ Limbic System: cingulate gyrus, hippocampus, and amygdala; primary role in
memory and emotions, center for gratification and aversion; gratification center
produces sensations of pleasure or reward, aversion center produces objectionable
feelings of grief or dread
UNIT 1: CHAPTER 35 INDEPENDENT REVIEW
Neurological System
CNS: brain and spinal cord
PNS: cranial nerves, spinal nerves + ANS
★ ANS divided into sympathetic and parasympathetic systems
Neuroglial Cells
★ “Glue” cells, hold neurons together and provide support, nutrition, and protection-
have ability to multiple, making them a common source for tumor growth in the brain
and spinal cord > other cells:
○ Astrocytes: structure and support, responsible in the blood-brain barrier
○ Ependymal: line ventricles of the brain and central canal of the spinal cord,
assist in production of CSF & protect brain from foreign materials that might
enter through the bloodstream
○ Microglial: phagocytic when they encounter inflammation or debris, defense
○ Oligodendrocytes: form myelin sheath, aid in impulses
○ Schwann: forms myelin sheath that cover axons in the PNS
Neurons
★ Afferent Neurons: detect sensory stimuli from sensory nerve endings and transmit to
CNS
★ Efferent Neurons: transmit messages from the brain back to the muscles or glands
that respond and are considered motor nerves
★ Interneurons: in the CNS, integrate incoming and outgoing messages, process and
store information, and make decisions about the body’s response to the stimuli
Conduction of Nerve Impulses
★ Action potential facilitates transmission of information from presynaptic neuron to a
receptor by the action of the sodium-potassium pump which creates changes in
electrical balance between outside and inside the cell
○ Na+ resides extracellularly and K+ intracellularly
○ At rest, the cell has a negative charge inside and a positive charge outside
○ When the cell receives stimuli, sodium channels are opened, potassium
channel also opens slowly
○ Sodium channel opens= positively charged sodium enters the cell= cell
becomes positive= depolarization
○ Repolarization occurs when sodium channels close and potassium is fully
open, allowing potassium to leave the cell= return to negative charge inside
the cell or “resting”
, NUR 221
UNIT 1: CHAPTER 35 INDEPENDENT REVIEW
Central Nervous System: The Brain
Divided into three parts:
1. Cerebrum
2. Cerebellum
3. Brainstem
Cerebrum
★ Largest portion, thin layer of gray matter
★ Majority is white matter containing myelinated nerve fibers
★ Longitudinal fissure divides into R&L hemispheres which are connected by the corpus
callosum= band of thick fibers that facilitates communication between the
hemispheres
★ Folds= gyri
★ Grooves= sulci
★ Divided into four different lobes:
○ Frontal: Motor cortex, voluntary movement; Broca’s expressive speech
center—dominant hemisphere; personality; behaviors: social, sexual, judgment,
and problem solving
○ Parietal: Sensation interpretation and perception; spatial relationships such
as body position; integration of sensory input, especially visual input
○ Temporal: Auditory sensation and perception; long-term memory; Wernicke’s
receptive speech center
○ Occipital: Process visual information; perception of color and shapes
★ Thalamus: relay center for sensory impulses= pain, temperature, taste, smell,
hearing, equilibrium, vision, touch
★ Basal Ganglia: regulate movement by sending information back and forth through
the thalamus to the cerebral cortex, balance of excitatory (cerebellum) and inhibitory
(basal ganglia) to operate properly, issues with basal ganglia result in movement
disorders= parkinson’s
★ Hypothalamus: regulator for ANS and sends signals to brainstem, regulating HR +
BP, also regulates metabolism, reproduction, growth, and stress responses by
secreting hormones that control the anterior pituitary, other functions=
thermoregulation, regulation of food and water intake, sleep, memory, and emotional
behavior
★ Limbic System: cingulate gyrus, hippocampus, and amygdala; primary role in
memory and emotions, center for gratification and aversion; gratification center
produces sensations of pleasure or reward, aversion center produces objectionable
feelings of grief or dread
