The peripheral nervous system (PNS) can be divided into the somatic nervous system and the autonomic nervous system (ANS). The PNS is not protected by bone, leaving it exposed to injury, unlike the central nervous system, which is made of the brain and spinal cord, to serve the limbs and organs. ^[1] The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. ... This article or section is in need of attention from an expert on the subject. ... This article is about the skeletal organs. ... For other uses, see Brain (disambiguation). ... The Spinal cord nested in the vertebral column. ...

General classification

The peripheral nervous system can be classified either by direction of neurons or by function. Neurons (also called nerve cells) are the primary cells of the nervous system. ...

By direction

There are three types of directions of the neurons: This article is about cells in the nervous system. ...

• Sensory system by sensory neurons, between the sensory and motor neurones. However, there are relay neurons in the CNS as well.

The human eye is the first element of a sensory system: in this case, vision, for the visual system. ...

By function

By function, the peripheral nervous system is divided into the somatic nervous system , autonomic nervous system and the enteric nervous system. The somatic nervous system is responsible for coordinating the body movements, and also for receiving external stimuli. It is the system that regulates activities that are under conscious control. The autonomic nervous system is then split into the sympathetic division, parasympathetic division, and enteric division. The sympathetic nervous system responds to impending danger or stress, and is responsible for the increase of one's heartbeat and blood pressure, among other physiological changes, along with the sense of excitement one feels due to the increase of adrenaline in the system. The parasympathetic nervous system, on the other hand, is evident when a person is resting and feels relaxed, and is responsible for such things as the constriction of the pupil, the slowing of the heart, the dilation of the blood vessels, and the stimulation of the digestive and genitourinary systems. The role of the enteric nervous system is to manage every aspect of digestion, from the esophagus to the stomach, small intestine and colon. The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. ... This article or section is in need of attention from an expert on the subject. ... The enteric nervous system (ENS) is an interdependent part of the autonomic nervous system. ... The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. ... This article or section is in need of attention from an expert on the subject. ... The Sympathetic Nervous System (SNS) is a branch of the autonomic nervous system. ... Autonomic nervous system innervation, showing the sympathetic and parasympathetic (craniosacral) systems, in red and blue, respectively The parasympathetic nervous system is one of three divisions of the autonomic nervous system. ... The enteric nervous system (ENS) is an interdependent part of the autonomic nervous system. ... This page is a candidate to be moved to Wiktionary. ...

Naming of specific nerves

The Human Nervous System. Blue is PNS while red is CNS.

Ten out of the twelve cranial nerves originate from the brainstem, and mainly control the functions of the anatomic structures of the head with some exceptions. The nuclei of cranial nerves I and II lie in the forebrain and thalamus, respectively, and are thus not considered to be true cranial nerves. CN X (10) receives visceral sensory information from the thorax and abdomen, and CN XI (11) is responsible for innervating the sternocleidomastoid and trapezius muscles, neither of which is exclusively in the head. Image File history File links Size of this preview: 363 × 599 pixelsFull resolution (421 × 695 pixel, file size: 176 KB, MIME type: image/png) A diagram of the Human Nervous system for the nervous system article. ... Image File history File links Size of this preview: 363 × 599 pixelsFull resolution (421 × 695 pixel, file size: 176 KB, MIME type: image/png) A diagram of the Human Nervous system for the nervous system article. ... Cranial nerves Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. ... The brain stem is the stalk of the brain below the cerebral hemispheres. ... In human anatomy, the sternocleidomastoid (pronounced ) muscles are muscles in the neck that act to flex and rotate the head. ... This article is about the human skeletal muscle. ...

Spinal nerves take their origins from the spinal cord. They control the functions of the rest of the body. In humans, there are 31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. The naming convention for spinal nerves is to name it after the vertebra immediately above it. Thus the fourth thoracic nerve originates just below the fourth thoracic vertebra. This convention breaks down in the cervical spine. The first spinal nerve originates above the first cervical vertebra and is called C1. This continues down to the last cervical spinal nerve, C8. There are only 7 cervical vertebrae and 8 cervical spinal nerves. The term spinal nerve generally refers to the mixed spinal nerve, which is formed from the dorsal and ventral roots that come out of the spinal cord. ... The Spinal cord nested in the vertebral column. ... A diagram of a thoracic vertebra. ...

Cervical spinal nerves (C1-C4)

Further information: Cervical plexus

The first 4 cervical spinal nerves, C1 through C4, split and recombine to produce a variety of nerves that subserve the neck and back of head. The cervical plexus is a plexus of the ventral roots of the first four cervical spinal nerves which are located from C1 to C4 cervical segment near the neck. ...

Spinal nerve C1 is called the suboccipital nerve which provides motor innervation to muscles at the base of the skull. C2 and C3 form many of the nerves of the neck, providing both sensory and motor control. These include the greater occipital nerve which provides sensation to the back of the head, the lesser occipital nerve which provides sensation to the area behind the ears, the greater auricular nerve and the lesser auricular nerve. See occipital neuralgia. The phrenic nerve arises from nerve roots C3, C4 and C5. It innervates the diaphragm, enabling breathing. If the spinal cord is transected above C3, then spontaneous breathing is not possible. See myelopathy The first spinal nerve, the suboccipital nerve exits the spinal cord between the skull and the first cervical vertebra, the atlas. ... For other uses of Skull, see Skull (disambiguation). ... The greater occipital nerve is a spinal nerve arising between the first and second cervical vertebrae, along with the lesser occipital nerve. ... For other uses of the word head, see head (disambiguation). ... The lesser occipital nerve is a spinal nerve arising between the first and second cervical vertebrae, along with the greater occipital nerve. ... For other uses, see Ear (disambiguation). ... The greater auricular nerve originates from the cervical plexus, composed of branches of spinal nerves C2 and C3. ... The lesser auricular nerve originates from the cervical plexus, composed of branches of spinal nerves C2 and C3. ... Occipital Neuralgia is a medical condition characterized by chronic pain in the upper neck, back of the head, and behind the ears. ... The phrenic nerve arises from the third, fourth, and fifth cervical spinal nerves (C3-C5) in humans. ... In the anatomy of mammals, the diaphragm is a shelf of muscle extending across the bottom of the ribcage. ... Spinal cord injury, or myelopathy, is a disturbance of the spinal cord that results in loss of sensation and mobility. ...

Brachial plexus (C5-T1)

Further information: Brachial plexus

The last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1,combine to form the brachial plexus, or plexus brachialis, a tangled array of nerves, splitting, combining and recombining, to form the nerves that subserve the arm and upper back. Although the brachial plexus may appear tangled, it is highly organized and predictable, with little variation between people. See brachial plexus injuries The brachial plexus is an arrangement of nerve fibres (a plexus) running from the spine (vertebrae C5-T1), through the neck, the axilla (armpit region), and into the arm. ... The brachial plexus is an arrangement of nerve fibres (a plexus) running from the spine (vertebrae C5-T1), through the neck, the axilla (armpit region), and into the arm. ... A common neurologic injury from trauma (such as being hit by a car) is that of brachial plexus avulsion. ...

Before forming three cords

The first nerve off the brachial plexus, or plexus brachialis, is the dorsal scapular nerve, arising from C5 nerve root, and innervating the rhomboids and the levator scapulae muscles. The long thoracic nerve arises from C5, C6 and C7 to innervate the serratus anterior. The brachial plexus first forms three trunks, the superior trunk, composed of the C5 and C6 nerve roots, the middle trunk, made of the C7 nerve root, and the inferior trunk, made of the C8 and T1 nerve roots. The suprascapular nerve is an early branch of the superior trunk. It innervates the suprascapular and infrascapular muscles, part of the rotator cuff. The trunks reshuffle as they traverse towards the arm into cords. There are three of them. The lateral cord is made up of fibers from the superior and middle trunk. The posterior cord is made up of fibers from all three trunks. The medial cord is composed of fibers solely from the medial trunk. The dorsal scapular nerve arises from the brachial plexus, specifically from spinal nerves C4 and C5. ... These shapes are Rhomboids In geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are oblique. ... The levator scapulae is a muscle of the back that affects the scapula. ... The long thoracic nerve (external respiratory nerve of Bell; posterior thoracic nerve) supplies the Serratus anterior. ... Serratus anterior Serratus anterior muscle is the surface of upper 9 ribs at side of chest - anterior aspect along entire length of medial border of scapula - (protraction) draws medial border of scapula away from vertebrae (upward rotation). ... The Nervus suprascapularis (Suprascapular nerve) is a nerve of the plexus brachialis. ... The rotator cuff (rotor cuff) is an anatomical term given to the group of muscles and their tendons that act to stabilize the shoulder. ... Look up ARM in Wiktionary, the free dictionary. ...

Lateral cord

The lateral cord gives rise to the following nerves:

• The lateral pectoral nerve, C5, C6 and C7 to the pectoralis major muscle, or musculus pectoralis major.
• The musculocutaneous nerve which innervates the biceps muscle
• The median nerve, partly. The other part comes from the medial cord. See below for details.

The Anterior Thoracic Nerves supply the Pectorales major and minor. ... Location The clavicular head of the pectoralis major takes its origin from the anterior surface of the medial half of the clavicle. ... The musculocutaneous nerve arises from the lateral cord of the brachial plexus, opposite the lower border of the Pectoralis minor, its fibers being derived from the fifth, sixth, and seventh cervical nerves. ... A person flexing his biceps brachii In human anatomy, the biceps brachii is a muscle on the upper arm that acts to flex the elbow. ... The median nerve is a nerve that runs down the arm and forearm. ...

Posterior cord

The posterior cord gives rise to the following nerves:

• The upper subscapular nerve, C7 and C8, to the subscapularis muscle, or musculus supca of the rotator cuff.
• The lower subscapular nerve, C5 and C6, to the teres major muscle, or the musculus teres major.
• The thoracodorsal nerve, C6, C7 and C8, to the latissimus dorsi muscle, or musculus latissimus dorsi.
• The axillary nerve, which supplies sensation to the shoulder and motor to the deltoid muscle or musculus deltoideus, and the teres minor muscle, or musculus teres minor, also of the rotator cuff.
• The radial nerve, or nervus radialis, which innervates the triceps brachii muscle, the brachioradialis muscle, or musculus brachioradialis,, the extensor muscles of the fingers and wrist (extensor carpi radialis muscle), and the extensor and abductor muscles of the thumb. See radial nerve injuries.

The upper subscapular (short subscapular) enters the upper part of the Subscapularis, and is frequently represented by two branches. ... The Subscapularis muscle is a muscle of the human body. ... The rotator cuff (rotor cuff) is an anatomical term given to the group of muscles and their tendons that act to stabilize the shoulder. ... The lower subscapular supplies the lower part of the Subscapularis, and ends in the Teres major; the latter muscle is sometimes supplied by a separate branch. ... Teres major is a muscle of the upper limb and one of six scapulohumeral muscles. ... The Posterior cord is a division of the brachial plexus. ... Latissimus dorsi is a large flat muscle located on the back. ... The axillary nerve is a nerve of the human body, that comes off the posterior cord of the brachial plexus at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. ... Deltoid can refer to: The deltoid muscle, a muscle in the shoulder A deltoid curve, a three-sided hypocycloid A type of quadrilateral A leaf shape The deltoid tuberosity, a part of the humerus Delta, an article with related definitions. ... The teres minor muscle is a muscle in the rotator cuff. ... The radial nerve is a nerve in the human body, that supplies the arm, the forearm and the hand. ... Triceps brachii The triceps brachii muscle is a large three-headed skeletal muscle found in humans. ... Brachioradialis is a muscle located in the forearm, that acts to flex the forearm. ... Extensor carpi radialis can refer to: Extensor carpi radialis brevis muscle Extensor carpi radialis longus muscle Category: Disambiguation ...

Medial cord

The medial cord gives rise to the following nerves:

• The median pectoral nerve, C8 and T1, to the pectoralis muscle
• The medial brachial cutaneous nerve, T1
• The medial antebrachial cutaneous nerve, C8 and T1
• The median nerve, partly. The other part comes from the lateral cord. C7, C8 and T1 nerve roots. The first branch of the median nerve is to the pronator teres muscle, then the flexor carpi radialis, the palmaris longus and the flexor digitorum superficialis. The median nerve provides sensation to the anterior palm, the anterior thumb, index finger and middle finger. It is the nerve compressed in carpal tunnel syndrome.
• The ulnar nerve originates in nerve roots C7, C8 and T1. It provides sensation to the ring and pinky fingers. It innervates the flexor carpi ulnaris muscle, the flexor digitorum profundus muscle to the ring and pinky fingers, and the intrinsic muscles of the hand (the interosseous muscle, the lumbrical muscles and the flexor pollicus brevis muscle). This nerve traverses a groove on the elbow called the cubital tunnel, also known as the funny bone. Striking the nerve at this point produces an unpleasant sensation in the ring and little finger.

The Anterior Thoracic Nerves supply the Pectorales major and minor. ... The Medial Brachial Cutaneous Nerve (lesser internal cutaneous nerve; nerve of Wrisberg) is distributed to the skin on the ulnar side of the arm. ... The Medial Antibrachial Cutaneous Nerve (internal cutaneous nerve, also sometimes spelled antebrachial) arises from the medial cord of the brachial plexus. ... The median nerve is a nerve that runs down the arm and forearm. ... The Pronator teres muscle is a muscle of the human body, in the forearm. ... In anatomy, flexor carpi radialis is a muscle of the human forearm that acts to flex and abduct the hand. ... OriginMedial epicondyle of humerus InsertionDistal half of the flexor retinaculum and palmar aponeurosis Innervation Median nerve(C7 and C8) Action Flexes hand(at wrist)and tightens palmar aponeurosis. ... Flexor digitorum superficialis is an extrinsic flexor muscle of the fingers. ... For other uses, see Thumb (disambiguation). ... The second digit of a human hand is also referred to as the index finger, pointer finger, forefinger, trigger finger, digitus secundus, or digitus II. It is located between the first and third digits - that is, between the thumb and the middle finger. ... This article is about the vulgar gesture. ... This article is about the medical condition. ... In human anatomy, the ulnar nerve is a nerve which runs from the shoulder to the hand, at one part running near the ulna bone. ... In anatomy, flexor carpi ulnaris muscle is a muscle of the human forearm that acts to flex and adduct the hand. ... The flexor digitorum profundis is a muscle in the forearm that flexes the fingers. ... Interosseous muscle can refer to: Palmar interossei muscles Dorsal interossei muscles Plantar interossei muscles This is a disambiguation page, a list of pages that otherwise might share the same title. ... The lumbrical muscles are intrinsic muscles in the fingers that allow flexion at the metacarpophalangeal joints, while maintaining extension at the interphalangeal joints. ... The Flexor pollicis brevis muscle is a muscle of the human body. ... alex is cool ...

Neurotransmitters

The main neurotransmitters of the peripheral nervous system are acetylcholine and noradrenaline. However, there are several other neurotransmitters as well, jointly labeled Non-noradrenergic, non-cholinergic (NANC) transmitters. Examples of such transmitters include non-peptides: ATP, GABA, dopamine, NO, and peptides: neuropeptide Y, VIP, GnRH, Substance P and CGRP. ^[2] Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a presynaptic and a postsynaptic neuron. ... The chemical compound acetylcholine, often abbreviated as ACh, was the first neurotransmitter to be identified. ... Norepinephrine, known as noradrenaline outside the USA, is a catecholamine and a phenethylamine with chemical formula C8H11NO3. ... Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... Chemical structure of GABA Gamma-aminobutyric acid (GABA) is a neurotransmitter in widely divergent species. ... For other uses, see Dopamine (disambiguation). ... R-phrases , , , , S-phrases , , , Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Nitric oxide or Nitrogen monoxide is a chemical compound with chemical formula NO. This gas is an important signaling molecule in the body of... Neuropeptide Y (NPY) is a 36 amino acid peptide neurotransmitter found in the brain and autonomic nervous system. ... VIP is a peptide hormone containing 28 amino acid residues. ... Gonadotropin Releasing Hormone (GnRH) is a peptide hormone responsible for the release of FSH and LH from the anterior pituitary. ... In neuroscience, Substance P is a neuropeptide: a short-chain polypeptide that functions as a neurotransmitter and as a neuromodulator. ...

References

1. ^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall, 132-144. ISBN 0-13-981176-1. 
2. ^ Pharmacology, (Rang, Dale, Ritter & Moore, ISBN 0443071454, 5:th ed., Churchill Livingstone 2003). Page 132.

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