Ch 24 Thoracic Wall Flashcards
The function of the thoracic wall is to form a protective cavity for the heart, lungs and ograns of the _ aspect of the abdomen
superoir
The sternum is AKA
breast bone
The sternum is the _ _ found at the anterior aspect of the thorax and it sits _.
flat bone
midline
“sternon” in Greek =
breast of man
The 3 parts of the sternum are:
Manubrium
Body
Xiphoid Process
The _ is the superior part of the sternum.
manubrium
“manus” from Latin =
hand
The sternum is thought to resemble a _ with the manubrium being the part that is held in a hand.
sword
A _ _ is found at the superior border of the manubrium
jugular notch
The manubrium articulates with the _ and the 1st _ pair of costal cartilages (hyaline cartilage between ribs and sternum)
clavicles
first 2 pair of costal cartilages
The _ is the middle portion of the sternum
body
T/F the manubrium of the sternum is thinner, and more narrow than the body.
False, the body is thinner, narrower and longer than the manubrium
The body of the sternum articulates with the costal cartilages of ribs _ to _.
2-7
The _ _ is the junction of the manubrium and body of the sternum and is a helpful landmark for counting ribs
sternal angle
The smallest, most variable, and inferior part of the sternum is the _ _
xiphoid process
“xiphon” and “oeides” in Greek=
sword shaped
The _ _ (pit of the stomach) is a depression on the anterior aspect of the xiphoid process which is palpable and visible
epigastric fossa
The _ _ is found between the xiphoid process and the body at the _ aspect of the epigastric fossa.
xiPHIsternal joint
superior
Ribs are AKA
costae
How many ribs are there in a typical adult body?
24 or 12 pair
If variations in the number of ribs occur they happen usually at _ and _
CV7 and LV1
Ribs course _ and _ from the thoracic vertebrae
anteriorly and inferiorly
The _ of the rib articulates with the bodies of the vertebrae
head
The _ of the rib is the constricted portion lateral to the head
neck
The tubercle of the rib articulates with the _ _ of its respective thoracic vertebrae.
transverse process
The _ of the rib is the shaft.
body
The _ of the rib is the point where the curve is the sharpest.
angle
The anterior end of the rib articulates with the _ _
costal cartilage
The costal groove is the ridge that lies on the _ surface of the shaft of the rib.
inferior
The intercostal vein, artery, and nerve lie in the _ _ of the ribs
costal groove
The length of the ribs increase from the _ to the _ rib and decrease all the way to the _ rib.
1-7 rib
12th rib
The first _ ribs are true ribs and are directly connected to the sternum via costal cartilage.
seven
The last _ ribs are false ribs
five
Each costal cartilage of ribs _ - _ joins its respective suprajacent costal cartilages.
8-10
(10 to 9, 9 to 8, and 8 to 7)
The costal cartilages of ribs _ and _ end blindly in muscle with no anterior articulation, these are called floating ribs.
11 and 12
The costal margin is formed by the costal cartilages of ribs _ - _ which course medially and superiorly.
7-10
The infrasternal angle is formed by the intersection of the _ _ and the _ joint.
costal margins and xiphisternal joint
The superior thoracic aperture is bounded by the upper border of the _ and the _ ribs
sternum
1st ribs
The _ _ aperture has an opening that the great vessels and visceral tubes ascend or descend between the thorax and neck.
superior thoracic aperture
The _ _ aperture is normally closed by the diaphragm
inferior thoracic aperture
3 major openings exist in the diaphragm which allow for the passage of the _ vena cava, _, and the _.
IVC, esophagus, aorta
There are 3 arrangements of layers of the muscles of the thorax:
External- external intercostal muscles
Middle- internal intercostal muscles
Internal- innermost intercostal muscles
External Intercostal Muscles origin:
Lower Margin of the rib above
External Intercostal Muscles insertion:
upper margin of the rib below
External Intercostal Muscles action
Elevation of the ribs during inspiration
External Intercostal Muscles innervation:
Intercostal Nerves T1-T6
Thoracoabdominal Nerves T7-T11
T/F :There are 12 pair of external intercostal muscles.
False, there are 11 pair
From their point of origin, the fibers of the external intercostal muscles pass _ and _ to their point of insertion
medially and inferiorly
The external intercostal muscles extend from the _ of the ribs posteriorly to the region of the _ _ anteriorly.
tubercles
costochondral junction
The external intercostal muscles thin out near the _ _ +turn into the external intercostal membrane
Costochondral junction
Internal Intercostal Muscles origin:
Upper Margin of the rib below and its costal cartilage
Internal Intercostal Muscles insertion:
Lower Margin of the rib above and its costal cartilage
Internal Intercostal Muscles action:
Depression of the ribs during expiration
Internal Intercostal Muscles innervation:
Intercostal nerves of T1-T6
Thoracoabdominal nerves of T7-T11
T/F there are 10 pairs of internal intercostal muscles
False, there are 11pairs
From their point of origin, the fibers of the internal intercostal muscles pass _ and _ to their point of insertion.
medially and superiorly
The internal intercostal muscles extend from the _ anteriorly to the _ of the ribs posteriorly where they thin out and become the _ _ _.
sternum
angle of the ribs
Internal Intercostal Membrane
The _ _ muscles have the same origin, insertion, action, and innervation as the internal intercostal muscles
Innermost Intercostal Muscles
There are _ pairs of innermost intercostal muscles
11 pairs
The innermost and internal intercostal muscles are separated by the _ vessels and nerve in a space called the _ plane.
intercostal vessels and nerve
Neurovascular Plane
Aside from the 3 layers of intercostal muscles, the _ _ and _ are muscles also associated with the thoracic wall.
Transversus Thoracis
Subcostales
There are _ pairs of thoracic spinal nerves and they all pass thru _ _ and divide into a dorsal and ventral ramus.
12 pairs
intervertebral foramen
The dorsal rami of the thoracic spinal nerves course _ and divide into _ and _ branches.
posteriorly
medial
lateral
The ventral rami of the thoracic spinal nerves are _ branches and they course _ into intercostal spaces.
larger
anteriorly
The ventral rami of the thoracic spinal nerves have 3 sets of regional names:
T1-T6: Intercostal nerves (proper)
T7-T11: Thoracoabdominal nerves
T12: Subcostal Nerve
Pathway of typical intercostal nerve (1/5): Passes _ the neck of the rib numerically corresponding to it (T4= below 4th thoracic rib)
below
Pathway of typical intercostal nerve (2/5): Courses between the _ and the _ intercostal muscles in the neurovascular plane
innermost and internal
Pathway of typical intercostal nerve (3/5): Passes forward in the _ _ on the lower surface of the rib, inferior to the intercostal vein and artery.
costal groove
Pathway of typical intercostal nerve (4/5): Gives off a lateral cutaneous branch that pierces the _ and _ intercostal muscles, and _ anterior muscles. It then divides into anterior and posterior branches that supply the skin of the chest wall.
internal and external intercostal muscles
serratus anterior muscles
Pathway of typical intercostal nerve (5/5): At the anterior end of the intercostal space it turns _ thru the internal intercostal muscle, the external intercostal _, and the _ _muscle then distributes as the anterior cutaneous branch to the skin in the front of the chest.
forward
membrane
pectoralis major muscle
Breasts are _ _ modified to produce milk and their major function is _.
sweat glands (eww)
lactation
The main constituents of the mammary gland are the _ to _ lobes of the glandular tissue (alveoli).
15-20 lobes
Lobes within the breast contain _ or milk secreting mammary epithelial cells and the lobes are arranged in _ -like clusters.
alveoli
grape
Of the 15-20 lobes in the breast only _ - _ are considered fully functional, the remaining majority are small and poorly developed.
6-8 lobes
The majority of the breast contains _ which covers the glandular tissue.
fat
Each breast lobe is drained by a _ duct that dilates near its end. This dilation is called the _ _ and its ducts empty at the nipple.
lactiferous
lactiferous sinus
Breast tissue is firmly attached to the skin over the organ by _ _ containing many ligamentous bands.
connective tissue
The _ _ divides the fat and anchors the glandular tissue with ligamentous bands to the skin of the breast.
retinacula cutis
Retinacula cutis is well developed in the _ portion of the breast and is called _ _ (Cooper’s Ligaments) in this area.
upper
suspensory ligaments
The _ is the pigmented part of the breast which contains sebaceous glands.
areola
The _ are conical or cylindrical prominences found at the center of the areola.
nipples
The tip of the nipple is _ and contains the opening to the _ ducts.
fissured
lactiferous ducts
The nipples are mostly composed of circularly arranged _ muscles.
smooth
Between the breast and deep fascia there is an area of _ _ tissue with almost no fat called the _ _.
loose connective tissue
retromammary space
The retromammary space allows the breast to move freely on the deep fascia covering the _ _ muscle.
pectoralis major
The breasts are found superiorly to inferiorly between the _ and _ ribs
2-6 ribs
The breasts are found medially to laterally between the _ and the _ line.
sternum
mid-axillary line
T/F The majority of the breast rests on the serratus anterior muscle and the rest lies on the pectoralis major muscle.
False, it lies mostly on the pectoralis major and the remaining is on the serratus anterior.
Breast tissue is highly vascularized via perforating branches from the _ _ artery (internal thoracic artery; 50% of blood), the _ _ artery, and the _ arteries.
Internal Mammary Artery (aka Internal Thoracic Artery)
Lateral Thoracic Artery
Intercostal Arteries
The larger vessels to the breast descend to it from a _ or _ position
supERolateral or suPERomedial position
The breast’s nerves are supplied by anterior and lateral branches from the _ to _ intercostal nerves
2nd-6th intercostal nerves
Lymph from the breasts drain mostly into the _ nodes (75%), the _ nodes (20%), and the _ _ nodes (5%)
axillary nodes
parasternal nodes
inferior phrenic nodes
The _ _ nerve is nearby the breasts and during surgery it can be injured and cause the pt to have a _ scapula and difficulty _ above the horizontal plane.
Long Thoracic Nerve
winged scapula
abducting
The long thoracic nerve courses along the breasts _ on the external surface of the _ _ muscle which it supplies.
inferiorly
serratus anterior
