Ch 2: Respiratoy muscles Flashcards
‘Sternocleidomastoid (function and description)
-elevate ribs, sternum
-stabilizes upper body thorax
-and tilt/rotation of head
-Accessory muscle of the neck for forced inspiration
-origin from two places- manubrium of sternum and clavicle
-innervated by accessory nerve
Scalenus
-elevate ribs, sternum
-Accessory muscle of the neck inspiration;
-Primary function is to balance the head
(medius,anterior, posterior)
Serratus Anterior
-elevates ribs;
-originates from ribs (#1-9),
-inserts at inner vertebral border of scapula
Levator Scapula
-Stabilize shoulder girdle, head
-Muscle of inspiration;
-origin from transverse process C1-C4
-insertion: scapula along midline
-Function; Stabilizes the scapula (lifts it) relative to the vertebral column
Rhomboidus Major/Minor
-Stabilize shoulder girdle, head
-function: anchors the scapula
-Accessory muscle for inspiration;
-originated from C7-T5
-insertion: Scapula at the midline
Trapezius (innervated, function)
-Stabilize shoulder girdle, head
-accessory muscle for inspiration;
-function: brace claivicle and scapula against action of other muscles;
-innervated by Accessory nerve
-origin: Spinous processes of C2 to T12
-insertion: Upper surface of the clavicle and scapula
Diaphragm* (origin and innervated)
-originates along vertebral column, lower rib cage (T7-T12) down to xiphoid process
-inserts at central tendon
-innervated by phrenic nerve (spinal nerve C3-C5)
Diaphragm* (description and function related to quiet respiration)
-inverted dome/sheet shaped muscle
-assists with respiration cycle by expanding the thoracic cavity inferiorly
(down)=inspiration
-this helps the thorax to expand vertically
-during quiet breathing, disphragmatic movement is enough to supply blood with oxygen, accessory muscles needed for speech and exercise for forced inspiration
When Diaphragm contracts
-The central tendon is pulled downward
-expands the thoracic cavity inferiorly (inspiration) (increases vertical dimension of thorax)
-compresses abdominal viscera
External intercostal muscle* (origin and innervated by)
accessory thoracic muscle for inspiration
-innervated by intercostal nerves
-originate from LOWER margin of each
rib, insert at upper margin of the rib below
Internal Intersoctal muscle* (description and function)
-Assists in expiration by pulling the ribs down
-can compress rib cage if lower ribs are stabilized
-originate from superior margin
of ribs 2-11, insert at inferior border of ribs above; innervated by intercostal nerves
External intercostal muscle*(description and function)
-elevate ribs, sternum
-Accessory muscle for inspiration
-fill 11 spaces between the ribs but end short of the sternum
-act as a single sheet of muscle pulling all the lower ribs toward the first rib (has the GREATEST) direct effect on ribs)
-runs between the ribs along the outside surface of the bones
pectoralis major
Accessory muscle for inspiration that is large and part of the upper chest
-Originates in two heads from sternum and clavicle, inserts into upper arm /humerus
-functions to assist drawing the sternum upward
Levatores Costarum Brevis
-elevate ribs, sternum
-Accessory muscle for inspiration
-pulls up on the rib to expand the rib cage
-runs from vertebrae (C7-T11
-insert near the head of the rib just below the vertebrae from which it originates
Internal intercostals (origin, insertion and innervated by)
Origin: originate from superior margin
of ribs 2-11 insert at inferior border of ribs above; innervated by intercostal nerve
Levatores Costarum Longis
-accessory muscle of inspiration
-Pulls upward on the rib, just like the levatores costarum brevis
-Run from middle vertebrae (T7-T10)
-Insert near the head of the rib that is two below the vertebrae from which it originate
Serratus Posterior Superior
-elevate ribs, sternum
-Accessory muscle of inspiration
-stabilize the upper ribs so the external intercostals can create maximal expansion of the rib cage
-Spinous processes of C7 through T3
Pectoralis minor
Accessory muscle in inspiration
-origin: Second through fifth ribs
-insertion: scapula
-function: If scapula is stabilized, these muscles too can aid in stabilizing and raising the upper ribs
Rectus Abdominis*
-accessory abdominal muscle for expiration to compress abdomens
-originates at xiphoid process, inserts at pubic symphysis
Transversus Abdominis
-Compress abdomen for expiration
-function: It compresses the viscera with more power than any other muscle
-origin: Lower vertebral column
-Central into the abdominal aponeurosis, Superior into cartilages of lower 6 ribs (7-12), Inferior to ilium and pubic bones
External Obliques
-Compress abdomen for expiration
-function: Can pull on lower ribs to compress rib cage and oppose diaphragm
-origin: lower seven ribs (6-12)
-insertion: iliac crest and abdominal aponeurosis
Internal Obliques
-Compress abdomen for expiration
-function: pull down on lower ribs and oppose diaphragm
-origin: iliac crest
-insertion: Insert at midline at the abdominal aponeurosis and cartilages of lower ribs
Quadratus Lumborum
accessory abdominal muscle for expiration
-function: Contraction stabilizes the posterior abdominal wall, supporting the compression created by the anterior abdominals
-origin: iliac crest
-insertion: lumbar vertebrae, and also into rib 12
Transverse thoracis*
accessory thoracic muscle for expiration
- pulls ribs down w costal cartilages; originates at sternum, inserts into
lower ribs (#2-6)
-innervated: intercostal nerve
