A&P of Speech SPTH 5570; Anatomy of Respiration C: Muscles of Respiration; Created 2-18-15; Dr. Gibson

Posterior Abdominal Muscles Exp. (1)

Muscle: -Quadratus Lumborum Function: -Bilateral compression fixes abdominal wall to support abdominal compression

Abdominal Muscles of Expiration: *Anteriolateral

Muscles: -Transeverse Abdominus -Internal Oblique Abdominus -External Oblique Abdominus -Rectus Abdominus Functions: -Compress abdomen -Rotate & flex trunk -Compress abdomen -Felxes vertebral column

Muscles of Upper Limb (1)

Muscles: Latissimius Dorsi Function: For respiration, stabilizes posterior abdominal wall for respiration

Vena Cava

One of two large veins that drain blood directly in the heart. The superior vena cava & inferior vena cava are the two largest veins in the body

Insp. Muscles of Upper Arm & Shoulder -Pectoralis Minor

Origin: Anterior surface ribs 2-5 near chondral margin Insertion: Coracoid process of scapula Function: Incorporates transverse dimension of rib cage

Aponeuroses

Layers of flat broad tendons

Alveolar Pressure

*Alveolar pressure, measured in cm H20, within the alveoli, is the smallest gas exchange unit of the lung. Alveolar pressure is given with respect to atmospheric pressure, which is always set to zero. Thus, when alveolar pressure exceeds atmospheric pressure, it is positive (high); when alveolar pressure is below atmospheric pressure it is negative (low).

Accessory Muscles of Inspiration (14)

*Anterior thoracic (2) *Posterior thoracic (2) *Accessory neck (2) *Upper arm & shoulder (8)

3 Hiatuses (Openings) of Diaphragm

*Aortic-Descending abdominal aorta *Esophageal- Esophagus, Small arteries *Foramen Vena Cava- Inferior vena cava, lymph vessles & nerves

What are the 5 Pressures for Non-Speech & Speech Functions

*Atmospheric: (measure for earth) *Intraoral (mouth): Mouth *Subglottic: Below vocal folds *Intrapleural (pleural): Between the pleura *Alveolar: Within alveouls *High pressure moves to low pressure

Exhalation

*During active exhalation the most important muscles are the abdominal wall (including the rectus abdominus, internal & external obliques & transverse abdominus) which drive intra-abdominal pressure up when they contract, & thus push up the diaphragm, raising pleural pressure , which raises alveolar pressure, which in turn drives air out. The internal intercostals assist with active expiration by pulling the ribs down & in, thus decreasing thoracic volume. This high (positive) pressure forces the air from the lungs & prepares them for another inhalation. *During quiet breathing exhalation is normally passive. The elastic recoil force does most of the work.

Phases of Exhalation

*Inhalation: the abdominal muscles and internal intercostals (rib muscles) relax but not completely, and the external intercostals contract to fully expand the rib cage; the diaphragm contracts and descends, which also enlarges the lung space. *Exhalation, first phase: since the rib cage has been expanded more than it is at rest, it will tend to 'relax' back to its rest position if no muscular effort is keeping it expanded; this "relax back" motion is called elastic recoil. The pressure from recoil is all that is needed to start the airflow; in fact, if an especially deep breath was taken, the pressure from the recoil will be greater than desired, and the air pressure will need to be restrained somewhat by continued contraction of the diaphragm *Exhalation, second phase: The last of the elastic recoil is used up in this phase, aided by contraction of the internal intercostals. These pressures shrink the rib cage, adding to the lung pressure. *Exhalation, third phase: The abdominal muscles are used to provide the last bit of lung pressure possible.

Muscles of FE: Anterior Lateral Thoracic Muscles (3)

*Internal Intercostal *Transverse Thoracis *Innermost Intersostals Function: Depress ribs & ribcage

Phrenic Nerves

*Originate in the cervical plexus *Signal nerves C3, C4 & C5 from both side of the spinal cord *Has both sensory and motor functions

Muscles of Upper Arm & Shoulder (8)

*Pectoralis Major *Pectoralis Minor *Lavatore Scapulae *Rhomboideus Major *Rhomboideus Minor *Trapezius *Serratus Anterior *Subclavius

Innervation of the Diaphragm

*Phrenic nerve: Bunches of cervical nerves bind to form phrenic nerve. The phrenic nerve innervates the diaphragm. *How it works: A need for oxygen (sensory) is sent to the medulla obongata (part of brainstem) in the form of neuronal impulses from the brain and spinal cord (sensory impulses). The medulla, then which sends impulses (motor) to phrenic nerve, which innervates the diaphragm. The ribcage which houses the diaphragm is attached anteriorly to the sternum and posteriorly to vertebrae. The diaphragm is the floor of the ribcage. The lungs (spongy with no muscle) rest on the diaphragm. The lining of the ribcage contains costal pleura and a deeper lining around the lungs called pulmonary pleura. The costal and pulmonary pleura work together to enable the lungs to change its shapes as the thorax changes. When the neuronal stimulation is large enough for a contraction, then the diaphragm flattens. The thorax and lungs expand to increase volume and air rushes in.

Alveolar Pressure/Pascal's Law

*Pressure is transmitted rapidly & uniformly throughout an enclosed fluid at rest *Tiny alveoli or air sacs in the lungs *Pascal's law says that the pressure in each of the air sacs is the same. Alveolar pressure is uniform throughout the lungs.

Diaphragm

*Primary of inspiration *Divides thorax from abdomen *Dome shaped underneath ribs *Higher on right side than left *Protects liver, spleen & kidneys

Muscles of FE: Posterior Thoracic Muscles (2)

*Subcostals *Serratus Post. Inf Functions: -Depress thorax -Pulls rib cage down

Summary of Inhalation

*The lungs are spongy bodies which have no muscles & some elasticity. They are controlled by the muscles of respiration: the external intercostal muscles (lie between cartilaginous parts of the rib) & the rotation of gartilages raise the ribs. *The diaphragm is convex & is flattened down by contraction, thus enlarging the chest by increasing its depth. The abdominal muscles relax & allow the stomach, liver & other organs in the abdomen to move downward to make room for the depressed diaphragm. This causes a vacuum (lower or negative air pressure) in the chest. The lungs (due to pleural linkage to rib cage & alveolar pressure) expand to fill this vacuum & the air rushes in to fill the expanding lungs.

Summary of Exhalation

*The movement of air out of the lungs (exhalation) also involves changes in volumes and pressures. However, in breathing at rest, no energy is required to contract the lungs which, being elastic in nature, contract automatically from their expanded state. Think of a bath sponge, which is quite similar in structure to the lungs, if you stretch it (as in inhalation), it will recoil of its own accord when released. The "stretchability" of the lungs is called compliance. The internal intercostal muscles, while not being used in quiet breathing, are necessary for forced expiration such as when coughing or during heavy exercise. Healthy lungs with good compliance recoil automatically and easily, but certain disease conditions such as emphysema, bronchitis, tuberculosis and cystic fibrosis can compromise this process. Mucus that is produced in disease such as bronchitis and asthma can partially block airways and result in ventilation problems (air passage and alveoli).

The Respiratory Pump

*The spongy lungs can be likened to two balloons that are inflated & deflated as if by a bicycle pump *The basis for the action of the respiratory pump is the way the lungs are linked to the ribcage (thorax) & abdomen by two pleurae (membranes). A layer of fluid between the pleaurae allows them to move freely and provides suction to maintain the linkage. *The consequence of the linkage is that the lungs expand & contract as the ribcage & abdomen expand & contract *Because volume & pressure are related, altering the lung volume changes the air pressure in the lungs by: -Increasing lung volume (by pushing the ribcage or abdomen outwards) lowers air pressure -Decreasing lung volume raises air pressure *Air flows from regions of higher to lower pressure, so air flows into the lungs when pressure decreases below atmospheric level & out when pressure increases above atmospheric level *Inhalation normally involves muscular effort; contracting external intercostal muscles to elevate ribs & diaphragm which lowers as it contracts, expanding volume of thorax

Central Tendon

*Tough fibrous tissue *Forms top of diaphragm with 3 leaves radiating from center

Diaphragm: Origin

*Xiphoid process (sternum) *Inferior ribs 7-12 *Corpus L1 *Transverse processes of L1-L4

Atmospheric Pressure Reference

-All measurements of air pressure are made relative to atmospheric pressure -Example: Vocal Fold Vibration +3 to +5 cm H2O of subglottic air pressure to set VFs into vibration, a simple "ah" That is, +3 to +5 cm H2O above atmospheric pressure +7-10cm H2O-conversational speech Stress or Prosodic Changes +2 cm H2O

Pressure

-Flow of air depends on the pressure gradient (atmospheric, Pa, and intra-alveolar, Pi) and the airway resistance, R -Resistance depends primarily on the radius of the conducting airways

Pleural Pressure

-Pleural pressure is the pressure surrounding the lung, within the pleural space. -The ribcage is lined with a membrane called the costal pleura. There is a second membrane that covers the lungs called the pulmonary or visceral pleura. The pleura allow the lungs to expand and contract as the thoracic cage changes volumes. As volume of the rib cage increases, so does the lung volume due to pleura. -Boyle's Law—Increased volume causes a proportional decrease in pressure.

Abdominal Muscles of Expiration: Force Exp

Anteriolateral Abdominal (4) Posterior Abdominal (1) Upper Limb (1)

Muscles of Thorax: Forced Exp

Anterior/Lateral Thoracic (3) Posterior Thoracic (2)

Insertion

Area of attachment of muscle to the bone it moves

Accessory Function of Upper Arm & Shoulder Muscles During Inspiration

Assist external intercostal muscles in elevating the thorax through their attachments to the ribs & sternum

Diaphragm: Innervation

Bilateral

Xiphoid Process

Cartilaginous section at lower end of sternum

Diaphragm: Insertion

Central Tendon

Diaphragm Action

Contraction- Pulls the central tendon down & forward

Insp. Anterior Thoracic Muscles (2) -External Intercostals -Internal Intercostals

Function: *Elevate ribs

Abdominal Muscles of Expiration: * Abdominal Aponeuroses

Function: *Tendons attach anterior abdominal muscles to form wall Aponeuroses: -Linea Alba: Xiphoid process to pubic symphysis -Linea semilunaris -Lumbodorsal fascia: Connective tissue surrounding muscle

Insp. Accesory Muscles of Neck cont. -Scalenes (Anterior, Middle, Posterior)

Function: -Elevate ribs 1-2 during respiration -Help rotate head

Muscles of Forced Expiration

Function: -To squeeze the air from the lungs front to back fall of the rib cage -Squeeze abdominal viscera pushing diaphragm upward

Insp. Posterior Thoracic Muscle (2) -Serratus Posterior -Levatores Costarum (Brevis & Longis)

Functions: -Elevate ribs

Insp. Accessory Muscles of Neck (2) -Sternocleidomastoid -Scalenes (Anterior, Middle, Posterior)

Functions: -Elevate sternum i.e ribcage -Elevate ribs 1-2 -Head rotation -Neck flexion & extension stability *Sternocleidomastoid also allows head to rotate side to side

Insp. Muscles of Upper Arm & Shoulder -Subclavius

Origin: Inferior surface of clavicle Insertion: Superior surface of rib 1 at chondral margin Function: Elevates rib 1

Isnp. Muscles of Upper Arm & Shoulder -Serratus Anterior

Origin: Ribs 1-9, Lateral surface of thorax Insertion: Inner vertebral border of scapula Function: Elevates rib 1-9

Insp. Muscles of Upper Arm & Shoulder -Trapezius

Origin: Sinous process of C2 & T12 Insertion: Acromion of scapula & superior surface of clavicle Function: Elongate neck; head control

Insp. Muscles of Upper Arm & Shoulder -Rhomboideus Major

Origin: Spinous process T2-T5 Insertion: Scapula Function: Stabilize shoulder girdle

Insp. Muscles of Upper Arm & Shoulder -Rhomboideus Minor

Origin: Spinous process of C7 & T1 Insertion: Medial border of scapula Function: Stabilize shoulder girdle

Insp. Muscles of Upper Arm & Shoulder -Pectoralus Major

Origin: Sternal head; Sternum length at costal cartilage Insertion: Greater tubercle of humerus (upper arm bone) Function: Elevate sternum increasing transverse dimension of rib cage

Insp. Muscles of Upper Arm & Shoulder -Levator Scapulae

Origin: Transverse process of C1-C4 Insertion: Medial border of scapula Function: -Neck support -Elevate scapula

Cranial Nerves

Origin: brainstem (pons & medulla) There are 12

Spinal Nerves

Origin: spinal cord *Names coincide with vertebral location Ex. Cervical Plexus & Brachial Plexus

Phrenic Nerve

Originates in the neck region of the spine. Its main role is to supply movement to the diaphragm, but it also supplies sensation to the chest & the upper part of the abdomen. The human body has 2 phrenic nerves, left & right. They both follow different paths, however they both begin in the C3-C5 vertebral region of the neck. The motor fibers in the phrenic nerves signal to the diaphragm when to contract & when to relax. If one phrenic nerve is left in tact, the patient will retain his ability yo breathe, though it will be more labored. Irritation of the phrenic nerve may cause a hiccup reflex, in which the diaphragm sudenly contracts.

Summary of Muscles Involved

Phase Muscles involved Inhalation- Diaphragm and/or external intercostals internal inter-costal muscles (lie between cartilaginous part of rib) and the rotation of cartilages raise the ribs. Exhalation Stage 1- Elastic recoil, diaphragm used to prevent excess pressure from recoil Exhalation Stage 2- Elastic recoil, internal intercostals, continuing until no more recoil remains Exhalation Stage 3- Internal intercostals, abdominals

Origin

Place of attachment of a muscle that remains relatively fixed during contraction

Passive/Quiet Respiration

Uses mainly elastic recoil; normal, resting breathing

Active Respiration

Uses mainly muscular control; forced breathing