Liam Carter
The human hand is a complex network of nerves, muscles, and bones. The fingertips are among the most sensitive parts of the body, with thousands of nerve endings that allow us to distinguish the size, shape, and texture of objects. The nail unit has a rich blood supply and is protected by a hard outer nail plate that does not contain any nerves or blood vessels. The nail matrix, which is the active tissue beneath the nail, contains nerves, lymph, and blood vessels. The median nerve, one of five nerve branches of the brachial plexus, is responsible for providing sensation to the palm, thumb, and fingers. The ulnar nerve provides sensation to the small finger side of the palm, the small finger, and part of the ring finger. These nerves play a critical role in our ability to perform precise and delicate movements with our fingers.
| Characteristics | Values |
|---|---|
| Location of sensory nerves | The nail matrix, which is the part of the nail bed that is beneath the nail plate |
| Composition of the nail plate | Made of translucent keratin protein |
| Composition of the nail matrix | Contains nerves, lymph, and blood vessels |
| Functions of the nail | Protects the distal phalanx, the fingertip, and the surrounding soft tissues from injuries; enhances precise delicate movements of the distal digits through counter-pressure exerted on the pulp of the finger; acts as a tool for an "extended precision grip" |
| Sensory nerve endings in the fingers | Meissner’s corpuscles, Pacinian corpuscles, free nerve endings, Merkel discs, and Ruffini endings |
| Functions of sensory nerve endings in the fingers | Allow for the sense of touch and discrimination of shapes, textures, and objects; responsible for the sensations of heat and pain; give information on where the hand and fingers are in relation to the body |
Explore related products
What You'll Learn
- The nail itself does not contain nerves
- Nerves under the nail help protect the digits and contribute to tactile sensation
- The median nerve is the most well-known nerve of the brachial plexus
- The ulnar nerve is close to the skin at the elbow and can be damaged by bumping
- The radial nerve wraps around the back of the upper arm bone
The nail itself does not contain nerves
The nail matrix, also known as the matrix unguis, keratogenous membrane, or onychostroma, is the part of the nail bed that is beneath the nail and contains nerves, lymph, and blood vessels. The matrix produces cells that become the nail plate. The width and thickness of the nail plate are determined by the size, length, and thickness of the matrix, while the shape of the fingertip bone determines the shape of the nail plate.
The distal digits have a rich neural innervation as the fingers are responsible for fine tactile discrimination. The nerves innervating the nail unit mimic the arterial supply. There are paired digital nerves innervating the palmar and dorsal surfaces of each digit. The dorsal digital nerve branches and runs over the distal interphalangeal joint to innervate the proximal nail fold. The palmar digital nerve travels with the proper digital artery past the distal interphalangeal joint. It then trifurcates into branches that supply the rest of the nail unit and the pulp of the distal finger.
The nerve endings in the fingertips can distinguish the orientation of edges and perform complex neural computations that were previously thought to be carried out by the brain. They can also deliver information on changes that occur at the skin, such as moving a finger over a gritty surface. The nerve endings in the fingertips contain two different types of touch receptor organs: Meissner corpuscles and Merkel discs, which are sensitive to fast and slow deformations across the skin, respectively.
Nutrient Deficiency: What Your Fingernails Are Trying to Tell You
You may want to see also
Explore related products
Nerves under the nail help protect the digits and contribute to tactile sensation
The nail is a protective plate found at the tip of the digits (fingers and toes) of primates, corresponding to the claws in other tetrapods. It is made of a tough, rigid protein called alpha-keratin. The nail consists of the nail plate, the nail matrix, and the nail bed below it. The nail matrix is the active tissue that generates cells, which then harden as they move outward from the nail root to the nail plate. The nail matrix is the part of the nail bed that is beneath the nail and contains nerves, lymph, and blood vessels.
The nail functions by protecting the digits and contributing to tactile sensation. The nail bed is strongly attached to the nail plate, which does not contain any nerves or blood vessels. The hyponychium, or the "quick", is the epithelium located beneath the nail plate at the junction between the free edge and the skin of the fingertip. It forms a seal that protects the nail bed. The growing part of the nail is under the skin at the nail's proximal end under the epidermis, which is the only living part of a nail.
The distal digits have a rich neural innervation as the fingers are responsible for fine tactile discrimination. The nerves innervating the nail unit mimic the arterial supply. There are paired digital nerves innervating the palmar and dorsal surfaces of each digit. The dorsal digital nerve branches and runs over the distal interphalangeal joint to innervate the proximal nail fold. The palmar digital nerve travels with the proper digital artery past the distal interphalangeal joint. It then trifurcates into branches that supply the rest of the nail unit and the pulp of the distal finger.
The nerve endings in the fingertips are among the most sensitive parts of the body. They are densely packed with thousands of nerve endings, which produce complex patterns of nervous impulses that convey information about the size, shape, and texture of objects. The nerve endings in the fingertips contain two different types of touch receptor organs: Meissner corpuscles and Merkel discs, which are sensitive to fast and slow deformations across the skin, respectively. These nerve endings can distinguish the orientation of edges and perform complex neural computations that were previously thought to be carried out by the brain.
Understanding Fingernail Creases: What Your Nails Are Telling You
You may want to see also
Explore related products
The median nerve is the most well-known nerve of the brachial plexus
The nail plate, or the nail body, does not contain any nerves or blood vessels. The nail matrix, which is the active tissue that generates cells, is the only living part of a nail. It is the part of the nail bed that is beneath the nail and contains nerves, lymph, and blood vessels.
The median nerve is formed from the C5, C6, C7, C8, and T1 nerve roots of the brachial plexus. It is likely the most well-known nerve of the brachial plexus because it can be compressed as it crosses the wrist, causing carpal tunnel syndrome and other health problems. The brachial plexus is a complex network of nerves that branches from the cervical spine (neck) and helps you move your shoulders, arms, and hands. It also sends sensory information.
The median nerve provides sensory and motor functions to the forearm, wrist, and hand. It supplies the thenar eminence, or the muscles at the base of the thumb, with nerves. It also supplies nerves to the lumbrical muscles of the index, middle, and half of the ring finger. The median nerve provides sensation to the palm, thumb, index, middle, and half of the ring finger.
The median nerve travels along the inside of the arm near the brachial artery and does not provide any function until after it crosses the elbow. In the forearm, the nerve supplies almost all the flexor muscles and all the pronator muscles of the forearm with nerves. Its function allows the wrist and fingers to bend and pronates the forearm (rotating the hand to face palm down).
The ulnar nerve, radial nerve, musculocutaneous nerve, and axillary nerve are other nerves that are part of the brachial plexus.
The Mystery of Splitting Fingernails: Causes and Solutions
You may want to see also
Explore related products
The ulnar nerve is close to the skin at the elbow and can be damaged by bumping
The nail plate, or the nail body, does not contain any nerves or blood vessels. The nail matrix, which is the active tissue that generates cells, is the only living part of a nail. It is the part of the nail bed that is beneath the nail and contains nerves, lymph, and blood vessels.
The ulnar nerve is indeed close to the skin at the elbow and can be damaged by bumping. This nerve travels down the arm to the wrist, hand, and ring and little fingers. It passes just beneath the surface of the skin near the elbow. When you hit your "funny bone", you are hitting your ulnar nerve, which crosses the inner part of the elbow joint. This can cause numbness and tingling in your fingers, as well as a sharp, electrical pain. This is because the ulnar nerve is very close to the skin at the elbow, making it easy to bump.
Ulnar nerve entrapment occurs when something puts pressure on the ulnar nerve in the elbow or wrist. This can lead to inflammation, causing neuropathic pain and nerve damage. Symptoms of ulnar nerve entrapment include numbness and tingling in the pinky and ring fingers, curving of these fingers (like a claw), and hand weakness. This weakness can make it difficult to grasp items, pick things up, or perform daily tasks such as writing or buttoning a shirt.
If you suspect ulnar nerve entrapment or damage, it is important to see a healthcare provider early. They may recommend physical therapy or occupational therapy to maintain muscle strength and suggest changes in the workplace. In some cases, surgery may be necessary to relieve pressure on the nerve.
The Purpose of Fingernails and Toenails Explained
You may want to see also
Explore related products
The radial nerve wraps around the back of the upper arm bone
The human body is a complex network of nerves, muscles, and bones. One such nerve is the radial nerve, which wraps around the back of the upper arm bone, also known as the humerus. This nerve is responsible for providing movement and sensory functions to the upper arm, forearm, wrist, and hand.
The radial nerve takes a winding path from the lower armpit, supplying movement and sensation to certain parts of the upper limbs. It plays a crucial role in allowing us to move our muscles and feel sensations in the skin of our upper arm, forearm, wrist, and hand. Specifically, it provides touch, pain, and temperature sensations to the skin on the inner upper arm, outer forearm, and the back part of the wrist and hand closest to the thumb.
The radial nerve wraps around the humerus bone, supplying function to the triceps muscles on the back of the arm, enabling us to straighten our elbows. This positioning of the nerve around the humerus bone makes it susceptible to stretching or tearing if the bone is broken. As it continues its path, the nerve travels on the outside of the elbow, known as the lateral side, and then into the outside of the forearm.
In the forearm, the radial nerve powers the muscles responsible for straightening the wrist and fingers. An injury to the radial nerve can lead to a condition called wrist drop, characterised by the inability to straighten the wrist. The nerve also provides sensation to the thumb side of the back of the hand.
The radial nerve has two major branches: the superficial branch and the deep branch. The superficial branch provides sensory information and travels from below the elbow to the wrist, hand, and fingers. It runs alongside the radial artery, which supplies blood to the forearm and hand. The deep branch, on the other hand, runs between the muscles in the forearm that enable forearm rotation. It stimulates muscles to extend the wrist, hand, and fingers, such as when opening the hand from a clenched fist.
The Painful Problem of Ingrown Nails
You may want to see also
Frequently asked questions
A fingernail is a protective plate found at the tip of the fingers and toes of all primates. It is made of a tough rigid protein called alpha-keratin.
The nail itself does not contain any nerves. However, the nail bed, which is the tissue beneath the nail, contains nerves, lymph, and blood vessels.
Sensory nerve endings in the fingers include Meissner's corpuscles, Pacinian corpuscles, free nerve endings, Merkel discs, and Ruffini endings.
Sensory nerves in the fingers help distinguish the size, shape, and texture of objects. They also provide information on changes that occur on the skin, such as moving your finger over a gritty surface.
