Motor Speech Planning and Production

Motor Speech Planning and Production

• Decision Making: The process of planning and deciding on the speech sounds and movements needed to produce a specific utterance. This involves retrieving and selecting the appropriate sounds and their sequence.

• Relay Center: The brain acts as a central processing unit, connecting different parts of the brain that contribute to motor speech.

• Neuromuscular Junction: The point where nerve impulses from the brain are transmitted to muscles, initiating muscle contraction.

• Cranial and Spinal Nerves: Conduct signals from the brain to muscles involved in speech production, controlling their movements.

• Primary Motor Cortex: The area of the brain responsible for initiating voluntary movements, sending signals through the pyramidal tract to the muscles.

• Pyramidal Tract: A bundle of nerve fibers that descends from the primary motor cortex and conducts motor impulses to the spinal cord and cranial nerves.

• Upper Motor Neuron: Nerve cells located in the brain, responsible for planning, initiating, and coordinating voluntary movements.

• Lower Motor Neuron: Nerve cells located in the spinal cord and brain stem, responsible for directly activating and controlling muscles.

• Cerebellum: A large structure located at the back of the brain, plays a crucial role in coordinating and fine-tuning movements.

• Involuntary Movement: Movements not under conscious control often caused by neurological disorders affecting brain regions like the basal ganglia.

Features of Speech Motor Control

• Speed: Refers to the rate of movement of speech structures, such as the tongue, lips, and jaw.

  • Slow: May be observed in motor speech disorders, including spastic dysarthria and Parkinson's disease (PD).
  • Fast: May occur in hypokinetic dysarthria due to reduced range of motion and increased muscle activity.

• Range: The distance traveled by speech structures during movements used for speech production.

  • Small: A common feature in dysarthria, reducing the amplitude and precision of speech movements.
  • Abnormal Variability: Observed in ataxic and hyperkinetic dysarthrias, resulting in inconsistent and imprecise movements.

• Steadiness: The stability and control of speech movements, ensuring smooth and consistent articulation.

  • Tremor: Involuntary rhythmic oscillations of body parts may be present at rest (resting tremor) or during movement.
  • Random Unpredictable Movements: These include dystonia, dyskinesia, chorea, and athetosis, often associated with dysfunction in the basal ganglia.

• Tone: The amount of resistance a muscle offers to passive stretching.

  • Increased Tone (Hypertonia): A characteristic of spastic and hyperkinetic dysarthrias, often resulting in stiff muscles and difficulty with movement.
  • Reduced Tone (Hypotonia): Found in flaccid dysarthria, leading to weakness and less muscle resistance.

• Accuracy: The precision and control of speech movements, directly affecting the clarity and intelligibility of speech.

• Confirmatory Signs: In addition to speech characteristics, other signs may indicate problems in speech motor control.

  • Cranial Nerve Exams: Examines the function of cranial nerves that control speech production.
  • Non-speech Examinations: Observe facial movement and symmetry, assess for facial expression, and look for involuntary movements.

This quiz explores the key concepts involved in motor speech planning and production. It covers decision making, the role of the brain as a relay center, and the neuromuscular junction's function in speech. Additionally, key structures like the primary motor cortex and pyramidal tract are discussed.