The Thorax Flashcards
Label the surface anatomy:
What makes up the thorax?
(3)
Sternum
12 pairs of ribs (24 individual ribs)
Costal cartilages
Label the thorax:
What does the clavicular notch connect to?
The clavicle
What happens at the sternal angle?
It’s where the manubrium connects to the body
Anteriorally, where do the ribs connect to?
The sternum, via costal cartilages
Posteriorally, where do the ribs connect to?
The vertebrae
What is the manubrium?
The head of the sternum
What are the features of the manubrium?
(4)
It’s the wider superior portion
It articulates with the clavicles and the first 2 pairs of ribs. The 2nd rib attaches to the sternal angle
The jugular notch can be easily felt at the anterior base of the neck, between the medial ends of the clavicles
The clavicular notch is the site of the sternoclavicular joint, between the sternum and clavicle
Label the sternum:
What are the features of the body of the sternum?
(2)
It’s the middle portion of
It gives attachment to the ribs 3-7 pairs
What are the features of the Xiphoid process of the sternum?
(2)
It’s the inferior tip
It gives attachment to the diaphragm and abdominal muscles
What’s really important to know about the placement of the ribs?
Since the 1st rib is hidden behind the clavicle, it’s hard to identify it. So the 1st rib we can actually see is the 2nd rib-not the 1st
Which type of imaging analyses the sternoclavicular joint the best?
CT scans
What are the features of the sternoclavicular joint?
(3)
It’s between the medial end of the clavicle and the manubrium of the sternum (clavicular notch)
It’s a saddle-type synovial joint
It allows the elevation, depression, protraction and retraction of the shoulders
How many pairs of ribs do we have?
12 pairs
What are the features of the ribs?
(5)
There’s 12 pairs of ribs
Pairs 1-7 directly attach to the sternum at their own costal cartilage- true ribs
Pairs 8-10 indirectly attach to the sternum at the costal cartilage- false ribs. They connect to 1 costal cartilage that then connects to the lowest bit of the body of the sternum
Pairs 11 and 12 aren’t attached to the sternum- floating ribs
Intercostal spaces
Which pairs of ribs are known as the true ribs?
Pairs 1-7
Which pairs of ribs are known as the false ribs?
Pairs 8-10
Which pairs of ribs are known as the floating ribs?
Pairs 11 and 12
How are the intercostal ribs named?
They’re named according to the rib that’s above
E.g.
rib 1
Rib 2
Intercostal space 2
Rib 3
Rib 4
Intercostal space 4
Rib 5
Label the ribs:
What are the 2 types of ribs?
Typical ribs
Atypical ribs
What are the features of the typical ribs?
(4)
Flat bones
The anterior end is connected to the sternum by the costal cartilage to form the sternocostal joints
The head of the clavicle is posterior and connects to the Demi-facets of the spine/vertebrae to form the costovertebral joints
The articular part of the tubercle with the transverse process of the vertebra to form the costotransverse joints
Label this typical rib:
How many Demi-facets does a typical rib have?
2
What are the features of the atypical ribs?
(5)
Rib 1 is shorter and wider than the other ribs. It only has 1 facet on its head so it can articulate with its corresponding vertebra T1
The superior surface is marked by 2 grooves, which makes way for the subclavian vessels and brachial plexus
Rib 2 is thinner and longer than rib 1 and has 2 articular facets on the head as normal
Rib 10 only has 1 facet- for articulation with its corresponding vertebra T10
Ribs 11 and 12 have no neck or tubercles, and only contain 1 facet, which is for articulation with their corresponding vertebra
How many ribs are atypical ribs?
5
Which ribs are atypical ribs?
(5)
Rib 1
Rib 2
Rib 10
Rib 11
Rib 12
What is a plexus?
A network of nerves that come from the spine. They go down the spine and the chest
Which atypical rib is this? (Superior view)
1st rib
Which atypical rib is this? (Superior view)
2nd rib
Which atypical rib is this? (Posterior view)
10th rib
Which atypical rib is this? (Posterior view)
11th rib
Which atypical rib is this? (Posterior view)
12th rib
What are the 2 types of intercostal muscles?
Internal intercostal muscles
External intercostal muscles
How many pairs of muscles do internal intercostal muscles have?
11 pairs
How many pairs of muscles do external intercostal muscles have?
11 pairs
Which type of intercostal muscles are more active during inspiration (inhaling)?
External intercostal muscles
Which type of intercostal muscles are more active during expiration (exhaling)?
Internal intercostal muscles
Label the internal and external intercostal muscles:
What are the features of the diaphragm?
(4)
Separates the thoracic and abdominal cavities
Convex superior surface
It’s the chief muscle of inspiration
It contracts and relaxes
Label the diaphragm (axial view):
Why do the ribs move?
So that we can breathe
What are the 3 origins of the diaphragm?
Sternum
Rib pairs 6-12
Lumbar vertebrae
What is ossification?
Bone formation
What are the ossification centres of the sternum (the stages that it forms)?
(4)
Manubrium
1st sternal segment
2nd sternal segment
3rd sternal segment
Where is the 1st rib in this x-ray of the thorax?
