Anatomy and Physiology of Speech & Language
Chapter 3: Anatomy & Physiology of Speech & Language
Page 1: Introduction of Chapter
Overview of the anatomical structures and physiological processes that contribute to speech and language production, emphasizing their interconnections and clinical relevance.
Page 2: Agenda
Topics Covered:
Introduction to speech anatomy and physiology
The respiratory system's role in speech production
The phonatory system and voice generation
The resonatory system's contribution to sound quality
The articulatory system for speech sounds
The nervous system coordinating these processes
Page 3: Introduction
Purpose: Understanding anatomy and physiology is essential for effective assessment and treatment in speech-language pathology, guiding clinical interventions.Foundation of Speech:
Anatomy: Involves the physical structures like the lungs, vocal folds, and articulators critical for speech.
Physiology: Refers to how these structures function and work in concert to produce speech, encompassing both voluntary and involuntary actions.
Clinical Practice: Recognizing that various conditions can alter these systems allows clinicians to devise targeted therapies; importantly, most speech processes occur without conscious effort.
Page 4: Speech Systems Overview
Key Structures:
Soft Palate: Crucial for separating oral and nasal cavities during speech.
Nasal Cavity: Plays a role in voice resonance and quality.
Pharynx: Functions in the passage of air and sound resonance.
Larynx: Houses vocal folds and is instrumental in phonation.
Trachea: Main airway conduit to the lungs.
Lungs (right and left, with lobes): Main organs for breathing; crucial for producing airflow.
Clinician Insight: Grasping the anatomy and physiology involved in speech helps professionals implement customized treatment plans.
Page 5: Respiratory System
Focus: Examination of the respiratory system, which is foundational for speech production, providing the necessary airflow.
Page 6: Respiratory System Fun Facts
Breathing Rate: Average of 15 breaths per minute, with cycles occurring approximately every 4 seconds.Key Terms:
Inspiration: The process of inhaling air into the lungs.
Expiration: The process of exhaling air from the lungs.
Page 7: Structures of Respiration
Components:
Rib Cage & Sternum: Provide vital structural support and protection for thoracic organs.
Thoracic Cavity: Encloses the lungs and heart; the measurement from the clavicle and first rib to the 12th rib is significant for respiratory expansion and contraction.
Page 8: Steps of Inspiration
Air Flow Process:
Air enters through the nostrils into the nasal cavities, where it gets filtered and warmed.
Passes through the larynx, bypassing the abducted vocal folds, minimizing resistance.
The trachea bifurcates into the mainstem bronchi, which penetrate the lungs.
Within the lungs, bronchi branch into smaller bronchioles, facilitating gas exchange.
Page 9: Bronchi Structure
Diagram:
The mainstem bronchus divides into secondary and tertiary bronchi, which lead to individual lung lobes, allowing for efficient air distribution.
Page 10: Muscles of Respiration
Muscle Count: 26 pairs of muscles collaborate in respiratory movements.
Diaphragm: The primary muscle of respiration, dome-shaped, separates thoracic and abdominal cavities, expanding when contracted (inspiration) and relaxing upwards during expiration.
Intercostal Muscles: Assist in expanding and contracting the rib cage, crucial for airflow regulation.
Page 11: Process of Respiration
Neural Control: The brainstem transmits signals to the respiratory muscles to initiate and modulate breathing.Mechanism:
As the diaphragm contracts, the thoracic cavity enlarges, resulting in reduced air pressure within the lungs.
This negative pressure draws air in via environmental pressure until the lungs inflate; during expiration, air is expelled as the diaphragm relaxes and internal pressures increase.
Page 13: The Phonatory System
Introduction: Exploration of the phonatory system and its critical role in generating voice.
Page 14: Framework of the Larynx
Larynx Location: Positioned between the trachea and the hyoid bone, integral for phonation.Cartilages:
Thyroid Cartilage: Protects the vocal folds and forms the prominent Adam's apple.
Cricoid Cartilage: Positioned atop the trachea, supports the larynx while facilitating movement.
Arytenoid Cartilages: Comprising a pair that regulates the opening/closing of vocal folds.
Epiglottis: Functions as a gatekeeper, preventing food from entering the trachea during swallowing.
Page 18: The Vocal Folds
True Vocal Folds: Composed of muscle and mucous membranes; they are integral to voice production and create a barrier to protect the airway.
Glottis: The area between vocal folds, critical in sound production.
False Vocal Folds: Serve a supportive role in voice and are not directly involved in sound generation.
Page 20: Process of Phonation
Steps:
The brain sends signals to the vocal folds to close as exhalation commences.
Air pressure accumulates below the closed folds, ultimately forcing them open to create sound.
The sound generated travels upward through the vocal tract, where it is articulated.
Page 23: Voice Characteristics
Frequency: Corresponds to the number of vibrations of the vocal folds per second (measured in Hz). Notably, fundamental frequency varies between genders, influencing voice pitch.Intensity: Reflects the force of vocal fold closure (measured in dB), contributing to loudness perception. Quality: Encompasses a subjective evaluation of voice attributes, e.g., tense, breathy or resonant qualities.
Page 24: The Resonatory System
Key Structures:
Facial Structures: Encompasses various articulators crucial for speech.
Articulators: Include hard palate, alveolar ridge, soft palate (velum), and pharynx, all integral for sound shaping and resonance.
Clinical Insight: Awareness that abnormal anatomical configurations can lead to physiological issues, resulting in speech and language disorders.
Page 26: Process of Resonation
Velopharyngeal Closure:
The soft palate elevates to ensure separation between oral and nasal cavities for optimal articulation of most sounds, except nasal sounds (/m/, /n/, /ng/).
Page 27: The Articulatory System
Overview: This system includes sensory and motor functions necessary for the precise movements of the articulators that create speech sounds.
Page 29: Skeletal Structures of Articulation
Facial Bones Involved:
Frontal Bone: Forehead region of the skull.
Temporal Bones: Side of the skull, important for hearing and balance.
Zygomatic Bones: Known as cheekbones, they structure the midface region.
Maxilla: The upper jaw; significant for articulation.
Mandible: The lower jaw, plays a key role in jaw movement and articulation.
Page 30: Lips and Cheeks
Articulation Support:
Orbicularis Oris: A circular muscle surrounding the mouth controlling lip movements, crucial for sound production.
Masseter: The primary muscle facilitating jaw movement and chewing activities.
Page 31: The Role of the Tongue
Functions: Responsible for taste, movement of food, and articulation of speech sounds.Abnormalities: Variations in range of motion or coordination of the tongue can significantly impact speech intelligibility.
Page 34: The Nervous System
Definition: Encompasses the brain, spinal cord, and peripheral nerves, facilitating communication within the body, including coordination of speech processes.
Page 36: Overview of CNS
Components:
Brain: The control center for most bodily functions.
Cerebellum: Coordinates voluntary movements and balance.
Brainstem: Connects the brain to the spinal cord, regulating vital functions like breathing and heart rate.
Spinal Cord: Transmits signals between the brain and the rest of the body.
Page 38: Brain Lobes and Functions
Lobes:
Temporal Lobe: Key in auditory processing and memory.
Frontal Lobe: Involved in cognition, planning, and motor function, including speech production.
Parietal Lobe: Affects sensation and perception.
Occipital Lobe: Responsible for visual processing.
Page 41: Brainstem and Spinal Cord
Roles:
The brainstem connects the brain with the body, housing cranial nerves that perform essential sensory and motor functions vital for speech.