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
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
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
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
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
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
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
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