What are the two parts of the skeleton
1. apical
2. appendicular
Intercostal muscles
- 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
- external intercostal (fibers point down)
- internal intercostal (fibers point up)
- innermost intercostal (fibers point up, don't extend as far anteriorly as internal intercostals)
What innervates upper extremity, serrati (serratus anterior), and intercostal muscles
Ventral rami of spinal nerves
Deep back muscles (and overlying skin) are innervated by...
Dorsal rami
Superficial muscles (attached to upper extremity), intercostals, intermediate muscles (serratus posterior, inferior and superior) are innervated by...
Ventral rami of spinal nerves
Where does the intercostal nerve run
Runs in costal groove under rib between intercostal muscle layers (slopes downward from back to front)
Describe dermatones in ventral surface (thoracic region)
Slope downward (correspond with nerve sloping)
Describe order of nerves and vessels in intercostal space
VAN = Vein, Artery, Nerve
situated directly under rib, so always want to do a pleural tap or chest tube placement above the rib
Where does intercostal rib drain
azygos
Where does intercostal artery arise from
aorta
Where does intercostal nerve arise from
intervertebral foramen
What path do arteries, veins, and lymphatics take in intercostal neurovascular plane
Arteries, veins, and lymphatics parallel the path of ribs (and spinal nerves) in intercostal neurovascular plane
collateral circulation
circulation in an area of tissue or organ with a number of different pathways for blood to reach it
anastamoses
branches formed between adjacent blood vessels (can be arterial system or venous system)
lymphatic drainage follows...
blood supply
Where do lymphatics drain above umbilicus? Below umbilicus?
Above umbilicus drains to Axillary Nodes; below umbilicus drains to Inguinal Nodes
gynecomastia
male breast enlargement due to hormone imbalance
lipomastia
male breast enlargement due to obesity
mammary gland
modified sweat gland found in female breast
In which layer of fascia is breast found
superficial fascia (anterior to deep fascia of pectoralis major)
retromammary space
loose connective tissue plane separates mammary gland from deep pectoral fascia (covering pectoralis major)
separation allows breast to move freely over pectoralis major muscle
areola
pigmented area surrounding nipple (pigmentation and size is highly variable)
Montgomery's glands
big goose-bumps in areola region; lubricate nipple and areola to prevent chapping
nipple erection
contraction of smooth muscle under areola causes nipple erection (similar mechanism to getting goose-bumps, Autonomic response because its smooth muscle)
in men, where is the nipple line
Intercostal Space 4 (ICS 4) near midclavicular line
suspensory ligaments (of Cooper)
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
mammography
breast x-ray
Two Views
- oblique (medial-lateral) includes axillary portion, where breast cancer tumors frequently occur
- superior-inferior
How do breast cancer cells spread
- Cancer cells spread by following major lymphatic drainage (mostly axillary nodes)
- these are thus considered sentinel nodes for biopsies
Mammary Gland function
lactation = milk production
anatomy of mammary gland
- lobules - gather lobes together
- lobes - arranged radially around nipple
lactiferous ducts
channel milk towards the nipple
Where is milk stored in the breast
lactiferous sinuses
Breast feeding
- 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)
breast function
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
accessory (supernumerary) nipple or breast
accessory (supernumerary) nipple or breast can appear anywhere along the milk ridge (milk line)