Respiratory Anatomy Flashcards
The thoracic cage
Structure -
Function -
Vertebral column
Ribs
Intercostal spaces
Costal cartilages
Sternum
Function: protects vital organs
Provides muscle attachments
Assists respiration
Thoracic cage
Joints of the thoracic vertebrae and joints of the ribs and their costal cartilages:
Posteriorly -
Intermediate -
Anteriroly -
Post - costovertebral joints
Costotransverse joints
Intermediate - costochondral joints
Ant - sternocostal joints
Interchondral joints
Thoracic cage
Joints of the sternum -
Manubriosternal joint
Xiphisternal joint (junction)
Movements of the thoracic cage
Inspiration -
Increase in anteroposterior diameter, 1st, 2nd to 5th and 6th and 7th ribs elevate carrying sternum upwards and forwards
(Pump handle)
Increase in transverse diameter. 6th and 7th and 8th to 10th ribs elevate the shaft moving upwards and outwards
(Bucket handle)
Increase in vertical diameter - diaphragm descends
Movements of thoracic cage
Expiration -
Expiration is passive!
Actions of breathing
Inhalation -
Exhalation -
Air inhaled, rib cage expands and external intercostals contract, diaphragm contracts and moves down
Diaphragm moves up and relaxes, rib cage get smaller as rib muscles relax and air is exhaled
Muscle groups involved in respiration -
Muscles of pharynx and larynx - these help prevent aspiration (food/liquid going down trachea)
Muscles of ribcage, thoracic spine and neck
Muscles of abdominal wall, and lumbar spine
Actions of the muscles of the ribs cage -
Increase thoracic dimensions during inspiration
Support thoracic cage Joints
Intercostal muscles prevent any recessions or bulging of the intercostal spaces
Inhibit the lungs natural tendency to collapse
Role and structure of the diaphragm -
Separates the thorax and the abdomen
Dome shaped sheet of muscles
Principle muscle of respiration
Has 3 muscular parts - sternal, costal and lumbar
2 surfaces - thoracic and lumbar
Several openings
Attachments of diaphragm and nerve innervation -
Origins - lumbar vertebrae: left and right crus and arcuate ligaments (tendinous in structure)
Costal cartilages of ribs 7-10 (attach directly to ribs 11-12)
Xiphoid process of sternum
Insertions - central tendon of diaphragm,
Nerve - phrenic nerve, provides primary motor supply to diaphragm (C3-5)
*there is a left and a right phrenic nerve… originates mainly from the 4th cervical nerve, but also receives contributions from the 3rd and 5th cervical nerves
Surfaces of the diaphragm
Thoracic surface -
Abdominal surface -
Thoracic - in contact with serous membranes of the heart and lungs; pericardium and pleura
Abdominal - in contact with liver, stomach and spleen
Openings of the diaphragm -
Caval opening
Oesophageal opening
Aortic opening
Functions of the diaphragm-
Primary muscle of respiration
Passageway for structures
Increasing intra-abdominal pressure needed in actions such as vomiting, passing urine and childbirth
What are the intercostal muscles?
Group of intrinsic rib cage muscles that occupy the 11 intercostal spaces Inhibit
Divided into 3 groups - going from superficial to deep
External intercostals
Internal intercostals
Innermost intercostals
External intercostal muscles -
Origin - inferior border of rib above
Insertion - superior border of rib below
Action - elevation of ribcage during inspiration
Internal intercostal muscles -
Origin - from the costal groove (lower part of inner surface of rib near the inferior border) of the rib above
Insertions- upper border of rib below
Action - depression of ribcage in FORCED expiration
Innermost intercostal muscles -
Origin - from costal groove of the robe above
Insertions - the superior border of rib below
Actions - assists in the function of external and internal intercostals
Innervation of intercostal muscles -
All are innovated by the anterior rami nerve T1-T11 ie the intercostal nerves of the corresponding intercostal space
Muscles of respiration (inspiration)
Primary -
Accessory -
Primary - diaphragm and external intercostals
Accessory - sternocleidomastoid
Scaleni
Serratus anterior
Pectoralis major and minor
Lat Dorsi
Serratus posterior superior
Muscles of respiration (expiration)
Accessory muscles -
When expiration is forced!!!
Internal intercostals
Abdominals: external and internal obliques
Rectus abdominus
Transversus abdominus
Thoracolumbar region - iliocostalis and longissimus
Serratus posterior inferior
Quadratus lumborum
Briefly summarise the phases of the cardiac cycle -
Atrial systole begins - atrial contraction forces blood into ventricles
Ventricular systole begins (first phase) - ventricular contraction pushes AV valves closed
Ventricular systole (second phase) - semilunar valves open and blood is ejected
Ventricular diastole (early) - semilunar valves closed and blood flows into atria
Ventricular diastole (late) - Chambers relax and blood fills ventricles passively
