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Flashcards in Thoracic walls Deck (44):
1

Breast tissue extends from

  • 2-6th rib
  • lateral border of sternum to mid-axillary line

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2

Base of the breast overlies

pec major and serratus anterior

*base is concave in shape

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3

What is the sub/retromammary space?

between breast tissue and pec major & serratus anterior

contains loose areola CT

where breast implants are inserted

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4

What is the blood supply of the breast?

shares arterial, venous, and lymphatic drainage with the thoracic wall and the upper limb

axillary atery laterally

internal thoracic artery medially

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5

Thoracic cage consits of

12 thoracic vertebrae & IV discs

12 pairs of ribs

manubrium and sternum

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6

Which costal cartilages articulate directly with the manubriosternal complex?

upper 7

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7

Which costal cartialges articulate with the one above it?

on ribs 8, 9, and 10

forms the costal margin

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8

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9

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10

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11

What are the thoracic three?

features that identify a thoracic vertebrae:

  • demi facets (body)
  • transverse facets (transverse process)
  • spinous process)

12

What are the two articulations between the ribs and thoracic vertebra posteriorly?

  • costovertebral joint
    • superior articular facet on head of rib with IV disc and inferior demi-facet on vertebra above; inferior articular facet of rib with superior demi-facet on vertebral body
    • covered by radiate ligament
  • costotransverse joint
    • tubercle of rib body with facet of transverse process
    • supported by costotransverse ligament

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13

The supeior aperture is reduced by

the suprapleural membrane

attaches ti the internal surface of the (flat) first rib

houses lung, pleural cavity, allows passage of mediastinum

14

What closes the inferior aperture?

diaphragm

15

What is the origin of the diaphragm?

  • circumferential:
    • xiphloid process
    • costal margin
    • tips of 11th and 12th ribs
    • arcuate ligaments
    • lumbar vertebral column
    • R & L crus

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16

What forms the arcuate ligaments?

fascia overluing quadratus lumborum and psoas major

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17

What are the borders of the R crus?

anterior L1-L3

because dome of R diaphragm is higher (over the liver), longer than L crus

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18

What are the borders of the L crus?

anterior L1-L2

(shorter than R bc L hemidiaphragm sits lower)

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19

What is the insertion of the diaphragm?

central tendon

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20

Where does the IVC enter the diaphragm?

caval orifice: T8, R of midline, through central tendon

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21

Where does the oesophagus enter the diaphragm?

oesophageal hiatus: T10, L of midline, through muscle

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22

Where does the aorta enter the diaphragm?

T12, midline, along the vertebral column between the crurae

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23

Where does the R phrenic nerve enter the diaphragm?

at T8 through the caval orifice with the IVC

24

Where does the left phrenic nerve enter the diaphragm?

pierces the left hemidiaphragm

25

Contraction of the diaphragm results in

central fibres pulling towards the margins

central tendon goes down

inspiration

26

What direction are the fibres of the external intercostals?

"hands in front pockets"

anteroinferior fibres

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27

What is the function of the external intercostals?

  • muscles of inspiration
  • contraction pulls rib below up and out, expanding the ribcage laterally (decreases pressure)

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28

What is the path of the external intercostal muscles?

extend over whole of rib space from posterior to costochondral junction

replaced with external intercostal membrane here

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29

What direction are the fibres of the internal intercostal muscles?

"hands in back pockets"

posteroinferior fibres

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30

What is the function of the internal intercostal muscles?

contraction pulls ribs down and in

theoretically expiratory but serve more of a splinting role w/innermost ICMs

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31

What is the path of the internal intercostals?

extends anterior to posterior

replaced with internal IC membrane

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32

What direction are the fibres of the innermost intercostals?

"hands in back pockets"

posteroinferior fibres

(follow internal intercostals)

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33

What is the function of the innermost intercostals?

splinting

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34

What is the path of the innermost intercostals?

discontinuous

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35

Where does the neurovascular bundle run?

in the costal groove

between innermost and internal ICMs

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36

What is the order of the intercostal neurovascular bundle from top to bottom?

Vein

Artery

Nerve

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37

What gives rise to the nerve supply of the intercostal neurovascular bundle?

  • thoracic spinal nerve exits through intervertebral foramen
  • gives off dorsal ramus that innervates the back muscles and skin
  • gives off ventral ramus that slips in between the innermost and internal ICMs
    • runs posterior to anterior
    • supplies muscles, cutaneous branches anterior and laterally to overlying skin (dermatomes)

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38

Where does the arterial supply to the intercostal neurovascular bundle arise?

posterior:

  • intercostal artery comes off dorsal aorta, splits into dorsal intercostal artery and posterior intercostal artery

anterior:

  • internal thoracic artery next to the sternum becomes the anterior intercostal artery which anastamoses with the posterior intercostal artery laterally in the thoracic cage

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39

What gives the venous supply to the intercostal neurovascular bundle?

  • intercostal veins follow the intercostal arteries
  • anterior intercostal vein in each intercostal space running opposite alongside arteries
  • azygous vein receives all posterior intercostal veins

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40

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41

What alters the vertical dimensions of the intra-thoracic space?

  • movement of the diaphragm:
    • down (contraction) increases thoracic space
    • up (relaxation) decreases thoracic space

42

What alters the lateral dimensions of the thoracic cage?

  • elevation and depression of the lower ribs (8-12)
    • bucket handle movement
  • elevation of the lateral ribs increases the diameter
  • depression decreases the diameter

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43

What alters the anteroposterior dimensions of the thoracic cavity?

  • elevation of the upper ribs
    • pump handle movement
  • upper ribs 1-7 (attached to sternum) push sternum forward on elevation
    • increases AP diameter

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44

What are the accesory muscles of respiration?

  • any muscle that attaches to the ribs
  • scalenes & sternocleidomastoid in the neck
    • elevate upper ribs
  • abdominal muscles
    • pull rib cage down and in

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