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!