Peripheral nerves (outside the central nervous system) are conduits that have a special ability to carry electrical impulses along their length and into or out of the central nervous system. Nerves have specialized receptors for various inputs, such as heat, cold, high-pitched sounds, and vibrations. Smaller nerves are grouped into larger cord-like groups that run up and down the body.
Peripheral nerves (outside the central nervous system) are conduits that have a special ability to carry electrical impulses along their length and into or out of the central nervous system. Nerves have specialized receptors for various inputs, such as heat, cold, high-pitched sounds, and vibrations. Smaller nerves are grouped into larger, cord-like bundles that run up and down the body.
Chicken couple:
- peripheral nerves
- brachial plexus
peripheral nerves
ulnar nerves
ulnar nervesThe ulnar nerve is formed from the C8 and T1 nerve roots. The C8 and T1 roots are part of the brachial plexus, which runs from the cervical spine below the clavicle through the armpit (armpit) and down the inside of the arm to the inside of the elbow.
When you hit the "fun bone" and feel numbness and tingling in your fingers, along with a sharp electrical pain, you are actually hitting the ulnar nerve as it crosses the inner (medial) part of the elbow joint. The ulnar nerve is very close to the skin at the elbow, making it easy to touch.
The ulnar nerve can also be compressed when it crosses the elbow, causing numbness and tingling in the little and ring fingers and weakness in the hand. is calledKubital tunnel syndrome. Cubital tunnel syndrome is a very common problem treated by hand surgeons.
The ulnar nerve then migrates to the inside of the forearm. It energizes the forearm muscles that flex the tips of the little and ring fingers (the flexor digitorum profundus) and also one of the muscles that flexes the wrist (the flexor carpi ulnaris). The main action of the ulnar nerve is in the hand. The nerve supplies nearly all of the small muscles of the hand, including the hypothenar muscles, the lumbricals of the ring and little fingers, the palmar and dorsal interosseous muscles, the adductor pollicis, and the deep head of flexor pollicis brevis. The ulnar nerve provides sensation to the little finger side of the palm, the little finger, and the side of the ring finger adjacent to the little finger. It also provides sensation on the back of the little finger side of the hand.
The ulnar nerve can be injured by a cut at any point along its path. A cut through the ulnar nerve in the forearm can result in a scratch on the little and ring fingers of the hand and weakness of most of the muscles of the hand. Also, such an injury can lead to a loss of sensation in the little and ring fingers. learn more aboutnerve damage.
radial nerves
The radial nerve is formed from the C5, C6, C7, C8, and T1 nerve roots of the brachial plexus. The brachial plexus is a group of nerves that branch from the cervical spine (neck). The brachial plexus travels below the clavicle and through the armpit (armpit).
In the arm, the radial nerve wraps around the back of the humerus. The nerve gives the triceps muscles on the back of the arm the function of extending the elbow. Because the radial nerve surrounds the humerus, it can be stretched or torn if the humerus is fractured.
The nerve then travels down the outside of the elbow (the lateral side) and down the outside of the forearm. In the forearm, the nerve supplies all the muscles that extend the wrist and fingers. Radial nerve injury can lead to wrist drop, the inability to straighten the wrist.
In addition to the thumb, the radial nerve also provides sensation on the back of the hand.
median nerve
The median nerve is formed from the C5, C6, C7, C8, and T1 nerve roots of the brachial plexus. The brachial plexus is a group of nerves that branch from the cervical spine (neck). The brachial plexus travels below the clavicle and through the armpit (armpit).
The median nerve travels along the inside of the arm near the brachial artery. The median nerve has no function until it crosses the elbow.
In the forearm, the median nerve supplies nearly all of the flexor and pronator muscles of the forearm. Its function allows bending the wrist and fingers. Also pronates the forearm (turn the hand so that it is palm down). The exception is that the ulnar nerve, not the median nerve, curves the flexor carpi ulnaris and flexor digitorum profundus muscles toward the little and ring fingers.
The median nerve is probably the best known nerve of the brachial plexus because it can be compressed and caused by crossing the wrist.Carpal tunnel syndrome.
In the hand, the median nerve supplies nerves to the thenar eminence, the muscles at the base of the thumb. It also supplies nerves to the psoas for the index and middle fingers. The median nerve gives sensation to the thumb side of the palm, the thumb, the index finger, the middle finger, and the middle of the ring finger.
musculocutaneous nerve
The musculocutaneous nerve is formed by the C5, C6, and C7 nerve roots of the brachial plexus. The brachial plexus is a group of nerves that emanate from the neck (cervical spine). The brachial plexus travels below the clavicle and through the armpit (armpit).
The musculocutaneous nerve runs along the front of the humerus and provides function to the coracobrachialis, biceps, and brachialis muscles. The coracobrachialis flexes and adducts (moves the arm toward the body) the shoulder. The biceps flexes the elbow and supinates the forearm (turns palm up), and the brachialis muscle flexes the elbow.
The musculocutaneous nerve also provides sensation to the lateral (outer) forearm.
axillary nerve
The axillary nerve forms from the C5 and C6 nerve roots of the brachial plexus. The brachial plexus is a group of nerves that emanate from the neck (cervical spine). The brachial plexus runs below the clavicle. At this point, the axillary nerve runs behind the humerus to supply the muscles around the shoulder.
The axillary nerve provides function to three muscles: the deltoid, the teres minor, and the long head of the triceps muscle. The deltoid is the large, fan-shaped muscle above your shoulder that allows you to raise your arm. Teres minor is one of the rotator cuff muscles that allows you to rotate your arm outward (external rotation). The triceps extend the elbow. Most of the triceps is innervated by the radial nerve; However, a part is innervated by the axillary nerve.
The axillary nerve also provides sensations to the side of the shoulder, sometimes referred to as the "regimental insignia" area, due to the area where insignia were attached to uniforms. Humeral neck fractures.
brachial plexus
The brachial plexus is a group of nerves that control the muscles of the shoulder, arm, forearm, and hand. The same nerves also supply sensitivity (sensation) to the entire upper limb. There are five components of the brachial plexus: roots, trunks, divisions, cords, and branches.
root
The brachial plexus is a group of nerves that control the muscles of the shoulder, arm, forearm, and hand. The same nerves also provide sensations (feelings) to the entire upper limb.
The brachial plexus nerves begin as the "roots" of the spinal cord. The roots of the brachial plexus exit the spinal column between the vertebrae. The roots are labeled C5, C6, C7, C8 for the cervical vertebrae and T1 for the first thoracic vertebra.
Brachial plexus injuries range from mild stress injuries that resolve naturally to complete root tears resulting in an arm that doesn't feel or function. Brachial plexus injuries can result from motorcycle or car accidents when the neck and shoulder are pushed in different directions. Babies can also sustain brachial plexus injuries during childbirth.
Some facts about each of the roots:
- C5 is the nerve root that exits the spinal cord above the fifth cervical vertebra. It travels to the brachial plexus and eventually becomes the nerves that supply the muscles around the shoulder and chest. It also gives a feel to parts of the upper arms.
- C6 is the nerve root exiting the spinal cord above the sixth cervical vertebra. It travels to the brachial plexus and eventually becomes the nerves that supply the muscles that flex the elbow and extend the wrist. It is also felt in parts of the thumb side of the forearm and hand.
- C7 is the nerve root exiting the spinal cord above the seventh cervical vertebra. It travels to the brachial plexus and eventually becomes the nerves that supply the muscles that straighten the elbow, flex the wrist, and extend the fingers. It also provides sensation around the middle finger of the hand.
- C8 is the nerve root exiting the spinal cord below the seventh cervical vertebra. It travels to the brachial plexus and eventually becomes the nerves that supply the muscles of the hand and the muscles that flex the fingers. It also offers sensation on the little finger side of the hand and forearm.
- T1 is the lowest nerve root that becomes part of the brachial plexus. It exits the spinal cord below the first vertebra in the thoracic spine. Eventually, it becomes the nerves that drive the muscles of the hand. It also offers sensation on the inside of the elbow and upper arm.
underwear
The second level of the brachial plexus consists of three "trunks". The upper, middle, and lower stems are formed from the five main roots that come from the spinal cord. As the three trunks continue toward the shoulder, each of them divides into two nerves called the "anterior department" and the "posterior department."
departments
The third level of the brachial plexus is called the "divisions". There are six divisions coming from the three "stems": three anterior divisions and three posterior divisions. The divisions then rearrange to create three new nerves called "cords."
strings
The nerves at the fourth level of the brachial plexus are called "cords" and come from the "splits" at level three. The three cords are named for their position relative to the lateral, posterior, and medial brachial artery. Many important nerves come from the cords. Some of these nerves create movement around the shoulder. Others travel to become the five main branches of the brachial plexus.
branch offices
The fifth and final level of the brachial plexus are the five nerves that innervate the shoulder and arm, called "rami." These five branches are called the musculocutaneous, axillary, radial, median, and ulnar nerves.