applied anatomical concepts

Question 1

what are the 2 phases of breathing?

Answer 1

1) inspiration

2) expiration

Question 2

what are the 2 areas of breathing?

Answer 2

1) thoracic

2) abdomen

Question 3

what are the 2 types of breathing?

Answer 3

1) quiet

2) forced

Question 4

what happens during inspiration?

Answer 4

• 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

Question 5

what happens during expiration?

Answer 5

• 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

Question 6

what are the 2 areas of dimensional change with thoracic breathing?

Answer 6

1) lateral/transverse diameter

2) anteroposterior diameter

Question 7

what is the area of diameter change with abdominal breathing?

Answer 7

vertical diameter

Question 8

what happens to the lateral diameter of the thorax?

Answer 8

• 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

Question 9

what happens to the anteroposterior diameter of the throax?

Answer 9

• 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

Question 10

what happens to the vertcial diameter of the thorax?

Answer 10

• 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

Question 11

what muscles are used during quiet inspiration?

Answer 11

• external intercostals
• scalene muscles
• diaphragm

Question 12

what happens during quiet expiration?

Answer 12

• normally a passive process

- elastic recoil of lungs expels air and chest wall falls back into resting position

Question 13

what muscles are used during forced inspiration?

Answer 13

• muscles used in quiet inspiration plus:
• pectoral muscles
• sternocleidomastoid (SCM)
• latissimus dorsi

Question 14

what muscles are used during forced expiration?

Answer 14

• internal intercostals
• oblique and transverse abdominal muscles
• quadratics luborum

Question 15

what is the general structure of the diaphragm?

Answer 15

• sheet of skeletal muscle with central tendon
• pericardium attached to middle of tendon on its superior surface
• diaphragmatic (parietal) pleura lines its superior surface

Question 16

what are the 3 parts of the origin of the diaphragm?

Answer 16

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)

Question 17

where is the insertion of the diaphragm?

Answer 17

central tendon

Question 18

where are the lumbar attachments of the diaphragm?

Answer 18

• 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

Question 19

where are the 3 openings of the diaphragm?

Answer 19

1) opening for inferior vena cava (T8)
2) oesophagus (T10)
3) aortic hiatus (T12)

Question 20

what is the blood supply of the diaphragm?

Answer 20

superior and inferior phrenic arteries

Question 21

what are the actions of the diaphragm that alters the volume of the thorax?

Answer 21

• quiet inspiration (descends approx 2cm)
• forced inspiration (descends approx 7-10cm)
• aids venous return
• hiccups

Question 22

what are the actions of the diaphragm that alters the volume of the abdomen?

Answer 22

• urinating and defecation
• lifting heavy objects (braces vertebral column)
• child birth

Question 23

where does the phrenic nerve arise from?

Answer 23

ventral rami of C3, C4 and C5

Question 24

what is the motor function of the phrenic nerve?

Answer 24

sole supply of the diaphragm

Question 25

what is the sensory function of the phrenic nerve?

Answer 25

• pericardium
• parietal pleura (mediastinal and central part of diaphragmatic)
• parietal peritoneum
• central region of diaphragm

Question 26

what is a pancost tumour?

Answer 26

• cancer located at the apex of the lung
• if on the left it can cause recurrent laryngeal nerve compression
• vocal cord paralysis = hoarsness

Question 27

how do you work out coronary circulation dominance?

Answer 27

• 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