Lecture 20: Thoracic and Abdominal Walls

Question 1

What does the thoracic cage consist of?

Answer 1

Vertebrae, ribs, and sternum

Question 2

How many pairs of ribs are there?

Answer 2

12 pairs

Question 3

Which ribs are true ribs?

Answer 3

1-7

Question 4

What defines true ribs as true?

Answer 4

They are attached to the sternum directly by costal cartilages

Question 5

Which are the false ribs?

Answer 5

8-12

Question 6

What defines a false rib?

Answer 6

Indirect or no attachment to the sternum

Question 7

Rib pairs 11 and 12 are called what?

Answer 7

False floating ribs

Question 8

What is the structure of a typical rib?

Answer 8

Head, neck, tubercle, body, costal groove, and angle

Question 9

What 3 parts make up the sternum?

Answer 9

The manubrium, body, xiphoid process

Question 10

What rib does the manubrium articulate for?

Answer 10

rib 1

Question 11

What part of the sternum is the jugular notch associated with?

Answer 11

The manubrium

Question 12

What does the body of the sternum articulate with?

Answer 12

Ribs 2-7

Question 13

What are the muscles of the thorax?

Answer 13

The intercostals, transversus thoracis, intercostal space

Question 14

The intercostal space contains what?

Answer 14

The intercostal vein, artery, and nerve

Question 15

What are the muscles of the abdominal wall?

Answer 15

External oblique, internal oblique, transverse abdominus and rectus abdominis

Question 16

What components make up the rectus abdominis

Answer 16

The linea alba and tendinous intersections

Question 17

What is the function of the costal groove?

Answer 17

Protects the intercostal nerve and blood vessels

Question 18

Describe the special structure of the 1st rib

Answer 18

Widest, shortest, and flattest

Question 19

Describe the special structure of ribs 10 11 and 12

Answer 19

They only have one facet on their head

Question 20

Describe the special structural component of ribs 11 and 12

Answer 20

They are short and have no tubercles

Question 21

What is a tubercle

Answer 21

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

Question 22

What is the costal margin?

Answer 22

Formed by the costal cartilages of ribs 7-10 as they link to the sternum

Question 23

What is the subcostal angle?

Answer 23

It’s where the costal cartilages meet the sternum

Question 24

Where does the external oblique muscle originate from and insert onto?

Answer 24

• Originates from the external surface of ribs 5-12
• Inserts onto the linea alba and hip bones

Question 25

What is the function of the external oblique muscle?

Answer 25

To compress and support the organs of the abdominal cavity and flex and rotate our trunk

Question 26

What does the internal oblique originate from the extend to?

Answer 26

Originates from the top of the hip bone
Inserts on the border of ribs 10-12

Question 27

What is the function of the internal oblique

Answer 27

Compresses and supports organs of the abdominal cavity. Flexes and rotates our trunk

Question 28

What does the transverse abdominis originate and insert onto?

Answer 28

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

Question 29

What is the function of the transverse abdominis?

Answer 29

Compresses and supports the abdominal organs

Question 30

What is the function of the rectus abdominis?

Answer 30

When it contracts the trunk is flexed and the abdominal organs are compressed

Question 31

Describe the structure of the thoracic diaphragm?

Answer 31

Dome shaped
Separates thoracic and abdominal cavities
Central tendon