Central Nervous System Flashcards
the —plays a key role in both the afferent and efferent pathways
thalamus (part of the diencephalon)
Thalamic excitation of the cerebral cortex is necessary for
almost all cortical activity.
Sensory neurons enter the spinal cord via the --- --- and then synapse with interneurons and/or motor neurons in the --- ----
dorsal root
gray matter
Motor neurons exit the spinal cord via the — — to go to
effectors
ventral root
The spinal cord contains
a central portion of — —
surrounded by — —
gray `matter (neuron cell bodies and interneurons) white matter (neuron axons)
The gray and white matter are organized. The dorsal columns and
spinothalamic tract contains — while the corticospinal tract contains
ascending sensory axons
descending motor axons
the brain regions (6)
- Cerebrum
- Diencephalon
- Midbrain
- Pons
- Medulla Oblongata
- Cerebellum
Cerebrum (2)
a. Cerebral Cortex
(Cortical Level)
b. Basal Nuclei
Diencephalon (2)
a. Hypothalamus
b. Thalamus
subcortical levels contain
- Diencephalon
- Midbrain
- Pons
- Medulla Oblongata
- Cerebellum
brainstem (3)
The midbrain/mesencephalon, pons
and medulla oblongata
There are two cerebral hemispheres (right and left) which are each
subdivided into lobes (Frontal, Parietal, Occipital and Temporal).
— classification uses numbers to label areas of the cortex
where localized physiological functions reside.
Brodmann
lobe: frontal
specialized areas: (4)
Premotor and Primary
Motor Cortex, Prefrontal
Cortex, Broca’s Area
lobe: parietal
specialized areas: (2)
Primary Sensory Cortex,
Primary Gustatory
Cortex
lobe: temporal
specialized areas: (3)
Primary Auditory Cortex,
Primary Olfactory
Cortex, Wernicke’s Area
lobe: occipital
specialized areas:
Primary Visual Cortex
For each sensory modality, there is a — as well as
primary Area (ex. Primary Olfactory Cortex)
modality-specific association areas (Olfactory Association Cortex)
Association (Secondary) areas receive and analyze signals from
multiple regions of both the sensory and motor cortices and subcortical areas.
In about 95% of people, the —
hemisphere is the
dominant/categorical
hemisphere
left
left hemisphere contains (2)
Wernicke’s Area and
Broca’s Area
Motor areas controlling hands
are also dominant leading to
—handedness in most people
right
The cerebral — is the gray matter
on the outer surface of the cerebrum.
Contains neuron cell bodies.
cortex
The — — allows
for information stored in one
hemisphere available to the
opposite hemisphere.
corpus callosum
Severing the corpus callosum
would prevent
somatic and visual information from the right side of the body from reaching the General Interpretive Area to be used for decision making.
association areas
Receive and analyze signals from multiple regions of
both the sensory and motor cortices and subcortical
areas.
prefrontal association area (cortex) (3)
- Decreased aggressiveness and inappropriate social responses
- Ability to progress towards goals or to carry through sequential thoughts
- Keep track of many pieces of information simultaneously and recall the information as needed (working memory).
Broca’s and Wernicke’s Areas (2)
• In left cerebral hemisphere in almost all right-handed individuals.
• Language Centers involved in production of speech (Broca’s) and
interpretation of spoken and written language (Wernicke’s).
The story of
Phineas Gage
illustrates the
functions of the
Prefrontal
Association Area
Wernicke’s Aphasia
Fluent, Receptive
Broca’s Aphasia
Non-fluent, Expressive
Basal Nuclei
Nuclei that are associated with the cerebrum.
skipped
Basal Nuclei includes (4)
Caudate Nucleus, Putamen, Globus pallidus, Subthalamic
Nucleus
Basal Nuclei is considered an
an accessory motor system as it
functions in close association with the cerebral
cortex (Frontal Lobe) and the Corticospinal
Descending Motor pathway
skipped
Striatum =
Caudate + Putamen
skipped
Lentiform Nucleus =
Corpus Striatum =
Globus Pallidus + Putamen
Lentiform Nucleus + Caudate
Disorders of the basal nuclei cause
movement disorders–
Dyskinesias
Hypokinetic disorders
(Parkinson’s disease) are due to
damage to the direct pathway
Hyperkinetic movement disorders
(Huntington disease) result from
damage to the indirect pathway
The basal nuclei forms two pathways –
direct and
indirect pathways
The direct pathway
increases cortical excitation and promotes movement
The indirect pathway
inhibits cortical activity and inhibits movement
DIENCEPHALON includes (4)
thalamus
hypothalamus
epithalamus
subthalamus
Thalamus:
Sensory relay for information for the cerebral cortex. Motor control pathways also synapse in the thalamus.
Hypothalamus:
Involved in maintaining homeostasis. Impacts
the autonomic, endocrine and limbic systems.
Epithalamus:
Contains the pineal body (secretes Melatonin)
that aids in the regulation of circadian rhythms.
Subthalamus:
Involved in the basal nuceli and control of
voluntary movement. Damage causes hemiballismus
(contralateral flinging movement of one or both extremities).
Limbic System consists of
cortical and diencephalic structures found on the medial aspect of each hemisphere
the limbic system is the neuronal circuitry involved in
emotion (fear, anxiety, sadness, happiness, etc.) and memory
The hypothalamus is an important output of the
limbic system for the expression of —
because its efferent connections coordinate (2)
emotions
autonomic and visceral functions
The — is a central structure in
mediating the fear response; lesions in
this area can prevent —
amygdala
fear
Higher cortical areas integrate sensory
information with learned experience and
produce descending input to the
amygdala, which results in the
sensation of fear
Output from the amygdala to the --- results in activation of the “fight or flight” response by the Sympathetic Nervous System.”
hypothalamus
