Curs 14. Sistemul Nervos Central
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Transcript of Curs 14. Sistemul Nervos Central
Human nervous system
Brain Fun Facts• SIZE OF THE HUMAN BRAIN
The average human brain weighs about 3 pounds (1300-1400 g). • At birth, the human brain weighs less than a pound (0.78-0.88
pounds or 350-400 g). As a child grows, the number of cell remains relatively stable, but the cells grow in size and the number of connections increases. The human brain reaches its full size at about 6 years of age.
• COMPOSITION OF THE BRAIN
The brain consists of gray matter (40%) and white matter (60%) contained within the skull. Brain cells include neurons and glial cells.
• NOURISHMENT OF THE BRAIN Although the brain is only 2% of the body's weight, it uses 20% of the oxygen supply and gets 20% of the blood flow. Blood vessels (arteries, capillaries, and veins) supply the brain with oxygen and nourishment, and take away wastes. • If brain cells do not get oxygen for 3 to 5 minutes, they begin
to die.
CENTRAL NERVOUS SYSTEM
(CNS)
PERIPHERAL NERVOUS SYSTEM
(PNS)
NERVOUS SYSTEM
SOMATIC NERVOUS SYSTEM
(voluntary)
AUTONOMIC NERVOUS SYSTEM
(involuntary)SENSORY AND MOTOR NEURONES TO / FROM
SKELETAL MUSCLE
MOTOR NEURONES TO INTERNAL ORGANS
SYMPATHETIC NERVOUS SYSTEM
(involuntary)
PARASYMPATHETIC NERVOUS SYSTEM
(involuntary)
CONTROLS ORGANS IN TIMES OR STRESS
CONTROLS ORGANS WHEN BODY IS AT REST
The Organisation of the Nervous System
BRAIN AND SPINAL CORD
PERIPHERAL NS
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The Organisation of the Nervous System
The spinal cord (SC) runs through the neural arches of
the vertebrae and in its centre is a canal containing
cerebrospinal fluid.
The brain is a highly specialised area of the SC.
See later
The spinal cord
The brain and spinal cord are surrounded by 3 membranes
called the meninges
The meninges secrete cerebrospinal fluid. The fluid
supplies oxygen and nutrients and acts as a shock absorber
The meninges
Butterfly shaped area of unmyelinated neurones (grey)
Myelinated neurones (white)
Canal
Lobes may vary from person to Simpson
The Brain’s 4 Major Regions• Cerebrum, the diencephalon, the
brainstem, and the cerebellum. • The cerebrum is divided into two halves,
called the left and right cerebral hemispheres.
• Each hemisphere is subdivided into five functional areas called lobes.
• Outer surface of an adult brain exhibits folds called gyri (gyrus) and shallow depressions between those folds called sulci (sulcus).
• The brain is associated with 12 pairs of cranial nerves.
Dezvoltarea encefalului
• Prosencephalon (forebrain)• Telencephalon: cerebrum• Diencephalon:epithalamus• thalamus,hypothalamus
• Mesencephalon (midbrain)• Mesencephalon: cerebral peduncles,
colliculi • Rhombencephalon (hindbrain)
• Metencephalon: pons, cerebellum • Myelencephalon: medulla oblongata
Organizarea țesutului nervos
• Gray matter:• motor neuron and interneuron cell bodies, dendrites, axon terminals• unmyelinated axons.
• White matter:• composed primarily of myelinated axons. • lies deep to the gray matter of the cortex. • Within the masses of white matter:
• discrete innermost clusters of gray matter called cerebral nuclei
(or basal nuclei).
• are oval, spherical, or sometimes irregularly shaped clusters of
neuron cell bodies. • During brain development, an outer, superficial region of gray matter
forms from migrating peripheral neurons. • External sheets of gray matter, called the cortex, cover the surface of
most of the adult brain (the cerebrum and the cerebellum).
Support and Protection of the Brain
• The brain is protected and isolated by multiple structures:• bony cranium • Meninges:
• Protective connective tissue membranes• surround and partition portions of the brain.
• Cerebrospinal fluid (CSF)• acts as a cushioning fluid.
• Blood-brain barrier:• prevents entry of harmful materials from the bloodstream.
• Three dense regular connective tissue layers:• separate the soft tissue of the brain from the bones of the cranium.• Enclose and protect blood vessels that supply the brain.• Contain and circulate cerebrospinal fluid.• Parts of the cranial meninges form some of the veins that drain
blood from the brain. • From superficial to deep, the cranial meninges are the dura mater, the
arachnoid, and the pia mater
Dura Mater• Tough membrane composed of two fibrous layers. • Strongest of the meninges. • Dura mater is composed of two layers.
• periosteal layer, the more superficial layer, attaches to the periosteum of the cranial bones
• meningeal layer lies deep to the periosteal layer • The meningeal layer is usually fused to the periosteal layer
• Exception: in specific areas where the two layers separate to form large, blood-filled spaces called dural venous sinuses.
Arachnoid • Also called the arachnoid mater or the arachnoid membrane. • Lies immediately internal to the dura mater.• Partially composed of a delicate web of collagen and elastic
fibers, termed the arachnoid trabeculae.• Between the arachnoid and the overlying dura mater is the
subdural space.• Immediately deep to the arachnoid is the subarachnoid space.
• The innermost of the cranial meninges. • Thin layer of delicate connective tissue that tightly
adheres to the brain and follows every contour of the brain surface.
Pia Mater
Cranial Dural Septa
• The meningeal layer of the dura mater extends as flat partitions (septa) deep into the cranial cavity;• at four locations• called cranial dural septa.
• Membranous partitions separate specific parts of the brain and provide additional stabilization and support to the entire brain.• falx cerebri• tentorium cerebelli • falx cerebelli• diaphragma sellae
The Spinal Cord
• The spinal cord is the major nerve pathway to and from the brain.
• It is protected by the vertebral column and the meninges.
• 31 pairs of spinal nerves branch out from the spinal cord, connecting the brain to the body.
• Certain kinds of information, such as reflexes, are processed directly in the spinal cord.
• A reflex is a quick, automatic response to a stimulus. It allows the body to respond to danger immediately.
Brain Ventricles
• Cavities or expansions within the brain that are derived from the lumen (opening) of the embryonic neural tube.
• Continuous with one another as well as with the central canal of the spinal cord.
• Four ventricles in the brain. • two lateral ventricles are in the cerebrum, separated by a thin
medial partition called the septum pellucidum • within the diencephalon is a smaller ventricle called the third
ventricle • each lateral ventricle communicates with the third ventricle
through an opening called the interventricular foramen
• The fourth ventricle is located within the pons and cerebellum.
Cerebrospinal Fluid
• A clear, colorless liquid that circulates in the ventricles and subarachnoid space.
• Bathes the exposed surfaces of the central nervous system and completely surrounds it.
• Performs several important functions. • buoyancy • protection • environmental stability
• Formed by the choroid plexus in each ventricle. • Produced by secretion of a fluid from the ependymal
cells that originate from the blood plasma. • Is similar to blood plasma.
Cerebrum
• Account for 83% of brain mass• Fissures – deep grooves – separate major regions of the brain
• Transverse fissure – separates cerebrum and cerebellum• Longitudinal fissure – separates cerebral hemispheres
• Sulci – grooves on the surface of the cerebral hemispheres • Gyri – twisted ridges between sulci • Prominent gyri and sulci are similar in all people• Deeper sulci divide cerebrum into lobes• Lobes are named for the skull bones overlying them• Central sulcus separates frontal and parietal lobes
• Bordered by two gyri• Precentral gyrus • Postcentral gyrus
• Parieto-occipital sulcus • Separates the occipital from the parietal lobe
• Lateral sulcus • Separates temporal lobe from parietal and frontal lobes
• Insula – deep within the lateral sulcus
Cerebral cortex • Composed of gray matter
• Neuronal cell bodies, dendrites, and short axons• Folds in cortex – triples its size • Approximately 40% of brain’s mass• Brodmann areas – 52 structurally distinct areas
Cerebrum: functional areas
• Home of our conscious mind • Enables us to:
• Be aware of ourselves and our sensations• Initiate and control voluntary movements• Communicate, remember, and understand
• Three kinds of functional areas• Motor areas• Sensory areas• Association areas
Motor areas
• Controls motor functions• Primary motor cortex (somatic motor area)• Located in precentral gyrus (Brodmann area 4)
• Pyramidal cells – large neurons of primary motor cortex• Corticospinal tracts descend through brainstem and spinal cord
• Axons signal motor neurons to control skilled movements • Contralateral – pyramidal axons cross over to opposite
side of the brain• Specific pyramidal cells control specific areas of the body• Face and hand muscles – controlled by many pyramidal cells• Motor homunculus – body map of the motor cortex
Sensory cortex
• Cortical areas involved in conscious awareness of sensation
• Located in parietal, temporal, and occipital lobes
• Distinct area for each of the major senses
Sensory Areas – Visual Areas
• Primary visual cortex • Corresponds to Brodmann area 17• Located deep within the calcarine sulcus
• On the posterior and medial part of the occipital lobe• Receives visual information that originates on the retina• First of a series of areas that interprets visual input
• Visual association area• Surrounds the primary visual area• Coincides with Brodmann areas 18 and 19• Continues the processing of visual information• Complex visual processing extends into:
• Temporal and parietal lobes
Sensory Areas – Auditory Areas
• Primary auditory cortex• Function – conscious awareness of sound• Location – superior edge of the temporal lobe• Corresponds to Brodmann areas 41 and 42
• Auditory association area• Lies posterior to the primary auditory cortex• Located within Brodmann area 22• Permits evaluation of different sounds• Lies in the center of Wernicke’s area • Involved in recognizing and understanding
speech
Sensory Areas – Gustatory Cortex
• Involved in the conscious awareness of taste stimuli
• Corresponds to Brodmann area 43• Located on the “roof” of the lateral sulcus
Sensory Areas – Vestibular Cortex
• Located in the posterior part of the insula• Deep to the lateral sulcus
Sensory Areas – Olfactory Cortex• Lies on the medial aspect of the cerebrum• Located in a region called the piriform lobe• Olfactory nerves transmit impulses to the olfactory cortex
• Provides conscious awareness of smells• Part of the rhinencephalon – “nose brain”• Includes – the piriform lobe, olfactory tract, and olfactory
bulb• Connects the brain to the limbic system
• Explains why smells trigger emotions• Orbitofrontal cortex
• Involved with consciously identifying and recalling specific smells
Association areas
• Make associations between different types of sensory information
• Associate new sensory input with memories of past experiences
• New name for association areas – higher order processing areas
Association Areas – Prefrontal Cortex
• Large region of the frontal lobe anterior to motor areas• Performs cognitive functions
• All aspects of thinking and perceiving • Remembering and recalling information • Also related to mood• Has close links to the limbic part of the forebrain
• Functional neuroimaging techniques • Reveal functions of specific parts of the prefrontal cortex
• Anterior pole of frontal cortex • Active in solving the most complex problems
• The farther rostrally one goes in the CNS, the more complex the neural functions
• Functional areas located on the medial side of the frontal lobe• Regions anterior to the corpus callosum
• Involved in complex personal and social interactions• Regions superior to the corpus callosum
• Involved in “mentalization
Association Areas – General Interpretation Area
• Function is currently under investigation• Located at the interface of:
• The visual, auditory, and somatosensory association areas
• Newer studies show most of this region is involved in the visual processing of spatial relationships
Association Areas – Language Area• Surrounds the lateral sulcus in the left cerebral
hemisphere• Five parts have been identified
• Broca’s area – speech production• Wernicke’s area – speech comprehension• Lateral prefrontal cortex – conceptual analysis of
spoken words• Five parts have been identified (continued)
• Most of the lateral and inferior temporal lobe• Coordination of auditory and visual aspects of
language• Parts of the insula
• Initiation of word articulation • Recognition of rhymes and sound sequences
Association Areas – Insula
• Functions of its cortex – not well understood• Some parts function in language and the sense of balance• Other parts – visceral function
• Conscious perception of: • Upset stomach• Full bladder• Some aspects of the sense of smell
Cerebral White Matter
• Different areas of the cerebral cortex communicate:• With each other • With the brainstem and spinal cord
• Fibers are usually myelinated and bundled into tracts• Types of tracts
• Commissures – composed of commissural fibers• Allows communication between cerebral
hemispheres• Corpus callosum – the largest commissure
• Association fibers - Connect different parts of the same hemisphere
• Projection fibers – run vertically • Descend from the cerebral cortex • Ascend to the cortex from lower regions
Basal nuclei
• A group of nuclei deep within the cerebral white matter• Caudate nucleus – arches over the thalamus• Lentiform nucleus – “lens shaped”• Amygdala – sits on top of the caudate nucleus
• Functionally belongs with the limbic system• Lentiform nucleus - Divided into two parts
• Globus pallidus• Putamen
• Cooperate with the cerebral cortex in controlling movements• Receive input from many cortical areas• Evidence shows that they:
• Start, stop, and regulate intensity of voluntary movements• In some way estimate the passage of time
The Diencephalon
• Forms the center core of the forebrain• Surrounded by the cerebral hemispheres• Composed of three paired structures:
• Thalamus, hypothalamus, and epithalamus• Border the third ventricle• Primarily composed of gray matter
The Thalamus
• Makes up 80% of the diencephalon• Contains approximately a dozen major nuclei• Send axons to regions of the cerebral cortex• Nuclei act as relay stations for incoming
sensory messages• Afferent impulses converge on the thalamus
• Synapse in at least one of its nuclei• Is the “gateway” to the cerebral cortex• Nuclei organize and amplify or tone down
signals
The Hypothalamus• Lies between the optic chiasm and the
mammillary bodies • Pituitary gland projects inferiorly • Contains approximately a dozen nuclei• Main visceral control center of the body• Functions include the following:
• Control of the autonomic nervous system
• Control of emotional responses• Regulation of body temperature• Regulation of hunger and thirst
sensations• Control of behavior• Regulation of sleep-wake cycles• Control of the endocrine system• Formation of memory
The Epithalamus• Forms part of the “roof” of
the third ventricle• Consists of a tiny group of
nuclei• Includes the pineal gland
(pineal body)• Secretes the hormone
melatonin • Under influence of the
hypothalamus
The Brain Stem
• Includes the midbrain, pons, and medulla oblongata
• Several general functions• Produces automatic behaviors
necessary for survival• Passageway for all fiber tracts running
between the cerebrum and spinal cord• Heavily involved with the innervation of
the face and head• 10 of the 12 pairs of cranial nerves attach to
it
The Midbrain• Lies between the diencephalon and the pons• Central cavity – the cerebral aqueduct• Cerebral peduncles located on the ventral surface of the brain
• Contain pyramidal (corticospinal) tracts• Superior cerebellar peduncles- Connect midbrain to the cerebellum• Periaqueductal gray matter surrounds the cerebral aqueduct
• Involved in two related functions • Fright-and-flight reaction• Mediates response to visceral pain• Corpora quadrigemina – the largest nuclei, divided into• Superior colliculi – nuclei that act in visual reflexes• Inferior colliculi – nuclei that act in reflexive response to sound
• Imbedded in the white matter of the midbrain, presents two pigmented nuclei
• Substantia nigra – neuronal cell bodies contain melanin, Functionally linked to the basal nuclei
• Red nucleus – lies deep to the substantia nigra, Largest nucleus of the reticular formation
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The Pons
• Located between the midbrain and medulla oblongata
• Contains the nuclei of cranial nerves V, VI, and VII
• Two general groups of cranial nerve nuclei• Motor nuclei• Sensory nuclei
The Medulla Oblongata• Most caudal level of the brain stem
• Continuous with the spinal cord• Choroid plexus lies in the roof of the fourth
ventricle• Pyramids of the medulla – lie on its ventral
surface • Decussation of the pyramids – crossing
over of motor tracts• Cranial nerves VIII–XII attach to the medulla
• The core of the medulla contains:• Much of the reticular formation
• Nuclei influence autonomic functions• Visceral centers of the reticular formation
include:• Cardiac center• Vasomotor center• The medullary respiratory center• Centers for hiccupping, sneezing,
swallowing, and coughing
The Cerebellum • Located dorsal to the pons and medulla• Smoothes and coordinates body movements • Helps maintain equilibrium
• Consists of two cerebellar hemispheres• Surface folded into ridges called folia
• Separated by fissures• Hemispheres each subdivided into:
• Anterior lobe• Posterior lobe
• Composed of three regions• Cortex – gray matter• Internal white matter• Deep cerebellar nuclei – deeply situated gray
matter • Cerebellum must receive information
• On equilibrium • On current movements of limbs, neck, and
trunk• From the cerebral cortex
Cerebellar Peduncles
• Fibers to and from the cerebellum are ipsilateral• Run to and from the same side of
the body • Thick tracts connecting the
cerebellum to the brain stem• Superior cerebellar peduncles• Middle cerebellar peduncles• Inferior cerebellar peduncles
Functional Brain Systems
• Networks of neurons functioning together• The limbic system – spread widely in the forebrain • The reticular formation – spans the brain stem
The Limbic System• Location
• Medial aspect of cerebral hemispheres• Also within the diencephalon
• Composed of:• Septal nuclei, cingulate gyrus, and hippocampal
formation• Part of the amygdala
• The fornix and other tracts link the limbic system together• The “emotional brain”
• Cingulate gyrus • Allows us to shift between thoughts• Interprets pain as unpleasant
• Hippocampal formation • Hippocampus and the parahippocampal gyrus
The Reticular Formation
The Reticular Formation• Widespread connections - Ideal for arousal of the brain as
a whole• Reticular activating system (RAS)
• Maintains consciousness and alertness• Functions in sleep and arousal from sleep
Brain Functions
• Vision• Taste• Cognition• Emotion• Speech• Language• Hearing• Motor Cortex• Sensory Cortex• Autonomic Functions
Vision
The visual cortex resides in the occipital lobe of the brain.
Sensory impulses travel from the eyes via the optic nerve to the visual cortex.
Damage to the visual cortex can result in blindness.
Taste
The gustatory complex (green circle) is the part of the sensory cortex (purple area) that is responsible for taste.
Cognition
The prefrontal cortex is involved with intellect, complex learning, and personality.
Injuries to the front lobe can cause mental and personality changes.
Emotion
Emotions are an extremely complex brain function. The emotional core of the brain is the limbic system. This is where senses and awareness are first processed in the brain.
Mood and personality are mediated through the prefrontal cortex. This part of the brain is the center of higher cognitive and emotional functions.
Prefrontal cortex
Limbic system
Speech
Broca’s area is where we formulate speech and the area of the brain that sends motor instructions to the motor cortex.
Injury to Broca’s area can cause difficulty in speaking. The individual may know what words he or she wishes to speak, but will be unable to do so.
Broca’s Area
Language
Wernicke’s area is a specialized portion of the parietal lobe that recognizes and understands written and spoken language.
Wernicke’s area surrounds the auditory association area.
Damage to this part of the brain can result in someone hearing speech, but not understanding it.
Wernicke’s Area
Auditory Association Area
HearingThere are two auditory areas of the brain:
• The primary auditory area (brown circle) is what detects sounds that are transmitted from the ear. It is located in the sensory cortex.
• The auditory association area (purple circle) is the part of the brain that is used to recognize the sounds as speech, music, or noise.
Motivational systems
• HUNGER
• THIRST
• SEXUAL BEHAVIOR
Hunger
LACK OF
FOOD
REDUCEDAVAILABILITYOF GLUCOSE
CONTRACTIONS OF EMPTYSTOMACH
LOWTRIGLYCERIDELEVELSIN FAT CELLS
GLUCOSE RECEPTORSIN HYPOTHALAMUS
MECHANO-RECEPTORSIN STOMACH
PANCREAS
HUNGER
Thirst
WATERDEFICIENCY
OSMORECEPTORSIN SUPRAOPTICAND SUPRA-VENTRICULARNUCLEI OFHYPOTHALAMUS
THIRST
ADHSERETIONBY PITUITARY
WATERRETENTION BY KIDNEY
Sexual behavior
• Anterior hypothalamus receives input from de receptors stimulated by feromones
• Androgens determine release of luteinizing hormones, cyclic or constant
Brain Plasticity
• The ability of the brain to change as a result of experience, drugs, or injury.
• Collateral sprouting: growth of new neuron branches
• Substitution of function: other areas of the brain take over for damaged areas
• Neurogenesis: generating new neurons
Learning takes place in the brain.
• However, various parts of the brain function differently and provide localized areas for the retention of diverse types of knowledge.
Human Memory System• 3 memory processes
• Encoding – getting information into memory• Storage – keeping the information in memory• Retrieval – getting the information back outExpert learners have successful strategies for using the first two
processes which makes the last one more probable.Types of Memory
• Sensory Store – how information enters • Gatekeeper of the mind• Much of this is ignored.
• Short-term Memory – “ working” memory• Decay’s after 30 seconds
• Can be renewed through maintenance rehearsal• Limited capacity (5-9 items)
• Can be expanded through chunking (ex.SSN)• Long-term Memory – What you “know”
• Unlimited capacity, unlimited duration• Must be retrieved before used (cues)
Two Basic Memory Processes
• Declarative memory• Facts and events• Occurs primarily in brain systems involving
the hippocampus• Procedural memory
• Skills or cognitive operations that cannot be represented in declarative sentences
• Occurs primarily in the brain systems involving the neostriatum
The brain is divided into two halves or hemispheres identified as right and left.
• The left hemisphereiconsidered analytic in
approach A successive processor (left brain) prefers to learn in a step-by-step sequential format, beginning with details leading to a conceptual understanding of a skill.
This part of the brain controls and makes the final decisions concerning information collected throughout the brain.
• At the same time, the left hemisphere simultaneously inhibits the visual-spatial right brain’s cognitive and decision making processes.
Conversely and concurrently…• The right brain
described as holistic or global. A simultaneous processor ( right brain) prefers to learn beginning with the general concept and then going on to specifics.
a “left brain person” is …1. Verbal2. Responds to word meaning3. Sequential 4. Processes information linearly5. Responds to logic6. Plans ahead7. Recall people's names8. Speak with few gestures9. Punctual10. Prefer formal study design11. Prefer bright lights while
studying
For example…
Let’s meet a week from today to talk about this.
If this is true, then it is logical that we …
Because left-brain thinkers are logical and practical, they are also …
• Ruled by facts• Detail oriented• Users of words and
language• Focused on the present
and past• Perceive order & pattern• Reality based• Strategy Formulators
a “right brain person” is …
1. Visual2. Responds to tone of voice3. Random4. Processes information in varied order5. Responds to emotion6. Impulsive7. Recall people’s faces8. Gesture while speaking9. Less punctual10. Prefer sound/ music background while
studying11. Prefer frequent mobility while studying
Because right-brain thinkers are intuitive and willing to take risks, they are also …
• Imaginative• “Big Picture”
oriented• Users of symbols and
images• Focused on the
present and future• Spatially perceptive• Fantasy based• Presenters of
Possibility
Specific learning skills are associated with right and left brain hemispheric dominance.
LEFT BRAIN • Reading & Language• Symbols• Locating details &
facts• Talking & Recitation• Following Directions• Listening• Auditory Association
RIGHT BRAIN• Computation & Patterns• Spatial Relationships• Singing & Music• Art Expression• Creativity• Visualization• Feelings & Emotions
brain dominance is concerned with ways of perceiving, processing, and
organizing information and experiences.
Adolescent brain development
• Underdevelopment of the frontal lobe/prefrontal cortex and the limbic system make adolescents more prone to “behave emotionally or with ‘gut’ reactions”
• Adolescents tend to use an alternative part of the brain– the AMYGDALA (emotions) rather than the prefrontal cortex (reasoning) to process information
• Amygdala and nucleus acumbens (limbic system within the prefrontal cortex) tend to dominate the prefrontal cortex functions– this results in a decrease in reasoned thinking and an increase in impulsiveness
• Because of immature brains, adolescents do not handle social pressure, instinctual urges, and other stresses the way adults do
• A major part of adolescence is learning how to assess risk and consequences — adolescents are not yet skilled at these tasks
Hot and cold cognition
• Thoughts and emotions are intertwined – teens need to develop a balance between cognitive and affective systems of the brain
• “COLD” cognition refers to thinking under conditions of low emotions and/or arousal
• “HOT” cognition refers to thinking under conditions of strong feelings or arousal
• Decisions made under conditions of strong affect are difficult to influence by cool rational thought alone
• Decision making in teens cannot be fully understood without considering the role of emotions and the interaction between thinking and feeling
• Teen decisions are unlikely to emerge from a logical evaluation of the risk/benefits of a situation – rather decisions are the result of a complex set of competing feelings – desire to look cool, fear of being rejected, anxiety about being caught, excitement of risk, etc.
Mental Disorders
• Creates problems with feeling, thinking and perception.• Affects a person’s behavior by involuntarily causing bizarre
and/or inappropriate behavior.• Are primarily brain disorders.• Can be short term (acute) or long term (chronic).• Can occur at anytime in a person’s life.• Associated with distress, or• With significant increased risk of suffering death, pain,
disability, or an important loss of freedom.• Not an expected response to a particular event (e.g., death
of a spouse).• Current manifestation of a behavioral, psychological, or
biological dysfunction.
Categorization of Mental Disorders
• Delirium• Psihotic disorders• Dementia• Cognitive disorders• Affective disorders• Anxiety disorders• Personality disorders• Substance abuse/dependence.• Impulse control disorders.• Adjustment disorders.• Sexual disorders
Alcohol & Other Drug Abuse
• Abuse and Dependence Both Defined as Mental Disorder in DSM IV. • Dependence is Pattern of Use Causing Impairment or Distress
Including • Tolerance• Withdrawal• Increasing Amounts Over Longer Time• Unsuccessful Attempts to Control Use• Time Spent Obtaining, Using, Recovering• Activities Given Up Due to Use• Continued Use Despite Problems
Alcohol & Other Drug Abuse:
• Long term use can result in deteriorated functioning.
• Can cause:• Depression.• Dementia.• Anxiety disorders.
• Use and withdrawal can cause acute psychotic symptoms.
• Addiction is chronic, progressive, & terminal.
Mental Retardation
• Below Average Intellectual Functioning.
• Begins Before Age 18, Usually Present at Birth.
• Unrelated to Other Mental Illness.• Impaired Social-living Adaptation &
Functioning:• Personal care & hygiene.• Money management.• Leisure activities.• Social relationships.
The Brain - Function
Shrinkage of brain tissue.Ventricles enlarge. short-term memory begins to decline ability to perform routine tasks also declines.
Emotional outbursts may occur and language is impaired. Progressively more nerve cells die with subsequent behaviour changes, such as wandering and agitation.
The ability to recognize faces and to communicate is completely lost in the final stages. Patients lose bowel and bladder control, and eventually need constant care.
The average length of time from diagnosis to death is 4 to 8 years, but can take 20
Alois Alzheimer
Alzheimer’s disease First recorded by Alzheimer after studying the brain of a woman who had died after suffering dementia in 1906.
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The Brain - Function
Ageing. Less than 1 in 1000 people < 65 have Alzheimer's. 1 in 20 > 65 has!
A small proportion of sufferers have a genetic (familial) form
A varied and active life may help avoid Alzheimer’s.
Severe blows to the head (especially in the over 50s) may increase the chance of developing the disease
Smoking and high cholesterol may also be risk factors for Alzheimer’s
Future therapy?
A vaccine to break down the β amyloid plaques? Trials in mice
An inhibitor of the membrane enzyme that breaks down APP into Aβ?
Risk factors
Alzheimer’s
…..WISH YOU GOOD LUCK IN MANAGING YOU BRAIN…