Lect 4 Mam Tissue Thoracic Wall

Front 1

anatomical borders of mam gland?

Back 1

clavicle (superior), rectus sheath (inferior), sternum (medial), and latissimus dorsi (lateral).

Front 2

Suspensory ligaments of Cooper

Back 2

Connective tissue extends from deep fascia to skin, provides structural support. These weaken with age, hence the effects of gravity and aging on your boobs.
Along with adipose tissue, compose supporting tissue of mammary tissue.

Front 3

Production and transport of milk?

Back 3

Mammary gland lobules produce, transported thru lactiferous ducts into sinus and out to the nipple.
Gland size does not correlate with amount of milk produced.

Front 4

Areola

Back 4

smooth muscle on surface of breast, controlled by autonomic system and contracts in response to crying babies, cold temps, etc.
Contains areolar glands (sebaceous glands) that enlarge during pregnancy and lubricate the breast.
Nipple and areola undergo pigment changes during 3rd trimester of pregnancy. Can tell if someone's ever been through 3rd trimester.

Front 5

Blood supply to mammary gland

Back 5

MAIN: Internal Thoracic Artery aka internal mammary artery (branch off the subclavian, goes to intercostals, redundancy makes good candidate for bypass) and Lateral Thoracic Artery (branch off axillary artery)
OTHERS: thoacodorsal artery (in back), intercostal artery (perforators, particularly 4th and 5th intercostal), thoracacromial artery (superior)

Front 6

Valves b/w intercostal veins & vertebral veins?

Back 6

NO! Influential in metastatic spread of breast cancer. BOO.

Front 7

Innveration of breast

Back 7

Mammary gland: lateral cutaneous branch of T4 off intercostal
Upper and lateral breast: supraclavicular nerves
Remaining: thoracic intercostal nerves from T3-T5

smooth muscle of areola under involuntary motor control from autonomic nervous system.

Front 8

Lymph drainage of breast

Back 8

(a) axillary lymph nodes: lateral, responsible for majority of lymph drainage
(b) supraclavicular: greater risk for cancer metastasis. Located superiorly to breast
(c) Parasternal "internal mammary": located inferiorly and medially to breast. Can allow for cancer to travel from one breast to other through pectoral major fascia, also can cause systemic metastasis.

Front 9

Breast Cancer stats

Back 9

1 in 8 women will face Bcancer by time they reach 90.
most common visceral cancer in women, 2nd most common cause of cancer mortality.
75% cancers drain to axillary lymph node.
Only 10% of breast lumps are cancerous.

Front 10

Clinical exams for B Cancer

Back 10

In self/ clinical exam, look for dimpling, thickening, lesions etc. If dimpling of skin--tumor has invaded suspensory ligaments of cooper.

Mammograms: light areas are "hot spots" that show where tumors (e-dense) may be present. Doesn't tell if benign or malignant. Craniocaudal view (top-down) or medial-lateral-oblique view.

Ultrasound to check if cystic or solid.

Breast MRI: evaluate how extensive the cancer is.

biopsy: remove tissue for inspection. Only way to confirm cancer.

Front 11

Clinical signs of B Cancer

Back 11

Dilated veins (req blood supply)
Peau d'orange & Edema (aggressive tumors block lymph nodes, cutaneous lympathic edema)
Skin dimpling (suspensatory ligaments of cooper shortened by tumor)
Nipple retraction (cancer moves to mammary ducts, ducts may shrink and retract)

Front 12

Treatment for B cancer

Back 12

Radical mastectomy (remove mammary gland, axillary nodes, pectoral major and minor muscles)
- run risk of damaging long thoracic nerve and thoracodorsal nerve (serratus anterior, latissimus dorsi muscles innervation)

Tram Flap reconstruction (flap of rectus abdominus used with innervation and blood supply intact to create a new breast. Prevents necrosis of tissue
Nipple reconstruction and areolar tattooing for cosmetic purposes.

Lumpectomy (removal of lump of cancerous tissue. Less invasive than mastectomy, preserves most of boob.)

Lymph mapping (flow of lymph directional. method used to asses how far cancer has spread via injection if indie dye into the breast which will travel the path of least resistance. When dye collects in node, dissect and check for cancer. Continue distal to site of injection until cancer-free node found).

Front 13

c

Back 13

g

Front 14

Thorax

Back 14

Function: protect vital organs, breathing, conduit for impt structures
anterior bones: clavicle, 12 ribs, sternum (manubrium, body, xiphoid process)
- ribs 1-7: direct attachment to sternum
- ribs 8-10 attach to superior rib--> creates costal margin
- ribs 11 and 12: floating ribs.
*ribs are mobile thanks to costal cartilage: surgical retractor to spread the ribs in thoracotomies. Allows access for cardiothoracic surgery. Also, shock absorption and resilience function--declines with age (ossification)
posterior bones: scapula, T1-T12 thoracic vertebrae

Front 15

Pneumothorax

Back 15

Collapsed lung due to air entering space b/w pung and thoracic wall. Complication from cracked rib
* Ribs 2-7 most likely ribs to be injured (Rib 1 protected by clavicle)

Front 16

Flail Chest

Back 16

Paradoxical movement of ribs during breathing b/c multiple fractures.
Inspiration causes free piece of rib to move inward, high potential of damaging smthng impt.

Front 17

Common sites for bone marrow extraction?

Back 17

Sternum, or in pelvis

Front 18

Extrinsic muscles of thorax

Back 18

Anterior: pectoralis major & minor, serratus anterior
Posterior: trapezius, rhomboids, latissimus dorsi--> IMPT in mvmnt of limbs

Front 19

Intrinsic muscles of thorax

Back 19

(1) extrinsic intercostals: muscle fibers oriented "hands in pocket." superior-lateral to inferior-medial obliquely.
Elevate ribs (1st rib is fixed), help expand chest during inhalation

(2) internal intercostals: fibers arranged perpendicular to external intercostals (Y!!MCA)
depress ribs during expiration (forceful exhalation of air) anchored by quadratus lumborum muscle on 12th rib.

(3) innermost intercostals: elevate ribs as well.

(4) transversus thoracis muscles: depress ribs in midline, help attach vessels/veins to sternum

Front 20

Rib VAN innervation and blood supply

Back 20

Superior--> inferior: intercostal vein artery and nerve
bundle runs between innermost intercostal muscle and internal intercostal muscle.
Needle is inserted on superior border of ribs to avoid damage of this bundle!!!!

Front 21

Two types of breathing?

Back 21

*Breathing expands thoracic cavity in 3D: vertical (diaphragm), AP and transverse (intercostal muscles open up chest)
(1) diaphragm breathing (deep)
(2) costal breathing (shallow)--preggie ladies rely on this as uterus enlarges and pushes against the abdomen.

Front 22

Inspiration v expiration

Back 22

Inspiration: requires muscular contraction
Expiration: completely passive process*

Exception: HYPERNEA (forced breathing) requires accessory muscles b/c active inspiration AND expiration.
Recruits transverse thoracic, internal intercostals, abs to help force air out of lungs. Common occurence with asthma.

Front 23

b

Back 23

b

Front 24

Suprasternal notch

Back 24

projects posteriorly onto T2/T3
AKA Jugular notch!

Front 25

Sternum

Back 25

Directly anterior to the heart (CPR compressions performed here to avoid cracking ribs)

Front 26

Xiphisternal joint

Back 26

projects posteriorly to T9

Front 27

Nipple

Back 27

4th intercostal space (only on males)

Front 28

Apex beat of heart

Back 28

5th intercostal space, 3-5 inches from midline on left side.