Chapter 10- Bony Thorax (Sternum and Ribs)

name the 2 major functions of the bony thorax

1. expansion and contraction for respiration

2. protection of respiratory organs and vital structures within the mediastinum

the bony thorax consists of the ____________ anteriorly, the ____________ ____________ posteriorly and the _____ pairs of ribs

sternum, thoracic vertebra, 12 pairs of ribs

the widest and most superior portion of the sternum is the _______________

manubrium

the middle and longest portion of the sternum is the __________, which projects anteriorly and inferiorly

body

the most inferior portion of the sternum is the _____________, which is composed of cartilage during youth and doesn't completely ossify until about 40 years old

xiphoid

which ribs are true ribs, meaning they connect directly to the sternum with a short piece of costocartilage?

rib pairs 1-7

which ribs are false ribs, meaning they have costal cartilage that joins with the cartilage of rib 7, then to the sternum?

rib pairs 8-12

which ribs are floating ribs, meaning they do not have costal cartilage and therefore do not connect to the sternum?

rib pairs 11 and 12

each rib has a ______________ end, which articulates with the thoracic vertebrae, and an _______________ end, which articulates with the costal cartilage

posterior/vertebral, anterior/sternal

the area between the two ends of the rib is known as the __________

shaft/body

the vertebral end of a rib consists of a ________, which articulates with 1-2 thoracic vertebral bodies, and a flattened _________

head, neck

lateral to the neck of the vertebral end of the rib is an elevated ______________, which articulates with the transverse process of the vertebra allowing for attachment of a ligament

tubercle

along the inferior internal margin of each rib is the _________ _________, which protects an artery, a vein, and a nerve

costal groove

which end of the rib is more superior?

the posterior/vertebral end

where is the bony thorax the widest?

around the 8th/9th ribs

the _____ pair of ribs have the sharpest curvature at the angle

1st

the superior border of the manubrium has a slightly notched area between the 2 clavicles called the ___________ __________

jugular notch

the jugular notch corresponds to what level?

T2-T3

the inferior end of the manubrium joins the body of the sternum to form a palpable anterior prominence, the ___________ ___________

sternal angle

the sternal angle corresponds to what level?

T4-T5

what is the only bony connection between each shoulder girdle and the bony thorax?

the sternoclavicular (SC) joints

the sternum has ___ pairs of facets/depressions located laterally along the manubrium and body to accept the costal cartilage

7

the second costal cartilage connects to the sternum at the level of the __________ _________

sternal angle

a costochondral union occurs between the ___________ _____________ and the ___________ end of a rib

costal cartilage, sternal end (labeled A)

a sternoclavicular joint occurs between a ____________ and the _______________ of the sternum

clavicle, manubrium (labeled B)

the sternocostal joints of the 2nd-7th ribs occur between _________ __________ and the ____________

costal cartilage, sternum (labeled D)

the interchondral (endochondral) joints occur between the __________ ___________ of the anterior 6-9th ribs

costal cartilages (labeled E)

RAO Sternum

Technical Factors

SID: 40"

Field Size: 10 x 12, portrait

Grid: Yes

kVp: 75-85

Positioning

-Patient erect in a 15-20 degree RAO

-CR to mid-sternum, 1" left of midline

Respiration

-Suspended on expiration

NOTES: begin with patient AP, light field ~2 inches above the jugular notch, then turn patient into RAO

Lateral Sternum

Technical Factors

SID: 72"

Field Size: 10 x 12, portrait

Grid: Yes

kVp: 75-85

Positioning

-Patient erect in a true lateral, hands clasped behind back to draw shoulders down, chest puffed out

-Place top of IR 1.5" above the jugular notch

-CR to mid-sternum, midway between jugular notch and xiphoid process

-Turn collimator to align long axis of sternum to CR

Respiration

-Suspended on expiration

AP Ribs Above Diaphragm

Technical Factors

SID: 40"

Field Size: 14x17 portrait (unilateral), 14x17 landscape (bilateral)

Grid: Yes

kVp: 75-85

Positioning- Unilateral

-Patient erect in AP projection

-Align the side of thorax of interest to midline of bucky

-Raise chin slightly, arm of side of interest out of the way

-CR 3-4" below jugular notch, midway between MSP and lateral margin of thorax

Positioning- Bilateral

-Patient erect in AP projection

-Raise chin slightly, arms away from sides

-Rotate shoulders anteriorly

-CR 3-4" below jugular notch to MSP

Respiration

-Suspended on deep inspiration

AP Ribs Below Diaphragm

Technical Factors

SID: 40"

Field Size: 14x14 (unilateral), 14x17 (bilateral)

Grid: Yes

kVp: 75-85

Positioning- Unilateral

-Patient erect in AP projection

-Align the side of thorax of interest to midline of bucky

-Arm of side of interest out of the way

-CR midway between xiphoid process and lower rib margin, midway between MSP and lateral margin of thorax

Positioning- Bilateral

-Patient erect in AP projection

-Arms away from sides

-CR midway between xiphoid process and lower rib margin at MSP

Respiration

-Suspended on deep inspiration

NOTES: bottom of light field at iliac crest

AP Oblique Axillary Ribs (RPO/LPO)

Technical Factors

SID: 40"

Field Size: 14x17

Grid: Yes

kVp: 75-85

Positioning

-Patient erect in AP projection, rotated into 45 degree posterior oblique w/ affected side closest to IR

-Arms out of the way

-Align thorax to midline of IR

-CR to T7

Respiration

-Suspended on inspiration

NOTES: LPO shows right side angles and left side elongated

RPO shows left side angles and right side elongated

PA Oblique Axillary Ribs (RAO/LAO)

Technical Factors

SID: 40"

Field Size: 14x17

Grid: Yes

kVp: 75-85

Positioning

-Patient erect in PA projection, rotated into 45 degree anterior oblique w/ affected side away from IR

-Arms out of the way

-Align thorax to midline of IR

-CR to T7

Respiration

-Suspended on inspiration

NOTES: RAO shows right side angles and left side elongated

LAO shows left side angles and right side elongated