Anterior Body Wall Flashcards
Pectoral region consists of
pectoral muscles, breast, vessels, nerves and lymphatics
pectoral muscles
the pectoralis major and minor (upper limb muscles) overlie the true muscles of the thoracic wall
pectoral major (origin, insertion)
origin: sternum, clavical upper costal cartilages, insertion: via tendon to the humerus,
pectoral minor (origin, insertion, )
origin: ribs 3-6 insertion: coracoid process of scapula
Mammary gland
modified sweat gland located withing the superficial fascia, composed of gland lobules and fat- they are radially arranged and drain to the nipple via lactiferous ducts
areola
deeply pigmented skin around the nipple or papilla
breast
15-20 gland lobules size varies with age, pregnancy and lactation.
suspensory ligaments
are connective tissue the seperate the loubules of fat between the glands in the breast
what nerves supply the breast
the cutaneous branches of intercostal nerves
what blood supplies the breast
vascularization is from the internal thoracic artery and veins and the lateral thoracic artery and vein
axillary lymph nodes
upper limb and breast lymphatic vessels drain here. they follow both superficial and deep veins
Breast lymphatics
clinically important in the spread of breast cancer most lymph 75% from breast drains to axillary nodes. doc check here to see if cancer has metastasized.
intervertebral disc
vertebrae are seperated by these, changes in density can affect body height, changes due to aging, collapse or curvature of spine
intervertebral formania
allow the passage of spinal nerves these will supply the body wall and limbs.
be able to id the body landmarks of lower anterior body wall
iliac crest, anterior superior iliac spine and pubic tubercle and pubic symphisis
body wall layers
skin, superficial fascia, muscle layers, transversalis fascial layer (in abdomen), endothoracic/abdominal layer, serous lining of body cavities
body wall
encloses the body cavities, protects the internal organs
skin has two major layers
epidermis and dermis
the dermis contains
hair follicles, arrector pili muscles, sebaceous and sweat glands, nerves and vessels
superficial fascia
deep to the skin, contains fat, cutaneous vessels and nerves (tele subcutanea)
fascia
connective tissue padding and casing. deep and superficial
deep fascia
dense connective tissue, white or shiny not easily seperable and covers over muscles like a glove
muscle layers in the thorax and abdomen
external, internal and innermost. the abdomen has an additional longitudinal muscle layer located anteriorly
Pectoralis major function?
Adduction (lowering of the arm), medial rotation (pictured), flexion of the arm (motion of lifting a child)
What is the innervation of the pectoralis major?
Medial and lateral pectoral nerves
what is the innervation of pectoralis minor
innervation: medial pectoral nerve
what is the function of the pectoralis minor
function: depress/ stabilize the shoulder and elevate the ribs when the shoulder is fixed in place (reason for hand on hips when breathing heavy)
What are the 2 layers of fascia between the muscle and serous lining layer?
- Endothoracic fascia or Endoabdominal fascia- Transversalis fascia
Define the serous membrane layer.
Outer lining layer of the body cavities deep to the muscles and fascia, where somatic sensory nerves are located
- Thorax = “parietal pleura”
- Abdomen = “parietal peritoneum”
What is the thorax?
- The upper part of the trunk
- Thoracic wall encloses and protects the thoracic cavity, which contains thoracic viscera
Name and describe the muscle layers of the thoracic wall.
- External intercostals, internal intercostals, innermost intercostals
- Lie between ribs, move the rib cage, maintain intercostal space
Describe the fibers of the external intercostal muscles.
- Fibers run anterior-inferior
- Anteriorly ends as a “membrane,” the external intercostal membrane (aponeurosis)
What direction do the internal intercostal muscles run?
Perpendicular to external intercostal muscles
Describe the innermost intercostal muscles.
- Lie deep to internal intercostal layer
- not a continuous layer
- transverse thoracis fans out from sternum to costal cartilages
- Separated from the internal layer by a neuromuscular plane
What are the layers of the abdominal wall?
- Skin
- Superficial fascia
- Muscles of the abdominal anterior wall
- Transversalis fascia
- Endoabdominal fascia
- Parietal peritoneum
What are the functions of abdominal muscles?
Move the trunk (lateral and anterior flexion)
- Support upright posture
- Compress abdominal contents during: defecation, urination, child birth, coughing, vomiting
Describe the location and direction of the external obliques.
Attach at the inferior ribs, iliac crest to the anterior superior iliac spine. Inferior border is the inguinal ligament.
- Fibers run in the same direction as the external intercostals (like putting hands in pockets)
What is the “linea alba?”
Place along the midline of the body where the tendon fibers of aponeuroses meet and hold body together
Describe the location and direction of the internal obliques.
Attachment from iliac crest to the inferior ribs and costal cartilages.
- medially becomes an aponeurosis (meet at linea alba)
Describe the location of the transversus abdominus.
- Innermost muscle layer
- Attaches to iliac crest and lower costal cartilages
- Medially becomes an aponeurosis attaching to the linea alba.
Describe the rectus abdominus.
Midline paired muscles
- Surrounded by an aponeurotic sheath (like an envelope)
- Attaches at pubic crest, costal cartilages and xiphoid process
- Muscle fibers are interrupted by tendinous intersections (forming the six-pack)
What is the rectus sheath?
- Tendinous sheath formed from the splitting of aponeuroses to create an envelope enclosing the rectus abdominus (anterior and posterior layers)
What is the innervation of the anterior body wall?
- Ventral rami of T1-T12 (the intercostal nerves) and L1 spinal nerves
- Lower intercostal nerves and L1 angle down to supply abdominal wall (T10 dermatome at level of belly button)
What is the arterial supply of the anterior body wall?
- Subclavian artery and branches supply upper limb and anterior thoracic wall
- At lower border of the first rib, subclavian artery changes name to axially artery (travels through axilla surrounded by cords of the brachial plexus)
Where is the internal thoracic artery?
- Branches from the subclavian arteries
- Runs just lateral (outside) of the sternum
- Ends by dividing into the:
>> Musculophrenic artery
>> Superior epigastric artery - Anterior intercostal arteries branch from the internal thoracic and the musculophrenic artery
Describe the arterial supply of the arm.
The axillary artery continues as the brachial artery
- Brachial artery continues into the forearm and becomes the radial and ulnar arteries
How is blood pressure measured?
Compressing the brachial artery against the humerus using a sphygmomanometer
How is wrist pulse taken in the clinic?
Compressing the radial artery (more superficial)
Describe the arterial supply of the POSTERIOR body wall.
- Segmental arterial supply from the thoracic and abdominal aorta
- Segmental arteries:
>> posterior intercostal arteries in the thorax
>> lumbar arteries in the abdomen
What is the midaxillary line?
Vertical line that runs through the middle of the axilla
- Where blood vessels meet
What is collateral circulation?
When an area of the body is receiving blood from more than one artery
Describe the venous drainage of the posterior body wall.
- Posterior intercostal veins drain in to the azygos and hemiazygos veins
- Lumbar veins drain into the inferior vena cava
Describe the venous drainage of the anterior body wall.
- Anterior intercostal veins drain into the internal thoracic veins
- Anterior abdominal veins drain into the epigastric veins
- There is an extensive network of superficial veins within the superficial fascia
Describe the venous drainage of the upper limb.
- Superficial veins of the upper limb begin as the dorsal venous arch of the hand
- They travel just under the skin in the superficial fascia
- They continue proximally as the:
>> Cephalic Vein (lateral)
>> Basilic Vein (medial) - They often connect by a median cubital vein in the cubital fossa
What is venipuncture?
Blood is drawn or intravenous infusions (like IV sedation) are injected into the medial cubital vein or the dorsal venous arch of the hand
How does venous drainage work?
- Deep veins follow arteries, usually have names similar to the arteries
- Veins within the limbs usually contain valves, which prevent back flow towards the heart
What are vaicose veins
- Incompetent valves cause varicose veins
when the valves are too loose
