Lecture 3: The arm and elbow Flashcards
what does brachium mean?
Arm
What does plexus mean?
braid
what is the brachial plexus?
The brachial plexus = nerve network that innervates the upper limb
Where is the brachial plexus located?
Located in the neck and axilla (armpit)
Where does the brachial plexus originate from?
It comes from the spinal cord
What does the brachial plexus give rise to?
It gives rise to 5 major branches that provide the motor and sensory innervation of the upper limb
What is the brachial plexus composed of?
The brachial plexus is composed of the ventral rami of the spinal nerves from the spinal cord segments C5 to T1
Which anterior rami come together to form the brachial plexus?
Anterior rami of C5, C6, C7, C8, and T1 come together to form the brachial plexus = innervates the muscles, skin and joints of the upper limbs
Define the arm region?
The ‘arm’ = region between the shoulder and elbow. The bone of this region is the humerus
what does the head of the humerus articulate with?
Glenoid fossa of scapula to form the shoulder joint.
What inserts itself into the proximal humerus and move the shoulder?
Several muscles
What does the distal humerus articulate with ?
The distal humerus articulates with the ulna and radius to form the elbow joint
What joint positions the hand?
The elbow joints
What is the clinical importance of the humerus?
Clinical importance: fractures common; close proximity of vessels and nerves
What bones are involved in the elbow joint?
3 bones involved:HumerusUlnaRadius
What are the two articulations of the elbow joint?
Humero-ulnar = between trochlea and trochlear notch Humero-radial = between capitulum and radial head
What does good congruity mean?
Very stable
What reinforces the joint capsule laterally?
Radial collateral ligament
What reinforces the joint capsule medially?
Ulnar collateral ligament
Is the joint capsule thick and tight?
No, Capsule is thin and loose anteriorly and posteriorly
What joint does the capsule of the joint contain?
the proximal radioulnar joint
Describe the proximal radioulnar joint.
This is an articulation between the radial head and the radial notch of the ulna – pivot joint
What type of joint is the elbow joint?
Hinge joint