SPPA 2050 Speech Anatomy & Physiology

Physics of BreathingKey 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

Vt = Palv

Palv < Patm

- Palv = - U

expiration

Vt = Palv

Palv > Patm

+ Palv = + U

Patm: atmospheric pressure Palv: alveolar pressureVt: thoracic volumeU: Airflow (- or +)P = k/V: Boyle’s Law

SPPA 2050 Speech Anatomy & Physiology

Changing thoracic volume (Vt)

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

SPPA 2050 Speech Anatomy & Physiology

Summary Vlung is changed by changing Vt (via pleural linkage)

Vt is changed by

raising/lowering the ribs (in/decreases circumference) Raising ribs will Vt = inspiration

Lowering ribs will Vt =expiration

Raising/lowering the diaphragm (vertical dimension) Raising diaphragm will Vt =expiration

Lowering diaphragm will Vt =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): 2nd 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.

InferiorOrigin: spinous processes of T11-L3Insertion: R8-R12Action: depresses ribsNerve 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