Lecture 20: Thoracic and Abdominal Walls Flashcards
What does the thoracic cage consist of?
Vertebrae, ribs, and sternum
How many pairs of ribs are there?
12 pairs
Which ribs are true ribs?
1-7
What defines true ribs as true?
They are attached to the sternum directly by costal cartilages
Which are the false ribs?
8-12
What defines a false rib?
Indirect or no attachment to the sternum
Rib pairs 11 and 12 are called what?
False floating ribs
What is the structure of a typical rib?
Head, neck, tubercle, body, costal groove, and angle
What 3 parts make up the sternum?
The manubrium, body, xiphoid process
What rib does the manubrium articulate for?
rib 1
What part of the sternum is the jugular notch associated with?
The manubrium
What does the body of the sternum articulate with?
Ribs 2-7
What are the muscles of the thorax?
The intercostals, transversus thoracis, intercostal space
The intercostal space contains what?
The intercostal vein, artery, and nerve
What are the muscles of the abdominal wall?
External oblique, internal oblique, transverse abdominus and rectus abdominis
What components make up the rectus abdominis
The linea alba and tendinous intersections
What is the function of the costal groove?
Protects the intercostal nerve and blood vessels
Describe the special structure of the 1st rib
Widest, shortest, and flattest
Describe the special structure of ribs 10 11 and 12
They only have one facet on their head
Describe the special structural component of ribs 11 and 12
They are short and have no tubercles
What is a tubercle
A bump of the bone that occurs at the junction of the head and body and has one articular part and a non articular part
What is the costal margin?
Formed by the costal cartilages of ribs 7-10 as they link to the sternum
What is the subcostal angle?
It’s where the costal cartilages meet the sternum
Where does the external oblique muscle originate from and insert onto?
- Originates from the external surface of ribs 5-12
- Inserts onto the linea alba and hip bones
What is the function of the external oblique muscle?
To compress and support the organs of the abdominal cavity and flex and rotate our trunk
What does the internal oblique originate from the extend to?
Originates from the top of the hip bone
Inserts on the border of ribs 10-12
What is the function of the internal oblique
Compresses and supports organs of the abdominal cavity. Flexes and rotates our trunk
What does the transverse abdominis originate and insert onto?
Originats on the costal cartilages of ribs 7-12 and the iliac crest
Inserts on the linea alba and inserts onto the anterior part of the pelvic bone
What is the function of the transverse abdominis?
Compresses and supports the abdominal organs
What is the function of the rectus abdominis?
When it contracts the trunk is flexed and the abdominal organs are compressed
Describe the structure of the thoracic diaphragm?
Dome shaped
Separates thoracic and abdominal cavities
Central tendon
