Muscles of Respiration Flashcards
Muscles of Inspiration..
- Sternocleidomastoid
- Scalenes
- Pectoralis Major
- Pectoralis Minor
- Subclavius
- Trapezius
- Diaphragm
- External Intercostals
Action of Sternocleidomastoid
- raise and expand rib cage (thoratic cavity)
Sternocleidomastoid Muscle
- anterior neck muscle
- flex and rotate the head
- cosists of
- Sternal Head
- Clavicular Head
What are the 2 origins of the Sternocleidomastoid muscle?
- Sternal Head Origin= manubrium
- Clavicular Head Origin= sternal end of clavicle
- 2 origins run into same muscle
Insertion of Sternocleidomastoid
- two heads unite and continue upward to insert as a single muscle into mastoid process of temporal bone
- INSERTION STAYS STABLE, RIB CAGE MOVES
- reverse typical function on origin-insertion
Scalenes
- anterior, middle, and posterior
- Cervical Vertebrae
- origin is above insertion
- insertion is pulled up towards origin and rib cage is pulled up
- as the rib cage expands, this helps us breathe
Anterior Scalenes Origin
- transverse process of C3-C6
Anterior Scalenes Insertion
- course down and insert at upper surface of 1st rib
Middle Scalenes Origin
- transverse process of C2-C7
Middle Scalenes Insertion
- upper surface of 1st rib
Posterior Scalenes Origin
- transverse process of lowest two cervical vertebrae
- C6 and C7
Posterior Scalenes Insertion
- outer surface of 2nd rib
Pectoralis Major
- powerful muscle
- adduction and rotation of arm
- elevate rib cage
- insertion stays stable!
Pectoralis Major Origin
- clavicle and sternum
Pectoralis Major Insertion
- humerus
Pectoralis Minor
- deep to pectoralis major
- depress shoulders
- elevate ribs
- insertion stays stable!
Pectoralis Minor Origin
- anterior surfaces of ribs 2-5
Pectoralis Minor Insertion
- scapula
Subclavius
- draws shoulders forward and slightly downward
- elevate ribs
- insertion stays stable!
Subclavius Origin
- junction of rib 1 and costal cart
Subclavius Insertion
- inferior border of clavicle
Trapezius
- superficial, thick, broad, trapezoid shaped muscle in the upper back
- elevates and upwardly rotates scapula
- retracts scapula
- tilts head backwards
- stablizes shoulders and indirectly the rib cage
Trapezius Origins
- cranial base
- cervical vertebrae
- thoracic vertebrae
Trapezius Insertion
- scapula
- lateral third of clavicle
Diaphragm
- divides thoracic cavity from abdominal cavity
- dome shaped structure
- penetrated by esophagus and aorta
Diaphragm Action
- flattens
- drives central tendon inferiorly
- inhalation
- creates more space in thoracic cavity
Diaphragm Origins
- lower perimeter of the rib cage (ribs 7-11)
- xiphoid process of sternum
- bodies of upper 4 lumbar vertebrae
- rising to an elevated central tendon
Diaphragm Insertion
- central tendon
External Intercostals
- between the ribs
- raise the ribs
External Intercostals Origin
- inferior margin (bottom) of one rib
External Intercostals Insertion
- superior margin (top) of the subadjacent rib
Muscles of Expiration
- Transverse Abdominal
- Internal Abdominal Oblique
- External Oblique
- Internal Intercostals
- Rectus Abdominis
Transverse Abdominal
- deepest and thinnest of 3 lateral abdominal muscles
- encircles the abdominal inner surfaces
Transverse Abdominal Action
- Antagonist to diaphragm
- compress abdomen
- = exhalation
- pushes up on diaphragm and creates less space in thoracic cavity
Transverse Abdominal Origins
- inner surfaces of ribs 6-12
- lumdodorsal fascia
- anterior 3/4 illiac crest
Transverse Abdominal Insertion
- abdominal aponeurosis
- ..is a broad tendon
Internal Abdominal Oblique
- compress abdomen
- push contents up
- exhalation
Internal Abdominal Oblique Origin
- lateral half of inguinal ligament
- anterior 2/3 of illiac crest
Internal Abdominal Oblique Insertion
- lower borders of ribs 8, 9, 10
- linea alba
External Oblique
- thickest of the 3 muscles of the lateral abdominal wall and most superficial
External Oblique Action
- Compresses abdominal contents
- exhalation
External Oblique Origin
- exterior surfaces and lower borders of ribs 5-12
External Oblique Insertion
- anterior half of illiac crest
- abdominal aponeurosis to linea alba
Internal Intercostals
- lie deep to the external intercostals
- fiber orientation is oblique
- superior attachment is more distant from the vertebral end than the inferior attachment
Internal Intercostals Action
- brings rib closer together up and inward
- less thoracic cavity space
Internal Intercostal Origin
- inferior margin of one rib
Internal Intercostals Insertion
- superior margin of subjacent rib
Rectus Abdominis
- depress rib cage
- causes content to be compressed
- less space
Rectus Abdominis Origin
- pubic bone
Rectus Abdominis Insertion
- xiphoid process and costal cartilage of ribs 5, 6, and 7.
