Lecture 2: Thoracic Walls & Breast

Question 1

What is the role of the thoracic wall?

Answer 1

To protect viscera

Is the mechanical basis of breathing

Question 2

What is the thoracic wall made up of?

Answer 2

The thoracic cage and coverings

Question 3

What are the three types of ribs?

Answer 3

True (1-7)
False (8-10)
Floating (11 & 12)

Question 4

Which ribs are atypical?

Answer 4

1
2
10
11
12

Question 5

Which ribs are typical?

Answer 5

3-9

Question 6

What is found in the intercostal space?

Answer 6

Muscle
Nerves
Vessels

Question 7

What are the three layers of intercostal muscle?

Answer 7

External intercostal muscles (and membrane)
Internal intercostal muscles
Innermost intercostal muscles

Question 8

What structures does the costal groove protect?

Answer 8

Intercostal vein
Intercostal artery
Intercostal nerve

Question 9

What are the superficial muscles that cover the thoracic wall?

Answer 9

Pectoralis minor
Pectoralis major
Subclavius
Serratus anterior
Serratus posterior

Question 10

What are the coverings of the thoracic cage?

Answer 10

Subcutaneous fat
Subcutaneous fascia
Skin

Question 11

Where does the mammary gland sit and how is it attached?

Answer 11

Sits on fascia superficial to pectoralis major

Attached to skin and fascia by suspensory ligaments

Question 12

How many lobules does the mammary gland have and what do they contain?

Answer 12

15-20 lobules
Contain alveoli (milk secreting portion of the lobule)

Question 13

What dermatome innervates the teets?

Answer 13

T4 teets

Question 14

What dermatome innervates the belly button?

Answer 14

T10

Question 15

What are the attachments and movements of pectoralis minor?

Answer 15

Coracoid process to ribs 3, 4, 5

Elevates ribes/stabilises scapula

Question 16

What are the 3 attachments and movements of pectoralis major?

Answer 16

Clavicular head and sternal head to humerus (bicipital groove)
Adducts the arm

Question 17

What are the attachments and movements of serratus anterior?

Answer 17

Lateral aspect of ribs 1-8 to the medial border of the anterior surface of scapula
Protracts the scapula

Question 18

What are the attachments and movements of serratus posterior?

Answer 18

Spinous processes of C7-T3 to angle of ribs 2-5
Elevates the ribs

Spinous processes of T11-L2 to angle of ribs 9-12
Depresses the ribs

Question 19

Where is the retomammary space and what can it be used for?

Answer 19

Between the pec major and breast tissue

Important in breast implants and mastectomy

Question 20

What is the mammary gland drained by?

Answer 20

The lactiferous duct which opens independently on the nipple

Question 21

What portion of breast sits on the serratus anterior and pectoralis major?

Answer 21

Serratus anterior: 1/3

Pectoralis major: 2/3

Question 22

What ribs can the breast be found on?

Answer 22

Ribs 2-6

Question 23

What is the areola?

Answer 23

The pigmented area around the nipple that has sebaceous glands for lubrication

Question 24

At what level is the nipple found?

Answer 24

At the 4th intercostal space in the mid-clavicular line (nulliporous women)

Question 25

What is the nipple?

Answer 25

The opening of the lactiferous ducts, smooth muscle, no fat/hair/sweat glands

Question 26

What are the two types of mammograms and who are they used on?

Answer 26

Dense (connective tissue & glands) - younger women
Low density (fatty) - older women

Question 27

What is the blood supply to the breast?

Answer 27

Subclavian artery > axillary artery > lateral thoracic artery > lateral mammary branches

Internal thoracic artery (through intercostal space) > medial mammary branches

Lateral mammary branches of posterior intercostal arteries

Question 28

What is the venous drainage of the breast?

Answer 28

Internal jugular vein > subclavian vein > axillary vein > lateral thoracic vein > lateral mammary vein

Internal thoracic vein > medial mammary vein

Question 29

Where does 75% of lymph from the breast end up?

Answer 29

In the axillary nodes