Lecture 5 - Brachium and elbow Flashcards
What joints make up the “elbow joint”?
Humero-ulnar and Radio-humeral joints
What bones make up the brachium?
humerus
What are the main joints in the brachium?
Glenohumeral and elbow
What are the three “spacial” compartments?
Lateral, caudal, and medial
What are the two action based compartments?
Flexor and extensor
What artery supplies the lateral compartment?
Suprascapular a.
What nerve supplies the lateral compartment?
Suprascapular a.
What artery supplies the medial compartment?
Subscapular a.
What nerve supplies the medial compartment?
Subscapular n.
What artery supplies the caudal compartment?
Caudal circumflex humeral a.
What nerve supplies the caudal compartment?
Axillary n. and Subscapular n.
What action is caused by the lateral compartment?
extension and stabilizing at GH
What action is caused by the medial compartment?
Adduction and extension at GH joint
What action is caused by the caudal compartment?
Flexion and lateral rotation at GH joint
What nerve supplies the flexor compartment?
Musculocutaneous n.
What artery supplies the flexor compartment?
Brachial a.
What nerve supplies the extensor compartment?
Radial n.
What artery supplies the extensor compartment?
Deep brachial a.
What action is caused by the flexor compartment?
Flexion (arm and forearm)
Supination (forearm)
What action is caused by the extensor compartment?
Extension (arm and forearm)
What is the primary job of the lateral, caudal and medial muscles?
move the GH joint
What is the primary job of the flexor and extensor muscles?
move the elbow joint
What is different about a horses forearm?
ulna and radius is fused
What are three structural landmarks that are different on the horse?
Interosseous space, distal end of ulna incorporated w/i radius, and radial tuberosity
What three “joints” are within the elbow?
Radio-humeral joint
Ulno-humeral joint
Radio-ulnar joint
What interacts with both the radius and the ulna?
Condyle of humerus
What articulates with just the ulna?
trochlea
What articulates with just the radial head?
capitulum
What are the collateral ligaments in the elbow?
Lateral collateral, annular ligament of radius, and medial collateral ligament
What supports the elbow joint?
muscle, tendon, and collateral ligaments
What movements are allowed at the elbow joint?
Flexion and extension along sagittal plane
Pronation and supination of ulna
What is the characteristic of the pronation and supination in arboreal primates?
very marked
What is the characteristic of the pronation and supination in terrestrial quadrupeds?
very limited
What is the origin of the suprascapular n.?
C6-7
What muscles do the suprascapular n. innervate?
supraspinatus and intraspinatus
What is the origin of the axillary n.?
C8
What muscles do the axillary n. innervate?
Teres major, teres minor, deltoideus, distal brachiocephalicus
What is the origin of the musculocutaneous n.?
C7-8
What muscles do the musculocutaneous n. innervate?
Coracobrachialis, biceps brachii, and brachialis
What is different about the musculocutaneous n.?
Has different path in dog, horse, and ungulates. (be sure to do over these)
What is the origin of the radial nerve?
C7-T1
What are the muscles innervated by the radial nerve?
Triceps brachii, anconeus, tensor fasciae antebrachii
What are the branches of the axillary a.?
Lateral thoracic a., Subscapular a., and caudal/cranial circumflex
What are the branches of the brachial a.?
Deep brachial a, collateral a., superficial brachial a., transverse cubital a., and common interosseous a.
What is different about the horses axillary a.?
has a suprascapular and throacodorsal branch
What is different about the horses brachial a.?
has a collateral ulnar and radial a.
What is the main vein that leaves the leg?
cephalic v.
What does the cephalic v. meet up with and through what?
External jugular v. via omobrachial v.
What muscles are in the lateral group?
Supraspinatus and infraspinatus
What muscles are in the caudal group?
Deltoideus, teres major, and teres minor
What are the parts of the deltoideus?
Scapular and acromial part
What muscles are part of the medial group?
subscapularis and coracobrachialis
What muscles are in the extensor group?
triceps brachii, tensor fasciae antebrachii, and anconeus
What are the heads of the triceps brachii?
lateral, medial, accessory, and long heads
What muscles are in the flexor group?
Biceps brachii and brachialis
Where does the proximal tendon of biceps brachii go along?
in the intertubercular sulcus
What holds the proximal tendon of the biceps brachii in place?
Transverse humeral retinaculum
What is different about the horse’s bicep brachii?
Have fibrous band that joins the tendons of origin and insertion - internal tendon
What comes off the internal tendon?
Lacertus fibrosus
What is the characteristic of the lacertus fibrosus in standing and flexed animals?
Standing - taut
Flexed joint - slackened
What occurs when the lacertus fibrosus and the internal tendon work together?
maintain carpal joint in extension
