The Elbow Flashcards
what is the elbow made out of
humerus
radius
ulnar
what are the 3 articulations of the elbow
- humeroradial
- humeroulnar
- proximal radioulnar
what do the 3 joints in the elbow all share
- they share the same articular capsule
what causes the flexion and extension movements of the elbow
this is a result of humeroradial and humeroulnar joint
what causes pronation and supination of the elbow
- Pronation and supination due to proximal radioulnar joint
the anatomical position in the humorous and bones of the forearm ….
are aligned differently in men and women.
what is the degrees of the anatomical position in men and women
- Men 5-15o (average ~6.7o)
* Women 10-25o (average ~13.6o) – wider because hips are wider
why do women have a larger angle that men
– wider because hips are wider
• Allows forearm to clear the hips and is important for carrying objects
describe the structure of humerus
- it has Condyles articulate with the radius and ulnar
- Capitulum (condyle)– articulates with the radius, it is spherical in shape
- Trochlea – articulates with the ulnar
- Either side of the condyles there are epicondyles, there are medial and lateral epicondyle
describe the radius
– lateral bone
- mobile bone of the forearm
describe the ulnar
– medial bone
– stabilising bone of the forearm,
- larger proximal end specialised for articulation
what is larger the medial epicondyle or the lateral epicondyle
- medial epicondyle - this is because there is a larger group of muscles that are attached to it
what muscles are attached to the medial epicondyle
- forarm flexors
the larger the bony prominence ….
the larger the muscle attached to it
what is larger the proximal end of the ulnar or the proximal end of the radius
- Proximal end of the ulnar is larger than the proximal end of the
what is the lump of the radius called
- There is a lump on the radius this is called the radius tuberosity
what is the olercranon process
- Olercranon process posteriorly large part of the ulnar bone
- just above the humorous there is a slight depression thisis so that when you extend the arm the olecranon fits into that slight depression this is called the olecranon fossa
what is the coronoid process
- On the front of the ulnar there is the coronoid process, this has a coronoid fossa
what ligaments are in the elbow
- radial collateral ligament
- ulnar collateral ligament
- anular ligament
what do the radial collateral ligament and the ulnar collateral ligament do
- the supports the flexion and extension movements of the elbow
what does the angular ligament do
- this encircles the head of the radius and keeps the radius in the radial notch of the ulnar
- creating the proximal radioulnar joint
- this causes pronation and supination of the forearm.
what are the two movements that the elbow can do
flexion and extension
pronation and supination
where are the muscles that cause flexion and extension in
they are in the arm
what are the two compartments involved in flexion and extension
anterior compartment of the arm
posterior compartment of the arm
what innervates the anterior compartment of the arm
musculocutaneous nerve
- C5, C6, C7
- biceps reflex C5,C6 is used to test if the musculocutaneous nerve is working
what innervates the posterior compartment of the arm
- Radial Nerve (C5-T1)
- C 7,8
- Triceps reflex – C7,8 - test to see if it works
what movements is the anterior compartment of the arm involved in
involved in shoulder and elbow flexors
what movements is the posterior compartment of the arm involved in
this is involved in shoulder and elbow extensors
what muscles make up the anterior compartment of the arm
- BBC
- Biceps brachii
- Brachialis
- Coracobrachialis
describe the biceps brachia
- most superficial muscles in the anterior compartment
- has a short head and a long head
Short head (more medial) - Corocoid process
Long Head ( more lateral) - Supraglenoid tubercle
- Inserts on the Radial Tuberosity and fascia of forearm
- powerful supinated arm flexes the elbow, pronate the arm the biceps get twisted therefore it does flex the elbow joint and this flexion then occurs by brachialis instead
can untwist pronation therefore it is a powerfrul suprinator
what muscles are responsible for pronation
bracialis
pronator teres
pronator quadratus
what muscles re responsible for supination
brachialis and biceps brachii
supinator
describe the brachilalis
- Distal humours
- Coronoid process of ulna
- Flexes in all positions
- Only acts on the elbow not on shoulder
describe the coracobrachialis
- Flexes and adducts shoulder
- Resists dislocation
- Only acts on shoulder not on elbow
what is the msuculatenous nevre innervate
- sensory branch that innervates lateral aspect of the forearm
- anterior compartment of the arm
what muscles make up the posterior compartment of the arm
- • - Triceps
• Anconeus
describe the triceps brachia
- 3 headed muscle
- Long head - infraglenoid tubercle of scapula
- Lateral head – comes from humerus
- Medial head – comes from humerus
- All 3 converted at the arm, insert by a single tendon onto the olecranon process of the ulnar
where does the radial nerve come into the arm
- In between the long head the lateral head and teres major this is a triangular space this is what the radial nerve comes through and this is also where the profundal brachii comes through
- Runs along the posterior aspect of the humerus
- Radial nerve is vulnerable to injury as it runs along the posterior aspect of that bone
describe where the radial nerve runs
• The Radial nerve runs in the posterior compartment of the arm, but pierces the intermuscular septum to run anterior to the lateral epicondyle at the elbow and then eneters the anterior part of the arm running anterior to the lateral epicondyle
describe where the ulnar nerve runs
- The Ulnar nerve runs in the anterior compartment of the arm, and pierces the intermuscular septa to pass posterior to the medial epicondyle to enter the forearm
- If you bang the medial epicondyle on a surface it compresses the ulnar nerve against the humerus causing you to get pins and needles
describe where the musculocutaneous nerve runs
• The Musculocutaneous nerve supplies the muscles of the anterior compartment of the arm, and the emerges lateral to the biceps as the lateral cutaneous nerve of the forearm
describe where the Median nerve runs
• The Median nerve runs in the anterior compartment of the arm, and crosses the anterior aspect of the elbow to enter the anterior compartment of the forearm
what are the bursae around the elbow
- deep (subtendinous) olecranon bursa
- intratendinous olecranon bursa
- Superficial (subcutaneous) olecranon bursa
where are the bursae located
1) Deep (subtendinous) olecranon bursa
– Between olecranon and triceps tendon
2) Intratendinous olecranon bursa
– Sometimes present in triceps tendon
3) Superficial (subcutaneous) olecranon bursa
- Located in subcutaneous connective tissue
what are bursae sacs
- these are sacs of fluid that reduce resistance
what bursae can become inflamed
- Can become inflamed by repeated excessive pressure and friction can cause bursitis- effects superficial(subcutaneous) bursa
what is another name for the curtail fossa
antecubrital fossa
what is the cubital fossa and where is it
- It is a triangular shaped depression found anterior to the elbow joint
- Between the brachloradis, flexor muscles and lateral and medial epicondyle
what are the cubital veins
- they are superficially in the subcutaneous tissue
- overly the curtail fossa
- it is called the median cubital vein
- joints the basilica and cephalic veins
what vein do you use for venipuncture
cubital veins
what is the cubital fossa made out of
- Biepital aponeruosis
- Biceps brachii tendon
- Bracihial artery
why do 2 veins rung alongside one artery
pulsatile action of the artery helps the blood move along the veins
what is at risk in a supracondylar fracture
- Brachial artery and median nerve are at risk
