Action & Innervation of Regional Anatomy of the Respiratory System & Chest (+ Path of airflow)

Anterior Scalene, Middle Scalene, Posterior Scalene (muscles of neck)

Anterior Scalene

• Action: elevate rib 1

Middle Scalene

• Action: elevate rib 1

Posterior Scalene

• Action: elevate rib 2

Pectoralis Major (Anterior muscles of thorax)

Action: flex arm and adduct arm

Pectoralis minor Anterior part of rib 3-5 (Anterior muscles of thorax)

Action: elevate ribs 3-5 and protract scapula

Serratus anterior (Anterior muscles of thorax)

Action: protract scapula

Subscapularis (Shoulder & Anterior Chest Wall Muscles)

Action: medially rotate arm

Supraspinatus (Shoulder & Anterior Chest Wall Muscles)

Action: abduct arm

Infraspinatus (Shoulder & Anterior Chest Wall Muscles)

Action: Adduct arm, laterally rotate arm

Teres minor (Shoulder & Anterior Chest Wall Muscles)

Action: adduct arm, laterally rotate arm

Rotator cuff Definition

the rotator muscles join the scapula to the humerus. This includes subscapularis, supraspinatus, infraspinatus, teres minor

Teres major

Action: adduct arm, medially rotate arm

External Intercoastal (Muscles of Respiration)

Action: Elevate ribs

Motor innervation: intercostal nerve

Internal Intercoastal (Muscles of Respiration)

Action: depress ribs

Motor innervation: intercoastal nerve

Diaphragm (Muscles of Respiration)

Action: compress abdominopelvic cavity for inhalation

Motor innervation: phrenic nerve

Path of airflow

Nares > Nasal Cavity > Nasopharynx > Oropharynx > Laryngopharynx > Larynx > Trachea > Primary bronchi > Secondary bronchi > Tertiary Bronchi > Bronchioles > Terminal Bronchioles > Respiratory Bronchioles > Alveolar ducts > Alveolar sacs