The Anatomy Of Breathing Flashcards
Types of breathing and the differences
Thoracic, uses the ribs and intercostals, v shallow
Diaphragmatic, uses the diaphragm
Describe thoracoabdominal breathing when upright
Inspiration
Diaphragm contracts, pushes liver and int organs down
Ant abd wall relaxes to pull D down
Expiration
Diaphragm relaxes, moves back up
Ant abd wall contracts and pushes liver and int organs up
Thoracoabdominal breathing laying supine
What is the best way to breathe?
Liver slides down into the diaphragmatic recess
Diaphragm needs to work harder to contract and move liver against gravity
45 angle, breathing not compromised
What are the intrinsic muscles
Ext intercostals (like EO) Int intercostals (like IO) Innermost intercostals (like IO
Functions of the intrinsic muscles in breathing
Ext intercostals are generally inspirations
Int, innermost are a mystery
How do the intercostals work in quiet breathing
Stiffening of ICS due to muscular contraction, prevents bellowing
How do the intercostals work in forceful breathing
Elevation of chest wall => forceful contraction
What are the mystery intrinsic muscles of the chest wall
Subcostal muscles (specialised innermost muscles) Transversus thoracis (attach to lower part of sternum to lower costal cartilage)
Serratus posterior (not involved in breathing)
Superior serratus posterior attach to upper ribs
Inferior serratus posterior attach to lower ribs
Where does the sternocleidomastoid attach to
What is its functions
What is it innervated by
Attached to sternum, clavicle, mastoid process
Extends head, flexes neck
Turns head
Inspiration accessory muscle (holds sternum and clavicle up)
Innervated by spinal accessory cranial 11
Where do each of the scalene attach
What are their functions
What are they innervated by
Ant, ant tubercle C3-6 to transverse process and scalene tubercle on R1
Middle, post tubercle C2-7 to transverse process and scalene tubercle on R1
Post, post tubercle C5-7 to transverse process and R2
Lateral neck flecion, neck flex ion
Inspiratory muscles to elevate R1 (tonic contraction)
Innervated by cervical plexus
What is a flail chest
What can happen as a result during breathing
When a rib fractures in 2 places => isolated segment of chest wall => paradoxical movement of chest wall
Isolated segment sucked in in inspiration, pushed out in expiration
Heart location can change
What are the 2 accessory muscles of respiration
Pectoralis major and minor
Serratus anterior
Where does the pectoralis major attach and how is it used in breathing?
Attaches to humerus, manubrium, sternum, clavicle, IC cartilage
When arms are attached, can be used in breathing
Where does the serratus anterior attach
How is it used in breathing
Attaches to R1-8 laterally and costal surfaces of medial borders of scapula
Contract in same direction as ext intercostals
How is the ant abd wall used in active expiration
Increases intraabdominal pressure
Pushing diaphragm up into thoracic cavity
Summary of quiet inspiration
Diaphragmatic breathing
Tonic contraction of scalenes to stabilise R1
Contraction fo intercostals => stiffen space, not to elevate
Summary of forced inspiration
Increased diaphragm contraction
Forced intercostal contraction for R movement and to stiffen
Pectoralis and serratus ant elevate R
Erector spinae, straighten vertebral column so chest wall not compressed
Quadratus lumborum stabilises FFR
Summary of quiet expiration
Muscles relax, elastic lung recoil
Rib cage falls with gravity
Tonic contraction of intercostals => stiffen
Elevation of relaxed diaphragm, pushed by abd muscle contraction
Summary of forced expiration
Abd muscles depress ribs, force air out
Tonic contraction of intercostals => stiffen
Abd muscles compress abd => life diaphragm
Latissimus dorsi, transverse thoracic may help bring chest wall down
