Lecture 2 - Overview of the Nervous System Structures Flashcards
historically, investigations into the structure of the nervous system relied on:
postmortem dissection and neuronal tracing
newer recording and imaging approaches have increased accessibility to the nervous system of “intact” humans and can provide:
functional information on the activity of specific brain regions
what does electroencephalography (EEG) do?
enables electrophysiological activity to be recorded from specific regions of the CNS (measures electrical activity in the brain during behaviour)
what does positron emission topography (PET) and magnetic resonance imaging (MRI) do?
imaging that can be used to observe the brain in action during behaviour to identify regions that are active
what are the two main parts of the nervous system?
the central nervous system (CNS) and peripheral nervous system (PNS)
ganglia and nerves that are connected to the CNS
the PNS
provides the CNS with information about muscle, limb position and sensory stimuli
somatic division of the PNS
provides information and control of viscera and smooth msucles
autonomic division of the nervous system
what are the three major components of the autonomic nervous system?
sympathetic, parasympathetic, and enteric system
the CNS can be broken up into seven main regions along the rostro-caudal and dorso-ventral axes:
- spinal cord
- medulla
- cerebellum
- pons
- midbrain
- diencephalon
- cerebral hemispheres
the caudal-most part of the CNS extending from the base of the skull
spinal cord
what are the major functions of the spinal cord?
- receives sensory information from the trunk and limbs
- contains motor neurons responsible for movement
- contains interneurons which mediate activity of the descending tracts
- receives sensory information from visceral organs
- contains neurons that control visceral organs
the human spinal cord is divided into ____ spinal segments, each receiving ____ information from, and sending ____ information to specific regions of the periphery
30, afferent, efferent
sensory information travels into the spinal cord via the:
dorsal root
efferent information exits the spinal cord via the:
ventral root
where does the spinal cord end?
between L1 and L2
the sack of nerve roots at the lower end of the spinal cord which which provide the ability to move and feel sensation in the legs
cauda equina
what is the purpose of the enlargements in the spinal cord?
enlargements contain motor neurons and interneurons for the arms and legs
the region of the CNS immediately rostral to the spinal cord (the most caudal part of the brainstem)
medulla
what are the four major functions of the medulla?
1) acts as an important conduit between the cortices and spinal cord
2) contains the reflex centres for vomiting, coughing, sneezing, and swallowing
3) important in regulating blood pressure
4) houses neural circuitry responsible for respiration
which cranial nerves are associated with the medulla?
CN IX, X, and XII
the region of the CNS immediately rostral to the medulla
pons
what are the two major functions of the pons?
1) important relay centre between the cortex and the cerebellum
2) contains tracts that carry the sensory signals from the spinal cord to the thalamus
which cranial nerves are associated with the pons?
CN V, VI, VII, VIII
dorsal to the pons and medulla, divided into three lobes
cerebellum
what kind of information does the cerebellum receive?
input from the spinal cord, motor info from the cortex, and vestibular information
coordinates planning, timing, and patterning of skeletal muscles during movement (refines movement), and is involved in motor learning
cerebellum
cells of the vermis are responsible for:
posture, coordination, and speech patterns
the cells of the vermis are susceptible to:
alcohol
region of the brain immediately rostral to the pons
midbrain
acts as an important relay station for auditory signals on the way to the cortex
midbrain
houses the substantia nigra and the mesencephalic locomotor region
the midbrain
part of the basal ganglia which produces dopamine and plays a role in movement and movement planning
substantia nigra
an essential relay point which transmits locomotor initiation commands from higher centres to the spinal circuitry (integrates inputs from higher brain regions)
mesencephalic locomotor region
what are the two major parts of the diencephalon?
the thalamus and hypothalamus
processes and distributes virtually all sensory (other than olfactory) and motor information on the way to the cortex
thalamus
part of the limbic system which is linked with emotion and behaviour, regulates the autonomic nervous system, and regulates the secretion of hormones by the pituitary gland
hypothalamus
is the hypothalamus ventral or dorsal to the thalamus?
ventral
what are the major parts of the cerebral hemispheres?
the cerebral cortex, underlying white matter, basal ganglia, hippocampus, and amygdala
primary processing areas for motor, sensory, visual, and auditory information receive input from:
secondary and tertiary areas which process complex aspects of a single sense
the association areas of the cortex are involved in:
planning and motivation (putting together motor and visual info)
regulates movement, receives input from all four lobes of the cortex, and provides output to the frontal cortex
basal ganglia
part of the brain essential for memory consolidation
hippocampus
part of the brain which coordinates the actions of the autonomic and endocrine systems, and regulates emotion
hippocampus
