1/27/09 lecture notes

Intro to Communication Disorders 1/27/09 -School-age Milestones -Functional flexibility -Ability to use language for an even larger variety of purposes: compare/contrast, persuade, hypothesize, explain, classify, predict -Reading and Writing: -Alphabetic principle: how orthography (graphemes) relates to phonology (phonemes) -Stages of reading: 1. Decoding k-1 2. Confirmation, fluency, and ungluing print 2-3 grade 3. Reading for learning the new 4-8 (children with reading difficulties begin to have academic difficulties as well) 4. Multiple viewpoints: High school 5. Construction and reconstruction- a world view: college -Form and Content Refinements -Complex syntax, more evident in written language (e.g., persuasive writing -High school graduation, command over 60,000 words -Content development areas: -Multiple meanings, lexical ambiguity, and figurative language Anatomy and Physiology of Speech, Language, and Hearing Sciences -Anatomy- Description of body structures -Physiology- Functions of these structures -Neuroscience- anatomy and physiology of the nervous system, including the brain -Relatively new field because of technological advances (e.g. MRI, PET, CT, etc) -Neurons- Billions of highly specialized cells that make up the nervous system -Cell body -Dendrites- afferent signals (electrical-chemical nerve impulses) -Asons- efferent -Synapse- where one cell?s dendrite meets another?s axon -Neurotransmitters help the nerve impulse across the synaptic cleft -Myelinization -Growth of the myelin sheath- neuron coating that speeds relay of nerve impulse -Slow process; not complete until late childhood -Multiple Sclerosis: neurological disorder caused by incomplete myelinization or loss of myelin -Last place to be myelinated- frontal lobes, which allow you to control and regulate your behavior -Central Nervous system- -Consists of the brain and spinal cord -Allows humans to have unique abilities (which other species don?t possess) -Damage to CNS: -Personality change, loss of cognitive abilities, loss of motor skills (breathing, swallowing, walking etc) -Three protective shields: 1. Bone- skull, vertebral column 2. Meninges (layered membranes)- dura mater, arachnoid mater, pia mater 3. Cerebrospinal fluid (CSF) -CSF is a clear fluid that circulates in the space surrounding the brain -CSF protects the brain and spinal cord from injury by acting like a liquid cushion -CSF is usually obtained through a lumbar puncture (spinal tap). During the procedure, a needle is inserted usually between the third and fourth lumbar vertebrae and the CSF fluid is collected for testing. -The brain -Commander-in-chief and mediator of the entire human body -Portions: -Brainstem -Location: directly on top of the spinal cord -Consists of nerve tracts for sending and receiving information -Major functions: relay station for nerves supplying head and face, visual and auditory reflexes, metabolism and arousal -Three major reflex centers: cardiac (heart), vasometer (blood vessels), respiratory (breathing) -Cerebellum -Location: ?little brain? behind the brainstem -Traditionally thought to be relatively uninvolved in the ?rational part of the brain -Regulates muscular and motor activity -Patients with isolated cerebellar disease have been shown to have impaired spatial cognition, dysprosody (speech problem in which emphasis in speech such as pauses, etc are interrupted), anomia (ability to think of desired words), and executive dysfunction -In normals, cerebellar activation is seen with learning and word generation tasks -Weak correlation between cerebellar activity and IQ and memory -Cerebrum -Largest of the three main parts of the brain -Thinking, problem-solving, planning, creating, and rationalizing -Consists of two hemispheres separated by the longitudinal fissure and connected by the corpus callosum -Peripheral Nervous System- nerves that innervate the rest of the body, cranial & spinal nerves