Arm Script Flashcards
The arm is the part of the upper limb which extends from the ________ to the ___________.
Axilla; elbow
Muscles of the arm. Of these muscles, which is the only one that does not move the forearm?
Corocobrachialis
Biceps
Brachialis
Triceps
As the radial nerve descends throught he midregion of the arm, it runs alongside the _______ of the humerus.
Spiral groove
As the ulnar nerve, descends from the arm into the forearm, it passes directly behind the __________ of the humerus.
Medial epicondyle
What are the three major features of the upper end of the radius?
Head of the radius (covered with hyaline cartilage)
Neck of the radius
Radial tuberosity
What are the two major features of the lower end of the radius?
Styloid process
Ulnar notch of the radius
Distal radius fracture
break of the part of the radius bone which is close to the wrist
the most common cause is falling on an outstretched hand (in older peeps)
NOTE: when such a fracure occurs in a young child, the fracture typically consists of deformations in the structure of the bone.
Torus fracture
Results when conpression forces along the length of the radius caused the cortical bone tissue in the distal radius to buckle outward
What are the two types of deformaties that can present as a result of a distal radius fracture?
Torus fracture
Greenstick fracture
Greenstick fracture
Results from excess stresses along the length of the radius causing a complete break in the continuity of the cortical bone tissue on one side of the shaft but only bent the cortical bone tissue on the opposite side
Colles’ fracture
A distal radius fracture that primarily occurs in older people when they fall on an outstreched hand.
The fracture typically extends transversely though the distal radius and results in the distal fragment being both posteriorly displaced and posteriorly angulated.
A.k.a. dinner fork deformity
The upper end of the ulna has two large processes: an anteriorly projecting _______________ and a superiorly projecting ___________
coronoid process; olecranon process.
. The olecranon and coronoid processes together form a large notch called the ______________ notch in the anterior surface of the upper end of the ulna
trochlear
Role of the elbow joint
Joins the distal end of the humerus with the oriximal ends of the radius and ulna
In the lateral side of the elbow joint, the _____________ of the humerus articulates with the head of the radius.
Capitulum
On the medial side of the elbow joint, the _________ of the humerus articulates with trochlear notch of the ulna.
trochlea
What movements can occur in the elbow joint?
Flexion and extension of the forearm
A lateral radiograph of the elbow joint is particular suitable for examining which parts of the forearm?
Olecranon process of the ulna
The head and neck of the radius
Radial tuberosisty
The fat pad overlying the coronoid fossa of the humerus is called the ______________, and the fat pad overlying the olecranon fossa of the humerus is called the ___________.
anterior fat pad; posterior fat pad.
How do elbow joint injuries usually present?
Usually present with an increase in fluid (effusion) within the synovial cavity of the joint. The swollen capsule of the elbow joint pushes the anterior fat pad forward and the posterior fat pad backward.
Can the posterior fat pad be found in a lateral radiograph of the elbow joint?
Not typically but may be visible when there is injury to the elbow joint due to the swollen capsule of the elbow joint
Proximal radioulnar joint
Synovial joint in which the head of the radius articules with radial notch of the ulna.
____________ surrounds the head of the radius in the proximal radioulnar joint.
Annular ligament
Distal radioulnar joint
Joins the lower ends of the radius and ulna
The head of the ulna articulates with ulnar notch of the radius
An integral component of the distal radioulnar joint is a triangular-shaped articular disc composed of ___________
fibrous cartilage
Action of the proximal and distal radioulnar joints
Provides for subination and pronation of the forearm
Partial dislocation of the elbow results when_____________
The radius is pulled away from the capitulum.
This sublaxation may produce a transverse tear in the annular ligement near its attachments to the neck of the radius
Pulled elbow
The underlying mechanism involves slippage of the annular ligament off of the head of the radius followed by the ligament getting stuck between the radius and humerus
When obtaining a X- ray for a pulled elbow, will the lateral radiograph show any displacement of the head of the radius?
No. Because, with a pulled elbow, it is the upper part of the annular ligament and not the head of the radius that is displaced at the time of examination
All the anterior arm muscles are innervated by the ________________ nerve; as a group, the anterior arm muscles _________ and ___________the forearm. There is only one posterior arm muscle, ____________.
musculocutaneous; flex; supinate; triceps brachii
What is the origin, insertion, and action of the coracobrachialis?
Origin: Coracoid process of the scapula
Insertion: Shaft of the humerus
Action: Flexion and adduction of the arm at the shoulder joint
Insertion of biceps brachii
Radial tuberosity
The tendon of the long head of biceps gives rise to a shett-like extension called the _____________.
Bicipital aponeurosis
Action of biceps branchii
Supination and flexion of the forearm
Purpose of the biceps branchii test
The biceps brachii tendon reflex test assesses spinal cord reflex activity in the C5 and C6 spinal cord segments because biceps brachii is innervated by nerve fibers that enter and exit the spinal cord chiefly via the C5 and C6 spinal nerves.
Origin, Insertion, and Action of the Brachialis
Origin: Lower half of the anterior surface of the shaft of the humerus
Insertion: Anterior surface of the upper ulna near the coronoid process
Actions: Chief flexor of the arm
Flexion of the forearm at the elbow joint is controlled mainly by which nerve fibers? Why?
C6 because biceps and brachii and brachialis muscles each receive more nerve fibers from C6 than C5.
Origin of triceps
Long head: Infraglenoid tubercle of the scapula
Lateral Head: posterior part of the humeral shaft which is lateral and superior to the spiral groove
Medial head: Posterior part of the humeral shaft which is medial and inferior to the spiral groove
Which muscle is the chief extensor of the forearm?
Triceps
Insertion of triceps
Olecranon
Extension of the forearm is controlled predominantly by ______ nerve fibers.
C7
Note: Triceps Brachii receive more innervation from C7 than C8 nerve fibers
Erb’s palsy
paralysis of the arm caused by injury to the upper group of the arm’s main nerves, specifically the severing of the upper trunk C5–C6 nerves.
What is the most common cause of Erb’s palsy?
shoulder dystocia during a difficult birth
Which muscles are most commonly affected by damage to damge to C5 and C6 nerve fibers?
Rotator cuff muscles
Deltoid
Teres major
Biceps Brachii
Brachialis
Which nerves are most affected by damage to nerve fibers C5 AND C6?
Axillary nerve
Musculocutaneous
Suprascapular nerve
Paralysis of supraspinatus and deltoid results in the inability to….
Abduct the arm at the shoulder joint
Paralysis of infraspinatus, teres minor, and delotid results in the inability to….
Externally rotate the arm at the shoulder joint
Paralysis of subscapularis, teres major, and deltoid results in…
Weakened ability to internally rotate the arm
What would be the result of paralysis of all muscles of the rotator cuff?
The shoulder joint would be profoundly destabilized
Paralysis of biceps brachii and brachialis would result in…
Weakened flexion of the forearm
Where does the brachial arty end?
By dividing into the ulnar and radial arteries at the level of the neck of the radius
The deep artery of the arm arises from the brachial artery immediately below the lower border of ___________, passes into the posterior muscular compartment, and then extends distally through the midregion of the arm by coursing alongside the ___________ of the humerus.
teres major; spiral groove
The ___________and ___________veins are the largest superficial veins of the arm.
basilic; cephalic
Which nerve fibers provides most of the sensory innervation to the skin on the lateral side of the arm?
. C5 provides most of the sensory innervation to the skin on the lateral side of the arm.
Which nerve fiber provides the most sensory innervation to the skin on the medial side of the arm?
T1 and T2 combine to provide most of the sensory innervation to the skin on the medial side of the arm.
