Neural Basis of Speech, Language and Hearing

association areas:

( association areas cover 86% of the cortex): the association areas elaborate information received at the primary motor and sensory areas. The motor association areas are the sites where motor plans, programs, and commands are formulated. The association areas ad meaning and significance to the sensory or motor information received in the primary motor or sensory areas. Certain association areas integrate sensory information from several association areas to establish a higher level of cortical sensory information. P.96

Diencephalon

("interbrain") is the region of the brain that includes the thalamus, metathalamus, hypothalamus, epithalamus, prethalamus or subthalamus and pretectum. The diencephalon is located near the midline of the brain, above the mesencephalon (midbrain).

Centrality of the Central Nervous System

- CNS is responsible for integrating all incoming and outgoing information and for generating appropriate responses to the information received. The response can be volitional such as spontaneous motor movement; or reflective such as withdrawal of a limb. No two parts in the peripheral body can directly communicate with eachother.

Hugo Liepmann

- elucidating the concept of apraxia around the turn of the century. Described as an apraxic disturbance of the tongue in 1866. He used early disconnection theory to explain apracia and demonstrated lesion sites to support the variety of apraxias he described.

Wilder C. Penfield

A Neurosurgeon, used a technique of electrical cortical stimulation to map cortical areas directly, particularly speech and language centers.

Superior, middle, inferior gyri

All in frontal Lobe. Page 26

Contralateral Sensorimotor control

All sensory and motor fibers in the nervos system decussate (cross) the body's midline. The left motor cortex controls movements in the right half of the body. Sensory information from the left hand of the body projects to the right sensory cortex. Most sensory and motor fivers cross the midline in the caudal medulla of the brainstem. Fibers carrying pain and temperature cross the midline in the spinal cord.

William Gowers

An English neurologist, surveyed the neurologic speech disorders known as dysarthrias, in the textbook, "A manual of Diseases of the Nervous system." Published in 1888

9. The central nervous system consists of two structures. Name them.

Brain and Spinal Cord

Third Frontal Convoltion

Broca's Area

Primary Sensory cortex

Brodmann Area 4. Voluntary control of skeletal muscles on the contralteral side of the body.

Supramarginal Gyrus

Brodmann Area 40. Symbolic integration for writing

Joseph Dejerine

Described 2 classic syndromes: 1) Alexia without Agraphia 2) Alexia with Agraphia. Alexia is an acquired reading disorder

Korbinian Brodmann

Developed the most popular map, in which each area of the cortex is numbered.

12. Describe what is meant between a "dominant" hemisphere and a "nondominant" hemisphere.

Dominant= left and Nondominant= Right for speech and language

Lateral Sulcus

Fissure of Sylvius laterally along the brain- separates temporal lobe from parietal and frontal lobes

Jean Charcot

French neurologist, brilliant clinician and neuropathologist who created neurology as a firm discipline. 1871 described "scanning speech" that he associated with "disseminated sclerosis" no known as multiple sclerosis. Described this speech as being very slow, with a pause after each syllable as if the words were being measured or scanned.

Plasticity in the Brain

Functional plasticity is the ability to reorganize and modify functions and adapt to internal and external changes. The inherent plasticity of brain cells permits repair of cortical circuitry, integrates other cortical areas to serve changed functions, and responds to various pathologies. Explains the organizational rearrangement of cellular functions and pathways after strokes and other pathologies

Nonmythical Brain

Its operations are not governed by any personal characteristics of gender, color or cultural variations

Hierarchy of Neuraxial Organization

Lower segment levels perform inherent specific functions that are modified to varying degrees by axial segments above. The spinal cord, the lowest segment level, serves simple sensory motor functions in the form of basic reflexes that are partly influences by the upper axial levels. The cerebral cortex, the highest segment level, is responsible for complex sensorimotor integration and high mental functions such as cognition, language and speech. The intermediate segment, which may be considered the nonthinking part of the brain, is tightly integrated with the cerebral cortex, that serves the highest segment level of decision making.

Superior

Refers to upper, cranial or cephalic can be used in place of superior

Spinal Cord

Serves as the reflex-control center containing fibers to and from the brain and connects the brain with peripheral functions.

Describe the location and primary function of the cerebellum.

The cerebellum is located at the rear of the brain, below and at the base of the cerebrum underneath the occipital lobe. The cerebellum provides fine coordination to the movements of the body and plays a key role in coordination the extremely rapid and precise movements needed for the normal articulation of speech. Involved in the 3 phases of speech production: respiration, phonation, and articulation.

Frontal Lobe

The frontal lobe is responsible for higher biological thought processing and plays a major role in thinking, memory, and language. Prefrontal cortex: contributes to various cognitive functions such as reasoning, abstract thinking, self monitoring, decision making, planning, and pragmatic behavior. Contains several cortical areas involved in the control of voluntary muscle movement like those necessary for production of speech and swallowing.

13. Describe the importance of the corpus callosum to speech and language functions, especially in light of the research conducted with split-brain patients

The importance of the corpus callosum to speech and language functions especially in the light of spilt brain research: provided information on the differing psychological functions of each hemisphere and on the role of the corpus callosum in the brain mechanisms for speech and language. It showed asymmetry for peech and language function. The corpus callosum plays a decisive role in transmitting language heard in the right ear to the left hemisphere. Language is processed in the dominant hemisphere by the major mechanism for speech and language.

Structural and functional specialization

The neuraxis of sensory and motor systems possess specialized nerve cells that are functionally specific and separable. White matter in the brain is composed of many parallel and adjacent pathways conducting various types of information. The motor system also consists of several distinct pathways that transmit differentiated motor information. A second pathway controls speech muscles in the face and neck through cranial nerves in the brainstem.

Dorsal

Towards the Back

Ventral

Towards the abdomen

Posterior

Towards the back

Anterior

Towards the front

Rostral

Towards the nose

Caudal

Towards the tail

Bilateral Anatomical Symmetry

Two cerebral hemispheres are similar anatomically with only minor differences. Both hemispheres are connected through the corpus callosum, the largest of the commissural fibers. Planum temporale appears to be a language coordination center, and connects to Wernicke's area and Heschi's gyrus, which lie just in front of it on the upper surface of the temporal lobe.

Horizontal

a cut perpendicular to both the coronal and saggital planes, divides the brain into upper and lower parts

diencephalon (thalamus and hypothalamus)

a double oval structure above the midbrain is made up of two structures: thalamus and hypothalamus.

Uncinate Fasciculus

a hook like configuration of fibers that passes from the frontal lobe to the temporal lobe.

inferior longitudinal fasciculus

a long association pathway that passes from the temporal lobe to the occipital cortex

Cerebellum

a love like structure lying underneath the occipital love and dorsal to the brainstem. Serves as the motor-coordination mechanism for voluntary motor activity and regulation of skilled movements. The cerebellum is involved in coordination of the 3 phases of speech production: 1)Respiration 2)Phonation 3) Articulation

Hypothalamus

a singular, less well-defined structure lying on the midline of the brain just below and in front of the thalamus. Central site of neuroendocrine production, and the central structure for the control of various metabolic activities such as water balance, sugar and fat metabolism, and body temperature.

Saggital

a vertical cut at any point that passes longitudinally and divides the brain into left and right portions

Coronal

a vertical section made perpendicular to the saggital section, divides the brain into front and back

Motor Cortex

a vertical strip of cortical tissue lying directly in front of the central fissure and is responsible for all voluntary motor activity.

Septum

also known as the septum pullucidum it is thin membrane that divides the lateral ventricles.

Transverse

any section that is at right angles to the longitudinal axis of the structure

primary motor projection areas:

are bilateral cortical strips in the frontal lobes in which voluntary movement patterns are initiated. The motor strip is also a source of descending motor pathways, projecting to lower levels of the nervous system.

Unilateral Functional Difference

at birth, the 2 hemispheres (left and right) has the functional ability to develop all types of skills. Left Hemisphere= Language, Speech production and speech perception. Right Hemisphere= Art, photography, and music also emotions, metaphors and humor. The right half of the brain is also involved with temporospatial attributes and regulating paralinguistic features such as stress and intonation.

Paul Broca

best known contribution to neurology is the concept of functional localization by cerebral convolution. He studied the brains of 2 patients who had a sustained language loss and motor speech disorders. This study allowed him to localize language to a definite circumscribed area of the left hemisphere and laid the foundation for the development of a brain science of speech and language.

Fornix

bundle of nerve fibers that mediates two way connections among hypothalamus, septum, and hippocampus and is important to visceral: respiration, phonation, and digestion.

caudal as it pertains to the human spinal cord

coccygeal end of the spinal cord

Neurophysiology

functional properties of the nervous system with respect to its structural, chemical, electrical and metabolic composition essential to living organisms. Note: Medical and Medical Genetics

lateral

further from the median plane

Neuroembryology

growth of the nervous system during the embryonic period of development extending from conception to 7 weeks, at which time, all brain structures have anatomically emerged Note: Medical and Metabolic Genetics

Neuroradiology

imaging techniques for differentiating pathologic changes of the CNS also Radiation therapy for CNS tumors

Parietal Lobe

is bounded anteriorly by the central sulcus, inferiorly by the posterior end of the lateral sulcus, and posteriorly by an imaginary borderline from the parieto-occipital sulcus extending to the preoccipital notch. Referred to as the "sensory lobe". Associated with sensation, sense of touch, kinesthesia, perception of warmth and cold, and of vibration.

Occipital-frontal fasciculus

is in white matter and passes from the occipital lobe to thr frontal lobe

Occipital Lobe

is located at the most posterior portion of the brain. It is bordered by the parietal and temporal loves and extends backward to occipital pole (most posterior part of the brain). It is dedicated to solely the sense of vision. The ability to recognize shapes, observe, and identify colors and lock onto visual images entering the visual field are visuosensory activities within the function of the occipital love. Coordinated eye movement and stereoscopic vision are also part of the occipital lobe

Temporal Lobe

is located underneath the lateral fissure, extending forward from the occipital lobe to the frontal lobe. It is bounded superiorly by the lateral fissure and posteriorly by an imaginary line that forms the anterior border of the occipital lobe. It is involved in the senses of smell and hearing, and is the seat of auditory processing. Wernicke's area is located here.

Arcuate Fasciculus

is made up of a part of the superior longitudinal bundle. Bundle of nerve fibers from posterior Temporal Lobe to Motor Association Cortex via another set of fibers

Angular gyrus

it is the third prominent gyrus in the parietal lobe. (Brodmann area 39) involved in the visual recognition of visual symbols, integrates visual auditory, and tactile information and carries out symbolic integration for reading.

pons

lies above the medulla, serves in part as a connection to the hemispheres of the cerebellum. (pons, bridge in latin, serves as a bridge to the cerebellum).

Cingulate gyrus

limbic-cortical structure that has emotional, somatic, and automatic functions. Arches of Corpus Callosum

Midbrain

linking the brainstem with the brain, the midbrain controls eye movements and pupil size. Superior to the pons

ventral as it pertains to the human spinal cord

loacations toward the abdomen

c. mesencephalon (midbrain)

located above pons and is the narrowest part of the brainstem. The inferior colliculi serve as way stations in the central auditory nervous system, and the superior colliculi are way stations in the visual nervous system.

Thalamus

located along the midline of the brain just below the corpus collosum, the tract system that connects the two cerebral hemispheres. There is one thalamus on either side of the midline, to which all sensory and motor fibers of a cerebral hemisphere connect. The two thalami are ovoid masses. The thalamus is responsible for- control of all objective behavior (including control of voluntary motor activity for the entire body) and the regulation of sensory input from all body parts, including the special senses for vision and hearing.

dorsal as it pertains to the human spinal cord

locations toward the back of the body

rostral as it pertains to the human spinal cord

locations toward the brain

inferior

lower

Hypothalamus

major diencephalic structure beneath the thalamus that secretes hormones and regulates feeding, fighting, and sexual behavior.

Thalamus

major diencephalic structure on either side of the third ventricle that is important in the sensorimotor integration and projection of the cortex.

Superior longitudinal fasciculus

makes connections from the frontal lobe to parietal, occipital, and temporal lobes in a fan like fashion.

Basil Ganglia

masses of gray matter in the depth of each cerebral hemisphere. Serves as an auxiliary motor system. Plays an important role in the regulation of motor activities (e.g. movement and tone) by modifying the information received from the motor cortex and returning it to the motor cortex.

Corpus Callosum

massive bundle of axonal fibers that interconnects the cortex of two cerebral hemispheres.

primary sensory reception areas

registers impulses relayed from the periphery to the thalamus and upward to the cortex.

Pons

regulates facial movements and sensation. Contains a center responsible for controlling the rhythm of respiration.

Midsaggital

sagittal section as the center separates the brain into two equal halves

Medulla

section of the brain located at the lower end of the brain where it blends into the spinal cord. Contains life-support centers concerned with respiration and circulation. The normal inhalation and exhalation cycles are automaticall regulated at the medullary level. Critical for speech production because of the need for an air supply to produce speech.

interconnectivity in the brain

sensory and motor regions in the cerebrum are connected through association and commissural fibers. Cortical association areas are directly connected to eachother. The primary cortical areas are indirectly connected via the cortical association areas. The 3 main association areas that are widely recognized are the (1) Prefrontal association (2) anterior temporal area (3) parietal-temporal-occipital areas

Nueroanatomy

structural framework of the nervous system, consisting of nerve cells (neurons), fiber tracts, nerves, ventricular structures, vascular networks and supporting glial and meningeal tissues

Neurosurgery

surgery for the removal and remediation of pathologic structures that impair functional organization of the nervous system and is used for the following condtions: ❁ Removal of neoplastic (tumor) tissue ❁ Extraction of blood clots (Hematoma) ❁ Excision of vascular aneurysm (weak bulging spot on the wall of a brain artery) ❁ Removal of carotid arterial plaque ❁ Ablation of functionally impaired "convulsing" tissues ❁ Placement od selective lesions in the thalamus (thalamotomy) for parkinsons disease ❁ Placement of brain stimulation electrodes in the meothalamus (midbran and thalamus) for chronic pain ❁ Removal of herniated disks from the the spine

Describe the primary function of the basal ganglia.

the basal ganglia make connections to other subcortical nuclei, thalamus, brainstem structures and cortical nuclei to form the basal ganglia control circuit, which is part of the extrapyramidal system. They function to help regulate and control motor movements and muscle tone.

Neurology

the diagnosis and treatment of nervous system disorder

Describe the location and primary function of the limbic system.

the limbic system (lobe) is on the medial surfaces of the two hemispheres. The limbic structures provide emotional drive to many visceral, behavioral, and vegetative functions through their connections with diencephalic and brainstrem nuclei. P. 124

medial

towards the medial plane

Central Sulcus

fissure of Rolando- divides the frontal lobe from parietal love

Sigmund Freud

founder of psuchoanalysis, his monumental work. The term Agnosia (disorder of recognition due to cerebral injury) was introduced to neurology by Freud in 1891.

8. Label the ten major structures of the central nervous system marked by the lead lines on the following figure.

...

17. The portions of the cortex on the various lobes that are not assigned as primary motor or sensory areas are categorized as association cortex. Name the three main association areas that comprise the association cortex.

1) Pre frontal association 2) Anterior Temporal Area 3) Parietal Temporal Occipital Areas

The three main parts of the basal ganglia are often grouped together and are referred to as the striatum. List these three main parts

1. Caudet nucleus 2. globus pallidus 3. putamen

William Ogle

1867 published a case that demonstrated that a cerebral writing center was independent of Broca's center for oral language. This was later described as agraphia. A disorder in writing due to cerebral injury

Carl Wernicke

1874, identified the auditory speech center in the temporal lobe. This center was associated with comprehension of speech as opposed to Broca's area in the frontal lobe, which was the expressive speech center. * Lesions in broca's area produced a motor aphasia; Lesions in Wernickes area produced a sensory aphasia

Roger Sperry

conducted split brain studies that revealed specific functions of the right hemisphere as different from the left hemisphere. Split brain patients clearly showed asymmetry for speech and language functions.

medulla oblongata

contains ascending and descending tracts plus the nuclei of several of the nerves tat control phonation, velopharyngeal closure, swallowing, and articulation. Important for the control of speech production.

Prefrontal Lobe

contributes to cognitive functions such as reasoning, abstract thinking, self monitoring, decision making, planning, and pragmatic behavior. Major biological correlate of human intelligence. Brodmanns 10-12

Noam Chomsky

created a scientific revolution in the understanding of syntax and other components of language argued that every human being has the innate capacity to use language.

Neuropathology

nature and etiology of diseased tissue that structurally and functionally disrupts the nervous system

Norman Geschwind

one of two towering figures that have dominated the field of speech and language. He is credited with almost resurrecting the early neurologic literature of Europe focusing on language disorders and related deficits. He highlighted the value of (1) identifying lesions in the connective pathways of the brain as well as (2) diagnosing lesions in the traditional localized cortical areas of the breain that has been associated w/ language disorders over the century.

Describe the location and function of the reticular system.

the reticular system: running throughout the entire length of the brain stem is a diffuse mass of grey matter. The term reticular means net like structure. The neurons of the reticular formation are involved with a wide range of automatic or unconscious functions, including motor control of the visceral organs and contribution to postural tone through input into flexion and extension muscles. The reticular activating system is compromised of a small group of reticular formation neurons and plays a role in consciousness and sleep/wake system.

Topographical organization in cortical pathways

the spatial arrangement of peripheral receptors on the body is discretely maintained within the information carrying pathway and is projected to the brain. This spatial organization of neurons, tracts, and terminals reflects the spatial relationships of the body surface and functionally related muscle groups. The cerebral cortex, is organized with a somatosensory homunculus. These topographical maps of functions help to precisely locate lesions in the CNS.