Cadaver Anatomy exam 2 - thoracic wall and diaphragm

Thorax definition

Region between neck and abdomen that houses heart and lungs

Main boundaries of thorax

Ribs, sternum, thoracic vertebrae, diaphragm

thoracic cavity is bounded by

ribs, costal cartilage, sternum, thoracic vertebrae, diaphragm

Main thoracic compartments

Mediastinum and two pleural cavities

Mediastinum contains

Heart, esophagus, structures the conduct blood and air

Pleural cavities contain

pleural fluid

Thoracic floor

Diaphragm

thoracic cage functions

Protect heart and lungs, support thoracic organs, provide muscle attachment, resists the negative internal pressures generated by the elastic recoil of the lungs and inspiratory movements

Thoracic cage resists

Negative pressure generated during inspiration

Thoracic cage protects

Superior abdominal organs

Thoracic cavity shape

Truncated cone

Narrowest part of thoracic cage

Superior thoracic aperture

Widest part of thoracic cage

Inferior thoracic aperture

Thoracic cage properties

Thin-walled but strong

Purpose of thoracic shape

Allow expansion during breathing

Thoracic vertebrae number

12

True ribs

1–7

False ribs

8–10

Floating ribs

11–12

True rib attachment

Direct to sternum

False rib attachment

Indirect to sternum via cartilage

Floating rib attachment

No sternal attachment

Costal cartilage function

Flexibility for respiration

Intercostal space definition

Space between adjacent ribs

Subcostal (infrasternal) angle formed by

Costal cartilages 7–10

what is the name for part of 1st rib and sternum

synchondrosis of 1st rib

where are costochondral joints

on rib side of sternum and rib attachment

what are the parts? starting from the top and going clockwise (T2- T8)

body, superior costal demi-facet, pedicle, costal facet on the transverse process, lamina, spinous process, superior articular facet, superior vertebral notch, vertebral foramen

what are the parts? starting from the top and going clockwise (T2- T8)

superior articular process, superior vertebral notch, superior costal demi-facet, body, inferior costal demi-facet, inferior vertebral notch, spinous process, inferior articular process, costal facet, transverse process, pedicle

what are the parts? starting from the top and going clockwise (T11/12)

body, superior articular process and facet, transverse process, spinous process, inferior articular process and facet, costal facet

Thoracic vertebrae articulate with

Ribs

Superior costal demi-facet function

Articulates with inferior articular facet on rib (same rib number)

Inferior costal demi-facet function

Articulates with upper part of the next rib head (different numbered vertebra)

how many facets do atypical ribs have on their head

1

how many facets do typical ribs have on their head

2

what rib is this and what are the parts

head, subclavian artery groove, subclavian vein groove, scalene tubercle, tubercle, neck (1st rib)

what rib is this and what are the parts

(2nd rib), head, body, tuberosity for serratus anterior, tubercle, neck

what type of rib is this and what are the parts and what view of the rib is this

(typical rib) crest of head, superior articular facet, cup for costal cartilage, costal angle, tubercle (superior view)

what rib is this and what are the parts

(11th rib) head, costal angle

what does the costal angle of the 11th rib do

lateral limit of attachment for erector spinae muscles

what type of rib is this and what are the parts and what view

(typical rib) (posterior view) superior articular facet, inferior articular facet, head, tubercle, internal surface, costal groove, body

Typical ribs

3–9

Atypical ribs

1–2, 10–12

Rib head articulates with

Vertebral body

articular facet of the rib tubercle articulates with

corresponding transverse process

what does the non articular part of the rib tubercle do

attachment site for the costotransverse ligament

Costal groove contains

Intercostal vein, artery, nerve

Costal angle location

Posterior rib bend

Rib cartilage attachment

Sternum

Sternum parts

Manubrium, body, xiphoid process

Jugular notch location

Superior manubrium

Clavicular notch articulates with

Clavicle

Sternal angle vertebral level

T4–T5

Sternal angle clinical importance

Landmark for tracheal bifurcation

Xiphoid process vertebral level

T9–T10

Tracheal bifurcation occurs at

T4

Sternal angle corresponds to

2nd sternocostal joint

Inferior border of heart level vertebral level

T9

Transverse thoracic plane passes through

T4 intervertebral disc

what is another name for sternum joints

synchondrosis

what vertebral level is the body of the sternum located at

t5-t9

what do the demi-facets at the manubriosternal joint articulate with

2nd rib

where does the aortic arch begin and end

manubriosternal joint

where is the inferior border of the superior mediastinum

manubriosternal joint

what is the term for an abnormal fusion where a joint should be

synostosis or ossification

what part of the sternum does the 7th costal cartilage articulate with

xiphisternal joint

what is the flat cartilaginous process at birth that ossifies and fuses with the sternal body after middle age

xiphoid process

what is the lower limit of anterior thoracic cavity

t10 (end of xiphoid process)

what is the level of the esophageal hiatus in the diaphragm

t10 (end of xiphoid process)

what is the vertebral level of the superior border of the aortic arch

t3

where are costochondral joints

anterior part of rib

what do costochondral joints do

cartilage and bone is bound by periosteum, no movement in the joint costal cartilage provides flexibility

what are costovertebral joints of

joint of head of rib

where is the costoclavicular igament

between clavicle and 1st rib

where are radiate sternochondral ligaments

on the sternalcostal joints

where are Interchondral joints

Between ribs 6–9

Ribs 1–7 movementat the costotransverse joint

Rotation

Ribs 8–10 movement at the costotransverse join

Gliding

Ribs 11–12 articulation

No transverse articulation

The rib moves (elevates and depresses) around …

an axis that traverses the head and neck of the ribs

Purpose of rib movement

Increase thoracic volume

Superior thoracic aperture structures passing through

Trachea, esophagus, vessels, nerves

Inferior thoracic aperture separates

Thorax and abdomen

Organs in the inferior thoracic aperture

Liver, stomach, spleen

Pectus excavatum

Funnel chest

Pectus carinatum

Pigeon chest

Cause of chest deformities

Improper sternal development

Sternal cleft

Incomplete sternum fusion

Ectopia cordis

Heart outside thoracic cavity

what diseases result from barrel chest

COPD (late stage emphysema and chronic bronchitis)

Barrel chest feature

Increased AP chest diameter and increased retrosternal space

result in barrel chest from

chronic overinflation of lungs with air, constant state partial rib cage expansion

what can be mistaken for a bullet wound or sternal disease

sternal foramen

what can a sternal foramen lead to

cardiac tamponade

what is cardiac tamponade

type of pericardial effusion where the pericardial sac accumulates fluid, pus, blood, clots or gas resulting in slow or rapid compression of the heart

what percentage of the population is sternal foramen found in

4-10%

what is the most common part of the sternum to break

manubriosternal joint

what muscle helps to prevent displacement of the sternum during sternum break

pectoralis

what are comminuted fractures

broken into several pieces

what is the mortality rate of a sternal fracture

25-45%