Math Quiz: Prime and Composite Numbers

Nerve injuries in the upper limb depend on the location and extent of the lesion.
Motor changes result in paralysis of innervated muscles, and loss of associated reflexes.
Sensory changes result in loss of cutaneous sensation in the affected area.
Trophic changes affect vascular control, leading to initial redness and heat, followed by blue discoloration and reduced temperature.
Skin becomes dry and scaly due to reduced sweat gland function.
Nail growth is also slowed.
There are different types of tendon reflexes, including biceps, triceps, and supinator reflexes.

Symptoms and signs depend on the specific nerve and the extent of the injury.
Motor changes involve paralysis of innervated muscles and loss of reflexes.
Sensory changes cause loss of cutaneous sensation in specific areas.
Trophic changes disrupt the autonomic nervous system, causing initial redness/heat followed by blue/cold skin, and ultimately, dry and scaly skin.
Nail growth can be affected.

Spinal nerves can be injured within the vertebral canal, during passage through the intervertebral foramen, or in the peripheral course.
Injuries at these levels may result from fractures of the vertebrae or narrowing of the intervertebral foramina.
Herniation of the intervertebral discs or degeneration of the intervertebral disc can result in injury.

Brachial plexus injuries can affect the roots, trunks, divisions, cords, and branches.
Supraclavicular injuries involve the roots and trunks, while infraclavicular injuries affect divisions and cords.
Injuries result from compression, traction, or stab wounds.
Symptoms vary according to the specific site of injury and the involvement of the nerve fibers.
Brachial plexus injuries are of two types: upper (C5-C6) and lower (C8-T1).

These injuries are due to traction and tearing of the 5th and 6th roots of the brachial plexus.
The causes in infants include difficult deliveries and in adults, falls or blows to the shoulder.
Key nerves involved: nerve to sublavius, suprascapular, axillary, and musculocutaneous nerves.
The affected muscles result in limp, medially rotated limbs with pronated and extended forearms and loss of sensation on the lateral aspect of the arm and forearm.

Lower plexus injuries are due to excessive abduction of the arm, often in difficult deliveries or falls from a height.
This is more common in infants.
The causes for adults is trauma to the shoulder causing excessive abduction.
Involves damage to nerves of the lower plexus (C8-T1).
Leads to paralysis and wasting of small hand muscles, with potential sensory loss in the medial aspect of the forearm and hand, Horner's syndrome, and clawed hand appearance.

Injury to the long thoracic nerve causes weakness or paralysis of the serratus anterior muscle.
It is often due to blows or pressure in the posterior triangle of the neck.
Surgical procedures like radical mastectomy may also cause this type of injury.
This leads to winged scapula deformity, when the medial border of the scapula is pulled and protrudes away from the thoracic wall.
The scapula is unable to be stabilized during abduction of the arm.

Axillary nerve injuries can result from downward dislocation of the humeral head.
Fractures of the surgical neck of the humerus.
The injury paralyzes the deltoid and teres minor muscles.
Results in loss of abduction of the shoulder.
Associated with atrophy of the deltoid muscle and loss of sensation in the lower half of the shoulder.

Radial Nerve is commonly injured in the axilla, radial groove, and the injury to the deep branch and injury to the superficial branch and in the axilla.
Resulting from pressure of badly fitting crutches, falls, and fractures of the humerus.
Common causes include pressure from poorly-fitting crutches, falls, and fractures of the humerus (especially the surgical neck).
Motor impairment causes wrist drop, paralysis of the triceps, anconeus muscles, and long extensors of the wrist.
Sensory changes can affect the sensation over parts of the hand, and there can be sensory loss on parts of the hand and related areas.

Median nerve injuries can occur at different levels — elbow, wrist, and carpal tunnel.
Causes include fractures of the humerus, penetrating wounds (stab, or cuts in the forearm), carpal tunnel compression, and the use of repetitive motions (overuse).
The injuries cause weakness or paralysis of the muscles in the forearm.
Loss of opposition of the thumb (ape hand). -Loss of sensation in the lateral three-and-a-half fingers and the lateral half of the palm.

Ulnar nerve injuries can occur at the elbow and wrist. This often happens with fractures, penetrating wounds, or repetitive movements.
Motor paralysis involves the flexor carpi ulnaris, medial half of the flexor digitorum profundus, small hand muscles (excluding thenar muscles and first two lumbricals), and the adductor pollicis.
There is sensory loss over the anterior and posterior surfaces of the palm and medial one-and-a-half fingers. The posterior surface of the hand is spared.

Entrapment of the median nerve within the carpal tunnel.
Causes include repetitive motions, swelling, or other conditions that constrict the nerve.
The symptoms include pain, tingling, and numbness in the hand and fingers; paralysis may occur.