Thoracic and Abdominal Walls Flashcards
3 Parts of the Sternum
- Manubrium
- Body
- Xiphoid Process (CPR)
Sternal Angle/Angle of Louis
- Trachea bifrucates into right and left bronchi in the thoracic cavity
- Arch of the aorta begins and ends
- SVC penetrates the pericardium to enter the heart
- It marks the second rib and the division between the manubrium and the body
Clavicle Connections
- Lateral: acromion process of scapula
- Medial: manubrium (thorax)
Most broken bone in body because it transmits force from the upper limbs to the thorax
Winged Scapula-surgical error
After a radical mastectomy, if a person comes in with a winged scapula, it means that the long thoracic nerve which innervates the serratic anterior (one muscle that keeps scapula from winging) was knicked
Coronoid Process
small hook/node-like structure on lateral edge of superior anterior portion of the scapula
Rib Types
- True (1-7)
- False (8-10)-they’re cartilage does not directly connect to the body of the sternum. Instead, it joins the costal cartilage to connect to the sternal body
- Floating (11, 12)-embedded in the musculature of the abdominal wall
What are the 6 posterior components of the rib?
Head, neck, tubercle, angle body, costal groove (N:179)
Costal Margin
The medial margin formed by the costal cartilage of the false ribs and the 7th rib
Costal Cartilage
Cartilage that attaches true ribs 1-7 to the sternal body and false ribs 8-10 to the costal cartilage of the 7th rib
Costo-chondral Junctions
Where the bony portion of the ribs meets the cartilaginous portion
Intercostal Spaces
Spaces between ribs, named for the rib above it
Where do you puncture when you have a collapsed lung?
The second intercostal space, just superior to the third rib because the nerve bundle goes inferior to each rib and you don’t want to hit
Name the anterior thoracic muscles
- pectoralis major
- pectoralis minor
- external intercostals
- internal intercostals
- serratus anterior
- latissimus dorsi
(N:182, 183)
Name the thoracic layers starting from the skin
- Skin
- Superficial fascia
- external intercostal muscle
- internal intercostal muscle
- innermost intercostal muscle
- deep facia
- pleura
- ->there are also the pectoralis muscles and the serratus muscles, make sure you know them too!
Function of external vs internal intercostal muscle
External=elevate ribs and sternum
Internal=depress them
What innervates the serratus anterior?
The long thoracic nerve
Lateral pectoral nerve
innervates pectoralis major
Medial pectoral nerve
Passes through the pectoralis minor and penetrates the deep surface of the pectoralis major
Pectoral branches of the thoracoacrominal artery
Branches of the thoracoacromonial artery, which is part of the axilary artery that supplies the anterior axilla, including the pectoral muscles, deltoid, clavicle, and acromioclavicular joint
–>in BREAST, it is the lateral source of blood supply
Axillary artery
Lateral source of blood for the breast
-very large artery with lots of branches coming from it
Mammary Gland
Secrete ze milk
Structure of the breast (posterior to anterior)
- The Pectoralis major
- Pectoral fascia
- Membrane of fat and suspensory ligaments/ligaments of cooper, which anchor the mammary gland to the skin
- Mammary glands are drained by a lactiferous duct into the lactiferous sinus
- This empties into the nipple
If a woman contracts her pectoral muscles, what should happen normally, and what happens in abnormal conditions
Normally: nothing, sags
Tumor of the retromammary space attaches to the pectoral fascia and the pec major so the breast moves up when pecs contract
What does dimpling of the breast imply?
Cancer has invaded the suspensory ligaments of cooper that anchor the glands to skin
What is peau d’orange
Dimpling and orange peel-like appearance of the skin. Retraction and elevation of the nipple. Signs of cancer spread to suspensory ligaments. Obstruction of cutaneous lymphatics. Involvement of lactiferous ducts. When all of this isn’t working, get this orange look and lots of inflammation
What two types of lymph nodes are involved in lymphatic draining of the breast?
75% axillary nodes
Rest=parasternal nodes deep to anterior thoracic wall
Radical mastectomy
Removal of skin over the tumor and of the dome of the breast, breast tissue, pectoralis major/minor, upper part of anterior sheath of rectus abdominus, nerves to pectoral muscles, intercosto-brachial nerve, thoracoacromial vessels, all tributaries to the axillary vein from the breast and axilla, *axillary lymph nodes and vessels and the fat in which they are embedded
Iliac crest
Form the superior margin of pelvic bones, anterior to anterior superior iliac spine. Highest point is a useful landmark for L4
Anterior superior iliac spine (ASIS)
Most anterior superior part of pelvic bone. Provides attachment for the inguinal ligament
Pubic tubercle
Portion of the pubic bone that the inguinal ligament attaches to. It is the forward projecting round nodule/small emenence (tubercle) on the upper boarder of the medial portion of the pubis
(N:241)
Pubic crest
Boarder between the pubic tubercle and the pubic symphesis. The pubic crest and the inguinal ligament form the base of the anterior abdominal wall
Pubic symphysis
Marks the inferior extent of the abdominal wall (pg 16 of the iBook)
Name the layers of the abdominal wall
- Skin
- Superficial fascia
- External abdominal oblique
- Internal abdominal oblique
- Transversus abdominus
- Transversalis fascia
- Extraperitoneal fascia/fat
- Peritoneum
Rectus abdominus
Muscle that extends from the xiphoid to the pubic symphysis
Aperneurosis
Flat tendons of the 3 anterolateral abdominal muscles
What is the rectus sheath? What does it cover?
The aponeruosis of the external oblique, internal oblique and transverse abdominus. It envelopes the rectus abdominus. The superior 3/4 of the rectus muscle in the abdomen wall is covered by the sheath front and back. The inferior 1/4 of the rectus muscle is covered by the sheath in the front only.
What is the arcuate line?
Arcuate line is the line that demarcates the upper 3/4 of the rectus abdominus from the lower 1/4. It also serves as the point where the inferior epigastric vessels enter the rectus sheath
Linea alba
A raphe, not a ligament that indicates the midline of the abdomen. Common site of incisions for abdominal surgery
Conjoint tendon
Along with the rectus abdominal muscle, it reinforces the posterior wall of the superficial inguinal ring to prevent hernias.
Formed by the aponeurosis of the transversis abdominus and internal oblique muscles
Conjoined tendon attaches to the pubic bone posterior to the superficial inguinal ring
Layers of the superficial fascia
- Camper’s: contains fat, continuous with superficial fascia everywhere. Is the outer layer
- Scarpa’s: lacks fat, is the inner layer
Triangle of Hesselbach
Lateral: inferior epigastric artery
Inferior: inguinal ligament
Medial: lateral part of the rectus abdominus
Inferior epigastric artery/vein
Artery: branch of the external iliac artery, it forms the lateral part of the triangle of Hesslebach
Medial to the deep inguinal ring
Superior epigastric artery
Branch of the internal thoracic artery that supplies the rectus abdominus muscle
Inguinal ligament
Divides the lower anterior abdominal wall from the proximal thigh. The three muscle layers of the abdominal wall are anchored to the inguinal ligament and the pubic crest
Inguinal canal and its walls
Allows the passage of testis and in females it transmits the round ligament
4 of the 8 layers of the abdominal wall form the inguinal canal. Each layer has a breach through it, but is organized in such a way to prevent herniation
There are 4 walls of the inguinal canal
- Posterior wall: transversalus fascia (contains deep ring)
- Anterior wall: aponeurosis of the external oblique muscle
- Floor: inguinal ligament
- Roof: Transversus abdominus and internal oblique muscles
Superficial/external inguinal ring
A fault in the external oblique aponeurosis that forms the anterior opening of the inguinal canal
Just above the pubus, medial to pubic tubercle
Breach in the inguinal ligament that fits tightly to the spermatic cord or round ligament which pass through it
Very rigid, does not dilate even when tensed by contraction of the external oblique
Give rise to external spermatic fascia
Deep inguinal ring
It is a fault in the transversalis facia which forms the posterior opening of the inguinal canal
An indirect hernia goes through it
Ilioinguinal nerve
Transmitted by the superficial ring. Supplies the abdominal musculature
If it is damaged, it can result in weakening of muscles in the inguinal region creating a predisposition to development of direct inguinal hernia
Cremaster muscle
It consists of fibers of the internal oblique that extend along the spermatic cord. Contraction of this elevates the testis and helps regulate thermal environment of the testis
Layers of the spermatic fascia and where they came from ????? We must ask????
- External spermatic fascia
- from the external oblique aponerosis - Cremasteric muscle and fascia
- the fascia is derived from the fascia of the internal oblique - Internal spermatic fascia
The transversus abdominus does not contribute to the spermatic fascia, but transversalis fascia does
Round ligament of the uterus
It is the remnant of the gubernaculum which passes through the inguinal canal and ends in the labia majus
Ductus deferens
In males, pass through the inguinal canal. Structure of the spermatic cord that conveys sperm from the epididymis to the ejaculatory duct
Processes vaginalis
An invagination of the parietal canal that descends through the inguinal canal during fetal life
Tunica vaginalis
Remnant of the processes vaginalis in the spermatic cord that covers the anterior and lateral parts of the testis
Out-pocketing/sac of the peritoneal layer that provides a double layer of friction reducing membrane that the testis can use to slide higher or lower
Epididymis
Site of spermatogenesis
Indirect inguinal hernia
Bowel can go through the deep ring and the superficial ring to form a hernia outside of hasslebachs triangle
More common in children and most common in adult men
Direct inguinal hernia
The peritoneal sac/bowel protrudes through the posterior wall of the inguinal canal due to weakening in the anterior abdominal wall. The protrusion is medial to the inferior epigastric artery and vein.
If the lump is inside hasselbach triangle, it is a direct hernia. It can or cannot go into superficial inguinal ring, but does not go through the deep ring
More common in older people and females
