Nucleus ganglion
A brain consists of 4
main areas; Cerebrum Cerebellum Diencephalon Brain
stem
Cerebrum
In two hemispheres,
right and left cerebral hemispheres, separated by the longitudinal fisure
Gyrus Sulcus Grey
matter White matter
Corpus callosum Lateral
ventricles
Left hemisphere
mathematical, analytical, verbal functions
Right hemisphere
visual, special, musical functions
Outer area is the
cerebral cortex which is 2 - 4 mm thick
Projection tracts
connect the cortex with the brain stem via the internal capsules. The thalamus
and cortex communicate via the projection tracts (corona radiate). These tracts
are continuous with the internal capsule.
Basal nuclei (ganglia) are collections of nerve cell bodies
low down in the cerebrum, caudate and lenticular
nucleus
Frontal
lobe - pre motor area, precentral gyrus (motor area), primary speech area (Broca`s area, on left side), reasoning, social functioning,
abstract thinking, personality, character, moral sense, wisdom, your ambition
Frontal and parietal lobes separated by central sulcus
Parietal
lobe - postcentral gyrus
(sensory cortex), taste, positional sense, three-dimensional representation of
the world, speech sensory area - understanding of language
Temporal
lobe - auditory area, Wernicke`s area
for language comprehension of language, olfaction, religious experience. The
temporal lobe is partly limbic.
In 95% of people Broca`s and Wernicke`s area are in the left hemisphere
Temporal lobe separated by lateral fissure
Occipital
lobe - vision
Generalised functions
include reasoning, memory, association with other areas, experience
of consciousness
Alcohol inhibits the
cerebral cortex
Cerebellum
Automatic learned
function Balance, maintenance
of posture, fine motor control
Diencephalon
Thalamus,
hypothalamus, pineal gland
Thalamus
Relay station Language Recent memory Emotion
Hypothalamus
Homeostasis Body temperature Hunger Thirst Endocrine homeostasis
Produced melatonin in
relation to a circadian cycle
The pineal gland is
the only unpaired structure in the brain
Consists of the
midbrain, pons and medulla oblongata
Medulla Nuclei
for VIII IX X
XI XII Vasomotor, respiratory and cardiac centres
An interconnected
range of nuclei deep in the cerebrum surrounding the hypothalamus
Parts of the frontal,
parietal and temporal lobes are limbic
Love, anger,
aggression, compulsion, sexual behaviour, drives, sorrow, docility
Emotions may be
completely shut down in emergencies, e.g. Dr. Livingston, soldiers, rape
Limbic system
includes reward and punishment areas
Punishment areas
generate displeasure, fear, terror, pain, punishment
Activation of
punishment areas inhibit activity in reward centres
Has nuclei for hunger, thirst, satiety, rage, sexual drive,
homeostasis of water and temperature
Damage causes anterograde amnesia (loss of memory for recent events)
Stimulation produces
similar effects as the hypothalamus
Seems to control a
wide variety of behaviours
Decides how
emotionally significant a stimulus is, eg. a chair or a tiger
Sexual pleasure,
orgasm
After a head injury a
mother was found to be an impostor
Eye to limbic
disconnection
Ear to limbic is a separate connection
A person thinking they are dead
A complete dissociation between sensory input and a limbic
generated emotional response
A relatively common symptom, "the world doesn't really
exist"
In autism, emotional reactions may be generated to
non-significant inputs eg. staring
at a grain of dust
There may be no reaction to another input such as another
persons eyes
So in autism there is a breach between input and emotional
reaction which appears arbitrary
Hysterical symptoms
reflect an individuals understanding of a disorder
A paralysis may
present in the presence of a nervous system
Prefrontal cortex
prepares the motor function before activation of the motor cortex
In hysteria the
prefrontal lights up but parts of the limbic system lobe also light up to
inhibit the function of the motor cortex
Disorders of cognition and affect
Delusions, hallucinations
Lack of volition, poverty of thought and emotion, loss of
insight
Increased dopamine activity in limbic and other areas
Amphetamines work through dopaminergic
mechanisms
Antipsychotic drugs block postsynaptic dopamine receptors
Increasing dopamine can aggravate schizophrenia
Genetics
Schizophrenia Affective psychosis
General pop 1% 3%
Siblings 9% 13%
One parent 13% 15%
Both parents 40%
MZ 40% 70%
Environmental stress may trigger a genetic predisposition
Confusion between internally generated thought and external
reality
Thoughts are not corrected in the light of reality
Unipolar and bipolar
Depression hypomania and mania
Lack of Noradrenaline and 5-HT
Reduced monoamine receptor sensitivity
Polygenetic interaction with environment
MZ concordance 70%
Affected parents gives a child
risk of 10 15%
Psychological
Selective serotonin reuptake inhibitors
Tricyclic antidepressants prevent reuptake
of nor adrenaline and serotonin
Monoamine oxidase inhibitors
Lithium may work by inhibiting catecholamine breakdown
GABA
Acute anxiety attacks
Cerebral circulation and breathing
Phobias
Cervical 1-8 (only 7 bones of course)
Thoracic 1 - 12
Sacral 1 5
Coccygear 1
An area of skin supplied by the axons of a single spinal
nerve, there is only a little overlap.
Start from the front and work back
I Olfactory
II Optic
III Oculomotor Pupils and some extrinsic
eye muscles
IV Trochlear
V Trigeminal Mastication
muscles and other facial muscles
VI Abducens Lateral
rectus of eyes
VII Facial Taste
receptors, glands of nasal and oral cavity, lacrimal
glands,
facial muscles
VIII Auditory
(vestibulocochlear) Hearing
and balance
IX Glossopharyngeal Taste from back of tongue,
mucous membranes back of mouth and pharynx, chemo and baroreceptors in carotid
artery and body
X Vagus External
ear, muscles of palate, heart, lungs, abdominal viscera
XI Spinal
accessory Trapezius and sternomastoid
XII Hypoglossal Extrinsic
and intrinsic tongue muscles