Unit 4_The Bony Thorax & Muscles Flashcards
What encompasses the bony thorax and thoracic wall?
Bony cage
Protects the Thoracic Viscera
- Heart
- Lungs
- Large Blood Vessels
The Midclavicular Line, Anterior and Posterior Axillary Line, Midsternal Line, and Paravertebral Line make up what landmarks?
External Landmarks of the bony thorax and thoracic wall
How many pairs of ribs make up the anterior and posterior boundaries of the thorax?
12
How many pairs of intercostal spaces make up the anterior and posterior boundaries of the thorax?
11
What kind of cartilage is included in the thorax?
Costal Cartilage (hyaline)
How many parts make up the sternum?
3-parts
Manubrium
Body
Xiphoid Process
How many thoracic vertebrae make up the posterior boundaries of the thorax?
12
What ribs does the scapula cover in the posterior boundary of the thorax?
Ribs 2-6
What covers the inferior thoracic outlet?
Diaphragm
What do the following structures make up?
Suprasternal notch (jugular notch)
Clavicular notch
Notch for Costal cartilage of 1st rib
Sternum-Manubrium
What supports the articulation of the body of the sternum with the manubrium?
The sternal angle (Louis)-called the manubriosternal joint
What articulates with the sternum body?
Articular facets-costal cartilages of ribs 3-6
What does the Xiphoid process articulate with for the costal cartilage of 7th rib and ossifies at ~15-30 years of age?
Xiphisternal Joint
What are ribs 1-7 known as and each attach (via costal cartilage) directly to the sternum from anteriorly?
True ribs
What are ribs 8-10 known as and attach to the sternum via the costal cartilage of the 7th rib?
False ribs
What are ribs 11-12 known as, do not attach to the sternum and have hyaline cartilage?
Floating ribs
What kind of ribs are 3-9 and include the following:
Angle
Head
Neck
Tubercle
Costal Groove
Sternal Extremity
Articular facet of tubercle of rib
Superior articular facet of head of rib
Inferior articular facet of head of rib
Typical Ribs
What kind of ribs are 1-2, 10-12?
Atypical ribs
Rib 1
Flat
No Costal Groove
No Angle
Note: Scalene Tubercle & Groove for the Subclavian A.
Rib 2
Flat
Angle closer to Tubercle
Ribs 10-12
Single articular facet on the head
What kind of joints are the Costovertebral and Transversocostal of the thorax?
Gliding Joints
What kind of joint is the Sternocostal joint of the thorax?
Cartilagenous joint
How many pairs of intercostal nerves (T1-T11) are there?
11
Where do the intercostal nerves lie (T1-T12)?
In the intercostal spaces
What do the intercostal nerves (T1-T11) supply?
General sensation to the bony thorax
Innervation to the intercostal muscles
Where does the subcostal nerve (T12) lie?
Below the 12th rib
What does the subcostal nerve help to supply innervation to?
Abdominal muscles
How many pairs of posterior intercostal arteries are there?
11
Where do the posterior intercostal arteries 3-11 arise from?
Thoracic Aorta
Where do the posterior intercostal arteries 1-2 arise from?
Costocervical Trunk (br. of the Subclavian A.)
How many pairs of anterior intercostal arteries are there?
11
Where do the anterior intercostal arteries 1-6 arise from?
Internal Thoracic Artery (br. of the Subclavian Artery)
Where do the anterior intercostal arteries 7-11 arise from?
Musculophrenic (artery) branch of the Internal thoracic artery
What veins make up the intercostal veins?
Anterior Intercostal Vein
Posterior Intercostal Vein
How many pairs of external intercostal muscles are there?
11
Where do the external intercostal muscles begin and end?
Begin at the Spine
End in the Parasternal Area-Anterior Axillary Line
Where do the external intercostal muscles attach to?
Sternum via External Intercostal Membrane
What do the external intercostal muscles facilitate?
Inhalation
How many pairs of internal intercostal muscles are there?
11
Where are the internal intercostal muscles located?
Deep to External Intercostals
Where do the internal intercostal muscles originate?
Sternum
Where do the internal intercostal muscles attach to?
Internal Intercostal Membrane
What do the internal intercostal muscles facilitate?
Forced Exhalation
How many pairs of innermost intercostal muscles are there?
11
Where are the innermost intercostal muscles located?
Deep to Internal Innercostals
What do the innermost intercostal muscles facilitate?
Forced exhalation
What is one procedure done when the Midsternal Line is cut?
Mid sternotomy
What is the space between the ribs called?
Intercostal Space
What is the space below the 12th rib called?
Subcostal Space
What is the right/left diaphragm also called?
Hemi-diaphragm
What side of the body does the diaphragm sit?
Right side
What do typical ribs articulate with?
Costal Facet
What rib do ribs articulate with?
The rib below articulates with the rib above
What virus lies dormant in the spinal cord and if it comes under stress, can express itself as pain, in a rash via the anterior cutaneous branch as part of the intercostal nerves.
Chickenpox
What single branch of the anterior intercostal arteries of the lower 5 ribs goes into the abdominal/stomach area?
Superior epigastric branch
What structure on the right side turns into the subclavian artery?
Brachiocephalic Trunk
What are the branches of the subclavian artery?
Internal Thoracic Artery (Posterior/Lateral to the sternum)
Costocervical Trunk (intercostal arteries come off = 1st deep cervical 2nd supreme thoracic)
Vertebral Artery
How do the external intercostal muscles run?
Fibers pass downward and forward
How do the internal intercostal muscles run?
Fibers pass downward and backward
How do the innermost intercostal muscles run?
Fibers run in the same direction as the Internal Intercostals
What does the costal cartilage-2nd rib articulate with?
Sternal angle (Louis)-called the manubriosternal joint
How are the intercostal nerves created?
Spinal cord –> dorsal root (spinal ganglion)/ventral root –> spinal nerve –> dorsal ramus/ventral ramus
Ventral ramus –> Lateral cutaneous branches = sensation in the thorax
Ventral ramus –> Anterior cutaneous branch = sensation (pain, temperature, etc)
VPR branches also give off motor branches to intercostal muscles and some abdominal region muscles
