Upper Limb II
What is the common attachment of the anterior forearm?
Medial epicondyle
The trunks are classified into Superior, Middle and Inferior – what is this in reference to?
Clavicle
What type of muscle contraction occurs when tension develops but the muscle does not change length?
Isometric contraction
What is the primary ophthalmic abnormality of Rheumatoid Arthritis?
Autoimmunity
What are the 4 deep muscles of the posterior forearm?
Extensor Pollicis Longus (EPL): Extension of the thumb at the IP joint.
Abductor Pollicis Longus (APL): Abduction of the thumb at the CMC joint.
Extensor Pollicis Brevis (EPB): Extension of the thumb at the MCP joint.
Extensor Indicis (EI): Independent extension of the index finger.
What does the plexus innervate?
Shoulder, brachium, antebrachium and hand.
What relationship describes the way a muscle’s force output is maximised when its fibres are at 80–120% of resting length?
The length–tension relationship
An osteophyte is a [X], and what condition does it predominantly arise in?
It is a bony outgrowth, and is a morphological change seen in OA.
What muscles make up the 'Mobile Wad of Three'?
Brachioradialis: Flexes elbow + pronates/supinates from supinated/pronated to neutral.
Extensor Carpi Radialis Longus: Extension of the wrist.
Extensor Carpi Radialis Brevis: Extension of the wrist.
The ventral rami of which spinal nerves form the brachial plexus?
C5-T1
What is the term for the smooth, sustained muscle contraction that occurs when stimuli are delivered so rapidly that no relaxation occurs between them?
Fused (complete) tetanus
What is the primary mechanism of pseudogout?
CPP crystals form in hyaline cartilage and fibrocartilage impacting the articular cartilage.
What are the borders of the anatomical snuff box? (1x Medial + 2x Lateral)
Medial Border: Extensor pollicis longus (EPL)
Lateral Border: Extensor pollicis brevis (EPB) + Abductor pollicis longus (APL)
What is the clinical correlation of a fractured surgical neck of the humerus? (HINT: 5)
Injury commonly damages the axillary nerve.
Paralysis of the deltoid and teres minor.
Inability to abduct the arm (especially from 15–90°).
Deltoid muscle atrophy, making the greater tuberosity more prominent.
Sensory loss over the “regimental badge” area (lateral shoulder).
Which specific ionic disturbance during repeated stimulation disrupts excitation–contraction coupling and contributes to muscle fatigue?
Accumulation of K⁺ in the T‑tubules, which disrupts membrane potential and impairs Ca²⁺ release
What enzymes create fibrillation in type II collagen of articular cartilage?
Activated MMPs