SPPA 2050 Speech Anatomy & Physiology Physics of Breathing Key Quantities  Pressure (P)  Volume (V)  Flow (U) Boyle’s Law  V=k/P or V P=k  As V ↑ P↓  As V ↓ P ↑

SPPA 2050 Speech Anatomy & Physiology Flow (U) A B

SPPA 2050 Speech Anatomy & Physiology Boyle’s law and breathing inspiration  V t =  P alv P alv < P atm - P alv = - U expiration  V t =  P alv P alv > P atm + P alv = + U P atm : atmospheric pressure P alv : alveolar pressure V t : thoracic volume U: Airflow (- or +) P = k/V: Boyle’s Law

SPPA 2050 Speech Anatomy & Physiology Changing thoracic volume (V t ) Requires  Muscular forces  Elastic forces Strategies  ∆ Length  ∆ Circumference

SPPA 2050 Speech Anatomy & Physiology Length: Diaphragm activity Figure 5.6

SPPA 2050 Speech Anatomy & Physiology Circumference: Rib Cage activity Figure 5.6

SPPA 2050 Speech Anatomy & Physiology

Summary  V lung is changed by changing V t (via pleural linkage)  V t is changed by raising/lowering the ribs (in/decreases circumference)  Raising ribs will  V t = inspiration  Lowering ribs will  V t =expiration Raising/lowering the diaphragm (vertical dimension)  Raising diaphragm will  V t =expiration  Lowering diaphragm will  V t =inspiration

SPPA 2050 Speech Anatomy & Physiology Selected Muscles of Respiration

SPPA 2050 Speech Anatomy & Physiology Intercostal M. Figure 5.9 From Snell

SPPA 2050 Speech Anatomy & Physiology Origin: Inner lip of caudal border of each rib Insertion: Inner lip of rostral border of rib below Action: Interosseus portion: rib depressor Intercartilaginous portion: rib elevator Nerve supply: Intercostal N. (from T1-T11) Internal Intercostal M. Figure 5.11

SPPA 2050 Speech Anatomy & Physiology Origin: Outer lip of caudal border of bony rib Insertion: Outer lip of rostral border of bony rib below Action: Rib elevator Nerve supply: Intercostal N. (from T1-T11) External Intercostal M. Figure 5.10

SPPA 2050 Speech Anatomy & Physiology Intercostal m.

SPPA 2050 Speech Anatomy & Physiology Intercostal M.

SPPA 2050 Speech Anatomy & Physiology Thoracic Wall (Transverse section) From Snell

SPPA 2050 Speech Anatomy & Physiology Levator Costarum M. (costal elevators) Origin: transverse processes of C7-T11 Insertion Brevis: rib immediately below Longis (caudal m. only): 2 nd rib below Action: elevates ribs Nerve supply: Intercostal N. Figure 2.5, 2.13

SPPA 2050 Speech Anatomy & Physiology Superior Origin: spinous processes of C7-T3 Insertion: R2-R5 Action: elevates ribs Nerve supply: Intercostal N. Inferior Origin: spinous processes of T11-L3 Insertion: R8-R12 Action: depresses ribs Nerve supply: Intercostal N. Serratus posterior superior M. Serratus posterior inferior M. Figure 2.5

SPPA 2050 Speech Anatomy & Physiology Scalene M. 3 muscles, anterior, middle and posterior scalenes Origin: transverse processes of C2-C7 Insertion: R1-R2 Action: elevates (or fixates) first 2 ribs Nerve supply: C4-C8 Figure 37.10

SPPA 2050 Speech Anatomy & Physiology Scalene m.

SPPA 2050 Speech Anatomy & Physiology Transverse thoracis M. Origin: body of sternum, xiphoid and chondral surface of R5-R7 Insertion: R2-R6 Action: depresses ribs Nerve supply: Intercostal N. Figure 5.11

SPPA 2050 Speech Anatomy & Physiology Transverse thoracis M. Figure 5.11

SPPA 2050 Speech Anatomy & Physiology Sternocleidomastoid M. Origin: manubrium of the sternum and medial clavicle Insertion: mastoid process of temporal bone Action: elevate the sternum and clavicle Nerve supply: spinal accessory nerve (C. XI) Figure 37.6

SPPA 2050 Speech Anatomy & Physiology Pectoralis Major M. Figure 19.19, 19.25, 22.31

SPPA 2050 Speech Anatomy & Physiology Pectoralis Minor M. Figure 19.19, 19.26

SPPA 2050 Speech Anatomy & Physiology Serratus Anterior M. Figure 19.27