Superficial Back Flashcards
True or false?
the skin of the back is of average thickness and unremarkable
true
Describe the superficial fascia of the back
loose network of connective tissue. varies in amounts of fat dispersed , contains superficial branches of nerves, blood vessels, and lymphatics
Describe the deep fascia of the back
more compact sheet dominated by collagen
deep fascia frequently surrounds or encases other structures, especially muscles, and is termed ___ fascia
investing
note: investing fascia is continuous with the epimysium of the muscle
deep fascia can also extend from the superficial fascia to skeletal features, in which case it is referred to as a ___
septum
in the back a portion of the deep fascia is specialized, termed the thoracolumbar fascia. describe it
an extensive sheet, extending from the sacrum and iliac crest superiorly to the neck and from the spinous processes laterally to the angle of the ribs
how many layers are found in the thoracolumbar fascia?
three layers of investing fascia
note: also plays role in spine stability
True or false?
the tendinous origins of many of the back muscles are integrated with the thoracolumbar fascia
true
What are the three insertion points of the superficial back muscles?
scapula, clavical, humerus
What is the source of innervation for the superficial back muscles
cranial and spinal nerves
What are the insertion points of intermediate back muscles?
ribs distal to angle
What is the source of innervation for the intermediate back muscles
spinal nerves, anterior rami
What are the insertion points for the deep muscles of the back?
vertebrae, ribs (angle and proximal)
What is the source of innervation for the deep muscles of the back?
spinal nerves, posterior rami
motor nerve cell bodies (motor neurons) are located in the ventral ___ matter of the spinal cord; their axons exit the spinal cord as the ventral rootlets, which collectively from the ___ ____
gray; ventral root
sensory nerve cell bodies (sensory neurons) are located in the dorsal ___ ___; their axons enter the dorsal gray matter of the spinal cord as dorsal rootlets, which collectively form the ____ ___
root ganglia; dorsal root
near the level of the _____ _____ the spinal nerve is formed by the combination of the ventral and dorsal roots; each of the 31 spinal nerves includes both sensory and motor axons
intervertebral foramen
each spinal nerve divides into a ___ ___ and ___ ___
posterior ramus; anterior ramus
A ___ forms when the anterior rami of multiple spinal nerves combine
plexus
True or false?
most of the spinal nerves in the thoracic region do not form plexi; the anterior rami of the thoracic spinal nerves form the intercostal nerves
true
plexi are located in the cervical, brachial, lumbar, and sacral regions. The anterior rams of T1 contributes to the ___ plexus and the anterior rams of T12 contributes to the ___ plexus
brachial; lumbar
nerves branching off the brachial plexus innervate some of the muscles in the superficial group of back muscles. true or false?
true
The cranial nerves are historically interpreted as modified spinal nerves that are associated with the ___ rather than the ____
brain; spinal cord
The eleventh cranial nerve is the ___ nerve
accessory
describe the route the accessory nerve takes
passes superiorly to enter the skull though the foramen magnum then reverses direction and exits the skull by way of the jugular foramen
upon exiting the jugular foramen, the accessory nerve crosses the internal jugular vein and passes into what?
hint: this portion of the neck is closely associated with the branches of the cervical plexus and is the site of administration of cervical plexus nerve blocks
posterior triangle of the neck
The accessory nerve pierces the ____ muscle before coursing along the deep surface of the ___ muscle.
note: it innervates both of these muscles
sternocleidomastoid; trapezius
Where does the accessory nerve have the highest incidence of iatrogenic injury?
between sternocleidomastoid and trapezius
Most of the attachments of the superficial back muscles are on the ___
scapula
What is the origin and insertion of the trapezius muscle?
origin: superior nuchal line, external occipital protuberance, nuchal ligament, and spinous processes of C7-T12
insertion: lateral 1/3 of the clavicle, and the acromion process and spine of scapula
What is the action of the trapezius?
elevation, depression, retraction, upward rotation of scapula, and extension of the neck/head
What innervates the trapezius?
accessory nerve is motor; anterior rami of C3-C4 are sensory
The ___ ___ is the largest of the superficial muscles, a broad triangular muscle with its apex on the humerus. The superior portion of this muscle is deep to the trapezius
latissimus dorsi
What is the origin and insertion of latissimus dorsi?
origin: spinous processes of T7-T12, ribs 9-12, thoracolumbar fascia, and iliac crest
insertion: the floor of the intertubercular sulcus on the anterior humerus
What innervates the lattisiums dorsi?
thoracodorsal nerve
What are the actions of lattisimus dorsi?
extends, adducts and medially rotates the humerus
This muscle is a strap muscle found deep to the trapezius. It elevates and downward rotates the scapula, and laterally flexes the neck
levator scapulae
What are the attachments of levator scapulae?
superiorly on the transverse process of vertebrae C1-C4. Inferiorly, onto the superior angle of the scapula
What innervates the levator scapulae?
dorsal scapular never
These two muscles are rhombus-shaped, divided into two parts, deep to the trapezius and immediately inferior to the levator scapulae. They act to retract and downward rotate the scapula
rhomboid major/minor
What is the origin and insertion of the rhomboid major/minor?
Origin: the nuchal and supraspinous ligaments, spinous processes of T12 to T5 (rhomboid major) and C7 to T2 (rhomboid minor)
insertion: the medial border of the scapula
What innervates rhomboid major/minor?
dorsal scapular nerve
The following is a thin sheet of muscle located deep to the rhomboids which acts to elevate the ribs 2-5 as well as providing sensory information
serratus posterior superior
What is the origin and insertion of serratus posterior superior?
origin: the nuchal ligament and spinous process of C7-T3
insertion: ribs 2-5
What innervates the serratus posterior superior?
anterior rami of spinal nerves T2-T5 (intercostal nerves)
The following is a thin sheet of muscle located deep to the latissimus dorsi that acts to depress the ribs 9-12 as wells as provide sensory information
serratus posterior inferior
What is the origin and insertion of serratus posterior inferior?
origin: spinous processes of T11-12
insertion: ribs 9-12
What innervates the serratus posterior inferior?
intercostal nerves and subcostal nerve
Cutaneous innervation of the back is via posterior rami of spinal nerves ___ to ___
C4; L3
____ branches of the posterior rami enter the superficial fascia near the median plane. These branches cover an area from cervical to mid-thoracic
medial
____ branches of the posterior rami enter the superficial fascia lateral to the thoracolumbar fascia to supply the lower thoracic & lumbar regions
lateral
each spinal nerve receives cutaneous sensation from a strip of skin. This coverage area is called a ____
dermatome
superficial back muscles receive blood supply which usually arises from branches of the ____ artery or ____ artery
subclavian; axillary
The ___ ___ artery is a branch off of the subclavian artery
transverse cervical
the transverse cervical artery has divides into a deep branch which runs deep to the levator scapulae and rhomboids along the medial border of the scapula. What is the name of this branch when it originates directly from the subclavian artery?
dorsal scapular artery
Where is the superficial branch of the transverse cervical artery located?
deep surface of the trapezius
The thoracodorsal artery is a branch off of the ___ artery; it passes through the axilla to the deep surface of the latissimus dorsi
axillary
The posterior intercostal arteries branch from the ___ ___ and proceed along the thoracic wall within the intercostal spaces
descending aorta
Give the arterial supply to each of the following back muscles: trapezius levator scapulae rhomboid mm. latissimus dorsi serratus posterior mm.
trapezius: superficial branch of transverse cervical a.
levator scapulae: dorsal scapular a. or deep branch of transverse cervical a.
rhomboid mm.: dorsal scapular a. or deep branch of transverse cervical a.
latissimus dorsi: thoracodorsal a.
serratus posterior mm.: posterior intercostal aa.
skin, superficial fascia and deep back muscles receive blood from regional aa. Which aa. supply most of the posterior thorax? Which aa. supply the inferior thorax?
superior thorax: posterior intercostal aa.
inferior thorax: lumbar or gluteal aa.
Venous drainage of back muscles is mostly via tributaries to the intercostal veins, which are tributaries of the _____ or ____ veins.
brachiocephalic; azygous
Additional venous drainage is via regional veins superiorly or inferiorly which subsequently drain to the inferior ___ ___ or superior ___ ___
vena cava; vena cava
True or false? the triangle of auscultation is the area of the back where the thoracic wall is the thickest, providing inadequate ability to hear the lungs
false; thinnest - provides best potential to hear lungs
What are the borders of the triangle of auscultation?
medial: inferior margin of trapezius
inferior: superior margin of latissimus dorsi
lateral: medial border of scapula
floor: 6th and 7th ribs and the external intercostal within the 6th intercostal space
The dimensions of the triangle of auscultation are dependent on the position of the ___
scapula
