Anatomy of Breathing 2 PDF

Anatomy of Breathing 2 Muscles of respiration Niggy Gouldsborough  Breathing/pulmonary ventilation Inspiration/inhalation Movement of air into the lungs Occurs when intrapulmonary pressure is lower than atmospheric pressure Expiration/exhalation Movement of air out of...

Anatomy of Breathing 2 Muscles of respiration Niggy Gouldsborough  Breathing/pulmonary ventilation Inspiration/inhalation Movement of air into the lungs Occurs when intrapulmonary pressure is lower than atmospheric pressure Expiration/exhalation Movement of air out of the lungs Occurs when intrapulmonary pressure is greater than atmospheric pressure Intrapulmonary pressure is altered by changes in  Thoracic Volume transverse Thoracic volume can be altered by changing the – vertical diameter – anterior posterior (AP) diameter – transverse diameter vertical AP (Drake, Vogl & Mitchell, 2018)  Altering the vertical diameter Contraction of diaphragm increases vertical diameter Relaxation of the diaphragm decreases vertical diameter relaxed diaphragm Contraction responsible for 75% increase in contracted thoracic capacity during inspiration diaphragm  Increasing AP & transverse diameters Elevation of the ribs increases the AP and transverse diameters responsible for 25% increase in thoracic capacity  Anteroposterior diameter vertebral column vertebral column ribs ribs sternum sternum Elevation of ribs at the sternal end makes them more horizontal and pushes sternum forward (pump handle movement) This increases AP diameter Transverse Diameter Many of the ribs are lowest near their middle and rise at each like the end handle of a bucket If the middle of the rib rises, it moves away from the midline of the body making the chest wider from left to right  Muscles of Breathing Muscles of Quiet inspiration & expiration Occurs at rest Forced inspiration & expiration Occurs during exercise or respiratory illness  Muscles of quiet inspiration External intercostals The contracted diaphragm flattens to increase the vertical The external diameter of the thorax intercostals elevate the is increased ribs & increase AP and  Quiet Expiration Passive process - the diaphragm and external intercostal muscles relax Relaxed diaphragm  Muscles of forced inspiration In addition to diaphragm and external intercostals these muscles are recruited to assist in rib elevation, increase the speed and amount of movement pectorails minor scalenes sternocleidomastoid serratus anterior pectoralis major  Muscles of Forced Expiration Rectus abdominis Transvers Extern us al abdominis obliqu e Internal Internal intercostal oblique (not shown) Internal and innermost Abdominal muscles intercostals compress the depress the ribs abdomen and force the diaphragm