Ch4 pt1-Anatomy of the Nervous System Flashcards
brain & the spinal cord
central nervous system (CNS)
nerves outside of the brain & spinal cord that connect them to the rest of the body
peripheral nervous system (PNS)
part of PNS that consists of axons conveying messages from sense organs to the CNS & from CNS to muscles [voluntary movement, react to touch stimulus]
somatic nervous system
controls the heart, intestines, & other organs (involuntary)
autonomic nervous system
toward the back
dorsal
toward the stomach (front)
ventral
toward front of brain
anterior
toward back of brain
posterior
part of the CNS within the spinal column; communicates with all the sense organs & muscles except those in the head
spinal cord
Law that states entering dorsal roots (axon bundles) [receive info from senses] carry sensory info, & exiting ventral roots carry motor info [carry info to muscles]
Bell-Magendie law
clusters of neurons outside spinal cord (contain cell bodies of sensory neurons)
dorsal root ganglia
_____: neuron cluster OUTSIDE CNS; ____: neuron cluster INSIDE CNS
ganglion; nucleus
in center of spinal cord; densely packed with cell bodies & dendrites
gray matter
consists mostly of myelinated axons (lighter in color); carry info from gray matter to brain or other areas of spinal cord
white matter
counterpart to somatic nervous system [mostly involuntary, automatic responses]
autonomic nervous system
network of nerves that prep organs for vigorous activity (exert energy) [fight or flight]
sympathetic nervous system
increased breathing & heart rate, decreased digestive activity (part of sympathetic nervous system)
fight or flight response
facilitates vegetative, nonemergency responses (conserve energy)
parasympathetic nervous system
3 major divisions of the brain
hindbrain, midbrain, forebrain
consists of medulla, pons, & cerebellum (most primitive area)
hindbrain
consists of medulla, pons, midbrain, & certain central structures of the forebrain
brainstem
enlarged extension of spinal cord, controls some vital reflexes through cranial nerves (breathing, heart rate, vomiting, salivation, coughing, sneezing)
medulla (medulla oblongata)
lies anterior & ventral to medulla & contains nuclei for several cranial nerves [location where axons from each half of the brain cross to the opposite side of the spinal cord] (increase arousal & readiness of other parts of brain)
pons
has ascending(output to cerebral cortex; increase arousal & attention) & descending(control motor areas of spinal cord) portions
reticular formation
sends axons to much of the forebrain, modifying brain’s readiness to respond to stimuli
raphe system
- large hindbrain structure with many deep folds
- contributes to control of movement, balance, & coordination
- helps people shift attention back & forth between auditory & visual stimuli
- sensory timing
cerebellum
roof of midbrain
tectum
swellings on each side of tectum (important for sensory processing)
superior colliculus [vision] & inferior colliculus [hearing]
intermediate level of midbrain (nuclei for 3rd & 4th cranial nerves; extension of pathways between forebrain & spinal cord or hindbrain)
tegmentum
gives rise to dopamine-containing pathway that facilitates readiness for movement
substantia nigra
most anterior & most prominent part of mammalian brain (consists of left & right hemispheres; each hemisphere organized to receive sensory info & to control muscles)
forebrain
outer portion of forebrain [controls motor movement from opposite side of body]
cerebral cortex
interlinked structures that form border around brainstem (important for motivations & emotions; consists of olfactory bulb, hypothalamus, hippocampus, amygdala, cingulate gyrus of cerebral cortex)
limbic system
consists of thalamus & hypothalamus
diencephalon
pair of structures in center of forebrain (sensory info is sent here, then processed & sends output to cerebral cortex) (except for smell)
thalamus
small area near base of brain just ventral to thalamus (related to motivated behaviors [eating, drinking, sexual behavior], alters release of hormones) [when damaged leads to abnormalities in motivated behaviors]
hypothalamus
endocrine gland attached to base of hypothalamus (releases hormones)
pituitary gland
group of critical structures lateral to thalamus [caudate nucleus, putamen, globus pallidus; exchange info with cerebral cortex, responsible for planning sequences of behavior & for certain aspects of memory & emotional expression]
basal ganglia
lie on ventral surface of forebrain (key role in arousal, wakefulness, & attention) [releases acetylcholine to widespread areas in cerebral cortex]
basal forebrain
large structure between thalamus & cerebral cortex (critical for learning & memory; especially encoding new memories)
hippocampus
four fluid-filled cavities within brain (filled with cerebrospinal fluid)
ventricles
membranes that surround brain & spinal cord (only source of pain receptors in brain)
meninges
cushion brain, source of nutrients, reservoir hormones; created by choroid plexus inside ventricles
cerebrospinal fluid (CSF)
condition in infants caused when flow of CSF is obstructed, accumulating within ventricles or subarachnoid space, increasing pressure on brain – skull bones may spread causing overgrow head
hydrocephalus
receives input from hypothalamus and basal ganglia and sends axons that release acetylcholine to widespread areas in the cerebral cortex
nucleus basalis
____ allow medulla to control sensations from the head, muscle movements in head, parasympathetic output to organs
cranial nerves
