mechanics of breathing

Question 1

how many pairs of ribs

Answer 1

12

Question 2

ribs derived from

Answer 2

paraxial mesoderm/sclerotome of somites

Question 3

sternum derived from

Answer 3

somatopleure

Question 4

3 parts of the sternum

Answer 4

manubrium/body/xiphoid

Question 5

false ribs

Answer 5

share a costal cartilage with the rib above

3 pairs

Question 6

floating ribs

Answer 6

don’t contribute to the costal margin - rib pairs 11 and 12

Question 7

2 types posterior costal joints

Answer 7

costovertebral

costotransverse

Question 8

costovertebral

Answer 8

synovial joint - cartilage on either side with fluid in between
rib head articulates with facet/demifacets

Question 9

costotrasverse

Answer 9

synovial joint

rib tubercle articulates with transverse facets

Question 10

facet of true rib

Answer 10

cup shaped - allows ribs to flare superior-laterally

articulates with transverse facet in costotransverse joint

Question 11

facet of false rib

Answer 11

plane facet (more flat) - allows lower thorax to open out (rotate out)

Question 12

facet of floating ribs

Answer 12

floating ribs don’t have a costotransverse joint

Question 13

how many false rib pairs

Answer 13

3

Question 14

which are false ribs

Answer 14

8, 9 ,10

Question 15

synovial joints movement

Answer 15

sternocosstal joints 2-7
relatively mobile
can move in all planes, just constrained

Question 16

synchrondoses

Answer 16

cartilaginous immovable joints

• all ribs with costal cartilages
• 1st stenrocostal joint is not mobile because it formss a fulcrum
• xiphisternal joint

Question 17

1st sternocostal joint

Answer 17

synchrondoses joinnt

immovable

Question 18

symphysis joint

Answer 18

cartilaginous movable joint

manubriosternal joint

Question 19

manubriosternal joint

Answer 19

bends and flexes with respiration
sternal angle becomes more acute with inspiration
the joint bends/flexes more

Question 20

pump handle movement of the chest wall

Answer 20

ribe 1 lifts the manubrium and pulls sternum forward
moves all true and false ribs
rotations of sternocostal joints 2-7

Question 21

bucket handle movement of the chest wall

Answer 21

true ribs 1-7 elevate

Question 22

calliper movement of the chest wall

Answer 22

false ribs 8-10 act on the costal margin, not sternum
widen laterally - widen costal margin
A shape becomes broader

Question 23

floating ribs action

Answer 23

support diaphragm and spread
lengthen thorax

anchor points for other muscles to attach to

Question 24

quiet - tidal respiration

Answer 24

inspiration - active

expiration - passive

Question 25

inspiration in tidal respiration

Answer 25

mostly diaphragm, but also intercostals and scalenes

Question 26

expiration in tidal breathing

Answer 26

elastic recoil of muscles and lungs, cartilages and ribs

Question 27

IVC when the diaphragm contracts

Answer 27

widens slightly - blood flow and venous return

Question 28

aorta passes through

Answer 28

aortic hiatus between the two crura at T 12

Question 29

oesophagus passes through

Answer 29

muscle of the crus at T10

Question 30

IVC passes through

Answer 30

central tendon at T8

Question 31

external intercostals

Answer 31

situated posteriorly, don't attach to costal cartilages | external intercostal membrane on superficial side

Question 32

internal intercostals

Answer 32

2 types

Question 33

2 types of internal intercostals

Answer 33

parasternal and interosseous

Question 34

innermost intercostals

Answer 34

very similar to internals but more transverse not continuous throughout the thorax active during inspiration and expiration dynamic changes in chest and compliance

Question 35

intercostal space and contents

Answer 35

neuromuscular bundles in costal groove

Question 36

deeper respiration

Answer 36

accessory muscles used because tidal muscles alone do not suffice - elevate upper ribs and spread lower ribs

Question 37

scalenes and sternocleidomastoid

Answer 37

lift the first rib or prevent depression

Question 38

serrates posterior

Answer 38

usually very thin superior - lift upper ribs inferior - depress lower ribs

Question 39

quadrates lumborum

Answer 39

holds rib 12 down

Question 40

postural muscles

Answer 40

maximum lung volume is dependant on posture | scapular retractors and vertebral extensors

Question 41

scapular retractors

Answer 41

trapezius, rhomboids, latissimus dorsi

Question 42

vertebral extensors

Answer 42

erector spinal groups

Question 43

forced exhalation

Answer 43

internal and anterior externals intercostals abdominal wall muscles - ractus abdomens, external and intercostal oblique, transverses abdominus - flatten the abdomen and organs are pushed into the diaphragm to force it upwards

Question 44

using limb muscles to breathe

Answer 44

pectoral girdle muscle elevate ribs if upper limbs are fixed to something

Question 45

residual volume

Answer 45

air you cannot exhale

Question 46

pluearal pressure

Answer 46

always negative

Question 47

pleural pressure becomes more negative

Answer 47

during inspiration

Question 48

mesothelium

Answer 48

is serous secreting | space in the pleura cannot be compressed

Question 49

cupula recess

Answer 49

slightly above the first rib | 1-3cm above clavicular head

Question 50

costomediastinal recess

Answer 50

either side of the sternum, between the body wall and pericardium

Question 51

3 pleural recesses

Answer 51

scapula costomediastinal costodiaphragmatic

Question 52

pleural recesses exist because

Answer 52

the lungs cannot fill all the space they have

Question 53

costodiaphragmatic recess

Answer 53

lungs stop higher than pleura - lungs extend to rib 8, pleura extends to rib 10 - pleura extends to rib 12 posteriorly

Question 54

clinical implications of the cupola

Answer 54

vulnerable in babies because of short necks | injury o lower necks may result in puncture or irritation

Question 55

clinical implications of costodiaphragmatic pleura

Answer 55

implications for abdominal surgery abdominal incision sites - right infrasternal angle and costovertabral angles - if pierced may cause collapse of the lung or other pathology thoracentesis/chest tube - to sample fluid, blood or excess fluid from pleural space - need to go into the 9th intercostal space in midaxillary line (without damaging the lung)

Question 56

clinical implications of costomediastinal pleural recess

Answer 56

pericardiocentesis - sampling/draining pericardial fluid left infrasternal angle, whilst supine allows safe sampling of pericardial fluid using a needle without damaging the pleura or the lung

Question 57

apertures

Answer 57

small superior aperture and large inferior aperture

Question 58

increasing venous return to the heart

Answer 58

when breathing in diaphragm contracts and goes down creates negative pressure in the thorax helps venous return

Question 59

external muscles pattern of action

Answer 59

posteror and superior fibres mechanically favour inspiration anterior and inferior fares mechanically favour expiration

Question 60

internal parasternal

Answer 60

inspiratory

Question 61

internal interosseous

Answer 61

expiratory

Question 62

pelvic floor muscles during forced expiration

Answer 62

pelvic floor muscle must be active and raise

Question 63

pectoral girdle in inspiration

Answer 63

can elevate ribs if the upper libs are fixed to something | common in COPD patients