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Okto the brain! Gross Anatomy of the brainMany
ways to organize the CNS
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Heres a good one!
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BRAINSTEM/ HINDBRAIN
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Bainstem (Medulla) critical functions

• Ascending and Descending Fiber Tracts
• All parasympathetic tone
• HR
• Temp
• BP
• Etc

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BrainstemThe Reticular activating system
Many tiny brain nuclei collectively involved in
modulation of arousal The reticular formation
is a comprehensive network of nerves that is
found in the central area of the brainstem. The
functions of the formation involve many of the
essential functions of the body, such as the
ability to obtain recuperative sleep, sexual
arousal, and the ability to focus on tasks
without being easily distracted. All in all,
reticular formation function is believed by some
researchers to be involved with at least 25
behaviors and functions that are considered
essential for the health and continued existence
of each individual.
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The RAS- Locus Coereleus
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RAS- the Raphe Nucleus
Raphe Nucleus High in Serotonin
(5HT) Modulation of mood, sleep states,
dreaming
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BRAINSTEM-Pons and Cerebellum
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Behavioral Functions of the Cerebellum

• Direction
• Amplitude
• Force
• Timing
• Posture
• Motor learning/speech

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Midbrain

• Major structures of interest
• Substantia nigra- projects to striatum (high
  Dopamine (DA) content)
• Peri-aqueductal grey- modulation of pain
• Ventral tegmental area- projects to nucleus
  accumbens ( high in DA content)

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Midbrain-
The ventral tegmental area (VTA)
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VTA to Nucleus Accumbens The Mesolimbic Dopamine
pathway
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Diencephalon

• Thalamus, Hypothalamus and Pituitary gland

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The Thalamus
Relays sensory information to the cortex
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The Hypothalamus -rostral and slightly inferior
to the thalamus. - Involved in modulation of the
4 Fs
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Forebrain

• (Telencephalon)
• Cortex
• Basal ganglia
• Limbic System

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Basal Ganglia

• Neostriatum
• Caudate nucleus and putamen
• Globus Pallidus
• Substantia nigra

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Nigro-striatal system
The substantia nigra sends DA axons to the
striatum
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Nigro-striatal CCT Functions

• Parkinsons

Slowness of movement (bradykinesia) Stiffness
(rigidity) Tremor Loss of balance (postural
instability) Speech and facial expression
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Difficulty in initiating Movement
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GLOBUS PALLIDUS
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Striatal-Pallidal CCT functions?

• Huntingtons
• Tourettes -

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Tourettes

• Tourette syndrome (TS) is a neurological disorder
  characterized by repetitive, stereotyped,
  involuntary movements and vocalizations called
  tics. The early symptoms of TS are almost always
  noticed first in childhood, with the average
  onset between the ages of 7 and 10 years. TS
  occurs in people from all ethnic groups males
  are affected about three to four times more often
  than females. It is estimated that 200,000
  Americans have the most severe form of TS, and as
  many as one in 100 exhibit milder and less
  complex symptoms such as chronic motor or vocal
  tics or transient tics of childhood. Although TS
  can be a chronic condition with symptoms lasting
  a lifetime, most people with the condition
  experience their worst symptoms in their early
  teens, with improvement occurring in the late
  teens and continuing into adulthood.

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• Tics are classified as either simple or complex.
  Simple motor tics are sudden, brief, repetitive
  movements that involve a limited number of muscle
  groups. Some of the more common simple tics
  include eye blinking and other vision
  irregularities, facial grimacing, shoulder
  shrugging, and head or shoulder jerking. Simple
  vocalizations might include repetitive
  throat-clearing, sniffing, or grunting sounds.
  Complex tics are distinct, coordinated patterns
  of movements involving several muscle groups.
  Complex motor tics might include facial grimacing
  combined with a head twist and a shoulder shrug.
  Other complex motor tics may actually appear
  purposeful, including sniffing or touching
  objects, hopping, jumping, bending, or twisting.
  Simple vocal tics may include throat-clearing,
  sniffing/snorting, grunting, or barking. More
  complex vocal tics include words or phrases.
  Perhaps the most dramatic and disabling tics
  include motor movements that result in self-harm
  such as punching oneself in the face or vocal
  tics including coprolalia (uttering swear words)
  or echolalia (repeating the words or phrases of
  others). Most patients experience peak tic
  severity before the mid-teen years with
  improvement for the majority of patients in the
  late teen years and early adulthood.
  Approximately 10 percent of those affected have a
  progressive or disabling course that lasts into
  adulthood.

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• Tics are involuntary. They are brief, repetitive
  movements, which are either motor such as
  blinking or head jerking, or vocal such as throat
  clearing.

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LIMBIC SYSTEM

• Basal forebrain
• Affective responses
• Impulsivelow consciousness
• Many structures
• Amygdala
• Hippocampus
• Septum/ nucleus accumbens- will be discussed later

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Amygdala general emotional significance of
environmental stimuli

• evaluate the significance of stimuli and generate
  emotional responses
• generate hormonal secretions and autonomic
  reactions that accompany strong emotions

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CEREBRAL CORTEX

• Wrinkled
• Thin
• Layered
• Interconnected
• Plastic

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Major regions of CTX
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Corpus collosum
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Hemispheres
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Almost all of Right handers and about 70 of left
handers show these kinds of functional asymmetries
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LOBES
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OCCIPITAL LOBE
The primary Visual Cortex -functional
blindness -Visual agnosias
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TEMPORAL LOBES
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Temporal lobe damage may result in any number of
problems including any of these syndromes

• Functional deafness
• -Anomias
• -Aprosodia
• -Werniches syndrome

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Parietal Lobes
Primary somatosensory cortex
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The sensory homunculus and somatotopic
organization
Primary somatosensory cortex damage may
produce -somatasagnosias -neglect -anosagnosia
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FRONTAL LOBES
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1st -Frontal lobes and speech
Brocas aphasia Werniches aphasia (temporal lobe
to frontal lobe circuits)
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What about the rest of the frontal lobe?-Phineas
Gage
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rod
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Brain-Based Theory of Emotions

• Frontal lobes
• influence peoples conscious emotional feelings
  and ability to act in planned ways based on
  feelings (e.g., effects of prefrontal lobotomy)
• Some scientists contend that the prefrontal
  cortex normally acts as a brake that can suppress
  urges or impulses by communicating with other
  brain areas that mediate fear and aggression,
  such as the amygdala.

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General frontal Lobe functions
Awareness Judgment , planning and
anticipation Personality Conscious
emotions Organization and mental
flexibility Attention and concentration Initiati
on and inhibition of behavior