LEC 12: Thoracic Wall and Breast Anatomy - 08.25.14

Question 1

What are the two parts of the skeleton

Answer 1

1. apical
2. appendicular

Question 2

Intercostal muscles

Answer 2

• 3 layers
  
  • external intercostal (fibers point down)
  • internal intercostal (fibers point up)
  • innermost intercostal (fibers point up, don’t extend as far anteriorly as internal intercostals)
• expand/contract thorax
• rotate ribs

Question 3

What innervates upper extremity, serrati (serratus anterior), and intercostal muscles

Answer 3

Ventral rami of spinal nerves

Question 4

Deep back muscles (and overlying skin) are innervated by…

Answer 4

Dorsal rami

Question 5

Superficial muscles (attached to upper extremity), intercostals, intermediate muscles (serratus posterior, inferior and superior) are innervated by…

Answer 5

Ventral rami of spinal nerves

Question 6

Where does the intercostal nerve run

Answer 6

Runs in costal groove under rib between intercostal muscle layers (slopes downward from back to front)

Question 7

Describe dermatones in ventral surface (thoracic region)

Answer 7

Slope downward (correspond with nerve sloping)

Question 8

Describe order of nerves and vessels in intercostal space

Answer 8

VAN = Vein, Artery, Nerve

situated directly under rib, so always want to do a pleural tap or chest tube placement above the rib

Question 9

Where does intercostal rib drain

Answer 9

azygos

Question 10

Where does intercostal artery arise from

Answer 10

aorta

Question 11

Where does intercostal nerve arise from

Answer 11

intervertebral foramen

Question 12

What path do arteries, veins, and lymphatics take in intercostal neurovascular plane

Answer 12

Arteries, veins, and lymphatics parallel the path of ribs (and spinal nerves) in intercostal neurovascular plane

Question 13

collateral circulation

Answer 13

circulation in an area of tissue or organ with a number of different pathways for blood to reach it

Question 14

anastamoses

Answer 14

branches formed between adjacent blood vessels (can be arterial system or venous system)

Question 15

lymphatic drainage follows…

Answer 15

blood supply

Question 16

Where do lymphatics drain above umbilicus? Below umbilicus?

Answer 16

Above umbilicus drains to Axillary Nodes; below umbilicus drains to Inguinal Nodes

Question 17

gynecomastia

Answer 17

male breast enlargement due to hormone imbalance

Question 18

lipomastia

Answer 18

male breast enlargement due to obesity

Question 19

mammary gland

Answer 19

modified sweat gland found in female breast

Question 20

In which layer of fascia is breast found

Answer 20

superficial fascia (anterior to deep fascia of pectoralis major)

Question 21

retromammary space

Answer 21

loose connective tissue plane separates mammary gland from deep pectoral fascia (covering pectoralis major)

separation allows breast to move freely over pectoralis major muscle

Question 22

areola

Answer 22

pigmented area surrounding nipple (pigmentation and size is highly variable)

Question 23

Montgomery’s glands

Answer 23

big goose-bumps in areola region; lubricate nipple and areola to prevent chapping

Question 24

nipple erection

Answer 24

contraction of smooth muscle under areola causes nipple erection (similar mechanism to getting goose-bumps, Autonomic response because its smooth muscle)

Question 25

in men, where is the nipple line

Answer 25

Intercostal Space 4 (ICS 4) near midclavicular line

Question 26

suspensory ligaments (of Cooper)

Answer 26

form boundaries for compartments that contain glandular tissue and fat

• fibrous bands
• anchor to skin
• divide into lobes
• seen in breast x-ray as white connective tissue bands

Question 27

mammography

Answer 27

breast x-ray

Two Views

• oblique (medial-lateral) includes axillary portion, where breast cancer tumors frequently occur
• superior-inferior

Question 28

How do breast cancer cells spread

Answer 28

• Cancer cells spread by following major lymphatic drainage (mostly axillary nodes)
• these are thus considered sentinel nodes for biopsies

Question 29

Mammary Gland function

Answer 29

lactation = milk production

Question 30

anatomy of mammary gland

Answer 30

• lobules - gather lobes together
• lobes - arranged radially around nipple

Question 31

lactiferous ducts

Answer 31

channel milk towards the nipple

Question 32

Where is milk stored in the breast

Answer 32

lactiferous sinuses

Question 33

Breast feeding

Answer 33

• engorged lactiferous sinuses
• tactile/visual stimulation
• nipple erection
• oxytocin release
• milk ejection reflex (milk “let down” in gland - gushing)
• baby “latches on”
• compression of lactiferous sinuses
• “stripping” of nipple (baby does this with tongue)

Question 34

breast function

Answer 34

1. reproduction

• sexual attractiveness
• possible cushioning in missionary position

2. provides all nutrition necessary for baby’s growth
3. transfer of maternal antibodies in colostrum (pre-milk) and milk will protect baby in first few months

Question 35

accessory (supernumerary) nipple or breast

Answer 35

accessory (supernumerary) nipple or breast can appear anywhere along the milk ridge (milk line)