applied anatomical concepts Flashcards
what are the 2 phases of breathing?
1) inspiration
2) expiration
what are the 2 areas of breathing?
1) thoracic
2) abdomen
what are the 2 types of breathing?
1) quiet
2) forced
what happens during inspiration?
- increase in intrathoracic volume = decreased intrathoracic pressure
- parietal pleura is pulled with the movement of the ribs and diaphragm
- visceral pleura moves with parietal pleura (surface tension)
- lung volume increases
- air moves into lungs towards lower pressure
what happens during expiration?
- decrease intrathoracic volume = increased intrathoracic pressure
- visceral pleura moves with elastic recoil of lungs
- parietal pleura moves with the ribs and diaphragm as they return to rest
- surface tension between parietal and visceral pleura prevents lung from collapsing
- lung volume decreases
- air moves out of lungs towards lower pressure
what are the 2 areas of dimensional change with thoracic breathing?
1) lateral/transverse diameter
2) anteroposterior diameter
what is the area of diameter change with abdominal breathing?
vertical diameter
what happens to the lateral diameter of the thorax?
- lateral edges of ribs are elevated supero-laterally during inspiration and the lateral diameter of thoracic cavity increases
- results in an increase in the transverse or lateral diameter of chest cavity
- also known as bucket handle movement
what happens to the anteroposterior diameter of the throax?
- anterior ends of ribs are raised during inspiration
- elevation causes sternum to also be raised
- movement is facilitated by costal cartilages
- results in an increase in anteroposterior diameter of chest cavity
- also known as pump handle movement
what happens to the vertcial diameter of the thorax?
- via diaphragm which forms floor of thoracic cavity
- resting position of diaphragm is domed
- upon contraction the diaphragm descends 5-10cm compressing abdominal organs
- increases vertical diameter of throax
what muscles are used during quiet inspiration?
- external intercostals
- scalene muscles
- diaphragm
what happens during quiet expiration?
- normally a passive process
- elastic recoil of lungs expels air and chest wall falls back into resting position
what muscles are used during forced inspiration?
- muscles used in quiet inspiration plus:
- pectoral muscles
- sternocleidomastoid (SCM)
- latissimus dorsi
what muscles are used during forced expiration?
- internal intercostals
- oblique and transverse abdominal muscles
- quadratics luborum
what is the general structure of the diaphragm?
- sheet of skeletal muscle with central tendon
- pericardium attached to middle of tendon on its superior surface
- diaphragmatic (parietal) pleura lines its superior surface
what are the 3 parts of the origin of the diaphragm?
1) sternal (xiphoid process)
2) costal (costal cartilages of ribs 7-10, ribs 11 and 12)
3) lumbar (medial and lateral arcuate ligaments and lumbar vertebral bodies)
where is the insertion of the diaphragm?
central tendon
where are the lumbar attachments of the diaphragm?
- lumber part of the diaphragm arises from the medial and lateral arcuate ligaments and from the lumbar vertebral bodies via right and left crura
- the right and left crura meet to form the media arcuate ligament to form aortic hiatus
- fibres of the right crus pass around the oesophagus forming the oesophageal hiatus
where are the 3 openings of the diaphragm?
1) opening for inferior vena cava (T8)
2) oesophagus (T10)
3) aortic hiatus (T12)
what is the blood supply of the diaphragm?
superior and inferior phrenic arteries
what are the actions of the diaphragm that alters the volume of the thorax?
- quiet inspiration (descends approx 2cm)
- forced inspiration (descends approx 7-10cm)
- aids venous return
- hiccups
what are the actions of the diaphragm that alters the volume of the abdomen?
- urinating and defecation
- lifting heavy objects (braces vertebral column)
- child birth
where does the phrenic nerve arise from?
ventral rami of C3, C4 and C5
what is the motor function of the phrenic nerve?
sole supply of the diaphragm
what is the sensory function of the phrenic nerve?
- pericardium
- parietal pleura (mediastinal and central part of diaphragmatic)
- parietal peritoneum
- central region of diaphragm
what is a pancost tumour?
- cancer located at the apex of the lung
- if on the left it can cause recurrent laryngeal nerve compression
- vocal cord paralysis = hoarsness
how do you work out coronary circulation dominance?
- blockage of the main right or left coronary artery will have different outcomes depending on coronary artery dominance
- coronary artery dominance is also important when planning for coronary artery bypass graft
- arteriograms are used to determine coronary artery dominance
