1. Physl important notes CNS
Mid2

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3. CEREBELLAR FUNCTIONS Maintenance of balance Enhancement of muscle tone
Coordination and planning of skilled voluntary muscle activity
Sequences the motor activities
Monitors and makes corrective adjustments in the activities initiated by other parts of the brain
Compares the actual motor movements with the intended movements and makes corrective changes.
The cerebellum does not initiate movement, but it contributes to coordination, precision, and accurate timing.
Functional imaging studies have shown cerebellar activation in relation to language, attention, and other cognitive functions.
Correlation studies have shown interactions between the cerebellum and non-motor areas of the cerebral cortex; and a variety of non-motor symptoms have been recognized in people with damage that appears to be confined to the cerebellum
functional MRI suggest that more than half of the cerebellar cortex is interconnected with association zones of the cerebral cortex.

4. Functional Organization of the Cerebellum
Functionally cerebellum can be divided into . . .
The Floculonodular lobe – Vestibulocerebellum
participates mainly in balance and spatial orientation
Intermediate zone - Spinocerebellum
Enhances muscle tone and coordinates skilled voluntary movements
Lateral zone - Cerebrocerebellum
controls sequencing movements of the muscle. Important for timing and coordination of movement.
Plays role in planning and initiating voluntary activity
Stores procedural memories

6. Neuronal Organization of the Cerebellar Cortex
Cerebellar Cortex is organized in three layers
Granular layer
It is thick inner most layer and contains Granule cells, Golgi type II cells and other interneurons
Purkinje cell layer
It is middle layer
Contains Purkinje cells
Output is always Inhibitory
Molecular layer
It is outermost layer
Contains stellate and basket cells, dendrites of Purkinje and Golgi type II cells and parallel fibers (axons of granule cells)

7. Circuit of the Cerebellum
Output of the Cerebellar cortex
Purkinje cells are the only output of the cerebellar cortex which goes to Deep cerebellar Nuclei
Output of the Purkinje cells is always inhibitory. the neurotransmitter is γ- aminobutyrie acid (GABA)
Output of the cerebellum regulates rate, range and direction of movement.
Input to the Cerebellar cortex
From Mossy fibers originating from brain stem and spinal cord and
From Climbing fibers originating from Inferior Olivary Nucleus in Medulla

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9. Functions of Brainstem
The nerve connections of the motor and sensory systems between the main part of the brain to the rest of the body pass through the brainstem.
Has role in Regulation of muscle reflexes involved with equilibrium and posture
Control of many stereotyped movements of the body such as suckling, yawn and stretch, cry and laugh etc.
Control of eye movements

10. Function of brainstem
Origin of majority (10) of cranial nerves is in Brainstem
Cranial nerves arising from brain stem
Mid-brain – III, IV
Pons – V, VI, VII, VIII
Medulla – IX, X, XI, XII
The brainstem provides the main motor and sensory innervation to the face and neck via the cranial nerves.
Note only Cranial nerves I (Olfactory) & II (Optic) do not have any origin from Brainstem

11. Function of brainstem
It also regulates the central nervous system, and is Important in . . .
Arousal and Activation of cortex,
Maintaining Consciousness and
Regulating the Sleep cycle.
Centers for Cardiovascular, Respiratory, and Digestive control are located in Brainstem
Thus basic functions controlled from Brainstem Include …
Heart Rate & Blood Pressure,
Breathing including Cough & Sneezing
Sleep, wakefulness, Consciousness
Digestive activities including swallowing, vomiting
Posture & Equilibrium

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13. PINEAL GLAND Pineal gland secret melatonin that have rule in timing
central role in control of diurnal rhythms while In Humans, the pineal and melatonin do play a limited role.
Recent investigations have demonstrated a role for melatonin in sleep, tumor reduction and aging.
And damage to it cause precocious puberty

14. THALAMUS Relay nuclei Association nuclei Nonspecific nuclei.
In general, there are three basic types of thalamic nuclei:
Relay nuclei
Association nuclei
Nonspecific nuclei.
Relay nuclei receive very well defined inputs and project this signal to functionally distinct areas of the cerebral cortex.
The association nuclei receive most of their input from the cerebral cortex and project back to the cerebral cortex in the association areas where they appear to regulate activity.
The nonspecific nuclei include many of the intralaminar and midline thalamic nuclei that project quite broadly through the cerebral cortex, may be involved in general functions such as alerting.
damage in thalamus cause coma

15. THALAMUS – Clinical Significance
Cerebrovascular accident (stroke) can lead to the Thalamic Syndrome which involves a one-sided burning or aching sensation often accompanied by mood swings.
Damage to the thalamus can result in coma.
Fatal Familial Insomnia is a hereditary prion disease in which degeneration of the thalamus occurs, causing the patient to gradually lose his ability to sleep and progressing to a state of total insomnia, which invariably leads to death.
Korsakoff's Syndrome occurs from damage to the medial thalamus & mammillary body due to Thiamine deficiency.

16. Hypothalamus
Have set point < diced what is the normal temperature any change in it will change the firing > autonomic nerve system < expose to all everything
Biological clock
Hyperpaxia < set point not change
Fever < set point change

17. FUNCTIONS OF HYPOTHALAMUS
Biological Functions
Controls body temperature
Controls thirst and urine output
Controls food intake Hunger and Satiety center
Participates in the sleep – wake cycle.
Contains the “biological clock” that regulates certain body functions that vary with time.

18. FUNCTIONS OF HYPOTHALAMUS
Endocrine Functions
Controls anterior pituitary hormone secretion
Produces posterior pituitary hormones ADH and oxytocin
Controls uterine contraction and milk ejection
Autonomic Nervous System Function
Serves as major ANS coordinating center

19. FUNCTIONS OF HYPOTHALAMUS
Emotion & Behavior
Plays role in emotional responses and behavioral pattern including rage, fear pleasure etc.
Reward & Punishment center
Role in sexual behavior and reproduction

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21. Limbic system Limbic system is motivation
Emotion > external or internal for benefit or harmful

22. Amygdala
Perform a primary role in the processing of memory, decision-making, and emotional reactions.
There are functional differences between the right and left amygdala and also between Male and Female Amygdala.
primary role in the formation and storage of memories associated with emotional events. E.g. Fear Conditioning.
Also involved in memory consolidation - Formation of Long Term Memory.
The amygdala plays a pivotal role in triggering a state of fear.
Amygdala is associated with Anxiety and panic attacks.
Studies link amygdalae to the emotional reactions of PTSD patients.
Social behavior
Stimulating the amygdala appears to increase both sexual and aggressive behavior.

23. Hippocampus
Has important role in formation of new memory about experienced events (Episodic Memory).
Bilateral hippocampal damage results mainly in Anterograde amnesia and often also retrograde amnesia
Believed to have role in spatial memory and navigation.

24. Behavior and its Control
Reward and punishment caused by the Limbic system are important for behavior.
Several limbic structures are concerned with sensory experience – is it pleasant or unpleasant?
Reward center located in
the lateral and ventromedial hypothalamus,
thalamus certain areas,
Amygdala
Punishment center located in
Hypothalamus
Thalamus
Amygdala and
Hippocampus

25. Neurotransmitters associated with limbic system
Norepinephrine
Dopamine
Serotonin
Many drugs increase dopamine in pleasure pathways in limbic system, therefore, cause intense sensation of pleasure e.g. cocaine blocks re-uptake of dopamine at synapses
Amphetamine, used in depression, causes increased release of dopamine from dopamine secreting neurons

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27. SPEECH Speech Centers: Broca’s area Wernicke’s area
motor speech area
Wernicke’s area
sensory speech area. Analyzing hear or written word
Understanding happen here and right response diced here.
Both connected by Arcuate Fasciculus.
Both areas also interact with association areas.
Association area remember the sequence of muscle contraction to pronounce the word

28. Broca’s area
It is located in left frontal lobe just front of the base of the Primary motor cortex.
It is for Articulation – Word formation
Broca’s area contains motor memories — in particular, memories of the sequences of muscular movements that are needed to articulate words.
Broca's area excites Motor area which controls the muscles necessary for articulation.

29. It is concerned with language comprehension (understanding).
Wernicke’s area
It is located in the left cortex at Superior gyrus of Temporal lobe at the juncture of parietal, temporal and occipital lobes.
It is concerned with language comprehension (understanding).
It plays important role in understanding of both spoken and written messages.
Wernicke’s area receives input from visual cortex in the occipital lobe and also auditory cortex in temporal lobe.

30. Not much important but remember is association area
Arcuate Fasciculus
Is a axon pathway between Wernicke’s area and Broca’s area
Higher-Order Association Cortex
Wernicke’s area has connections with various association areas in …
Left Frontal
Left Temporal
Left Parietal
Are involved with mediating between concepts and language

31. Lateralization:
Speech area are located in one sphere (on one side), usually the dominant hemisphere.
Left hemisphere is therefore called DOMINANT SPHERE.
90% of left handed people have left cerebral hemisphere as dominant also.
Right hemisphere for expression and narrative selection.

32. SPEECH DISORDERS
Thus Damage to the specific regions of brain can result in selective disturbance of speech.
Damage to Brocas’s area (motor aphasia)
Damage to Wernicke’s area (sensory aphasia)
Damage to ARCUATE FACICULUS (Conduction aphasia)
Speech Disorders of Articulation (Dysarthria)

33. SPEECH DISORDERS
It results in failure of word formation, but patient can understand the spoken and written words.
Broca’s aphasia is much more than a deficit in pronouncing words. In general, three major speech deficits are produced by lesions in and around Broca’s area: agrammatism, anomia, and articulation difficulties.

34. SPEECH DISORDERS Damage to Wernicke’s area: (sensory aphasia)
These patients can not understand the words they hear or see.
what they say is full of jargon and neologisms that make little sense.

35. SPEECH DISORDERS Anomic aphasia (anomia):
is a type of aphasia characterized by problems recalling words, names, and numbers.
Conduction Aphasia:
Patients may be able to understand speech as well as produce meaningful speech, but have difficulty repeating a spoken sentence.

36. SPEECH DISORDERS
Dyarthria in parkinson