Module 1 Anatomy & Physiology of the Speech and Hearing Mechanisms

Physiology: the function of living organisms
- Greek origin: “Physis” means “nature” or “origin”
- Physiology studies the function of the living organism and its parts, including the chemical processes involved
Speech physiology: study of the speech mechanism
- Key questions:
- How does the brain control speech production?
- How are speech sounds produced?
- How does speech production change under various task demands (e.g., multitasking, fast speech)?

Axial skeleton: head and trunk; spinal column is the axis
Appendicular skeleton: upper and lower limbs
Planes:
- Sagittal: divides the body into left and right portions
- Frontal/Coronal: front and back portions
- Transverse: upper and lower portions
Orientation terms (anterior/ventral vs dorsal/posterior):
- Anterior (ventral): front surface of the body (ventral in quadrupeds)
- Dorsal (posterior): back surface of the body or toward the rear
Peripheral vs central relations: peripheral relates to the periphery or away from the center
Distal vs proximal: distal is away from the midline or point of attachment; proximal is toward the root or attachment point

Body planes and directional terms include:
- Cranial, Superior, Inferior
- Right, Left
- Proximal, Distal
- Posterior (dorsal), Anterior (ventral)
- Medial, Lateral
Views: Lateral view, Anterior view
Directional references summarize how structures relate to each other in three dimensions

Palmar: palm of the hand
Plantar: sole of the foot
Pronation: to place an organism in prone position or rotate so that the palm/sole faces downward
Supination: place an organism in supine position or rotate so that the palm/sole faces upward

Four primary tissue categories:
- Epithelial
- Connective
- Muscular
- Nervous
Epithelial tissue basic classifications:
- Simple epithelium: single layer of cells
- Compound (stratified) epithelium: multiple cell layers
- Basement membrane: baseplate that anchors epithelium to connective tissue

Simple epithelium varieties:
- Squamous: flat cells; locations include lining of blood vessels, heart, alveoli
- Cuboidal: secretory in function; locations include glands
- Columnar: cylindrical cells; lining for stomach, intestines, gall bladder and bile ducts
- Ciliated: columnar cells with cilia; lining of nasal cavity, larynx, trachea, bronchi
Compound (stratified) epithelium:
- Stratified: flattened cells on a bed of columnar cells; example: epidermis of skin, lining of mouth, pharynx, esophagus, conjunctiva
- Transitional epithelium: pear-shaped cells; example: lining of the bladder
Basement membrane: mainly collagen; serves to join epithelial and connective tissues

Simple squamous: lines blood vessels and air sacs of lungs; permits exchange of nutrients, wastes, and gases
Stratified squamous: outer layer of skin, mouth, vagina; protects against abrasion, drying out, infection
Simple cuboidal: lines kidney tubules and glands; secretes and reabsorbs water and small molecules
Stratified cuboidal: lines ducts of sweat glands; secretes water and ions
Simple columnar: lines most digestive organs; absorbs nutrients, produces mucus
Goblet cells: mucus-secreting cells often associated with epithelium
Stratified columnar: lines epididymis, mammary glands, larynx; secretes mucus
Basal basement membrane as a structural foundation

Types:
- Striated (skeletal): voluntary muscle
- Smooth: muscles of internal organs; involuntary
- Cardiac: combination of striated and smooth features; heart muscle

Involves integrated action of multiple body systems:
- Respiratory system
- Phonatory system
- Articulatory system
- Resonatory system
- Nervous system
None of these systems operates in isolation; coordinated interaction is essential for speech, hearing, and swallowing
Practical takeaway: Understanding structure and function at multiple levels helps explain how speech is produced, heard, and swallows are managed in real-world tasks