Thoracic Osteology And Wall Structure Flashcards
The 4 components of the thoracic cage?
- 12 thoracic vertebrae
- 12 PAIRS of Ribs and their costal cartilage
- Sternum
- Intercostal Muscles
Superior boundary of the thoracic cage?
4 things total
- First Thoracic vertebra
- First pair of ribs and costal cartilage
- Manubrium
- Smaller of the two opening
Inferior border of the thoracic cage?
4 things total
- 12th thoracic vertebra
- 12th pair of ribs and their cartilage
- Xiphisternal Joint
- Larger of the two openings
Bones of the thoracic cage
5 total
- Manubrium
- Sternum
- Xiphoid process
- Ribs
- Thoracic vertebrae
Where does the Manubrium articulate with the Sternum?
At the Manubriosternal Joint
Features of the Manubrium?
- Sup Jugular notch
- CONCAVE surfaces for clavicle
- Concave surfaces for first rib
What is the first rib that you can palpate?
Where is it located?
The second rib
At the Manubriosternal joint
Body of the Sternum
- Made up of 4 FUSED Sternebrae
- Ossification occurs during the 3rd trimester
- Fused into a single bone in young adult
Xyphoid process
- Fibrocartilage extension of sternum into abdominal musculature
- Marks level SIX of Dermatome
The Sternum attaches to what ribs?
Ribs 2 - 10
The ribs are attached to the sternum by what?
Costal cartilage
What is the the Infrasternal Angle?
- AKA Subcostal angle
- The lower opening of the thoracic cage
What forms the Infrasternal angle?
- 12th Thoracic Vertebra (Behind)\
- the 11th/12th ribs (Side)
- the cartilages of the 7th-10th ribs (Front)
- Xiphoid process (Top)
Ribs 1 - 7 are also known as what type of ribs?
Vertebrosternal
Ribs 8 - 10 are also known as what type of ribs?
Vertebrochodral ribs
Ribs 11 - 12 are also known as what type of ribs?
Vertebral (Floating) ribs
Main parts of a rib?
- Head
- Neck
- Tubercle
- Shaft
- Costal cartilage
The tubercle articulates with what?
The transverse process of the vertebra of the same #
The costal groove on the shaft contains what?
(Sup to Inf)
- Intercostal Vein
- IC Artery
- IC Nerve
“VAN”
The Sternal end of each rib lies ____ than the vertebral end.
One level LOWER
What ribs are know as TYPICAL ribs?
Ribs 3 - 9
Characteristics of the 1st Rib?
- Flattened in a HORIZONTAL (Tansverse) plane
- Scalene tubercle for Scalenus Ant.
- Shallow groove for Subclavian VEIN (Anterior to tubercle)
- Shallow groove for Subclavian ARTERY (Post. To tubercle)
What vertebrae have Sup and Inf costal demifacets?
T2 - T9
What is the first spinous process to be palpated?
C7
What spinous process is the most prominent?
T1
Why is T1 Atypical?
Has a Full superior costal facet
- Not a DEMI-facet
Why is T10 Atypical?
Has one pair of costal facets located partly on BODY and Partly on the PEDICLE
Why is T11/12 Atypical?
One pair of costal facets on the PEDICLES
Characteristics of a “Typical” Rib articulation
- Head articulates with demifacets of SAME # vertebra and the Vertebra ABOVE
(As well as the intervertebral disc) - Tubercle articulates w/ the Transverse process of the SAME # vertebra
Characteristics of the Sternal Angle?
- Marks Rib 2
- Lies at Level T4-5 (IV Disc)
Where can the AORTIC Valve heart sound be heard?
At the SECOND IC space on the RIGHT side of sternum
Where can the PULMONARY Valve heart sound be heard?
At the SECOND IC space along the LEFT Side of the Sternum
Where can the TRICUSPID Valve heart sound be heard?
THe FIFTH IC Space on the RIGHT side of the Sternum
Where can the Bicuspid the Valve heart sound be heard?
The FIFTH IC space about 10cm to the LEFT of the Sternal midline
Where is the bifurcation of the Trachea?
B/w Sternal angle and T4/T5 vertebral level
Scapula in reference to the thorax
- Scapular spine at 3rd rib and T2
- Inf scapular angle at 7th rib and T7. Or body of T9
Infrasternal angle
- Important in CPR
- Depression b/w is the Infrasternal FOSSA
- Xiphisternal Joint w/in the fossa is at T9
How is the ANTERIOR Axillary line Formed?
By the Lower border of the Pectoralis MAJOR
How is the POSTERIOR Axillary line Formed?
By the Tendon of the LATSSIMUS Dorsi
Cutaneous innervation for
- Clavicle and Scapular region
- Upper Thorax
- Xiphoid process
- Lower Thorax
- C3-C4
- T1-T5
- T6
- T7-T12
The Medial/Lateral pectoral nerves arise from where?
From the Medial/Lateral (respectively) cord of the BP
The Proximal and Distal attachment of the Pectoralis Minor?
Prox: Ribs 3 - 5
Dist: Coracoid Process
Prox/Dist attachments of the Serratus Ant.
Prox: Ribs 1 - 9
Dist: Ant Surface of the medial border of the scapula
Blood supply of the Serratus Ant.
SUP thoracic and LAT thoracic arteries
Innervation of the Serratus Ant.
Long thoracic nerve (C5-C7)
The pectoral region is supplied by the _______ Artery?
Axillary
The three muscle layers of the Thoracic Wall
- External IC
- Internal IC
- Innermost IC
Tranversus Thoracis
4-5 slips that originate from the Inf. Sternum and extends Superolaterally to Internal surface of Upper Ribs
Mammary glands are modifies ______?
Sweat glands
What nerves innervate the mammary glands?
Intercostal Nerves 4-6
