Cortical White Matter, Aging, Diencephalon
Objectives
• Identify all of the subcortical fasciculi and tracts
• Define projection, commissural, and association fibers
• For each fasciculus or tract, identify the type of fibers it consists of and the regions it connects.
• Compare and contrast the changes that occur to the different regions of the cortex
throughout a lifespan.
• Describe the Anatomy, Blood supply and Functions of Diencephalon structures:
• Thalamus
• Hypothalamus & Pituitary Gland
• Epithalamus & Pineal Gland
• Subthalamus
White MatterProjection Commissural Association
Projection Fibers
• Capsules – Internal, External, Extreme
• Subcortical structures that communicate with cerebral cortex
• Thalamus
• Basal Ganglia
• Brainstem
• Spinal Cord
• Examples:
• Thalamocortical, Corticospinal, Corticobrainstem
Internal capsule
Internal capsule
Your patient has suffered a stroke to their right MCA, resulting in damage to the internal
capsule. Your patient’s body will likely have sensory deficits on the _____ and motor
deficits on the ______.
A.Right, right
B.Left, left
C.Right, left
D.Left, right
Right,
right
Left, le
ft
Right,
left
Left, ri
ght
25% 25%25%25%
:30
Which specific arteries supply the internal capsule in the patient from the previous
question?
A.Thalamic branches
B.Striate arteries
C.M1 segment of MCA
Thala
mic bran
ches
Striate
arter
ies
M1 segm
ent of M
CA
33% 33%33%
:30
Commissural Fibers
• Connect homologous structures between hemispheres
• Corpus callosum
• Anterior commissure
• Posterior commissure
Association Fibers
• Short
• Long
• Cingulum
• Superior Longitudinal Fasciculus
• Inferior Longitudinal Fasciculus
• Uncinate Fasciculus
Table 17-2 LE
Central Nervous System Aging
• Focus on cerebrum
• Focus on anatomical changes
• Neurological changes are discussed in other courses
• Synapse density (volume)
• Myelination
Cortical trends with age• Infancy through
childhood
• Gray
• Visual and Auditory
• Motor
• Association
• White
Cortical trends with age
• Puberty through adolescence
• Gray
• Visual and Auditory
• Motor
• Association
Cortical trends with age
• Middle-age (35) through old age
• Gray
• Visual and Auditory
• Motor
• Association
During what 2 periods would the pre-frontal cortex have
the most synapses? (multiple answer)
A.0-2 years
B.2-12 years
C.12-16 years
D.16-25 years
E.25-35 years
0-2 year
s
2-12 years
12-16 yea
rs
16-25 yea
rs
25-35 yea
rs
20% 20% 20%20%20%
:30
Which of the following is TRUE concerning a critical
period?
A.Synaptic density is low during a critical period.
B.Exposure to the stimulus is necessary to develop normal function.
C.Critical periods typically occur later in life.
Synaptic d
ensity i
s low durin
...
Exposu
re to
the s
timulus i
s ...
Critica
l peri
ods typ
ically
occu...
33% 33%33%
:30
Objectives
• Identify all of the subcortical fasciculi and tracts
• Define projection, commissural, and association fibers
• For each fasciculus or tract, identify the type of fibers it consists of and the regions it connects.
• Compare and contrast the changes that occur to the different regions of the cortex
throughout a lifespan.
• Describe the Anatomy, Blood supply and Functions of Diencephalon structures:
• Thalamus
• Hypothalamus & Pituitary Gland
• Epithalamus & Pineal Gland
• Subthalamus
Thalamus
Thalamus
• 3 types of nuclei (by function)
• Relay nuclei – relays information not involved in a loop
• Example: sensory information from face VPM somatosensory
cortex
• Association nuclei – nuclei involved in executive functioning loops
• Example: mediodorsal nucleus is involved in the limbic loop (pg 421
LE)
• Nonspecific nuclei – receive info from several regions, send info
to entire cortex, involved with alertness and arousal
• Example: intralaminar nuclei
Thalamus Blood Supply
Hypothalamus
Hypothalamus
• 3 zones:
• Periventricular zone
oxytocin - intimacy
vasopressin - water retention
• Medial zone (3 regions):
• Supraoptic region
satiety center – body composition
Suprachiasmatic n. - circadian rhythm
• Tuberal region
satiety center – body composition
behavioral center – aggression, rage
• Mammillary region
converts short term memory to long term memory (by connections with hippocampus through
fornix)
• Lateral zone
involved with satiety
Hypothalamus and Pituitary
It’s Complicated!!
• Do NOT need to know
Full list of functions of hypothalamus and pituitary
• Growth
• Blood pressure
• Some aspects of pregnancy and childbirth including stimulation of uterine contractions during childbirth
• Breast milk production
• Sex organ functions in both males and females
• Thyroid gland function
• The conversion of food into energy (metabolism)
• Water and osmolarity regulation in the body
• Water balance via the control of reabsorption of water by the kidneys
• Temperature regulation
• Pain relief
Source: Wikipedia
Hypothalamus Blood Supply
Same as Thalamus!
Epithalamus• Pineal Gland
• Releases melatonin
• Collects mineral deposits
• Calcium, flouride, phosphorous
• Blood supply – no BBB!
• Posterior Choroidal A.
Subthalamus
• Involved in motor control
• Associated with the Basal Ganglia (striatum, lentiform, PPN, substantia nigra)
Conclusion• Literature Review Outlines
• Send your outline to both teammates
• Read two team members’ outlines for Monday
• Plan for audience
• Plan for genre
• Plan for semantic structure/schema of entire piece
• Scaffold reader - expect what they know/do not know and account for every piece of information that they will need
• "Novice [writers]… were concerned about what to write next and limited their planning to thinking about the topic or assignment and the last sentence they had written. Thus they failed to develop an adequate goal structure for the total work to guide their sentence planning" (Doyle, 1983, p. 168).
Primary Content Course ObjectivesNeuroembryology
Normal development of the nervous systemDevelopment of the nervous system in the presence of teratogens and trauma
Summarize the principles and the time sequence for neurodevelopment.
Differentiate the sequelae of impaired development during various critical periods of sensorimotor systems.
Integrate knowledge of maturation of the nervous system with knowledge about automatic and volitional movements.
Summarize genetic and epigenetic influences of CNS development.
NeuroanatomyClassification of neuronsAscending pathways, descending pathways, and interconnectionsComposition and functions of regions or systems (e.g. cerebrum, brainstem, cerebellum, cranial nerves, spinal cord)Blood supply of cerebrum, brainstem, cerebellum and spinal cordVentricular system / cerebrospinal fluidMeninges and meningeal spacesPlasticity and somatotopic organization
Describe the gross anatomy of the cerebrum, brainstem, cerebellum, and spinal cord.
Correlate the role of major ascending and descending systems to clinical signs and symptoms.
Describe the role of the extrapyramidal system (e.g. cerebellum, basal ganglia) with regard to movements and motivation.
Explain the function of the meningeal layers. Compare and contrast cerebral and systemic
circulation. Correlate results from imaging techniques to the
structure and function of the nervous system. Describe the effects of aging on the nervous
system.Neurological Function
Cognition – memory, language, arousal and attention, reasoning, problem-solving, and categorizationSensory systems – neuroanatomy and physiology of sensory systems (vision, auditory, olfaction, gustatory)Affective control – limbic system
Describe processes involved with higher cognitive function.
Describe the theories of memory formation. Explain the arousal and attention mechanisms of
the CNS. Describe the gross anatomy of the sensory systems
(vision, auditory, olfaction, gustatory). Describe clinical influences of emotion.
Organization of the Course
Spinal Cord
Brainstem/ Cerebellum
Sensory Pathways
Cerebrum
Motor Pathways
Presentations!