AP Chapter 12

Cerebral Cortex

Thin 2-4 mm superficial layer of gray matter with 40% of mass of brain and site of conscious mind.

Reticular Formation

Three broad columns along the length of the brain stem: raphe nuclei, medial (large cell) group of nuclei, and lateral (small cell) group of nuclei. Has far-flung axonal connections with hypothalamus, thalamus, cerebral cortex, cerebellum, and spinal cord.

Brain Stem

Three regions of the brain stem: midbrain, pons, and medulla oblongata. Similar structure to spinal cord but contains embedded nuclei, controls automatic behaviors necessary for survival, contains fiber tracts connecting higher and lower neural centers, and associated with 10 of the 12 pairs of cranial nerves.

Paraplegia

Transection between T₁ and L₁.

Quadriplegia

Transection in the cervical region.

Dorsal Column Medial Lemniscal Pathways

Transmit input to the somatosensory cortex for discriminative touch and vibrations plus composed of the paired fusciculus cuneatus and fasciculus gracilic in the spinal cord and the medial lemniscus in the brain (medulla to thalamus).

Pons

Trigeminal nerve (V) Both Abducens nerve (VI) Motor Facial nerve (VII) Both

Cranial Nerve V

Trigeminal-both largest cranial nerve, major sensory nerve serving face (skin, mucosae of mouth, surface of eyes), motor nerves: chewing, sensory nerves: receive sensation of the face.

Cranial Nerve IV

Trochlear-motor enters/leaves through superior orbital fissure or sphenoid bone, superior oblique muscle of eye.

Anatomy of the Cerebellum

Two hemispheres connected by vermis. Each hemisphere has three lobes: anterior, posterior, and flocculonodular. Folia- transversely oriented gyri. Arbor vitae- distinctive treelike pattern of the cerebellar white matter. (Arbor day- tree).

Motor Homunculi

Upside-down caricatures representing the motor innervation of body regions.

Cranial Nerve X

Vagus- both exits/enters through jugular foramen motor to: pharynx and larynx for swallowing and speaking,(somatic) lungs, and abdominal viscera (ANS: parasympathetic) sensory from: thoracic and abdominal viscera.

Lower Motor Neurons

Ventral horn motor neurons and innervate skeletal muscles.

Medulla Oblongata

Vestibulocochlear nerve (VIII) Sensory Glossopharyngeal nerve (IX) Both Vagus nerve (X) Both Accessory nerve (XI) Motor Hypoglossal nerve (XII) Motor

Cranial Nerve VIII

Vestibulocochlear- sensory enters through internal acoustic meatus, and hearing and balance from inner ear.

Cranial Nerve VII

acial- both enters/exits through stylomastoid foramen, sensory: from taste buds on tongue, motor: salivary and lacrimal glands (ANS), and muscle of facial expression (somatic).

Beta Waves

(14-30 Hz) rhythmic, less regular waves occurring when mentally alert.

Theta Waves

(4-7 Hz) more irregular; common in children and uncommon in adults.

Delta Waves

(4Hz or less) high-amplitude waves seen in deep sleep and when reticular activating system is damped, or during anesthesia; may indicate brain damage.

Alpha Waves

(8-13 Hz) regular and rhythmic, low amplitude, synchronous waves indicating an "idling" brain.

Alzheimers Disease

(AD) a progressive degenerative disease of the brain that result in dementia.

Slow Wave Sleep

(NREM stages 3 and 4) is presumed to be the restorative stage, people deprived of REM sleep become moody and depressed, REM sleep may be a reverse learning process where superfluous information is purged from the brain, daily sleep requirements decline with age, stage 4 sleep declines steadily and may disappear after age 60.

Declarative Memory

(factual knowledge) explicit information, related to our conscious thoughts and our language ability, and stored in LTM with context in which it was learned.

Cerebellum

11% of the brain mass, dorsal to the pons and medulla, and subconsciously provides precise timing and appropriate patterns of skeletal muscle contraction.

Cranial Nerves consist of

12 pairs

Spinal Cord consist of

31 pairs

Thalamus

80% of the diencephalon, superolateral walls of the third ventricle, connected by the interthalamic adhesion (intermediate mass), contains several nuclei (named for their location), and nuclei project and receive fibers from the cerebral cortex.

Epilepsy

A victim of epilepsy may lose consciousness, fall stiffly, and have uncomfortable jerking. It is not associated with intellectual impairments, and epilepsy occurs in 1% of the population.

Amyotrophic Lateral Sclerosis (ALS)

AKA: Lou Gehrig's Disease, involves progressive destruction of ventral horn motor neurons and fibers of the pyramidal tract, symptoms- loss of the ability to speak, swallow, and breathe; death typically occurs within five years, linked to glutamate excitotoxicity, attack by the immune system, or both.

Cranial Nerve VI

Abducens- motor enters/exits cranial cavity through superior orbital fissure and lateral rectus muscle of eye.

Epileptic Seizure

Absence seizures, or petit mal- mild seizures seen in young children where the expression goes blank. Tonic-clonic (grand mal) seizures- victim loses consciousness, bones are often broken due to intense contractions, may experience loss of bowel and bladder control, and severe biting of the tongue.

Cranial Nerve XI

Accessory-motor enters/exits through jugular foramen and the muscles of neck.

Indirect Pathways

All Others

Cerebellar Peduncles

All fibers in the cerebellum are ipsilateral. Three paired fiber tracts connect the cerebellum to the brain stem: superior peduncles connect the cerebellum to the midbrain, middle peduncles connect the pons to the cerebellum, inferior peduncles connect the medulla to the cerebellum.

Selective Barrier

Allows nutrients to move by facilitated diffusion and allows any fat-soluble substances to pass including alcohol, nicotine, and anesthetics. Absent in some areas, ex., vomiting center and the hypothalamus, where it is necessary to monitor the chemical composition of the blood.

Sleep Patterns

Alternating cycles of sleep and wakefulness reflect a natural circadian (24-hour) rhythm, RAS activity is inhibited during, but RAS also mediates, dreaming sleep. The suprachiasmatic and preoptic nuclei of the hypothalamus time the sleep cycle, a typical sleep pattern alternates between rem and REM and NREM sleep.

Emotional and Affective part of the brain are:

Amygdala- recognizes angry or fearful facial expressions, assesses danger, and elicits the fear response. Cingulate gyrus- plays a role in expressing emotions via gestures, and resolves mental conflict. Put emotional responses to orders (ex. skunks smell bad).

Broca's Area

Anterior to the inferior region of the premotor area, present in one hemisphere (usually the left), a motor speech area that directs muscles of the tongue, and is active as one prepares to speak.

Premotor Cortex

Anterior to the precentral gyrus, controls: learned, repetitious, or patterned motor skills, coordinates simultaneous or sequential actions, and involved in the planning of movements that depend on sensory feedback.

Frontal Eye Fluid

Anterior to the premotor cortex and superior to Broca's area and controls voluntary eye movements.

Control of Epilepsy

Anticonvulsive drugs and vagus nerve stimulators implanted under the skin of the chest can keep electrical activity of the brain from becoming chaotic.

Functions of the Hypothalamic

Autonomic control center for many visceral functions (ex. blood pressure, rate and force of heartbeat, digestive tract motility). Center for emotional response: involved in perception of pleasure, fear, and rage and in biological rhythms and drives. Regulate body temperature, food intake, water balance, thirst, sleep, sleep cycle, control release hormones by the anterior pituitary and produces posterior pituitary hormones.

Language

Basal nuclei, broca's area and Wernicke's area (in the association cortex on the left side), analyzes incoming word sounds, produces outgoing word sounds and grammatical structures, corresponding areas on the right side are involved with nonverbal language components.

Protection of the Brain

Bone (skull), membranes (meninges), watery cushion (cerebrospinal fluid), and blood-brain barrier.

Spinal Cord Protection

Bone, meninges, and CSF; cushion of fat and a network of veins in the epidural space between the vertebrae and spinal dura mater, and CSF in subarachnoid space.

CNS

Brain and Spinal Cord

Myelencephalon

Brain stem; medulla oblongata and fourth ventricle.

Mesencephalon

Brain stem; midbrain and cerebral aqueduct.

Metencephalon

Brainstem, pons, cerebellum and fourth ventricle.

Age Effects of the CNS

CNS is the established during the first month of development, gender-specific areas appear in both brain and spinal cord, depending on presence or absence of fetal testosterone, maternal exposure to radiation, drugs (ex. alcohol and opiates), or infection can harm the developing CNS, smoking decreases oxygen in the blood, which can lead to neuron death and fetal brain damage. Hypothalamus is one of the last areas of the CNS to develop, visual cortex develops slowly over the first 11 weeks, neuromuscular coordination progresses in superior-to-inferior and proximal-to-distal directions along with myelination. Age brings some cognitive declines, but these are not significant in healthy individuals until they reach their 80s, shrinkage of brain accelerates in old age, and excessive use of alcohol causes signs of senility unrelated to the aging process.

Cerebellar Processing for Motor Activity

Cerebellum receives impulses from the cerebral cortex of the intent to initiate voluntary muscle contraction, signals from proprioceptors and visual and equilibrium pathways continuously "inform" the cerebellum of the body's position and momentum, cerebellar cortex calculated the best way to smoothly coordinate a muscle contraction, a "blueprint" of coordinated movement is sent to the cerebral motor cortex and to brain stem nuclei.

Telencephalon

Cerebrum: cerebral hemispheres (cortex, white matter, basal nuclei), lateral ventricles.

State of the Brain of the Brain Waves

Change with age, sensory stimuli, brain disease, and the chemical state of the body. EEGs used to diagnose and localize brain lesions, tumors, infarcts, infections, abscesses, and epileptic lesions. A flat EEG (no electrical activity) is clinical evidence of death.

Left and Right Hemispheres

Communicate via fiber tracts in the cerebral white matter.

Cerebrospinal Fluid

Composition is a: watery solution, less protein and different ion concentrations than plasma, and constant volume. Functions are: gives buoyancy to the CNS organs, protect the CNS from blows and other trauma, and nourishes the brain and carries chemical signals.

First Order Neuron

Conducts impulses from cutaneous receptors and proprioceptors, branches diffusely as it enters the spinal cord or medulla, and synapses with second-order neuron.

Ependymal Cells

Connected to one another and to the central canal of the spinal cord plus lined with this.

Sensory Area

Conscious awareness of sensation.

Consciousness

Conscious perception of sensation, voluntary initation and control of movement, capabilities associated with higher mental processing (memory, logic, judgment, etc.), and loss of consciousness (ex. fainting or syncopy) is a signal that brain function is impaired. Clinically defined on a continuum that grades behavior in response to stimuli: alertness, drowsiness (lethargy), stupor, and coma.

Spinal Nerves

Consist of 31 pairs, cervical and lumbar enlargements are the nerves serving the upper and lower limbs emerge here, and the cauda equina "horse tail" is the collection of nerve roots at the inferior end of the vertebral canal.

Primary Motor Cortex

Consist of large pyramidal cells of the precentral gyri, long axons → pyramidal (corticospinal) tracts, allows conscious control of precise, skilled, voluntary movements.

White Matter

Consists mostly of ascending (sensory) and descending (motor) tracts, transverse tracts (commissural fibers) cross from one side to the other, tracts are located in three white columns (funiculi on each side- dorsal (posterior), lateral, and ventral (anterior) and each spinal tract is composed of axons with similar functions.

Dorsal Root (Spinal) Ganglia

Contain cell bodies of sensory neurons.

Motor Area

Control voluntary movement.

Right Hemisphere

Controls insight, visual-spatial skills, intuition, and artistic skills.

Left Hemisphere

Controls language, math, and logic.

Meninges

Cover and protect the CNS, protect blood vessels and enclose venous sinuses, contain cerebrospinal fluid (CSF), and form partitions in the skull. Three layers include: dura mater, arachnoid mater, and pia mater.

Spastic Paralysis

Damage to upper motor neurons of the primary motor cortex, spinal neurons remain intact; muscles are stimulated be reflex activity and no voluntary control of muscles. Transection is cross sectioning of the spinal cord at any level, results in total motor and sensory loss in regions inferior to the cut.

Fissures

Deep Groves

Parkinson's Disease

Degeneration of the dopamine-releasing neurons of thee substantia nigra.

Poliomyelitis

Destruction of the ventral horn motor neurons by the poliovirus, muscles atrophy, death may occur due to paralysis of respiratory muscles or cardiac arrest, and survivors often develop postpolio syndrome many years laters, as neuron lost.

Diencephalon

Diencephalon (thalamus, hypothalamus, epithalamus), retina and third ventricle.

Lateralization

Division of labor between hemispheres.

Cerebral Dominance of the Hemispheres

Dominant for language (left hemispheres is 90% of people.

Electroencephalogram

EEG, Records electrical activity that accompanies brain function and measures electrical potential differences between various cortical areas.

Cephalization

Evolutionary development of the rostral (anterior) portion of the CNS, increased number of neurons in the head, and the highest level is reached in the human brain.

Denticulate Ligaments

Extensions of pia mater that secure cord to dura mater.

Primary Visual Cortex

Extreme posterior tip of the occipital lobe, most of it is buried in the calcarine sulcus, and receives visual information from the retinas.

Transfer from STM to LTM

Factors that affect transfer from STM to LTM. Emotional state- bast if alert, motivated, surprised, and aroused. Rehearsal- repetition and practice. Association- tying new information with old memories. Automatic memory- subconscious information stored in LTM.

Huntington's Disease

Fatal hereditary disorder caused by accumulation of the protein huntingtin that leads to degeneration of the basal nuclei and cerebral cortex.

Filum Terminale

Fibrous extensions from conus medullaris, anchors the spinal cord to the coccyx.

Prosencephalon

Forebrain

Pons

Forms part of the anterior wall of the fourth ventricle. Fibers of the pons connect higher brain centers and the spinal cord and relay impulses between the motor cortex and the cerebellum. Origin of cranial nerves V (trigeminal), VI (abducens), and VII (facial). Some nuclei of the reticular formation and nuclei that help maintain normal rhythm of breathing.

Hypothalamus

Forms the inferolateral walls of the third ventricle. Contain many nuclei (ex. mammillary bodies) paired anterior nuclei and olfactory relay stations. Infundibulum- stalk that connects to the pituitary gland.

Neural Groove

Fuses dorsally to form the neural tube and it gives rise to the brain and spinal cord.

Basal Nuclei

Ganglia, Subcortical nuclei and consists of the corpus striatum that includes caudate nucleus plus lentiform nucleus (putamen + globus pallidus). Functionally associated with the subthalamic nuclei (diencephalon) and the substantia nigra (midbrain).

Function of Thalamic

Gateway to the cerebral cortex. Sorts, edits, and relays information. Afferent impulses from all senses and all parts of the body except smell, impulses from the hypothalamus for regulation of emotion and visceral function, and impulses from the cerebellum and basal nuclei to help direct the motor corticles. Meditates sensation, motor activities, cortical arousal, learning, and memory.

Cranial Nerve IX

Glossopharyngeal- both exits/enters through jugular foramen, the border of temporal and occipital bones, motor: pharyngeal muscles and salivary glands, sensory: from taste buds.

Motor Function

Helps control coarse limb movements, reticular autonomic centers regulate visceral motor functions with: vasomotor, cardiac, and respiratory centers.

Blood Brain Barrier

Helps maintain a stable environment for the brain and separates neurons from some bloodborne substances. Composition is continuous endothelium of capillary walls, basal lamina, and feed of astrocytes (which are the abundant and provide signal to endothelium for the formation of tight junctions).

Rhombencephalon

Hindbrain

List of the Brain Structures Involved in Declarative Memory

Hippocampus and surrounding temporal loves function in consolidation and access to memory and ACh from basal forebrain is necessary for memory formation and retrieval.

Cranial Nerve XII

Hypoglossal- motor enters/exits through hypoglasssal canal (superior to occipital conddyles off occipital bone), Muscles of tongue for: chewing, swallowing and speech.

Direct (Pyramidal) System

Impulses from pyramidal neurons in the precentral gyri pass through the pyramidal (corticospinal) I tracts, axons synapse with interneurons or ventral horn motor neurons, and the direct pathway regulates fast and fine (skilled) movements.

Primary Somatosensory Cortex

In the postcentral gyri, receives sensory information from the skin, skeletal muscles, and joints, plus being capable of spatial discrimination: indentification of body region being stimulated.

Indirect (Extrapyramidal) System

Includes the brain stem motor nuclei, and all motor pathways except pyramidal pathways, also called the multineuronal pathways. These pathways are complex and multisynaptic, and regulate: axial muscles that maintain balance and posture, muscles controlling coarse movements, plus head, neck, and eye movements that follow objects. Reticulospinal and vestibulospinal tracts- maintain balance. Rubrospinal tracts- control flexor muscles. Superior colliculi and tectospinal tracts mediate head movements in response to visual stimuli.

Functions of Basal Nuclei

Influence of muscular control, help regulate attention and cognition, regulate intensity of slow or stereotyped movements and inhibit antagonistic and unnecessary movements.

Second Order Neuron

Interneuron, cell body in dorsal horn of spinal cord or medullary nuclei, and axons extend to thalamus or cerebellum.

Third Order Neuron

Interneuron, cell body in thalamus, and axons extends to somatosensory cortex.

Dorsal Horns

Interneurons that receive somatic and visceral sensory input.

Conscious Behavior

Involves the entire cortex

Medulla Oblongata

Joins spinal cord at foramen magnum, forms part of the ventral wall of the fourth ventricle, contains a choroid plexus (form CSF) of the fourth ventricle. Pyramids- two ventral longitudinal ridges formed by pyramidal tracts. Decussation of the pyramids- crossover of the corticospinal tracts (motor tracts). Inferior olivary nuclei- relay sensory information from muscles and joints to cerebellum. Cranial nerves VIII, X, XI, and XII are associated with the medulla. Vestibular nuclear complex- mediates responses that maintain equilibrium. Several nuclei (ex. nucleus cuneatus and nucleus gracilis) rlay sensory information. Autonomic reflex centers include: Cardiovascular centers- cardiac centers adjusts force and rate of heart contraction and vasomotor center adjusts blood vessel diameter for blood pressure regulation. Respiratory Centers- generate respiratory rhythm and control rate and depth of breathing, with pontine centers. Other additional centers regulate: vomiting, hiccuping, swallowing, coughing, and sneezing.

Posterior Association Area

Large region in temporal, parietal, and occipital lobes. This also plays a role in recognizing patterns and faces and localizing patterns and faces and localizing us in space plus involved in understanding written and spoken language (Wernicke's area).

Anterolateral Pathways

Lateral and ventral spinothalamic tracts and transmit pain, temperature, and coarse touch impulses within the lateral spinothalamic tract.

Pia Mater

Layer of delicate vascularized connective tissue that clings tightly to the brain.

Spinal Cord Trauma

Lead to: functional losses leading to parasthesias which is sensory loss, paralysis is the loss of motor function.

Nondeclarative Memory

Less conscious or unconscious, acquired through experience and repetition, best remembered by doing; hard to unlearn, includes procedural (skills) memory, motor memory, and emotional memory.

Midbrain

Located between the diencephalon and the pons. Cerebral peduncles contain pyramidal motor tracts. Cerebral aqueduct is channel between third and fourth ventricles.

Spinal Cord

Located in the central canal (cavity) is surrounded by a gray matter core and external white matter composed of myelinated fibers.

Gustatory Cortex

Located in the insula and involved in the perception of taste.

Spinal Cord

Location: begins at the foramen magnum and ends as conus medullaris L₁ vertebra. Functions: provides two-way communication to and from the brain and contains spinal reflex centers.

Olfactory Cortex

Medial aspect of temporal lobes (in piriform lobes). Part of the primitive rhinencephalon, along with the olfactory bulbs and tracts and remainder of the rhinencephalon in humans is part of the limbic system. This region of conscious awareness of odors.

Mesencephalon

Midbrain

Arachnoid Mater

Middle layer with weblike extensions, separated from the dura mater by the subdural space, subarachnoid space contains CSF and blood vessels, and arachnoid villi protrude into the superior sagittal sinus and permit CSF reabsorption.

Anterior Association Area

Most complicated cortical region that is involved with: intellect, cognition, recall, and personality. It also contains working memory needed for judgement, reasoning, persistence, and conscience. Development depends on feedback from social environment.

Epithalamus

Most dorsal portion of the diencephalon and forms roof of the third ventricle. Pineal gland- extends from the posterior border and secretes melatonin. Melatonin help regulates sleep wake cycles at night. Serotonin in daytime and makes you feel good about yourself.

Cerebral White Matter

Myelinated fibers and their tracts. Responsible for communication by: commissures (in corpus callosum)- connect gray matter of the two hemispheres, association fibers- connect different parts of the same hemisphere, projection fibers- (corona radiata) connect the hemispheres with lower brain or spinal ford.

Sleep Disorders

Narcolepsy is lapsing abruptly into sleep from the awake state. Insomnia is chronic inability to obtain the amount or quality of sleep needed. Sleep apnea is temporary cessation of breathing during sleep.

Functional Brain Systems

Network of neurons that work together and span wide areas of the brain by: limbic system and reticular formation.

Ectoderm and Neural Plate

Neural plates forms from this to make a neural groove and neural folds.

Midbrain Nuclei

Nuclei that control cranial nerves III (oculomotor) and IV (trochlear). Corpora quadrigemina- domelike dorsal protrusions. Superior colliculi- visual reflex centers. Inferior colliculi- auditory relay centers. Substantia nigra- functionally linked to basal nuclei (linked to parkinson's). Red nucleus- relay nuclei for some descending motor pathways and part of reticular formation

Midbrain

Oculomotor nerve (III) Motor Trochlear nerve (IV) Motor

Cranial Nerve III

Oculomotor-motor superior orbital fissure enters/leaves cranial extrinsic muscles of eye except lateral rectus and superior oblique for eye movement, intrinsic smooth muscle of iris the constriction in response to brightness, and lens controls shape for focusing.

Cranial Nerve I

Olfactory -sensory smell fibers in nasal mucosa outside the skull, enters cranial cavity through olfactory foramina in cribiform plate (ethmoid bone), synapse with other neurons in the olfactory bulb, then continues through thee olfactory tract.

Lateral Horns

Only located in thoracic and lumbar regions and are sympathetic neurons.

Cranial Nerve II

Optic- sensory sight, enters cranial activity through optic forammina the sphenoid bone, fibers from retina, medial fibers cross at optic chiasma, continue as optic tracts.

Limbic Association Area

Part of the limbic system and provides emotional impact that helps establish memories.

Brain Waves

Patterns of neuronal electrical activity, generated by synaptic activity in the cortex, each person's brain waves are unique, and can be grouped into four classes based on frequency measured as Hertz (Hz).

Vestibular Cortex

Posterior part of the insula and adjacent parietal cortex and responsible for conscious awareness of balance (position of the head in space).

Visceral Sensory Area

Posterior to the gustatory cortex and conscious perception of visceral sensations e.x. upset stomach or full bladder.

Somatosensory Association Cortex

Posterior to the primary somatosensory cortex, integrates sensory input from primary somatosensory cortex, and determines: size, texture, and relationship of parts of objects being felt.

Auditory Areas

Primary auditory cortex is superior margin of the temporal lobes and interprets information from inner ear as pitch, loudness, and location. Auditory association area is located posterior to the primary auditory cortex and stores memories of sounds and permits perception of sounds.

List of Brain Structures Involved in Nondeclarative Memory

Procedural memory- basal nuclei relay sensory and motor inputs to the thalamus and premotor cortex and dopamine from substantia nigra is necessary. Motor memory- cerebellum. Emotional memory- amygdala.

Choroid Plexus

Produce CSF at a constant rate, hang from the roof of each ventricle, clusters of capillaries enclosed by pia mater and a layer of ependymal cells, and ependymal cells use ion pumps to control the composition of the CSF and help cleanse CSF by removing wastes.

Upper Motor Neurons

Pyramidal Cells in primary motor cortex.

Direct Pathways

Pyramidal Tracts

Reticular Activating System

RAS, sends impulses to the cerebral cortex to keep it conscious and alert, filters out repetitive and weak stimuli (~99% of all stimuli!), and severe injury results in permanent unconsciousness (coma).

Cognitive Function of the Cerebellum

Recognizes and predicts sequences of events during complex movements and plays a role in non motor functions such as word association and puzzle solving.

Gyri

Ridges

Transverse Cerebral Fissure

Separate the cerebrum and the cerebellum.

Longitudinal Fissure

Separate two hemispheres.

Flaccid Paralysis

Severe damage to the ventral root or ventral horn cells, impulses do not reach muscles; there is no voluntary or involuntary control of muscles and muscles atrophy.

Sulci

Shallow Grooves

Brain

Similar pattern of spinal cord, but with additional gray matter, nuclei in the cerebellum and cerebrum, and cortex of cerebellum and cerebrum.

Ventral Horns

Somatic motor neurons whose axons exit the cord via ventral roots.

Sleep

State of partial unconsciousness from which a person can be aroused by stimulation. Two major types of sleep (defined by EEG patterns): nonrapid eye movement (NREM) and rapid eye movement (REM). First two stages of NREM occur during the first 30-45 minutes of sleep, fourth stage is achieved in about 90 minutes, and then REM sleep begins abruptly.

Memory

Storage and retrieval of information. Two stages of storage: short term memory (STM, or working memory)- temporary holding of information; limited to seven or eight pieces of information. Long term memory (LTM) has limitless capacity.

Dura Mater

Strongest meninx and two layers of fibrous connective tissue (around the brain) separate to form dural sinuses. Dural septa limit excessive movement of the brain. Falx cerebri- in the longitudinal fissure; attached to crista galli. Falx cerebelli- along the vermis of the cerebellum. Tentorium cerebelli- horizontal dural fold over cerebellum and in the transverse fissure.

Limbic System

Structures on the medial aspects of cerebral hemispheres and diencephalon and includes parts of the diencephalon and some cerebral structures that enclose the brain stem.

Visual Association Area

Surrounds the primary visual cortex, uses past visual experiences to interpret visual stimuli (e.x. color, form, and movement) and complex processing involves entire posterior half of the hemispheres.

Limbic System: Emotion and Cognition

The limbic system interacts with the prefrontal lobes, therefore: we can react emotionally to things we consciously understand to be happening and we are consciously aware of emotional richness in our lives. Hippocampus and amygdala plays a role in memory.