Upper Limb: Arm Flashcards
what nerve innervates the muscles of the anterior compartment of the arm
musculocutaneous nerve
the musculocutaneous nerve is a terminal branch of what
lateral cord of brachial plexus
the muscles of the anterior compartment of the arm ___ the shoulder or elbow joints
flex
the muscles of the anterior compartment of the arm cross the ____ surface of the glenohumeral or elbow joints
anterior
what muscles are found in the anterior compartment of the arm
biceps brachii
coracobrachialis
brachialis
what is the most anterior muscle of the anterior compartment of the arm
biceps brachii
the 2 heads of biceps brachii originate from where
scapula
the short head of biceps brachii attaches to the
coracoid process
the long head of biceps brachii attaches to the
the supraglenoid tubercle of scapula
how does the long head of biceps brachii attach to the supraglenoid tubercle of scapula
forms a tendon that creates a groove at the proximal end of the humerus before attaching
where does the biceps brachii insert
radial tuberosity
what are the actions of biceps brachii
supination and flexion of elbow when supine
weak flexion of arm at shoulder
what is the requirement for a muscle to be involved in supination or pronation of the forearm
muscle must attach to the radius
what happens in supination and pronation
radius moves around the ulna
biceps brachii rotates the radius to create ____
supination
what is the most powerful supinator of the forearm
biceps brachii
both heads of biceps brachii help to what
support glenohumeral joint to resist dislocation
which head of biceps brachii assists in flexing the arm at the shoulder
short head - passes across anterior surface of glenohumeral joint
which head of biceps brachii prevents head of humerus moving superiorly
long head
which head resists dislocation of shoulder
short head - also long helps
what is the innervation of biceps brachii
musculocutaneous nerve (C5 6)
where does the coracobrachialis originate
coracoid process of scapula
where does the coracobrachialis insert
medial mid-shaft humerus
what are the actions of coracobrachialis
flexion of arm at shoulder
assists in adduction of arm
what is the innervation of coracobrachialis
pierced and innervated by musculocutaneous nerve (C5 7)
does coracobrachialis act on the elbow joint
no it doesnt cross elbow joint
what is a landmark for coracobrachialis
as the musculocutaneous nerve divides from the lateral cord it usually pierces coracobrachialis
where does brachialis originate
distal half of anterior surface of humerus
where does brachialis insert
ulnar tuberosity and coronoid process
what is the action of brachialis
flexion of elbow
is brachialis involved in pronation or supination
no, it attaches to the ulna not radius
what is the most powerful flexor of the elbow
brachialis
what is the innervation of brachialis
mainly musculocutaneous nerve (C5 6) but some of lateral fibres of muscle are supplied by radial nerve (C7)
brachialis is ____ biceps brachii
under
what muscles are found in the posterior compartment of the arm
triceps brachii
what nerve innervates the posterior compartment of the arm
radial nerve (C6-8)
the long head of the triceps brachii originates where
infraglenoid tubercle of scapula
the medial head of the triceps brachii originates where
posterior surface of shaft of humerus (inferior to radial groove)
lateral head of triceps brachii originates where
humerus - superior to radial groove
the triceps brachii inserts where
olecranon of ulna
what is the action of triceps brachii
extends elbow
which head of the triceps brachii resists dislocation of shoulder
long head
the brachial artery is a continuation of the axillary artery at what point
once axillary artery has crossed the inferior border of teres major
what are the branches of the brachial artery
- deep brachial artery (profunda brachii) which forms radial collateral artery
- superior and inferior ulnar collateral branches
- radial artery
- ulnar artery
where does the brachial artery divide into its terminal branches of the radial and ulnar arteries
in or close to the cubital fossa
the radial and ulnar collateral arteries also supply blood to an anastomosis around
the elbow joint
what forms the anastomoses around the elbow joint
the radial and ulnar collateral branches from the brachial and profunda brachii arteries join with recurrent arteries from radial and ulnar nerves
the ulnar artery goes onto form what to supply what
a common interosseous branch that forms anterior and posterior interosseous branches to supply deep structures of the forearm
what structures cross the anterior surface of the humerus to enter the cubital fossa
brachial artery and median nerve
what nerve lies under the biceps brachii
musculocutaneous nerve
the radial nerve passes through what to reach the forearm
lateral intermuscular septa
the ulnar nerve passes through what to reach the forearm
medial intermuscular septa
what is the main tributary of the axillary vein
basilic vein
the cephalic vein travels _____ as it passes to the deltopectoral groove
superficial
what is the attachment site for muscles of the anterior compartment of forearm
medial epicondyle
what is another name for the medial epicondyle and why
common flexor origin - attachment site for muscles of anterior compartment of forearm - the flexors of the wrist and digits
what is the attachment site for many of the extensors of the wrist and digits - common extensor origin
lateral epicondyle
what is the articulation at the elbow between
between the rounded capitulum of the humerus and the head of the radius and with the trochlea of the humerus with the ulna
where does the anconeus attach
posterior surface of distal humerus
what is the action of anconeus
extends the elbow
what is the innervation of anconeus
radial nerve (C7 - C8 (T1))
what compartment is anconeus
included either in posterior compartment of arm or forearm as is somewhere in between
