Anatomy and Physiology Exam 1 - October 16

Chapters 1-4

Anatomy

Structure

Physiology

Function

Structure → function → behavior =

Vocal folds → adduct +vibrate → voice

Communication is a system

Thought → (brain → nerves → muscles → structure → air → sound) → (ear → nervous system → brain) → understanding.

Stages of spoken communication

1. Neural

2. Muscular

3. Structural

4. Aeromechanical

5. Acoustic

6. Auditory mechanical

7. Sensory

8. Neuroperceptural

Neural

Brain plans and sends message

Muscular

Nervous signals activate muscles to produce force

Structural

Structures of speech mechanisms move

Aeromechanical

Movement change air pressure and cause air to flow

Acoustic

Sound waves are produced and travel through the air

Auditory mechanical

Sound waves reach the ear and cause its structures to vibrate and move slightly

Sensory stage

Sensory cells convert vibrations to electrical signals that are sent through the nervous system

Neuroperceptual

The brain processes and interprets the signals to perceive and understand the message

Velopharyngeal - Nasal

Includes both velopharngeal and nasal structures. Nasal is important for understanding the aeromechanical and acoustic functions of this part of the speech system.

Pharyngeal - oral

Middle and lower pharynx and oral cavity and associated structures. Reflects the fact that during speech production the part of pharynx act as an articulator and resonator along with oral counterparts.

Respiratory subsystem

The pulmonary apparatus (lungs and lower airways) and the chest wall that surrounds it (rib case, diaphragm, abdomen and contents)

Laryngeal

Vocal folds and other structures located at the exit of the respiratory system.

Hearing subsystems

Outer/ middle/ inner ear

Toward directional terminology

Anterior, superior, meidal, proximal, superficial, ipsilateral

Away directional terminology

Posterior, inferior, lateral, distal, deep, contralateral

Neural tissue

Found throughout the nervous system. Includes brain, spinal cord, and peripheral nerves

Efferent

OUT

CNS → peripheral nerves → muscles

Carries motor commands

Afferent

IN

Sensory receptors → peripheral nerves → CNS

Carries sensory info

Mechanoreceptors

Respond to mechanical stimuli. Convert mechanical changes into neural signals, particularly important for speech and hearing.

Motor unit

One efferent peripheral nerve = the muscle fibers it controls.

• Motor units vary in size

• May include few or many muscle fibers

Muscle tissue

Involuntary

• Smooth: organs, blood vessels

• Cardiac: heart

Voluntary

• Skeletal: movement and posture

• Most relevant to speech and hearing

Fascicles

• Bundles of parallel muscle fibers

• Surrounded by connective tissue

Fast contracting

• Rapid force

• Fatigue more quickly

Slow contracting

• Sustain force longer

• More resistant to fatigue

Connective tissue

Supports, connects, and stabilizes structures

Supports: Bone and cartilage

Connect tissue proper

• Tendon: muscle → bone/ cartilage

• Aponeurosis: broad, flat tendon

• Ligament: connect bone/ cartilage to bone/ cartilage

Epithelial tissue

Covers and lines body surfaces

Ex:

• Surface of the skin

• Lining of the oral cavity

Primary role: protection of underlying tissues

Stratified squamous epithelium

Multiple layers of cells and protective surface

Pseudostratified columnar epithelium

Single layer that appears multilayer

Neural signal → muscle activation → force

Vocal folds → adduct + vibrate → voice

Concentric muscle contraction

Shorten and produces movement

Isometric

Stays the same length and holds/ stablizes

Eccentric

Lengthens and controls movement

CNS

• Brain/ spinal cord

• Process and control

PNS

• Cranial nerves/ spinal nerves

• Connect CNS to body and vise versa

Process of nervous system

1. plan

2. motor command

3. movement

4. sensory feedback

5. compare and adjust

White matter

Myelinated axons. CONNECTIONS.

Gray matter

Neuronal cell bodies. PROCESSING

Location and name changes

CNS (cell bodies → nucleus) (axons → tract)

PNS (cell bodies → ganglion) (axons → nerve)

Cerebral hemispheres

• Separated by: longitudinal fissure

• Connected by: corpus callosum

• Surface: gyri + sulci

Cortex

Outer gray matter

White matter

Axonal connections

Subcortical nuclei

Deep gray matter

Lobes

1. frontal: movement and planning

2. parietal: somatosensory processing

3. temporal: auditory processing

4. occipital: visual processing

Basal ganglia

Refines motor commands

Thalamus

Major relay station

Cerebellum

Coordinate timing and movement

Brainstem

Midbrain → pons → medulla → spinal cord

Brainstem role

Speaking, swallowing, hearing → brainstem and cranial nerves

Spinal cord

• Central H-shaped gray matter

• Surrounding white matter

• Dorsal: sensory input

• Ventral: motor output

“Good morning”

Cortex → white matter → brainstem/ spinal cord → peripheral nerves → muscles → sensory info returns

Specialization

Different regions make different contributions

Integration

Complex behaviors depend on connected networks

Speaking - Hearing - Swallowing

Networked behaviors

Primary motor cortex = precentral gyrus

Issue motor commands → brainstem/ spinal cord → muscles

Somatotopy

Body is represented systematically across motor cortex

Larger cortical area does not equal larger body part.

• Face

• lips

• tongue → large representation

Premotor + supplementary motor areas

Plan movement → primary motor cortex

Planning problem

Apraxia

Execution problem

Dysarthria

Angular gyrus

Higher order language and meaning

Supramarginal

Speech sounds, words, action-language connections

Temporal lobe

Heschls gyrus → initial cortical processing of auditory signals → more complex auditory/ language processing

Wernickes area

Language comprehension but meaning recruits distributed cortical networks

Corticospinal

Cortex → spinal cord motor neurons → spinal nerves → BODY

Corticobulbar

Cortex → brainstem motor nuclei → crainial nerves → Head and neck/ speech and swallowing

Corticospinal tract (most fibers cross in the medulla)

Left cortex → cross → right body → right cortex → cross → left body

Corticobulbar tract

Left and right cortex → brainstem motor nuclei → crainal nerves → head and neck muscles

Basic motor pathway

Upper motor neuron → lower motor neuron → muscle

Spinal cord dorsal

Primarily sensory increase sensory info enters/ ascends

Spinal cord ventral

• Motor descend motor info exits

• Spinal nerves (mixed): contain sensory and motor fibers

Phrenic nerve

C3/ C4/ C5 → phrenic nerve → diagram → respiration

Motor direction - efferent

Cortex → descending tract → brainstem/ spinal cord → peripheral nerve → MUSCLE

Sensory direction - afferent

Sensory receptor → peripheral nerve → brainstem and spinal cord → ascending tract → cortex

Sensory pathway (may include touch, pressure, pain, temperature, taste, sound)

Position and movement → brainstem and spinal cord → ascending tracts → thalamus → cortex

Movement is NOT an open loop

Move → feel and hear → compare → adjust

Cranial nerves

Cortex → corticobulbar tract → brainstem motor nucleus → cranial nerve → speech/ swallowing muscle

V

Trigeminal - jaw movement and facial/ oral sensation

VII

Facial - facial/ lip movement and taste

VIII

Vestibulocochlear - hearing and balance

IX

Glossopharyngeal - pharyngeal sensation/ function and taste

X

Vagus - voice, pharynx, larynx, swallowing

XI

Spinal accessory - head and neck movement

XII

Hypoglossal - tongue movement

Respiration in speech

1. Respiration (energy/ airflow)

2. Phonation (sound source)

3. Resonance (filter)

4. Articulation (shape speech)

Pulmonary apparatus

• Luns

• Pulmonary airways

• Air containing and conducting, gas exchanging portion of the system

Chest wall

• Rib cage

• Diaphragm

• Abdominal wall

• Abdominal content

• Surrounds and mechanically acts on the pulmonary apparatus

Skeletal framework

• vertebral column (posterior midline support)

• 12 pairs of ribs (form most of the rib cage)

• sternum and costal cartilage (anterior connections)

• pectoral girdle (clavicles and scapulae)

• pelvic girdle (base of lower framework)

• Matters because bone/ cartilage provide the framework and attachment points that respiratory muscles act on

Thorax

heart and lungs

Abdomen

Abdominal content

Lungs

Paired, porous, spongy structures with elastic fibers

Pulmonary airways

Flexible branching tubes that conduct air to, from, and within the lungs

The pulmonary tree

1. trachea (trunk)

2. mainstem bronchi (R and L)

3. lobar bronchi (5 lobes)

4. smaller bronchi (branching)

5. bronchioles (smaller)

6. alveolar region (gas exchange)

Alveoli

extremely small, air-filled cul-de-sacs at the distal end of the pulmonary tree

Primary role

Site where oxygen and carbon dioxide are exhanged

Parietal pleura

Lines the inner surface of the chest wall