Exam #1: CH. 3-4 - COMD242

Peripheral Nervous System (PNS)

• Cranial + Spinal nerves

• Carries sensory information to CNS + motor commands away from CNS

• Controls voluntary/involuntary activity

Central Nervous System (CNS)

• Brain + spinal

• Carries sensory info from body to brain via afferent pathways

• Carries motor commands from brain to rest of body via efferent pathways

• Severe damage can:

  • Alter personality (damaged brain)

  • Restrict performance of functions like walking, swallowing, etc. (damaged spinal cord)

Cranial nerves

• 12 pairs, emerging from brain

• Carry motor impulses from brain to face muscles

Spinal nerves

• 31 pairs, emerging from spinal cord

• Interacts w spinal cord to modulate motor + sensory info from body’s periphery

Neurons

Highly specialized cells that make up nervous system; Carry its sensory + motor info

Dendrites

Afferent extensions; Bring nerve impulses into cell body

Axons

Efferent extensions; Take nerve impulses away from cell body

Neurotransmitters

Chemical agents; Help carry info across synaptic cleft (the space btwn axon of transmitting neuron + dendrite of receiving neuron)

Brain stem

• Sits on top of spinal cord

• Conduit btwn rest of brain and spinal cord

• Has nerve tracts that carry sensory info to brain + motor info away from brain; A major relay station for nerves supplying head + face + controlling visual/auditory reflexes

• 3 major reflex centers:

  • Cardiac center (controls heart)

  • Vasomotor center (controls blood vessels)

  • Respiratory center (controls breathing)

Cerebrum

• Largest part of the brain that governs thinking, problem-solving, planning, creating, rationalizing

• Contains:

  • Frontal lobe

  • Occipital lobe

  • Parietal lobe

  • Temporal lobe

Cerebellum

Oval-shaped part of brain, responsible for regulating motor + muscular activity

• ex. Motor-monitoring functions: motor movement coordination, maintain muscle tone, maintain movement range/strength, posture and equilibrium

Corpus callosum

Band of fibers; connects the 2 hemispheres; serves as a conduit for communication between them

Auditory nerve

Auditory info carried in moving fluid of cochlea, interpreted by Corti hairs; Hairs connected to nerve fibers that exit cochlea + travels to brain thru this nerve

Interconnectedness

2 hemispheres + combined lobes constantly interact via a rich weaving of brain fibers; while one area brain might be recognized as critical for a particular brain function, brain activity reflects ongoing info from across brain’s regions.

• ex. When children comprehend verbs (but not adjectives), regions of the brain that correspond to motor behaviors are also activated

Specialization

Brain organized into 2 hemispheres that communicate via the corpus callosum

Plasticity

Learning overtime; Brain’s capacity to (re)organize its functions as a result of experience

• ex. Children who lose their sight early in life can process auditory info. better than children w sight (brain reorganizes itself to compensate for the visual deprivation)

Hierarchical Organization

Central nervous system is organized in manner which the more sophisticated or complex the behavior, the greater the involvement of the brain:

• Lower-level functions can be directed by the spinal cord

• Higher-level functions require mediation by brain’s cerebral cortex

Central Nervous System (CNS)

Brain + spinal cord; carries sensory info to brain and motor commands to body; damage can alter personality or impair functions.

Swallowing phases

1. Oral (preparatory + transport)

2. Pharyngeal

3. Esophageal

Oral Phase

• Bolus modified into form that’s readily transported thru pharynx + esophagus to stomach

• Requires mastication

• Has 2 phases within itself

Oral Preparatory Phase

Preparation of bolus and placement of bolus

• Bolus preparation needed to reduce food to digestible form (ex. popcorn)

• Bolus enters oral cavity → tongue moves it to middle cavity, sits on tongue blade btwn molars

• Bolus broken down thru chewing + grinding process using molars

• Saliva secreted by salivary glands, moistens bolus to reduce it

• Once masticated, bolus again placed on tongue blade btwn molars → awaits transport via swallow

Oral Transport Phase

4 acts in swallow:

• Soft palate elevates + closes off nasal cavity

• lips contract → creates tight oral seal

• tongue blade drops, bolus descends into oral cavity

• tongue tip rises to press against the hard palate

Pharyngeal Phase

When bolus reaches tonsils:

• Epiglottis drops to protect + seal larynx from bolus

• From tonsil ring in rear of oral cavity, bolus descends into the pharynx

Esophageal Phase

Esophagus has 2 sphincter muscles, aid in propelling the bolus thru esophagus:

• Involuntary contractions aka peristalsis

• Bolts reaches stomach and intestines for digestion

Penetration

Entry of food/drink into laryngeal area

Aspiration

If penetration goes too far; Passage of food/drink beyond larynx and into lungs

Deglutition

3 phase process; Moves a bolus from lips to stomach → keeps it from penetrating larynx + respiratory system

Dysphagia

Disorder of swallowing

Complex communication causes

• Intellectual Disability

• Cerebral Palsy

• Autism Spectrum Disorder

• Childhood Apraxia of Speech

• Traumatic Brain Injury

• Stroke

• Degenerative Disease

AAC System Components

• Symbols

• Aid

• Strategy

• Technique

AAC Technique

The way messages are transmitted through:

• Direct selection

• Indirect selection

AAC Aid

Type of assistive device used to send/receive messages

Electronic AAC aid

Speech‐generating devices (SGDs)

Non-electronic AAC aid

Either no technology or low/light technology

• ex. Child using communication book with photographic symbols

Assistive technology

Aids promoting communication + other aspects of well‐being, such as physical or motor performance

AAC Symbols

Aided and unaided

• Acoustic

• Graphic

• Manual

• Tactile

AAC Team Members

• Complex communication needs individuals

• Parents

• Teachers

• SLPs, PTs, OTs

• Rehabilitation engineers

• Social workers, psychologists, counselors

• Nurses, doctors

AAC Strategy

Way symbols are effectively, efficiently conveyed; how AAC is used

• ex. Setting topic before initiating convo; Using software that predicts letters or words, eliminating keystrokes; Giving an index card to unfamiliar complex comm. partners to explain how one communicates

AAC Intervention program

Determining ways to support individual’s use of strategies to enhance communicator’s effectiveness/efficiency

Purpose of AAC

Factors affecting communication, barriers to desired participation, AAC system that would enhance:

• Express needs, wants

• Transfer info

• Social closeness + etiquette

• Communication + participation

Complex Communication Needs

• Exists when individuals cannot meet daily communication needs through their current method(s) of communication

• Emphasizes importance of speech, language, and/or cognitive abilities for a person’s participation in society rather than focusing on the disorder

Feature Matching

Approach to determine which technology best supports communication; a framework of clinical decision making

Direct selection

A motor act that is not dependent on time; contains four types:

1. Physical pressure/depression (selecting symbol w pressure, like instrument attached to body)

2. Physical contact (touching aid)

3. Pointing with contact (ex. eye pointing)

4. Speech/voice recognition

Indirect selection

Motor act dependent on time; contains three types:

1. Scanning (AAC user waits til desired symbol is presented)

2. Directed scanning (uses switches/joysticks to select target location)

3. Coded access (ex. Morse code)

Directed scanning

Indirect technique using switches/joystick to move a cursor to target location; Hybrid of typical scanning; Individual selects a scanning direction, then makes a selection

Coded access

Requires individuals to use a sequence of movements to select a symbol from a set

• ex. Morse code inputted to SGD by using switches

Speech

Neuromuscular process allowing language expression as a vocal product

Model of Speech Production

3 stage process:

• Perceptual Target

• Motor Schema

• Speech Output

Perceptual Target

Cognitively based conceptualization of phonemes (smallest unit of sound); Abstract representation of speech sound stream is generated

• ex. The word mama has 4 phonemes: /m/ /a/ /m/ /a/

Motor Schema

Neurological brain systems generate rough plan of abstract representation; phonemes organized into syllable chunks to muscle groups involved with speech

• ex. /ma/ /ma/

Speech Output

Carried out by air flow, vocal cords, oral cavity

Speech Production

• Respiration

• Phonation

• Articulation

Systems Involved in Respiration

Lungs, trachea

Respiration in Speech Production

Initiates and modulates exhaled airflow sent thru larynx, over the vocal folds, into muscles from oral + nasal cavities → Manipulated to make different speech sounds

Systems Involved in Phonation

Larynx, epiglottis

Phonation in Speech Production

Takes energy sent upward from lungs and further modulates airflow → Converts the energy into sound

Systems Involved in Articulation

Mandible, lips

Articulation in Speech Production

Manipulation of airflow submitted by the phonatory system → Creates highly precise speech sounds