Posterior Cervical Triangle And Intro To UE / Brachial Plexus Flashcards
The posterior cervical triangle (PCT) is a junction between the ____ and the ___ skeleton.
Upper extremity ; axial
The pectoral region of the PCT is the (anterior/posterior) triangle of the upper extremity to the axial skeleton
Anterior
The scapular region of the PCT is the (anterior/posterior) junction of the upper extremity to the axial skeleton
Posterior
The axillary region of the PCT is the (medial/lateral) junction of the upper extremity to the axial skeleton.
Lateral
The axillary region is located between what two regions of the posterior cervical triangle as well as the chest wall of the humerus?
Pectoral & Scapular
What are the boundaries in the axillary region?
Anterior, posterior, medial, lateral, base, and the apex
What is the anterior boundary of the axillary region made up of?
The anterior boundary of the pyramid is made up of the pectoralis major and minor.
What is the posterior boundary of the axillary region made up of?
The posterior boundary is made up of the teres major, the latissimus dorsi, and the subscapularis muscle.
What is the medial boundary of the axillary region made up of?
The medial boundary is made up of the serratus anterior muscle.
What is the lateral boundary of the axillary region made up of?
The lateral boundary is made up of a small portion of the humerus.
What is the apex of the axillary region made up of?
The apex is made up of the first rib, the clavicle, and the superior boarder of the scapula.
The axilla region creates a pyramid that is encased in a lot of _____ tissue and ____ and there is a sheet that surrounds the nerves and blood vessels that is called the axillary sheet
Connective; fat
What does the axillary sheet contain?
The axillary sheet contains the brachial plexus, the axillary artery, and the axillary vein
The ______ is the first site where you can see the major neurovascular structures of the upper extremities
Posterior Cervical Triangle
The posterior cervical triangle is the triangle that is created by the
Posterior boarder of the sternocleidomastoid (SCM), the anterior edge of the upper trapezius muscle, and the middle 1/3 of the clavicle
In the posterior cervical triangle, is there a lot of fat and connective tissue?
Yes (it is a very deep triangle)
What muscles make up the floor of the posterior cervical triangle?
The floor of the posterior cervical triangle is made up of the anterior scalene, middle scalene, posterior scalene, levator scapulae, and the splenius capitis.
As we open up and get rid of all of the fat and fascia in the PCT, what structures will you find?
As we open up and get rid of all of the fat and fascia in the PCT, you should find cutaneous branches of the cervical plexus, lymph nodes, superior portion of the brachial plexus (supraclavicular region), and the subclavian artery
What nerve runs somewhere between the middle and upper portion of the SCM?
The lesser occipital nerve
What nerve is around the middle of the SCM and runs straight superior to the ear (runs pretty much across the upper third of the SCM)?
The greater auricular nerve
What nerve runs from the middle of the SCM on the posterior boarder and comes out and wraps around the inferior third of the SCM?
The transverse cervical nerve
What nerves are a whole bunch of branches coming off above the clavicle and underneath the middle portion of the SCM?
The supraclavicular nerves
What nerve is a very superficial structure in the PCT and passes through the triangle and follows a line from the ear lobe down the neck to the tip of the shoulder and goes deep to the trapezius?
The spinal accessory nerve (cranial nerve XI)
What nerve has a potential for injury during surgery in the neck and if someone is carrying a heavy backpack on the base of their neck?
The spinal accessory nerve (cranial nerve XI)
The spinal accessory nerve innervates what two muscles?
The SCM and the trapezius
If you injure the spinal accessory nerve in the PCT and lacerate it completely, which muscle will be affected? If the nerve gets injured outside of the PCT, deeper in the neck and higher in the neck, then which muscle(s) will be affected?
If the nerve gets injured in the PCT after innervating the SCM, only the trapezius will be affected.
If the nerve gets injured outside of the PCT, deeper in the neck and higher in the neck then both muscles will be affected
In the PCT floor, there is a little gap called the ____
Scalene groove
The scalene groove is created by two muscles and a bone, name the two muscles and the bone.
The posterior boarder of the anterior scalene and the anterior boarder of the middle scalene, and a portion of the third rib
What is the opening in the floor that allows the brachial plexus to emerge?
The scalene groove
The section from the shoulder to the elbow is called what?
The arm or the brachium
What is the name of the region between the arm and forearm?
The elbow
What is another name for the elbow?
The cubital region
What is the name of the region between the elbow and wrist?
The forearm
What is another name for the forearm?
The antebrachium
What is the name of the region just distal to the wrist?
The hand
The ______ is superficial fascia and fat under the skin that runs all the way around the arm. This fascia contains lots of veins and subcutaneous nerves.
Subcutaneous tissue
Is the subcutaneous tissue loose or dense connective tissue?
Loose because it’s fascia
After removing the superficial fascia, what layer do you find?
Deep fascia
Deep fascia has this investing fascia that goes between muscles, works its way to the bone, and creates compartmentalization. What is this fascia called?
Septa
Since we know that deep fascia surrounds every muscle, how is it determined for the deep fascia to create the septa?
It is only the deep fascia that goes towards the bone that creates the septa.
How many compartments are there in the forearm?
2
In your forearm, your anterior compartment starts out at the (medial/lateral) side of the elbow and runs to the anterior side of the wrist. The posterior compartment runs from the (medial/lateral) side of the elbow and runs to the posterior surface of the wrist.
Medial; Lateral
Muscles within a compartment tend to have similar functions
Muscles in a compartment are innervated predominantly by one nerve
T or F
True
The anterior divisions of the nerves of the brachial plexus innervate the (anterior/posterior) compartment muscles.
Anterior
The posterior divisions of the nerves of the brachial plexus innervate the (anterior/posterior) compartment muscles.
Posterior
Vessels (arteries and veins) tend to run (with/against) the corresponding nerves in connective tissue bundles (neurovascular bundles) that are surrounded by connective tissue.
With
What is the name of the connective tissue that surrounds the neurovascular bundles ?
Sheaths
The brachial plexus starts with ___ spinal nerves and ends up with ____ terminal nerves.
5;5
The bones that connect the UE to the trunk are the ____ and the ______
Clavicle; Scapula
The clavicle and the scapula articulate with the bones of the thorax at the _____ joint
Sternoclavicular (SC)
The medial end of the clavicle articulates with the sternum to form the ______ joint
Sternoclavicular (SC)
The lateral end of the clavicle articulates with the acromion, forming the _____ joint
Acromio-clavicular (AC joint)
What is the name of the well marked groove on the anterior aspect of the proximal humerus?
Bicipital groove
What runs in the bicipital groove?
The tendon of the longhead of the biceps
At the proximal end of the bicipital groove, what two structures do you find?
The lesser and greater tubercles
What is another name for the bicipital groove?
The intertubercular groove (because it is between two tubercles)
Rotation which moves the front of the arm towards the body is called what?
Internal rotation
Rotation which moves the front of the arm away from the body is called what?
External rotation
What nerve emerges near the posterior boarder of the SCM, running downward and backward across the splenius muscle, and passing beneath the trapezius ?
The spinal accessory nerve (cranial nerve 11)
What are some of the nerves we learned in class that are a part of the cervical plexus ?
The lesser occipital, greater auricular, supraclavicular, and transverse cervical nerves.
Many of the branches of the cervical plexus arise around the (medial/posterior) boarder of the SCM
Posterior
The greater occipital nerve is found more (medially/laterally) than the lesser occipital nerve
Medially
The inferior belly of the ____ divides the posterior cervical triangle into an upper triangle (occipital triangle) and a lower triangle (supraclavicular triangle)
Omohyoid
The cervical plexus and brachial plexus are exiting the neck between what two muscles?
The anterior and middle scalenes
The cervical plexus is (superior/inferior) to the brachial plexus
Superior
The _____ nerve is directed inferiorly and splits into three branches
Supraclavicular
The _______ nerve runs parallel to the posterior boarder of the SCM
Lesser occipital
The nerve that emerges from the SCM and enters the deeper surface of the trapezius is what?
The spinal accessory nerve
Above and below the glenoid fossa are the _____ tubercle and the ____ tubercle.
Supraglenoid; infraglenoid
The brachial plexus starts at ___ of the spinal cord and terminates at ___
C5;T1
For the brachial plexus: Left To Right – Remember To Drink Cold Nector
R - Rami To - Trunks Drink - Divisions Cold - Cords Nector - Terminal nerves
For the brachial plexus: Top To Bottom – M A R M U
M - Musculocutaneous A - Axillary R - Radial M - Median U - Ulnar
In the brachial plexus, the ___ and ___ nerve roots come together to form the superior trunk
C5 & C6
In the brachial plexus the ___ nerve root feeds into its own trunk which is the middle trunk
C7
In the brachial plexus the ___ and ___ nerve root come together to form the inferior trunk
C8 & T1
In the brachial plexus the superior trunk branches into an ____ and ____ division
Anterior & Posterior
In the brachial plexus the middle trunk branches into an ____ and ____ division
Anterior & Posterior
In the brachial plexus the inferior trunk branches into an ___ and _____ division
Anterior & Posterior
When drawing the anterior and posterior division in the inferior trunk of brachial plexus, draw the posterior division on “top” and the anterior division on the “bottom”.
Roger that
All of the posterior divisions in the brachial plexus come together to form the _____ cord that branches into the ____ and _____ nerves
Posterior; Axillary & Radial
The anterior divisions of the superior and middle trunks come together to form the _____ cord that branches into the ____ and _____ nerves
Lateral ; Musculocutaneous & Median
The anterior division of the inferior trunk all by itself makes the _____ cord which branches to the___ and ___ nerves
Medial ; Median & Ulnar
What innervates the serratus anterior?
The long thoracic nerve (C5-C7)
Most of the merging, diverging, and merging of the brachial plexus predominantly occurs in the _____ region of the posterior cervical triangle.
Axillary
Anything above the clavicle is considered the ____ region
Supraclavicular
The _____ and the ___ are what is found in the supraclavicular region
Trunks; Ventral rami
The ventral rami of what segments are found in the supraclavicular region?
C5-T1
A prefix plexus is when the nerve plexus runs from __ to ___ instead of C5 to T1
C4 to C8
A postfixed plexus is when the nerve plexus runs from ___ to ____ instead of C5 to T1
C6 to T2
Are there any dorsal rami in the brachial plexus?
No
The ventral rami go to the (extremities/deeper layer of the skin)
Extremities
Somewhere in the ____ you will find the ventral rami or the trunks coming out.
Scalene groove
All of the trunks of the ventral rami are in the ______ region.
Supraclavicular
Fibers from a single spinal cord segment always end up in more than one terminal nerve.
True or False?
True
Each of the five terminal nerves and most of the collateral branches contain fibers from more than one spinal cord segment
True or False?
True
The musculocutaneous nerve runs from ___ to___
C5 to C7
Where does the musculocutaneous nerve innervate?
The muscles of the anterior compartment of the arm (coracobrachialis, biceps brachii, and brachialis) and the skin of the lateral aspect of the forearm
The axillary nerve runs from ____ to ___
C5 to C6
Where does the axillary nerve innervate?
The glenohumeral joint, teres minor and deltoid muscles, and the skin of the superolateral arm
The radial nerve runs from ___ to ____
C5 to T1
Where does the radial nerve innervate?
All muscles of the posterior compartments of the arm and forearm, skin of the posterior and inferolateral arm, posterior forearm, and dorsum of the hand lateral to the axial line of digit 4.
The median nerve runs from __ to ___
C5 to T1
What does the median nerve innervate?
The muscles of anterior forearm compartment (except for flexor carpi ulnaris and ulnar half of the flexor digitorum profundus) and five intrinsic muscles in the thenar half of the palm and palmar skin
The ulnar nerve runs from ___ to ___
C7 to T1
Where does the ulnar nerve innervate?
The flexor carpi ulnaris and ulnar half of the flexor digitorum profundus, the most intrinsic muscles of the hand, and the skin of the hand medial to the axial line of digit 4
If there is an injury to C6 on the musculocutaneous nerve, will it affect the whole musculocutaneous nerve?
No, just a part of it
Out of the five terminal nerves the axillary and the radial make up the _____ division nerves.
Posterior
Out of the five terminal nerves the musculocutaneous, median, and ulnar nerves make up the ____ division nerves.
Anterior
The dorsal scapular nerve comes off of the ventral rami of C5 and has segments where?
In C5
The dorsal scapular nerve often has a frequent contribution from what nerve segment?
C4
Where does the dorsal scapular nerve innervate?
Rhomboid minor, rhomboid major, and the levator scapulae
The long thoracic nerve comes off behind the ventral rami of ___ to ___
C5 to C7
What does the long thoracic nerve innervate?
The serratus anterior
The suprascapular nerve comes off of the ____ trunk and will have___ to ___ segments.
Superior; C5 to C6
The suprascapular nerve often has a contribution from which nerve segment?
C4
The suprascapular nerve innervates what?
The supraspinatus, infraspinatus, and the glenohumeral joint.
The suprascapular nerve is vulnerable to entrapment in the _____ and the _____
Suprascapular foramen and the spinoglenoid notch
The lateral, posterior, and medial cords are named based on their location to the ______
Axillary artery
The upper subscapular nerve comes off of the ____ cord and it runs from _____ to _____
Posterior; C5 to C6
What does the upper subscapular nerve innervate?
The superior portion of the subscapularis
The thoracodorsal nerve comes off of the ____ cord and it runs from ____ to ____
Posterior; C6 to C8
What does the thoracodorsal nerve innervate?
The latissimus dorsi
The lower subscapular nerve comes off of the ____ cord and it runs from ____ to _____
Posterior; C5 to C6
Where does the lower subscapular nerve innervate?
The inferior portion of the subscapularis and teres major
The lateral pectoral nerve comes off of the ____ cord and it runs from____ to ___
Lateral; C5 to C7
Where does the lateral pectoral nerve innervate?
Primarily the pectoralis major but some lateral pectoral nerve fibers pass to the pectoralis minor
The medial pectoral nerve comes off of the _____ cord and it runs from ___ to _____
Medial; C8 to T1
Where does the medial pectoral nerve innervate?
The pectoralis minor and sternocostal part of the pectoralis major
What runs between the medial and lateral pectoral nerves?
A communicating branch
The medial cutaneous nerve of the arm (brachium) comes off of the ____ cord and runs from ____ to _____
Medial; T1 to T2
Where does the medial cutaneous nerve of the arm (brachium) innervate?
The skin of medial side of arm, as far distally as the medial epicondyle of the humerus and olecranon of ulna
The medial cutaneous nerve of the forearm (antebrachium) comes off of the ____ cord and runs from ____ to ____
Medial; C8 to T1
Where does the medial cutaneous nerve of the forearm (antebrachium) innervate?
The skin of the medial side of the forearm, as far distally as the wrist
The superior trunk nerves for the most part do not reach muscles in the (hand/arm), they predominantly work in the (arm/hand)
Hand;Arm
The nerves from the inferior trunk go all the way in the (hand/arm) and predominate the (hand/arm) and are less involved in the (arm/hand) .
Hand;Hand;Arm
The right subclavian artery comes off of the _____ artery.
Brachiocephalic
The brachiocephalic artery comes off of the_____
Aortic arch
The left subclavian artery comes off of the____
Aortic arch
Where does the subclavian artery run to ?
The axillary artery as it crosses the first rib
The subclavian artery is found in the _____ and it is broken down into three parts.
Scalene groove
Part one of the subclavian artery goes from where to where ?
When it comes off of the brachiocephalic on the right or when it comes off of the aortic arch on the left to the most medial edge of the anterior scalene.
The first part of the subclavian artery terminates when it goes where?
Behind the anterior scalene
The third part of the subclavian artery runs from where to where ?
The lateral edge of the anterior scalene to crossing the first rib
The second part of the subclavian artery is found where?
Behind the anterior scalene
The axillary artery is broken down into how many parts?
Three
The axillary artery runs from where to where ?
The first rib to the inferior boarder of the teres major muscle.
The parts of the axillary artery are named for where they are in relation to what muscle?
Pectoralis minor
Part one of the axillary artery runs from where to where?
The first rib to the superior edge of the pectoralis minor
Part two of the axillary artery is found where ?
Behind the pectoralis minor
Part three of the axillary artery is from where to where ?
The lateral edge of the pectoralis minor to the inferior edge of the teres major
How many arteries are in part one of the axillary artery?
One
In part one of the axillary artery there is a very tiny artery. What is it called?
The supreme thoracic artery
How many arteries are in part two of the axillary artery?
Two
Which artery in part two of the axillary artery branches off into three different directions (it goes to the thorax, the acromion process, and up into the neck)?
Thoracoacromial artery
What is the other artery found in part two of the axillary artery?
The lateral thoracic artery
How many arteries are found in part three of the axillary artery?
Three
The most proximal artery in part three of the axillary artery is the ____
Subscapular artery
Which artery is found in part three of the axillary artery and goes in front of the humerus?
Anterior humeral circumflex artery
Which artery is found in part three of the axillary artery and goes behind the humerus?
Posterior humeral circumflex artery
• For the most part the subclavian and axillary veins are parallel with the arteries and run with the arteries.
True or false?
True
What is the only difference between the axillary and subclavian veins and arteries?
The subclavian veins do not go to the scalene groove like the arteries do.
The prevertebral layer is a layer of deep fascia in the cervical fascia.
True or False?
True
The axillary sheath is a continuation of the prevertebral layer that surrounds what three structures going into the upper extremities?
Axillary arteries, axillary veins, and the brachial plexus
If the C5 nerve gets injured, will the nerves that have C5 contributions into them be affected ?
Yes
All the sensory nerve branches that makeup the C5 distribution is called a what?
A dermatome
If you are going to evaluate someone’s dermatomes to see if there is sensory loss you have to go in the middle and stay (close / away) from the different nerve segment boundaries.
Away
Typically, muscles are supplied by more than one segmental nerve. If there was a laceration of C5, the coracobrachialis, biceps brachii, and the brachialis would still somewhat function because they have C6 & C7 nerve contributions. If the musculocutanous nerve was lacerated then those muscles would not work very well.
True or False?
True
Typically, each muscle is supplied by one peripheral nerve. The rhomboids for example are typically innervated by the dorsal scapular C5 nerve (unless they have a C4 contribution) and if the C5 ventral rami gets injured the rhomboids will be shut down.
True or False
True
Segmental – Preplexus or Post plexus?
Peripheral (into the terminal nerves) - Preplexus or postplexus?
Segmental - Preplexus
Peripheral - Postplexus
With a segmental injury (preplexus) we get (large/small) areas of skin that are supplied by one segmental level, that is the dermatomes.
Large
A peripheral injury, sensory wise affects only a (small/large) patch of skin. A segmental injury affects a much more (larger/smaller) area of injury.
Small; Larger
Are the effects on muscles due to segmental injuries is widespread muscle weakness, or paralysis?
Widespread muscle weakness
The effect on sensation for a segmental injury is what?
Dermatomal sensory loss
The effect on muscle in a peripheral injury is what?
More focused muscle loss
The effect on sensation for a peripheral injury is what?
A portion of the dermatome being affected.
As a therapist, if you are suspecting a ventral rami segmental injury, you should expect what?
Dermatomal loss and specific muscles to be weak and not lost.
As a therapist, if you are suspecting the patient has a terminal nerve injury, you will be looking for what?
A loss of the muscles that are innervated by that nerve and a smaller patch of sensory loss.
Where does the lesser occipital nerve (C2) supply?
The skin of the lateroposterior portion of the ear up until the occipital bone
Where does the greater auricular nerve (C2 & C3) supply?
The skin of the ear and a little bit down distally from the ear
Where does the transverse cervical nerve (C2 & C3) supply?
The skin covering the anterior cervical region
Where does the supraclavicular nerves (C3 & C4) supply?
The skin over the shoulder
What are the two nerves that originate completely from the ventral rami of the brachial plexus?
Dorsal scapular (C5) & Long thoracic nerve (C5-C7)
What nerve branches from the superior trunk?
Suprascapular nerve (C5-C6)
Are there any nerves that branch from the middle and inferior trunks?
No
Are there any nerves that branch from the anterior and posterior divisions?
No
How many nerves branch off of the lateral cord?
1
What nerve branches off of the lateral cord?
Lateral pectoral nerve (C5-C7)
How many nerves branch off of the medial cord?
3
What nerves branch off of the medial cord?
Medial pectoral nerve (C8-T1), medial cutaneous nerve of the arm (T1-T2), and the medial cutaneous nerve of the forearm (C8-T1)
How many nerves branch off of the posterior cord?
3
What nerves branch off of the posterior cord?
Upper subscapular nerve (C5-C6), the thoracodorsal nerve (C6-C8), and lower subscapular nerve (C5-C6)
If there is a C5 ventral rami injury, then any nerves (proximally/distally) that have a C5 contribution will be affected.
Distally
If the C5 nerve was completely lacerated, then the C5 dermatome will be (completely/partially) desensitized.
Completely
A peripheral nerve injury is going to cause loss of sensation to a (small / large) portion of a dermatome.
Small
Thoracic outlet syndrome is a neurovascular entrapment in what region?
The posterior cervical triangle and axillary regions
What syndrome causes mechanical compression and increased pressure on neurovascular structures resulting in symptoms in the upper extremity?
Thoracic outlet syndrome
Where are the 5 places of entrapment for thoracic outlet syndrome that start at the brachial plexus and run to the terminal nerves?
The superior thoracic aperture, scalene groove, space between the mid clavicle and first rib, the pectoralis minor coracoid loop, and the humeral head.
Where is the superior aperture of the thoracic cage located?
It is a hole at the top of the rib cage that is formed by T1, rib 1, and the sternum
What is the only thing coming out of the superior thoracic aperture that we have to be concerned about in regard to entrapment?
The subclavian artery and vein
What is the reason the superior thoracic aperture is a possible impingement point?
It has the lungs in this region and when you expand the lungs all the way they could potentially compress those arteries and veins.
What do we have to be concerned about in the scalene groove in regard to entrapment?
The ventral rami and / or trunks of the brachial plexus and the subclavian artery
What is the reason the scalene groove is a possible impingement point?
The cervical rib and due to the position of our rib cage and shoulder, muscle spasms and muscle contractions can make the area smaller.
Where is the pectoralis minor coracoid loop located?
It is the area underneath the pectoralis minor and around the coracoid process
Why is the humeral head an entrapment point in regard to thoracic outlet syndrome?
The humeral head can come forward and compress the brachial plexus and the vasculature.
The ____ nerve comes off of the posterior cord and goes to the armpit area
Axillary
The _____ nerve comes off of the posterior cord and goes to the posterior compartment of the arm and goes down the spiral groove of the humerus within the triceps.
Radial
The _____ nerve comes off of the medial cord and goes into the arm region and will be the most medial out of all of those nerves innervating the arm
Ulnar
The _____ nerve comes off of the lateral cord and will pierce the coracobrachialis.
Musculocutaneous
In the brachial plexus, the middle of the “M” that is formed by contributions from the lateral cord and medial cord is the _____ nerve and it enters the brachium region and it is lateral to the ulnar nerve.
Median
The _____ nerve comes off of the medial cord and is found in the middle of the arm (brachium).
Median
The terminal nerves that are in the arm (brachium) from lateral to medial are the _____ nerve, _____ nerve, and then the _____ nerve.
Radial; median; ulnar
The _____ nerve pierces the pectoralis minor and innervates the pectoralis major.
Medial pectoral
The cords are named based on their position to the _____
Axillary artery
The _____ nerve comes off of the posterior cord and theoretically should be between the upper subscapular nerve and the lower subscapular nerve.
Thoracodorsal
What are the names of the trunks in the brachial plexus ?
Superior, middle, and inferior
What are the divisions in the brachial plexus called ?
Anterior and posterior divisions
What are the cords in the brachial plexus called?
Lateral, posterior, and medial cord
Where does the greater occipital nerve (C2) supply?
The skin of the occipital bone
On the dermatome map, where is C2?
Skin of the neck below the chin up to to the manubrium
On the dermatome map, where is C3?
The skin of the neck from the manubrium down to the level of the acromion
On the dermatome map, where is C4?
Level with skin of the anterior shoulder going medially
On the dermatome map where is C5?
Below the skin of the shoulder, the skin of the lateral aspect of the arm
On the dermatome map, where Is C6?
The skin of the lateral aspect of the forearm all the way down to the thumb and index finger
On the dermatome map, where is C7?
The portion of the skin of the middle finger up to the wrist
On the dermatome map, where is C8?
The portion of the skin from the fake middle finger and pinky to the wrist
On the dermatome map, where is T1?
The skin of the medial aspect of the forearm
On the dermatome map, where is T2?
The skin of the medial aspect of the arm up to level of the armpit going medially
