Flashcards in Lecture 3.3 Deck (63):
What causes bicipital tendonitis?
Long head of biceps can cut through the bicipital groove causing pain This results in bicipital tendonitis.
Where does each head of the biceps originate?
Short head of biceps originates from the coracoid process of the scapula.
Long head of the biceps originates at the supraglenoid tubercle of the scapula it then passes through the intertubercular groove.
What causes popeye syndrome?
Proximal or distal insertion can get avulsed this causes popeye syndrome. In this case tendon needs to be surgically fixed.
What are the muscles of the posterior compartment of the arm?
Triceps and anconeus.
What nerve supplies posterior comparment of the arm?
Where does the long head of the triceps originate?
Long head: infraglenoid tubercle of scapula.
Where do the lateral and medial heads of the triceps originate?
Lateral head: above the radial sulcus.
Medial head: below the radial sulcus
Both of these points are on the shaft of the humerus.
Where do the triceps insert?
all 3 bellies of the heads of the triceps converge and insert onto the olecranon process of the ulna.
What is the function of the triceps?
The triceps can work on extinding at shoulder joint and on the elbow joint.
Long head can also assist in adduction.
What is the origin and insertion of the anconeus?
Anconeus is small muscle that starts at supracondylar ridge and inserts onto the ulna.
What is the function of the anconeus?
It assists the triceps in extension.
Which nerve roots form the radial nerve?
C5 - T1
In which fracture is the radial nerve endangered?
Where do the suprascapular nerve and artery travel relative to the suprascapular foramen and the transverse ligament of the scapula?
Suprascapular nerve goes through suprascapular foramen.
Suprascapular artery travels superior to the transverse ligament of scapula.
What are the boundaries of the quadrangular space?
Long head of the triceps
What structures travel through the quadrangular space
Posterior humeral circumflex artery.
What are the boundaries of the triangular space?
Long head of the triceps
Supscapularis superiorly and teres minor superiorly
Where do the axillary nerve and the posterior humeral circumflex artery go after passing through the quadrangular space? What is the problem with this passage?
Posterior humeral circumflex artery and the axillary nerve go around the surgical neck of the humerus and are susceptible to damage from breaking of the surgical neck.
What structures pass through the triangular space?
Circumflex scapular artery (goes to posterior side and supplies posterior side of the scapula.)
What are the boundaries of the triangular interval?
Long head of the triceps
What is the function of the circumflex scapular artery?
Major blood supply for the posterior muscles of the scapula.
What structures pass through the triangular interval?
Profunda brachii (deep brachial artery)
What structure of the humerus does the ulna hold onto?
Trochlea takes semilunar notch of the ulna.
Where does the semilunar notch sit in flexion?
Coranoid fossa is the hole in which the ulna's coranoid fossa sits.
Where does the radial notch sit while in flexion?
Where does the ulna sit on the humerus when in extension?
The olecranon fossa.
Which of the radius and the ulna is wide proximally and narrow distally?
Ulna. Head is distal
What is the name of the projection of the ulna and the radius that incorporates the carpal bones?
The styloid processes.
What is the notch that holds the radius to the ulna proximally?
Radial notch of ulna
What is the notch that holds the ulna to the radius distally?
The ulnar notch of radius.
What type of joint does the interosseus membrane form and what is the function of this?
Interosseus membrane forms a syndesmosis joint between radius and ulnar this transfers force from one bone to the other bone.
What kind of fracture happens to the radius and ulna in a FOOSH?
Colles fracture of radius causes hand to move posteriorly and flex slightly. This fracture often transfers to the ulna.
What kind of injury can happen to the ulnar from falling on a flexed elbow?
falling on flexed elbow can cause olecranon process to break away and this endangers the structures of the cubital fossa. Most importantly the median nerve and the brachial artery. This in turn can cause volkmann's ischaemia and contracture.
What is the sequence of structures affected by compartment syndrome?
Veins/lymphatics -> Superficial nerves -> Arteries -> deep nerves
What are the boundaries of the cubital fossa.
Roof: bicipital aponeurosis
Pronator teres on the medial side.
Brachioradialis on the lateral side.
What are the contents of the cubtal fossa?
Median cubital vein
Lateral cutaneous nerve of the forearm and medial cutaneous nerve of the forearm.
Ulnar and radial arteries.
Median and radial nerves.
What are the main principles regarding the difference between anterior and posterior compartments?
Skin overlying flexor muscles is more sensitive than over extensors.
Flexor muscles are stronger than extensor muscles
What nerves supply the forearm?
Forearm supplied by median, ulnar, and radial nerve.
How many flexor muscles are there in the anterior compartment of the forearm? How many in each layer?
What are the origin and insertion of the pronator teres?
Pronator teres starts from ulnar and goes to radius and does not cross the wrist.
Where doe the superficial forearm muscles originate?
The common flexor origin at the medial epicondyle.
Where does Flexor carpi radialis insert?
Bases of second and third metacarpal bones
Where is palmaris longus located? Where does it insert? What is the clinical significance of it being absent in 15% of the population?
Palmaris Longus inserts onto the palmar aponeurosis. Palmaris longus sits right on top of the median nerve and protects it in its absense the median nerve is exposed and prone to injury.
What nerve innervates flexor carpi ulnaris and where does this muscle insert?
Flexor carpi ulnaris is innvervated by the ulnar nerve and inserts onto the pisiform and the 5th metacarpal.
What is the muscle of the intermediate layer?
Flexor digitorum superficialis.
Where does the muscle of the intermediate layer originate and where does it insert?
Origin: Common Flexor Origin + shaft of the radius + shaft of the ulna.
this muscle goes deep to the flexor retinaculum.
Insertion: Base of the middle phalanges after splitting. Each split end inserts onto the medial and lateral sides of the phalanges.
What are the deep layer muscles of the flexor compartment?
Flexor Pollicis Longus
Flexor Digitorum Profundus
What is the origin of the deep muscles of the flexor compartment of the forearm?
Radius + Ulna +/- IO membrane
Where does flexor pollicis longus insert?
Flexor pollicis longus inserts onto the distal phallanx of the thumb.
What structures do the tendons of flexor digitorum profundus pass through when inserting at the distal phallanges?
Flexor digitorum profundus goes through the space formed by split tendons of the flexor digitorum superficialis and inserts onto the distal phallanges.
What is the function of pronator quadratus?
Pronator Quadratus goes from ulna to radius and assists pronator teres in pronation.
Which muscles are responsible for supination of the forearm?
Supinator is a muscle in the posterior compartment that allows supination along with the biceps
Which bone moves during pronation and supination?
Pronation and supination is movement of the radius relative to ulna. ( i remember this by the hooking of the ulna at the elbow preventing the ulna from twisting.)
Where do superficial muscles of the extonsor compartment originate? What is the exception to this rule?
Superficial extensor compartment start at common extensor origin on the lateral epicondyles. Brachioradialis is an exception and start from the lateral supracondylar ridge.
What is the function and innervation of brachioradialis?
Brachioradialis is innervated by radial nerve but functionally it works with anterior compartment and is found at the border between compartments. It assists with flexion of the elbow.
Where do extensor carpi radialis longus and brevis insert (respectively)?
2nd and 3rd metacarpals
Where does extensor digiti minimi insert and what is the advantage of this muscle?
At the extensor expansion at the base of the proximal phallanx.
The advantage of this muscle is that the small digit can be extended independantly of the other digits.
Where does extensor carpi ulnaris insert?
The 5th metacarpal
What happens when both flexor carpi ulnaris and extensor carpi ulnaris work together? What about on the radial side?
If flexor and extensor carpi ulnaris work together this allows ulnar deviation. Opposite is true for radialis muscles.
What nerve crosses the 2 heads of the pronator teres?
The median nerve
What artery lies laterally to the flexor carpi radialis?
The radial artery.
Where does the extensor digitorum communis insert?
Superficial to the extensor carpi radialis longus and brevis is the extensor digitorum communis which inserts onto the medial 4 digits. Tendons of this muscle form extensor expansion hoods.