Arm And Cubital Fossa Flashcards
What (in general) provides cutaneous innervation to the arm and cubital fossa?
Ventral primary rami of C3-T3
What nerves supply the cutaneous innervation to the skin of the upper shoulder?
Supraclavicular nn. (C3-4)
What suppies cutaneous innervation to the skin of brachium, antebrachium, and hand?
Brachial plexus (C5-T1)
What provides cutaneous innervation to the skin over the deltoid region?
Superior lateral brachial cutaneous nerve (from axillary n.)
What provides cutaneous innervation to the skin over the lateral aspect of the arm?
Inferior lateral brachial cutaneous n. (From radial n.)
What provides cutaneous innervation to the skin of the posterior aspect of the arm?
Posterior brachial cutaneous n. (From radial n.)
What provides cutaneous innervation to the skin of the upper medial aspect of the arm?
Medial brachial cutaneous n. (From medial cord of brachial plexus)
What provides cutaneous innervation to the skin of the lower medial and anterior aspects of the arm?
Medial antebrachial cutaneous n.
What provides cutaneous innervation to the skin of armpit and part of medial arm?
Intercostobrachial n. (T2-3)
Describe the fascia of the brachium and antecubital region. What fascia is it continuous with?
Deep brachial fascia surrounds the arm muscles like a sleeve; it is continuous with the pectoral fascia above and antebrachial fascia distally
2 septa connect the “sleeve” with the humerus
2 septa of the deep brachial fascia connect the overall “sleeve” to the humerus. What are these 2 septa?
Lateral intermuscular septum - sits between insertion of deltoid and lateral epicondyle of humerus
Medial intermuscular septum - connects brachial fascia with humerus
What is the significance of the 2 intermuscular septa created by the deep brachial fascia?
Divides the arm into 2 compartments. Anterior compartment contains flexor mm., posterior compartment contains extensor mm.
What are the 3 muscles present in the anterior compartment of the brachium?
Coracobrachialis m.
Biceps brachii m.
Brachialis m.
What muscle is present in the posterior compartment of the brachium?
Triceps brachii m.
Origin of coracobrachialis m.
Coracoid process
Insertion of coracobrachialis m.
Medial side of mid-humeral shaft
Innervation of coracobrachialis m.
Musculocutaneous n.
Actions of coracobrachialis m.
Flexes and adducts arm
Origins of biceps brachii m.
Long head - supraglenoid tubercle of scapula
Short head - coracoid process
Insertion of biceps brachii m.
Biceps tendon into radial tuberosity
Bicipital aponeurosis blends with deep fascia of flexor mm. in proximal forearm
Innervation of biceps brachii m.
Musculocutaneous n.
Actions of biceps brachii m.
Flexes elbow joint, supinates radius (forearm), and weak flexor of shoulder joint
Which of the following is the MOST important action of biceps brachii m.?
A. Supination of radius
B. Flexion at elbow joint
C. Flexion of shoulder joint
D. Extension of radius/ulna
B. Flexion at elbow joint
A and C are functions of biceps brachii m., but not its major actions. D is not a function of biceps brachii m.
Origin of brachialis m.
Distal 1/2 of anterior humerus
Insertion of brachialis m.
Ulnar tuberosity on the anterior aspect of the coronoid process of ulna
Innervation of brachialis m.
Musculocutaneous n.
Action of brachialis m.
Flexion of elbow
Origins of triceps brachii m.
Long head - infraglenoid tubercle of scapula
Lateral head - posterior humerus, proximal to radial groove
Medial head - posterior humerus, distal to radial groove
Insertion of triceps brachii m.
Olecranon process of ulna
Innervation of triceps brachii m.
Radial n.
Action of triceps brachii m.
Elbow extension
[chief function is to keep elbow extended when pushing an object]
What is the primary arterial supply to the brachium?
Brachial a.
Where does the brachial a. begin and travel?
Begins at lower border of teres major m. as a continuation of the axillary a.
Courses inferiorly on medial aspect of arm until it disappears deep to the bicipital aponeurosis
The brachial a. courses inferiorly on the medial aspect of the arm until it disappears deep to the bicipital aponeurosis.
It bifurcates 1 inch distal to the crease of the elbow into what 2 branches?
Radial a.
Ulnar a.
The brachial a. has several branches in the arm. Which one arises just distal to the teres major m. and supplies the triceps brachii m. as it travels with the radial n. in the posterior compartment?
Profunda brachii a.
The profunda brachii a. anastomoses with what artery in order to connect with the ulnar and radial aa.?
Axillary a.
What 2 arterial branches of the brachial a. supply the elbow joint?
Superior ulnar collateral a.
Inferior ulnar collateral a.
What arterial branch of the brachial a. is responsible for supplying the humerus?
Nutrient artery of the humerus
What arterial branch of the brachial a. anastomoses with the radial recurrent a.?
Radial collateral a.
The deep brachial veins (venae commitantes) run parallel to the ________ artery and commence at the elbow where they eventually become tributaries to the _______ veins
Brachial
Axillary
What vein passes upward from the forearm in the superficial fascia in the groove lateral to the biceps, then in the groove between the deltoid and pectoralis major m.?
Cephalic v.
The cephalic vein becomes a tributary of what vein?
Axillary v.
The cephalic v. passes upward from the forearm in the superficial fascia in the groove lateral to the _______, then in the groove between the _______ and _______ muscles. (Deltopectoral triangle)
Biceps
Deltoid
Pectoralis major
What vein passes from the forearm to the arm in superficial fascia on the medial side of the front of the elbow and penetrates the brachial fascia at the junction between the distal third and middle third of the arm to enter the anterior muscular compartment?
Basilic v.
The basilic v. eventually becomes the _______ vein
Axillary
What is the term for the triangular shaped depression on the anterior surface of the elbow?
Cubital fossa
What are the superior, medial, and lateral boundaries of the cubital fossa?
Superior = imaginary line connecting medial and lateral epicondyles
Medial = pronator teres m.
Lateral = brachioradialis m.
What 2 muscles make up the floor of the cubital fossa?
Brachialis m.
Supinator m.
What structures make up the roof of the cubital fossa?
Continuity of the brachial and antebrachial fascia, subcutaneous tissue, and skin
What are the contents of the cubital fossa?
Brachial a. + terminal branches (radial and ulnar aa.)
Venae commitantes
Biceps brachii tendons
Median n.
Radial n.
Cephalic, basilic, and median cubital vv.
Medial and lateral cutaneous nn.
The brachial a. and its terminal branches - the radial and ulnar aa. - can be found in the cubital fossa sitting between what 2 structures?
Biceps tendon
Median n.
What is the insertion point for the biceps brachii tendon?
Radial tuberosity
What nerve lies medial to the biceps tendon in the cubital fossa?
Median n.
What nerve lies deep to the brachialis m. in the cubital fossa?
Radial n.
The median cubital vein connects what other 2 veins in the cubital fossa?
Cephalic v.
Basilic v.
What is the variation in veins of the cubital fossa present in 20% of the population?
Median antebrachial v. bifurcates into median cephalic and median basilic v., which replace the median cubital v.
Origin/insertion/innervation/action:
Coracobrachialis m.
Origin: coracoid process
Insertion: medial side of mid-humeral shaft
Innervation: musculocutaneous n.
Action: flexion and adduction of arm
Origin/insertion/innervation/action:
Biceps brachii m.
Origins: long head from supraglenoid tubercle of scapula, short head from coracoid process
Insertion: biceps tendon into radial tuberosity; bicipital aponeurosis blends with deep fascia of flexor mm. In proximal forearm
Innervation: musculocutaneous n.
Actions: flexes elbow, supinates radius, and weak flexor of shoulder
Origin/insertion/innervation/action:
Brachialis m.
Origin: distal 1/2 of anterior humerus
Insertion: ulnar tuberosity on the anterior aspect of coronoid process of ulna
Innervation: musculocutaneous n.
Action: flexes elbow
Origin/insertion/innervation/action:
Triceps brachii m.
Origins: long head from infraglenoid tubercle of scapula, lateral head from posterior humerus (proximal to radial groove), medial head from posterior humerus (distal to radial groove)
Insertion: olecranon process of ulna
Innervation: radial n.
Action: elbow extension
In 20% of the population, a median antebrachial vein bifurcates into the median cephalic and median basilic veins, which replaces what diagonal vein?
Median cubital v.
