Anatomy dissection 11 Flashcards
What is the deltoid muscle innervated by ?
Axillary nerve (hence damage to this gives the badge patch area)
What are the attachments of the deltoid muscle ?
- It attaches proximally to the lateral third of the clavicle and the inferior aspects of the scapular spine and acromion
- Attaches distally to the deltoid tuberosity of the humerus
What is a common site for cardiac referred pain in the arm ?
The posterior aspect of the arm
What are the compartments of the arm ?
Posterior and anterior
What are the muscles of the posterior compartment of the arm ?
Triceps brachii - has a lateral, medial and long head
What is the innervation of the posterior compartment of the arm ?
Radial nerve
What are the attachments of the triceps brachii ?
Proximal Attachments:
- Long head - Infraglenoid tubercle of the scapula
- Lateral head - superior to radial groove of humerus
- Medial head - inferior to radial groove of the humerus
Distal attachment:
All the heads attach to the olecranon process of the ulna
What is the function of the triceps brachii ?
Extension of the forearm at the elbow joint and weak extension of the arm at the shoulder joint
Where is the axillary nerve found ?
The quadrangular space
Its boundaries are:
- Superior – Subscapularis and teres minor.
- Inferior – Teres major.
- Laterally – Surgical neck of humerus.
- Medially – Long head of triceps brachii.
What muscles does the axillary nerve supply ?
Supplies the deltoid and teres minor
When must patients have there axillary nerve function tested ?
Followin an inferior dislocation of the shoulder
Describe the route of the radial nerve
- Passes from axilla to posterior compartment of the arm (found in the radial groove of the humerus here)
- Then enters lateral aspect of the cubital fossa
- The goes into the posterior compartment of the forearm
What is the cubital fossa ?
An area located on the anterior surface of the elbow joint
What is the nervous supply of the posterior compartment of the arm ?
Radial
The posterior compartment of the arm is similar to the posterior compartment of the leg, its split into superifical and deep muscles, what are the superficial muscles ?
There are 7 muscles:
- Brachioradialis
- Extensor carpi radilais longus and brevis
- Extensor digitorum
- Extensor digit minimi
- Extensor carpi ulnaris
- Anconeus
(the ones with radilis in are because the are on the radial side - the list goes from lateral to medial)
What is special about the brachioradialis muscle ?
It is located at the boundry between the anterior and posterior compartments of the forearm
Classified as posterior because supplied by the radial nerve
What is the function of the extensor carpi radialis longus and brevis ?
Extension and abduction at the wrist
What is the other function of the extensor digit minimi?
Extends the little finger, and extends the wrist
What is the function of the brachioradilis muscle ?
Flexes at the elbow
What is the function of the extensor digitorum ?
Extends medial four fingers at the MCP and IP joints
What is the function of the extensor carpi ulnaris ?
Extension and adduction of wrist.
What is the function of the aconeus muscle ?
Extends and stablises the elbow joint. Abducts the ulna during pronation of the forearm.
What are the deep muscles of the posterior compartment of the forearm ?
- Supinator
- Abductor pollicis longus
- Extensor pollicis brevis and longus
- Extensor indicis.
What is the function of the supinator muscle of the deep posterior forearm ?
Supinates the forearm
What is the function of the extensor pollicus longus and brevis ?
Extension of the thumb
What is the function of the abductor pollicus longus ?
Abducts the thumb
What is the function of the Extensor indicus ?
Extension of the index finger
What is a wrist drop a clinical sign of ?
Radial nerve injury
What are the tendons of the muscles of the posterior comapartment of the forearm held in place by as they cross the wrist ?
Extensor retinaculum
Where does the radial nerve branch into superifical and deep (note if it wants to be really specific guess deep radial nerve for supply of posterior forearm muscle)
Just anterior to the lateral epichondyle
Note the the deep radial nerve can be called the posterior interosseous nerve
