Neuro Midterm

Cerebral Cortex

(gray matter) is arranged in horizontal order: § 3-layered pattern is called the archicortex (hippocampus, amygdala, & septum) used for short-term memory, emotion related experiences, & emotional behavior control § 3- to 6- layered pattern is called the mesocortex (para-hippocampal cortex & olfactory bulb) § 6-layered pattern is called the neocortex (the 1 Anema talks about int class) contains most of the dorsal and lateral cerebral cortex and is responsible for higher mental functions (language, thinking, memory, attention)

Petit Mal (Absence) Seziures

- Chur in children aged 3-12 and they usually disappear after the 3rd decade of life. - These seizures involve a varied loss of awareness and are often associated with staring, chewing, blinking, and occasional myoclonic jerks. - A dominant familial predisposition is evident - Drug therapy is effective in controlling this type of seizure.

Partial Simple seizures

- Usually caused by a single cortical or subcortical lesion - Symptoms are characterized by sudden onset of sensory and/or motor behaviors confined to a single body part, such as the leg, arm or face, depending on the site of the lesion. (ex: a lesion in the motor cortex may generate the jerking of the opposite side arm.) - Involvement of the sensory cortex causes altered sensory reception, such as numbness or tingling. An aura is the first sign of a focal seizure For most focal seizures, antiepileptic drugs (AEDs) are effective, however some don't respond to AEDs.

Grand Mal (Tonic Clonic) Seizure

- Usually involve the cortex, basal ganglia, diencephalon, and brainstem reticular formation. - Symptoms include loss of consciousness followed by tonic convulsions consisting of repeated hyperextension of the body and breath holding spells resulting in cyanosis and tongue biting - The average length of this type of seizure is 1-3 minutes - A heredity predisposition is thought to be the underlying substrate for most patients having grand mal epilepsy.

Partial Complex (Psychomotor) Seizures

- Very often the result of congenital and postnatal lesions of the medial temporal lobe structures consisting of the amygdala, hippocampus, and overlying temporal cortex. - There are also notable cognitive deficits characterized by inattentiveness, unclear thinking, compulsive thoughts, sensory, illusions and apathy.

How many cranial nerves are there?

12 on left 12 on right = 24 cranial nerves

Outter surface of the brain

2-4 mm thick

Hierarchy of neruoaxial organization

3. Hierarchy of Neuraxial Organization- maintain homeostasis(react to nonspecific stress & body changes) o Lower levels: specific function; Upper levels: complexity increases as level of processing becomes more brain controlled o Spinal cord (lowest level of organization): simple sensorimotor function (controls reflexes) o Brainstem & Diencephalon (intermediate level of organization/ non-thinking part of brain): consists of autonomic, chemical, & visceral systems which all contribute to regulation of blood pressure, respirations, sleep, temperature, endocrine, and neurotransmitter interactions o Cerebral Cortex (highest level of organization): complex sensorimotor integration & higher mental functions (tightly integrated with intermediate level)

Laterality of brain organization

4. Laterality of Brain Organization- o Bilateral Anatomic Symmetry: the 2 cerebral hemispheres are similar with minor differences § Language dominance there's diff. function in the temporal lobe (planum temporale) § Typically, language happens on the left, but if there is an enlarged planum temporale on the left than this is associated with sidedness o Unilateral Functional Differences: § Immediately after birth the 2 hemispheres are functionally equipotential meaning each hemisphere has the capacity to develop all kinds of skills § After the first year each hemisphere is specialized in specific function (left = language, right = emotions, metaphors, humor, & musical, temporospatial & paralinguistic skills o Contralateral Sensorimotor Control: all sensory and motor fibers decussate (or cross) § Sensory & motor fibers cross at the caudal medulla of the brain stem § Pain & temp. cross in the midline of the spinal cord

Functionally specialized networking

5. Functionally Specialized Networking- the cortical org. of neurons is functionally specialized meaning the motor system has parallel pathways that control motor info. & the same for sensory system/info.

Topographical organization in cortical pathways

6. Topographical Organization in Cortical Pathways- cerebral cortex has a somatosensory homunculus which has a topographical organization for sensory & motor function (each area of the homunculus is responsible for a specific area)

Plasticity in the brain

7. Plasticity in the Brain- o Plasticity- brain's ability to reorganize & modify tissue function and adapt internal & external changes o Plasticity is greatest in early years during development & diminishes with age o Brain regions are either committed or uncommitted to specific function, so at a young age these functions are established (critical period- when an experience is the most effective in influencing the brain's potential)

Culturally Neutral Brain

8. Culturally Neutral Brain- personal characteristics don't affect the brain (ex: gender)

Magnetic Resonance Imaging Techniques (MRI)

A method of generating pictures of brain structures using a powerful magnetic field that alters the electrical activity of the brain. The pt's head is placed in strong magnetic field. The protons (charged atoms) in the brain align themselves with the external magnetic field. Then an electromagnetic pulse is introduced. MRI is particularly well suited for the imaging of soft tissue, like the brain, eyes, and other soft tissue structures in the head. Magnetic resonance imaging has replaced CT and other techniques in the evaluation of many disease conditions.

Degeneration

AD - Alzheimer's Disease and ALS - amyotrophic lateral sclerosis

Apraxia of Speech

Abnormal articulation of sequences of phonemes (inconsistent) Inability to program sound sequences Rarely seen without aphasia Usually an aphasic deficit, particularly broca's aphasia

Temporal Lobe

Area concerned with audition, memory, thought elaboration, comprehension of spoken language (Wernicke's Area - Brodmann's Area 22), and olfaction. Located ventral to the frontal and parietal lobes. Contains 3 important gyri: Superior temporal gyrus Runs parallel to the lateral fissure and posteriorly turns upward in the parietal lobe. The dorsal surface of the superior temporal gyrus dips into the insular cortex Houses a few short, oblique convulsions = The Heschl Gyri Heschl's Gyri form the Primary Auditory Cortex (Brodmann's Area 41-42) - this is buried beneath the lateral sulcus & in front of the insular cortex. Middle temporal gyrus Inferior temporal gyrus

Aphasic Alexia

Association with aphasic disturbances Third alexia- broca's aphasia Deep dyslexia= grapheme-phoneme correspondence Second alexia syndrome (phonological dyslexia)= similar to deep dyslexia, but reading single content words is normal Surface dyslexia- can read with grapheme-phoneme correspondence but cannot comprehend

Electroencephalography (EEG)

Brain signals are recorded from the front, parietal, occipital and temporal scalp areas. EEG is an excellent diagnostic procedure for seizures and measures abnormal brain wave patterns that are usually combinations of high voltage spikes and or sharp wave discharges of varied frequencies. It is not feasible to run an EEG when the patient is going through a seizure for two reasons. 1. Because the movement artifacts 2. Most patients have their seizures outside the hospitals · Standard specific seizure-evoking methods are hyperventilation, photic stimulation, sleep induction and sleep deprivation. - Hyperventilation - is used to activate the epileptic brain which may be in a state of relative low excitability. It is most effective for evoking abnormal discharges in patients with petit mal and psychomotor seizures. - Photic stimulation, consisting of repeated flashes of light can also elicit abnormal discharges in some patients having idiopathic (with no known cause) epilepsies. - Sleep is effective for activating discharges in all forms of epilepsy and most productive in psychomotor epilepsy. - Sleep deprivation has also been known to elicit paroxysmal activity in some patients having epilepsy. EEG has also been used to evaluate brain death, which refers to an irreversible loss of functions in the brain and brainstem. An EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20-40 minutes, as recorded from multiple electrodes placed on the scalp. In neurology, the main diagnostic application of EEG is in the case of epilepsy, as epileptic activity can create clear abnormalities on a standard EEG study. · Evoked potentials

Brodmann's Areas

Brodmann's Area- divides the brain into 50 regions and serves as a standard for referring to specific brain areas by number o Primary motor cortex = Brodmann's Area 4 o Primary sensory cortex = Brodmann's Area 3, 1, 2 o Primary visual cortex = Brodmann's Area 17 o Primary auditory cortex = Brodmann's area 41 & 42

Occipital Lobe contains

Calcarine cortex Pericalcarine cortical area

3 major sulci present on the dorsolateral surface of the brain

Central Sulcus (fissure of Rolando) Begins at the top of the brain, ends at the lateral sulcus. 2 cm deep, marks the boundary between frontal & parietal lobes Separates the primary motor cortex from the primary sensory cortex Lateral Sulcus (sylvian fissure) Begins rostrally below the frontal pole, ends toward the inferior parietal lobe. Separates the frontal and temporal lobes Parieto-Occipital Sulcus Vertically oriented deep fissure on the lateral and medial surfaces of the cortex Separates the parietal lobe from the occipital lobe

Centrality of the central nervous system

Centrality of the Central Nervous System (CNS)- o CNS- responsible for incoming & outgoing info. for generating appropriate responses to info. received o Volitional = internally generated (ex: motor movement); Environmentally Elicited = reflex o Because of this centrality no 2 body parts directly communicate (no matter how close in proximity) everything is mediated through CNS

Gross anatomic structures of the telencephalon

Cerebral Cortex (frontal, parietal, occipital, and temporal cortices) Basal Ganglia (caudate nucleus, putamen, and globus pallidus) Limbic System (cingulate, hippocampus, amygda

Cerebrum

Cerebrum has 2 hemispheres that are separated by the interhemispheric fissure (each hemi. contains cerebral cortex, basal ganglia, & diencephalon)

Orientation to Basic Terminology

Comparing dogs to humans: dogs CNS is a straight line across the plane of their body; humans have a longitudinal CNS that bends just above the brainstem (this comparison is important because terminology is different based on the structure of the CNS) · Since the CNS bends (the bend is called the cephalic flexure), it's organized along 2 different axes: horizontal (brain) & vertical (spinal cord)

Peripheral Nervous System (PNS)

Consists of sensory & motor nerves that are connected to the spinal cord (spinal nerves) and brainstem (cranial nerves). The PNS consists of two major systems: Somatic nervous system: Voluntary control. Sensory and motor nerves innervate muscles and skin. Autonomic nervous system: Involuntary control. Sensory and motor nerves innervate visceral organs and glands. The autonomic nervous system consists of 2 divisions: Sympathetic and Parasympathetic System Sympathetic System: Spends energy & prepares for fight or flight Parasympathetic System: Conserves energy & is dominant during relaxation or sleep.

Left hemisphere

Dominant hemisphere. Superior in processing language, speech, calculation, and verbal memory.

Epilepsy

Epilepsy refers to two or more (recurring) unprovoked seizures. In epilepsy, the brain's electrical activity becomes unstable and it's characterized by a prolonged high frequency neuronal discharge which represents rapid and excessive depolarization of membrane potentials. Partial and generalized epileptic seizures

Wernicke's Aphasia

Fluent and effortless, but meaning is obscured Reading mirrors the poor language comprehension Writing is abnormal like the speaking (writing samples are a good way to detect wernicke's aphasia) Lesions: posterior 2/3 of left superior temporal gyrus Variant= pure word deafness (unilateral, left temporal lobe damage)

Organizational Principles of the Brain

I can hear lauren falling, there is plenty of cuts 1. Interconnectivity in the brain 2. Centrality of the central nervous system 3. Hierarchy of Neuroaxial organization 4. Laterality of brain organization 5. Functionally specialized networking 6. Topographical organization in cortical pathways 7. Plasticity in the brain 8. Culturally neutral brain

Interconnectivity in the brain

Interconnectivity in the brain - primary sensory & motor regions of cerebrum are connected through association and commissural fibers o Cortical association areas = directly connected o Primary cortical areas = indirectly connected (connected through cortical association areas) o Homologous area of 2 hemispheres are connected through interhemispheric commissural fibers

Visual Evoked Potentials

Is used to evaluate electrical conduction along the optic nerve, optic tract, lateral geniculate body, optic radiations, and visual cortex. Elicited in the CNS through the electrical stimulation of a peripheral nerve, such as the median nerve. The lesion may be in the nerves, nerve roots, or spinal cord.

5th cell layer

Large pyramidal cells, project to motor centers beyond the cerebrum

Parietal Lobe

Located between the frontal and occipital lobes, above the temporal lobe. Concerned with spatial orientation, cross-modality integration, memory, recognition & expression of emotions & prosodies, cognition, and the perceptual interpretation/elaboration of somatic sensation. Contains: Post central gyrus = Primary Sensory Cortex !!! (Brodmann's Area 3, 1, & 2). All modalities of bodily somatic sensation are perceived here. The sensory homunculus = face & head in the lower third of the post central gyrus. Trunk, hands, arms, and legs in the upper portion of the post central gyrus. The oblique intraparietal sulcus = divides the parietal lobe into the superior and inferior parietal lobules.

Central Nervous System CNS

Made up of brain and spinal cord Brain is responsible for initiating, controlling, and regulating all sensorimotor & cognitive functions. Spinal cord responsible for transmitting motor commands to various body parts. Also - sensory information is transmitted to the brain through the spinal cord. The CNS is encased in 3 membranous coverings - aka meninges. Between the two inner layers, there is the cerebrospinal fluid (CSF). CSF serves as both a protective mechanical buffer and as a chemical mediator for metabolic functions.

Auditory Evoked Potentials

Neural activity generated in response to the controlled acoustic stimuli presentation (clicks, tones, and speech sounds) is recorded from the scalp. Auditory evoked potentials can also help identify the site of dysfunction in the auditory system.

Neurology

Neurology- diagnosis & treatment of nervous system disorders o Neurologist will look at data obtained from the clinical examination referring to all disordered areas to make this diagnosis (sensory, motor, higher mental functions, comm., & cog. areas)

Neurophysiology

Neurophysiology- chemical, electrical, & metabolic functions of the nervous system (functional properties)

4th cell layer

Non-pyramidal cells, receives sensory input

Right hemisphere

Nondominant hemisphere. Superior in processing and regulating pragmatic skills & visual/spatial concepts. Also superior in orientation of time & space, perceiving music, and expressing emotions.

Broca's Aphasia

Nonfluent, halting, ungrammatical speech Difficulty comprehending syntax Auditory comprehension is normal besides in multi step commands or in complex sentences Difficulty writing because of right hemiparesis and bc of damage to left frontal lobe Aphemia- rare result of Broca's that causes muteness, but language comprehension and writing is preserved

Motor Disorders

Parkinson's Disease and Cerebral Palsy

Frontal Lobe contains

Precentral gyrus Anterior to precentral gyrus prefrontal region inferior frontal lobule

Calcarine cortex

Primary visual cortex- b area - 17

Each hemisphere consists of 4 primary lobes and 1 secondary lobe

Primary: Frontal, Parietal, Occipital, and Temporal Secondary: Insular

3 major vesicles of the embryonic brain

Prosencephalon Mesencephalon Rhombencephalon

6th cell layer (deepest)

Pyramidal cells, project to thalamus

Aphasia

Quired disorder of language processing secondary to brain disease EXCLUDES developmental or congenital language problems

Radiologic Studies

Radiologic studies: x-rays pass through body tissue · Standard x-rays · Cerebral angiography · Computed tomography (CT scans)

limbic system

Regulates emotion, motivation, learning, and memory o Provide motivation for behaviors that are fundamental to survival (feeding, mating, aggression, and flight · Refers to closely related functional structures of the limbic lobe, diencephalon, septum, and midbrain o The key limbic structures are connected by an extensive network of afferent and efferent fibers · Basic limbic functions are served by four structures: amygdala, hippocampal formation, cingulate gyrus, and septum o Amygdala - aggression, mating, stress-mediated responses, memory, feeding, and drinking o Hippocampus - memory and new learning o Cingulate gyrus - anxiety and altered behavior (panic and compulsion) · Clinical symptoms that appear after limbic system lesions involve emotions and motivation; they are characterized by uninhibited instinctual acts, altered sexual behavior, excessive fear, aggression, and disturbances in circadian rhythms

autonomic nervous system (ANS)

Regulates the functions of the heart, lungs, and blood vessels as well as the organs of the digestive, reproductive, and urogenital systems

Cerebral angiography

Risks include the possibility of transient ischemic attack (TIA) or stroke, arterial injuries, and groin hematomas. Remains the "gold standard" by which to evaluate the cerebral vasculature, primarily cerebral aneurysms, arteriovenous malformations (AVMs), fistulas, and hypervascular tumors. Typically a catheter is inserted into a large artery (such as the femoral artery) and threaded through the circulatory system to the carotid artery, where a contrast agent is injected. A series of x-rays is taken as the contrast agent spreads through the brain's arterial system, then a second series as it reaches the venous system.

Frontal Lobe

Rostral to the central sulcus, Dorsal to the lateral fissure Largest of the 5 lobes (occupies one third of the entire hemisphere) Contains 4 important gyri: Vertical precentral gyrus AKA: Primary Motor Cortex !!! - regulates fine and graded movements of the arms, legs and face Brodmann's Area 4 Contains the motor homunculus - disproportionate representation of various body portions is based on their role in skilled movements. Rostral to the central sulcus - posterior to precentral sulcus Three horizontal gyri Superior (first) Middle (second) Inferior (third) → Broca's area !!! (Brodmann's Area 44 & 45). Controls jaw, lip, tongue, and vocal cord movement. The area immediately rostral to the precentral sulcus = the premotor cortex. Premotor cortex = Brodmann's Area 6 Involved in complex, skilled movements. Regulates the responsiveness of the primary motor cortex. Specific areas in the premotor cortex control speech, hand & finger movements, and hand eye coordination. Remaining anterior portion of the frontal lobe = the prefrontal cortex Prefrontal cortex = Brodmann's Area 10 & 12 Contributes to personality, mood, cognitive/executive functioning, abstract thinking, pragmatic behaviors.

Seizures

Seizures are sensory, motor, cognitive and affective disorders that are the clinical manifestations of abnormal electrical neuronal discharges in the brain. The causative factors in 50% of seizure disorders are metabolic abnormalities, tumors, infarcts, infections, trauma, anoxia, perinatal insult and physiologic disturbances.

The human nervous system has four categories of function

Sensor Effector Integrator Regulator

Occipital Lobe

Small portion of the occipital lobe lies on the lateral surface - mostly developed along the medial surface of the cortex. Contains: Primary visual cortical area = Brodmann's Area 17 Secondary visual cortical area = Brodmann's Area 18

Hippocampus

Structure identified with the encoding of short-term memory Beneath the parahippocampal gyrus *Clinical Symptoms and Associated Lesion sites - SEE TABLE 2.2 (pg. 43)*

Temporal Lobe contains

Subtemporal and posterior temporal gyrus and planum temporale Heschl's gyrus

Global Aphasia

Sum of deficits of wernicke's and broca's Nonfluent and impaired comprehension ALL elements of language are severely impaired Less severe symptoms are "mixed aphasia" Lesions with global: Left Middle Cerebral Artery (Circle of Willis) Recovery often turns to broca's aphasia

Computed (axial) tomography (CT) (CAT) Techniques

The CT scanner sends X-rays through the body area being studied. Each rotation of the scanner provides a picture of a thin slice of the organ or area. An iodine dye (contrast material) is often used to make structures and organs easier to see on the CT pictures. The dye may be used to check blood flow, find tumors, and look for other problems. Remains the examination of choice or the first-line test in may indications including subarachnoid hemorrhage, trauma, and hydrocephalus - High density intracranial regions which are especially significant to students in COMDIS are acute hemorrhages and calcified lesions. - Low density lesions are cerebral chronic infarction, edema, and cystic lesions. Tumors may be either high or low density. · Various radiopaque contrast agents can be used to better characterize pathologic processes. · Intravascular contrast agents can be injected intravenously (most common) or intra-arterially. · Disadvantages - using ionizing radiation, limited resolution, poor differentiation between gray and white matter as well as the inability to diagnose an acute infarct · Advantage - CT remains cost effective compared to newer imaging techniques, especially the MRI.

Cortical mapping

The process of recording electrical activity in the brain by placing electrodes in direct contact with the cerebral cortex. Also, a technique of measuring the electrical activity of the cerebral cortex. · Cortical stimulation brain mapping is used to avoid damaging sensory motor and speech-language areas during cortical resections for seizures, tumors and aneurysms. This technique was extensively used to treat patients with epilepsy and in surgical management of other conditions such as tumors and AVMs.

Sodium Amytal Infusion

WADA test; John Wada language dominance in patients with epilepsy and psychiatric conditions so that electro-convulsive therapy The WADA test became the standard tool for evaluating language dominance in patients with medically contractible epilepsy. Starts with a cerebral angiogram The WADA test has been extensively used for exploring the relationship between cerebral dominance and handedness. The WADA test confirmed that most right handed individuals have left hemisphere dominance for speech, however so do most left handed individuals

Event Related Potentials

Whether the sensory stimulus is visual, somatosensory, or auditory, the ERPs are recorded using electrodes placed at different points on the scalp, usually over the receptive sensory cortex.

Bradykinesia

a slowness of movement

Dysarthria

abnormal strength, speed of articulators (Basal ganglia***) Can comprehend expressive and receptive but articulation is off Hypokinetic- PD Hyperkinetic- Huntington's Spastic can be bilateral, but is often a result of unilateral lesion (stroke) of UMN = breathy, nasal, harsh, slow speaking rate Ataxic= cerebellar disorders

ticks

abrupt and transient stereotypical movements

Integrator

analyzes and combines info received from all sources & modalities

dystonia

atypical posture with abnormally sustained muscle contraction

Lateral

away from the middle

commissure

band of fibers connecting part of the brain or spinal cord on one side with the same structures on the opposite side of the midline

Flexion

bending at limb

CNS

brain and spinal cord

Adduction

bring limb toward center

Two parts to the nervous system

central nervous system and peripheral nervous system

action tremor

cerebellar pathology

prefrontal region

cognitive association cortex - b area 9-11

parasympathetic system

conserves energy and stabilizes system after sympathetic activation

Midbrain

controls eye movement and auditory refelexes

Medulla

controls heart rate and blood pressure

Pons

controls rhythm for respiration

Gyri

cortical ridges

Sulci

cortical valleys

PNS

cranial and spinal nerves

gyrus or convolution

crest of every fold

Subcortical Aphasia

defined by lesions localization rather than characteristics Dysarthric speech/ nonfluent

Mesencephalon (midbrain)

develops into midbrain structures

Rhombencephalon (hindbrain)

develops into the metencephalon & the myelencephalon

Prosencephalon (forebrain)

develops into the telencephalon & the diencephalon

Wilhelm Conrad Roentgen

discovered x-rays in 1895

Agnosia

disorder of recognition

Coronal

divides into front and back parts

Sagittal

divides into left and right parts

Hypothalamus

endocrine and automatic functions o Food, water intake, sexual behavior, body temperature o Hypophysis (pituitary gland)-master gland of the body, secretes hormones that regulate systems involved in sexual drive, pain, emotional drive, temperature control electrolyte control and metabolism

Demyelination

example: MS - Multiple Sclerosis

Dorsal

forebrain - top of brain spinal cord/brainstem - back of body

Rostral

forebrain - toward the nose spinal cord/brainstem - toward the brain

Caudal

forebrain - towards the back of brain spinal cord/brainstem - coccygeal end of spinal cord

Ventral

forebrain - towards the lower brain - towards the jaw spinal cord/brainstem - towards abdomen

efferent

from CNS to body

afferent

from the body to the CNS

inferior frontal lobule

frontal association language cortex; Broca area - b area - 44,45

1st cell layer

glial cells, axons

sulcus or fissure

groove or valley separating gyri

Effector

initiates and controls all body movements

Thalamus

integrates sensorimotor information with speech-language-hearing functions

viscera

internal organs containing nonstriated smooth muscles such as digestive, respiratory

Cerebrovascular accident/ stroke

interruption of blood supply

dyskinesia

involuntary and abnormal movement - squirming

Craniotomy

is a surgical operation in which a bone flap is temporarily removed from the skull to access the brain · Craniotomy is undertaken to remove diseased brain tissue.

Akinesia

lack of voluntary motor activity

3rd cell layer

large pyramidal cells

Corpus Callosum

largest interhemispheric commissural fiber bundle which interconnects most cortical areas of both hemispheres o Parts of corpus callosum § Rostrum, genu, body, splenium o Memories, experiences and actions of both hemispheres are shared and integrated by corpus callosum

Abduction

limb moving away from midline

Regulator

maintains the homeostatic state for the optimum control of peak body performance and repair.

opercular

margins of the cerebral convolutions serving as a cover

Rhombencephalon becomes

metencephalon and myelencephalon

mesencephalon becomes

midbrain

somatic

most axial skeletal and associated muscles that are derived from the somite

What makes up most of the cortex

neocortex

smooth muscles

nonstriated muscles involuntary control (not voluntary)

The beginning of neurolinguistic studies

o 1861- Broca said we speak with left hemi. bc of a lesion on the lower posterior frontal region o 1876- Wernicke noticed a different aphasia impairing comprehension due to a lesion on the left posterior temporal lobe o Broca's & Wernicke's set the groundwork for modern neurolinguistic studies

sympathetic nervous system

o Also called the thoracolumbar system because the preganglionic cell bodies are located in the intermediate-lateral gray matter between the sensory and motor columns in the thoracic and upper lumbar segments of the spinal cord o The sympathetic system mobilizes metabolic energy for expenditure and plays an important role in stressful situations in which a person's heart rate accelerates, arterial pressure rises, blood sugar level increases, and blood flow diverts from the visceral structures to the skeletal muscles

Pons

o Contains all descending motor fibers and ascending sensory fibers, numerous cranial nuclei, the reticular formation and transverse fibers that form the middle cerebellar peduncle (attaches cerebellum to the brainstem)

reticular formation

o Influences brain activity by regulating the altering mechanisms o Integrator of the sensory and motor mechanisms; participates in the generation of well-coordinated motor functions, such as speech, eye-body coordinated movements, swallowing, and respiration o Regulates blood pressure rate, respiration, cortical arousal, and sleep and wake states

Insular Lobe

o Insular cortex- isle of Reil o Concealed within lateral fissure and frontal, parietal, and temporal lobes o Location reveals it is related to limbic and sensorimotor functions

Neocortex

o Layer 1: Molecular- (associational function) terminal dendrites and axons from cortical neurons communicate with neighboring cortical areas o Layer 2: External Granular- (associational function) small granular interneurons receive inputs from other cortical regions o Layer 3: External Pyramidal- (associational function) small pyramidal neurons with projections of neighboring ipsilateral & contralateral cerebral cortex & basal ganglia o Layer 4: Internal Granular- (somatosensation) granular interneurons receive input from thalamus and other subcortical nuceli (all the cortex's listed below help form this layer) o Layer 5: Internal Pyramidal- (descending motor fibers) large pyramidal neurons that project to subcortical sites (brainstem, cerebellum, & spinal cord) o Layer 6: Multiform- multiform layer with some neuronal projections to basal ganglia and remaining to superficial cellular layers within same cortical area

Midbrain

o Link between the cerebral hemispheres and the peripheral and cranial sensory input systems o Contains all incoming sensory and outgoing motor fibers and important reticular and CN nuclei o Responsible for generating neurotransmitters vital to telencephalic, diencephalic, brainstem, and spinal cord functions

Medulla

o Most caudal part of brainstem o Contains all motor fibers that descend to the spinal cord and all the sensory fibers that carry sensory information from the body to more rostral brain areas o Nuclei of medullary reticular formation § Cardiac center- regulates heartbeat § Vasomotor center- monitors blood vessel diameter § Respiratory center - breathing o Injuries to medulla can be fatal

Limbic Lobe

o Older parts of brain, includes the mammalian brain structures o Provide emotional drive to visceral and vegetative functions which are fundamental to survival § Instinctual reflexes and drives, aggression, anxiety, fear o Governs values and decisions about perceptions and feelings, which regulate the intensity and strength of the emotional drive

Basal Ganglia

o Regulates cortical output processing o Regulates motor functions and muscle tone, structures also participate in processes that regulate cognitive functions o Five nuclear masses § Caudate nucleus, putamen, globus pallidus, claustrum, amygdaloid nucleus o Damage to basal ganglia by injury or loss of neurotransmitters causes release of inappropriate behavioral and movement patterns because of disinhibition § Parkinson's, Huntington disease, Tourette's § Involuntary movements- tremors, chorea, ticks, ballism o Substantia nigra, red nucleus, and subthalamic nucleus—additional subcortical nuclei that participate in motor activity § Only functionally related to basal ganglia not structurally

parasympathetic nervous system

o Restores the spent metabolic energy o This system is also known as the craniosacral system because the cell bodies giving rise to preganglionic fibers are in the brainstem and sacral region of the spinal cord o The parasympathetic efferent fibers innervate the visceral structures in the head, neck, thorax, much of the abdominal cavity, and pelvic organs o The cranial section of the parasympathetic system includes the following four cranial nerves (CNs): oculomotor (CN III), facial (CN VII), glossopharyngeal (CN IX), and vagus (CN X)

Cerebellum

o Separated from the cerebral hemispheres above by a meningeal layer of dura mater o 3 layered structure o Contributes to the equilibrium, coordination of skilled motor activity by modifying cortical motor functions o Coordinates and modifies tone, speed, and range of motor functions o Does not initiate motor activity o Each hemisphere has 3 lobes § Anterior, posterior, flocculonodular o Cerebellar peduncles § Connected to brainstem by 3 fiber bundles—superior, middle, inferior peduncles o Afferents from motor cortex by way of pons enter through fibers of middle peduncles o Inferior peduncles- transmit proprioceptive afferent information o Superior peduncle- output of information to opposite motor cortex

Brainstem

o Short extension of the brain that connects the diencephalon to the spinal cord o Consists of the midbrain, pons, medulla o Monitors all brain outputs o Consists of crania nerve nuclei, longitudinal fiber tracts, and reticular formation internally § Reticular formation- integrates all sensorimotor stimuli with internally generated thoughts, emotions and cognition; also responsible for maintaining homeostatic state of brain · Regulates respiration and swallowing · Lesion on reticular activating system- altered state of arousal

Diencephalon

o Thalamus § Above the hypothalamus § Relay sensorimotor information to the cortex § Lesions cause low pain threshold o Hypothalamus § Communicates with the brain, brainstem, and spinal cord by neural and hormonal efferents § 4 primary functions · Autonomic, endocrine, regulatory, drive/emotion § Controls ANS and its functions via brainstem and spinal cord § Contributes to drives and emotions via limbic system

Limbic-axial brain

o The autonomic nervous system (ANS) o Limbic lobe o Hypothalamus o Reticular formation (RF) All are functionally and anatomically integrated and identified as the limbic-axial brain Together, these four components control all visceral and somatic activities vital to sustaining body functions

Limbic lobe

o Transitional structure and central unit of the limbic system o Connects the thinking (neocortical) brain to the non-thinking and older (subcortical) axial brain o Regulates drives, moods, motivation, and visceral activities that relate to the emotional aspects of sensorimotor behaviors and learning

Hypothalamus

o Visceral-somatic and metabolic control system o Functionally related to the limbic system, controls activity of the ANS and regulates instinctual behaviors including copulation, defecation, urination, alimentation, and aggression o Contains selective centers that control respiration, blood pressure, pulse rate, temperature, electrolyte balance, fluid balance, food intake, metabolism, diurnal rhythms, and endocrine production o Contributes to internal emotional state of well-being and pleasure

resting tremor

parkinsons

Pneuoencephalography

performed by injecting air into cerebrospinal spaces through a lumbar puncture

Parietal Lobe contains

postcentral gyrus posterior to the postcentral gyrus angular gyrus

Subtemporal and posterior temporal gyrus and planum temporale

posterior association language cortex, wernicke area - b area 22

anterior to precentral gyrus

premotor cortex - brodmann area 6,8

Heschl's gyrus

primary auditory cortex - b area 41, 42

Precentral Gyrus

primary motor cortex - brodmann area 4

Postcentral gyrus

primary sensory cortex - b area - 3,1,2

angular gyrus

reading and writing - b area - 39

Sensor

receives all environmental and bodily generated changes & stores it

Reticular formation

regulates cortical arousal and attention

tremor

repetitive movement secondary to alternate contraction of opposing muscles

Transverse

right angle to the longitudinal axis

Midsagittal

sagittal cut at the center dividing the brain into 2 equal halves

Longitudinal Fissure

separates cerebral hemispheres

2nd cell layer

small pyramidal cells

posterior to post central gyrus

somoatosensory and association cortex - b area- 5,7

sympathetic system

spends energy in response to fight/flight

Extension

straightening limb

skeletal muscles

striated muscles under volitional control

cardiac muscles

striated muscles, not under voluntary control

Where is dopamine made?

substantia nigra

myoclonus

sudden and momentary contraction of one or a group of muscles

Autonomic system of the PNS

sympathetic and parasympathetic systems

Prosencephalon becomes

telencephalon and diencephalon

Medial

toward middle

Neoplasm

tumor

Prontation

turn palm downward

Supination

turn palm upward

Alexia with agraphia

unable to read or write Auditory comprehension and naming are impaired Lesions to Left Inferior parietal lobe (supramarginal and angular gryi) Overlaps with Wernicke's

Pericalcarine cortical area

visual association cortex - b area- 18, 19

Alexia without agraphia

word blindness- inability to read Left posterior cerebral artery Disconnection syndrome

reticular formation

· Consists of a group of neurons that are interconnected by a complex web of parallel and serial running neuronal circuits · Composes most of the brainstem (medulla, pons, and midbrain) · Inhibit, facilitate, modify and regulate all cortical functions; also integrate all sensorimotor stimuli with internally generated thoughts, emotions, and cognition o "fine-tuner" of cortical functions · Maintains homeostatic state of the brain · The RF uses convergent multimodal input and diffuse divergent output to control the vital centers of the brainstem that regulate cardiac activity, respiration, and swallowing · Clinical symptoms that may occur after lesions of the RF are irregularities in sleep, blood pressure, pulse rate, respiration, vigilance, and states of consciousness

Non-radiologic Studies

· Magnetic resonance imaging (MRI) · Positron emission tomography (PET)

Neuroanatomy

· Neuroanatomy- structural framework of nervous system, consisting of neurons & their tract (fibers) o Also includes ventricular structures, vascular networks, & supporting glial & meningeal tissue

Neuroscience

· Neuroscience- used to identify & explain mechanisms the brain uses to acquire & regulate higher mental functions & to produce both basic & skilled actions (refers to anatomical structures, cellular function, & physiological processes of nervous system)

Hypothalamus

· Occupies a small area in the anterior region of the diencephalon beneath the thalamus · Interconnected with the forebrain, brainstem, and spinal cord, the hypothalamus is the central structure for controlling autonomic and visceral behaviors, such as vasodilation, body homeostasis, anger, reproduction, hunger, and thirst · With projections to the limbic lobe, it provides the substrates for regulating motivation and emotions · Neurosecretory cells regulate the production and circulation of hormones by the pituitary gland · The hypothalamus is connected to the cerebral cortex, thalamus, and midbrain with extensive afferent and efferent fiber tracts · A few functions of the hypothalamus o Regulating autonomic (sympathetic and parasympathetic) functions o Body temperature regulation o Water intake regulation o Feeding o Punishment o Regulation of pituitary gland (secretes hormones and chemical messengers) · Clinical symptoms that commonly result from hypothalamic dysfunction are characterized by disturbances of food intake, water balance, libido, menstruation, and temperature control

Phylogenetically definition

· Phylogenetically- evolution of brain is progressively linear (sequential development of brain) o These structural advancements/ evolutions refer to increased cellular complexity/ cell growth o Cellular growth refers to neurocortex OR 6-layered cellular organization · Neurocortex- Occupies large % of cerebral cortex (only in human brain) o Human brain takes up 2% of our body weight

Autonomic Nervous System

· The ANS involuntarily regulates visceral body functions by controlling the cardiac muscles, smooth muscles, and glands · The ANS is composed of the parasympathetic and sympathetic systems

Standard x-rays

· X-ray technology uses electromagnetic radiation to make images. The image is recorded on a film, called a radiograph. · The parts of your body appear light or dark due to the different rates that your tissues absorb the X-rays. · Calcium in bones absorbs X-rays the most, so bones look white on the radiograph. Fat and other soft tissues absorb less, and look gray. Air absorbs least, so lungs look black. Metal absorbs even more X-rays than bone, as soon by this filling in the tooth