Upper Extremities (Muscles) Flashcards
(111 cards)
How are the Muscle Compartments of the Upper Extremities divided from each other?
- Bones
2. Enclosements of Deep Fascia
What is the common action of most of the muscles in the Anterior Compartment of the Arm?
- Flex Elbow
- Flex Arm
- Forearm Supination
What is the common action of most of the muscles in the Posterior Compartment of the Arm?
Extend Elbow (only one muscle there)
What is the common action of most of the muscles in the Anterior Compartment of the Forearm?
- Flex Wrist and FIngers
2. Pronation
What is the common action of most of the muscles in the Posterior Compartment of the Forearm?
- Extend Wrist and Fingers
2. Supination
What area of the Upper Limb has the most muscles?
Forearm (about 24) split into 4 muscle groups:
- Anterior Superficial Compartment
- Anterior Deep Compartment
- Posterior Superficial Compartment
- Posterior Deep Compartment
How are the muscles of the Hand divided?
- Extrinsic Muscles (Muscle bellies in Forearm, but Tendons extend to hand)
- Intrinsic Muscles (Muscle bellies and tendons in Hand)
What are the muscles of the Anterior Compartment of the Arm?
“3 Brachi’s”
1. Coracobrachialis
- Brachialis
- Biceps Brachii
What nerve innervates the muscles of the Anterior (Flexor) Compartment of the Arm?
Musculotaneous Nerve (Part of the Brachial Plexus)
NOTE: Also does Lateral Cutaneous Forearm innervation
Coracobrachialis:
- Origin
- Insertion
- Action
- Innervation
- Coracoid Process of the Scapula
- Medial Surface on Shaft of the Humerus
- Flexion of the Shoulder
- Musculotaneous Nerve
Brachialis:
- Origin
- Insertion
- Action
- Innervation
- Humerus
- Ulna
- Flexion of the Forearm
- Musculotaneous Nerve
Biceps Brachii:
- Origin(s)
- Insertion
- Action
- Innervation
“2-Headed muscle”-noted from the name “bi”cep
- Coracoid Process (short head) and top of Glenoid Cavity AKA Supraglenoid Tubercle (long head)
- Radial Tuberosity of the Radius
- Flexion AND Supination of the Forearm
- Musculotaneous Nerve
When do Biceps Brachii perform Supination more effectively?
When Supination and Flexion are in conjuction
For Example: It is easier to open a lid when your elbow is bent
What are the muscle(s) of the Posterior (Extensor) Compartment of the Arm?
Triceps Brachii
“the 3 Headed muscle”
Triceps Brachii:
- Origin(s)
- Insertion
- Action
- Innervation
- 3 Origins:
A. Bottom of Glenoid Cavity AKA Infraglenoid Tubercle (Long Head)
B. Humerus (Medial Head)
C. Humerus (Lateral Head) - Olecranon Process of the Ulna
- Extension of Forearm
- Radial Nerve (arises from Posterior Cord)
Describe the pathway of the Radial Nerve
The Radial Nerve passes through the Triangular Interval to the back of the Humerus where it travels down in the “Spiral Groove” between the Medial and Lateral Heads of the Triceps with the artery that supplies the posterior part of the upper limb called the Deep Brachial Artery (Profunda)
What are the two spaces formed between the muscles of the upper limb through which nerves travel?
- Quadrangular Space (more superior)
2. Triangular Interval
What muscles form the borders of the Quadrangular Space?
- Teres Major
- Teres Minor
- Long Head of the Triceps Brachii
What vessels pass through the Quadrangular Space?
- Axillary Nerve (innervates Deltoid and Teres Minor)
2. Posterior Circumflex Humoral Artery (branch of Axillary Artery that goes around the Humerus)
What is the Cubital Fossa?
“An Anatomical Space on the Anterior Side of the Elbow Joint”
Palpable depression on the front of your elbow
What are the borders of the Cubital Fossa?
Superior Border- Imaginary Line between the Epicondyles of the Humerus
Lateral Border- Brachiaoradialis Muscle (Forearm)
Medial Border- Pronator Teres Muscle (Forearm)
What are the contents of the Cubital Fossa?
- Tendon of the Biceps muscle (Distal attachment going towards the Radius)
- Median Nerve (middle nerve from the Brachial Plexus “M”)
- Brachial Artery (Pulse can be felt medial to Biceps tendon)
Order from Medial to Lateral is “NAT” for Nerve, Artery, Tendon
Describe pathways of the Terminal Nerves of the Brachial Plexus:
- Median Nerve “middle of the M” (got contributions from lateral and medial cords) travels anterior to the Elbow Joint through the Cubital Fossa medial to the Biceps Tendon
- Musculocutaneous Nerve “Lateral side of the M” innervates the Anterior Compartment of the Arm and travels to the forearm superficially to innervate Lateral Cutaneous Forearm
- Ulnar Nerve “Medial side of the M” travels behind Medial Epicondyle in a groove
- Radial Nerve “Posterior to the M” to innervate Posterior Arm and Ultimately Forearm
What happens when you “hit your funny bone”?
The Ulnar Nerve that travels behind the Medial Epicondyle is stimulated and specific cutaneous sensation is felt