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Nerves Upper Body

R Spinal Cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone where it passes through the foramen magnum, and meets and enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae where it ends. The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, and from the afferent fibers of the sensory neurons to the sensory cortex. It is also a center for coordinating many reflexes and contains reflex arcs that can independently control reflexes and central pattern generators.

 

R Cervical Spinal Nerve C2

C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. These nerves also play key roles in breathing. The C2 dermatome handles sensation for the upper part of the head.    Source

 

R Cervical Spinal Nerve C1

C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. (C1 does not have a dermatome.)     Source

 

R Cervical Spinal Nerve C3

\C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. the C3 dermatome covers the side of the face and behind the head.      Source

 

R Cervical Spinal Nerve C4

C4 helps control the shoulders as well as the diaphragm—the sheet of muscle that stretches to the bottom of the rib cage for breathing. The C4 dermatome covers the neck and top of the shoulders.      Source

 

R Cervical Spinal Nerve C5

C5 controls upper body muscles like the deltoids (which form the rounded contours of the shoulders) and the biceps (which allow flexion of the elbow and rotation of the forearm). The C5 dermatome covers the shoulders and outer part of the arm down to about the elbow or close to the wrist.      Source

 

R Cervical Spinal Nerve C6

C6 controls the wrist extensors (muscles like the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris that control wrist extension and hyperextension) and also provides some innervation to the biceps. The C6 dermatome covers the top of the shoulders and runs down the side of the arm and into the thumb side of the hand.       Source

 

R Cervical Spinal Nerve C7

C7 controls the triceps (the large muscle on the back of the arm that allows for straightening of the elbow). The C7 dermatome goes from the shoulder down the back of the arm and into the middle finger.       Source

 

R Cervical Spinal Nerve C8

C8 controls the hands. The C8 dermatome covers the lower part of the shoulder and goes down the arm into the pinky side of the hand.       Source

 

R intercostal Nerve 1

Any of 11 nerves on each side of which each is an anterior division of a thoracic nerve lying between a pair of adjacent ribs. Its the ventral rami of the thoracic nerves from segments t1 through t11. The intercostal nerves supply motor and sensory innervation to the thorax and abdomen. The skin and muscles supplied by a given pair are called, respectively, a dermatome and a myotome.       Source

 

R Sympathetic Nerves

The sympathetic nervous system (SNS) is a part of the autonomic nervous system, an extensive network of neurons that regulate the body’s involuntary processes. The autonomic nervous system mediates actions that occur without voluntary control such as heart rate or blood pressure. It consists of both the sympathetic and parasympathetic nervous systems, and they often act in a complementary manner. known for its stimulation of the body’s fight-or-flight response. Specifically, when the entire SNS is activated, there is a cascade of reactions from all the organ systems of the body, which prepare the individual to deal with an emergency. This includes an increase in heart rate, bronchial dilation, increase in cardiac output, and dilation of pupils, all of which are directed towards heightened awareness and preparation to combat danger. The SNS consists of two sets of neurons – those that have their cell bodies within the spinal cord, and those whose soma resides in ganglia outside the central nervous system. The first set, called presynaptic neurons, has its cell bodies within the thoracic and lumbar sections of the spinal cord, and release a neurotransmitter called acetylcholine at synapses within ganglia. Acetylcholine is taken up by receptors on postsynaptic neurons. The activation of postsynaptic neurons leads to the transmission of an electrochemical impulse along the length of their axons, till there is a release of noradrenalin at the synapses with peripheral tissues. Among the many targets for presynaptic neurons, is the adrenal medulla. Prolonged systemic activation of the SNS leads to the release of adrenaline and noradrenaline from the adrenal medulla. The Sympathetic Nervous System is also known for regulating the body temperature, both by mobilizing fat reserves to enhance heat production and by changing blood flow to the skin. The SNS can also stimulate sweat glands to cool the body down. It can initiate a long-term response to prolonged cold periods by controlling some cells of adipose tissues and stimulating the release of fatty acids from them. At the same time, heat is lost from peripheral extremities through sweat, even when the body is at rest. Additionally, the sympathetic nervous system regulates minute changes to the cardiovascular system. When there is a change in posture, from sitting to standing, for example, cardiac output needs to change to accommodate this alteration. In people suffering from disorders of the SNS, one of the first signs of an ailment is postural dizziness. Similarly, during intense exercise, the body needs to focus on delivering nutrients and oxygen to skeletal muscle and quickly removing the metabolic waste generated in the tissue. This is also mediated by the sympathetic nervous system.      Source 

 

R Phrenic Nerve

The phrenic nerve is a bilateral, mixed nerve that originates in the neck and descends through the thorax to reach the diaphragm. As the only source of motor innervation to the diaphragm, this nerve has an important role in breathing. The phrenic nerve mainly originates from the C4 spinal root, but it also receives contributions from C3 and C5. It also receives some communicating fibres from the cervical plexus.     Source

 

R Recurrent Laryngeal Nerve

This is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and left, in the human body. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery then traveling upwards. They both travel alongside of the trachea. Additionally, the nerves are one of few nerves that follow a recurrent course, moving in the opposite direction to the nerve they branch from, a fact from which they gain their name. The recurrent laryngeal nerves supply sensation to the larynx below the vocal cords, gives cardiac branches to the deep cardiac plexus, and branches to the trachea, esophagus and the inferior constrictor muscles. The posterior cricoarytenoid muscles, the only muscles that can open the vocal cords, are innervated by this nerve. Inconclusion, the recurrent laryngeal nerves control all intrinsic muscles of the larynx except for the cricothyroid muscle. These muscles act to open, close, and adjust the tension of the vocal cords, and include the posterior cricoarytenoid muscles, the only muscle to open the vocal cords. The nerves supply muscles on the same side of the body, with the exception of the interarytenoid muscle, which is innervated from both sides. The nerves also carry sensory information from the mucous membranes of the larynx below the lower surface of the vocal fold, as well as sensory, secretory and motor fibers to the cervical segments of the esophagus and the trachea. 

 

R Intercostal Nerve 2

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The second intercostal nerve: Its lateral cutaneous branch is named intercostobrachial nerve. It lessons around the axilla and joins the medial cutaneous branch of the arm. The intercostobrachial nerve supplies the skin of the floor of the axilla and upper part of the medial side of the arm. In coronary arterial disease, the cardiac pain is attributed along this nerve to the medial side of the arm. The lateral cutaneous branch of the second intercostal nerve does not divide, like the others, into an anterior and a posterior branch, it is named the intercostobrachial nerve. It pierces the Intercostalis externus and the Serratus anterior, crosses the axilla to the medial side of the arm, and joins with a filament from the medial brachial cutaneous nerve. It then pierces the fascia, and supplies the skin of the upper half of the medial and posterior part of the arm, communicating with the posterior brachial cutaneous branch of the radial nerve. It is often the source of referred cardiac pain. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. first two intercostal nerves (T1 and T2) in addition to supplying the thorax also give branches to the brachial plexus.     Source

 

R Intercostal Nerve 3

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.     Source 

 

R Intercostal Nerve 4

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The fourth intercostal nerve is enervated by cutaneous slowly-adapting and rapidly-adapting mechanoreceptors, especially by ones densly-packed under the areola, enervation subsequently triggers oxytocin release, which, when in the peripheral bloodstream, causes myoepithelial cell contraction and lactation: this is an example of a non-nerve-innervation muscular reflex. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.       Source

 

R Intercostal Nerve 5

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.        Source

 

R Intercostal Nerve 6

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.        Source

 

R Intercostal Nerve 7

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. Seventh to eleventh intercostal nerves: These nerves leave the corresponding intercostal spaces to goes into the abdominal wall, for this reason they’re termed thoraco abdominal nerves. These nerves supply intercostal muscles of the corresponding intercostal spaces. T7 – T11 also supply the muscles of the anterior abdominal wall (e.g. the obliques, rectus abdominis). The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum        Source

 

R Intercostal Nerve 8

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.       Source

 

R Intercostal Nerve 9

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. T7 – T9 nerves run all the way around to the anterior aspect of the thorax. They then dive deep to the costal cartilages of the ribs and travel inferiorly, to the abdominal wall. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) also supply the abdomen and peritoneum.       Source

 

R Intercostal Nerve 10

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. T10 – T11 nerves enter the anterior abdominal wall directly because they are floating ribs and have no costal cartilage. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.       Source

 

R Intercostal Nerve 11

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. Seventh to eleventh intercostal nerves: These nerves leave the corresponding intercostal spaces to goes into the abdominal wall, for this reason they’re termed thoraco abdominal nerves. These nerves supply intercostal muscles of the corresponding intercostal spaces. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.       Source

 

R Intercostal Nerve 12

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura.  T12, also called the subcostal nerve, runs along the inferior border of the twelfth rib and then directly enters the anterior abdominal wall to supply the muscles there. It communicates with the iliohypogastric nerve of the lumbar plexus, and gives a branch to the Pyramidalis. It also gives off a lateral cutaneous branch that supplies sensory innervation to the skin over the hip.     Source  

 

L Cervical Spinal Nerve C1

C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. These nerves also play key roles in breathing. The C2 dermatome handles sensation for the upper part of the head, and the C3 dermatome covers the side of the face and behind the head. (C1 does not have a dermatome.)      Source

 

L Cervical Spinal Nerve C2

C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. These nerves also play key roles in breathing. The C2 dermatome handles sensation for the upper part of the head, and the C3 dermatome covers the side of the face and behind the head. (C1 does not have a dermatome.)      Source

 

L Cervical Spinal Nerve C3

C1, C2, and C3 (the first three cervical nerves) control the head and neck, including movements forward, backward, and to the sides. These nerves also play key roles in breathing. The C2 dermatome handles sensation for the upper part of the head, and the C3 dermatome covers the side of the face and behind the head. (C1 does not have a dermatome.)      Source

 

L Cervical Spinal Nerve C4

C4 helps control the shoulders as well as the diaphragm—the sheet of muscle that stretches to the bottom of the rib cage—for breathing. The C4 dermatome covers the neck and top of the shoulders.        Source

 

L Cervical Spinal Nerve C5

C5 controls upper body muscles like the deltoids (which form the rounded contours of the shoulders) and the biceps (which allow flexion of the elbow and rotation of the forearm). The C5 dermatome covers the shoulders and outer part of the arm down to about the elbow or close to the wrist.      Source

 

L Cervical Spinal Nerve C6

C6 controls the wrist extensors (muscles like the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris that control wrist extension and hyperextension) and also provides some innervation to the biceps. The C6 dermatome covers the top of the shoulders and runs down the side of the arm and into the thumb side of the hand.        Source

 

L Cervical Spinal Nerve C7

C7 controls the triceps (the large muscle on the back of the arm that allows for straightening of the elbow). The C7 dermatome goes from the shoulder down the back of the arm and into the middle finger.     Source

 

L Cervical Spinal Nerve C8

8 controls the hands. The C8 dermatome covers the lower part of the shoulder and goes down the arm into the pinky side of the hand.      Source

 

L Intercostal Nerve 1

T1 also gives off a branch to the brachial plexus. This is a bundle of nerves at the root of the neck that provides almost all of the nerve supply to the upper limb. The anterior division of the first thoracic nerve divides into two branches: one, the larger, leaves the thorax in front of the neck of the first rib, and enters the brachial plexus (the other and smaller branch), the first intercostal nerve, runs along the first intercostal space, and ends on the front of the chest as the first anterior cutaneous branch of the thorax. first two intercostal nerves (T1 and T2) in addition to supplying the thorax also give branches to the brachial plexus.     Source

 

L Sympathetic Nerves

The sympathetic nervous system (SNS) is a part of the autonomic nervous system, an extensive network of neurons that regulate the body’s involuntary processes. The autonomic nervous system mediates actions that occur without voluntary control such as heart rate or blood pressure. It consists of both the sympathetic and parasympathetic nervous systems, and they often act in a complementary manner. known for its stimulation of the body’s fight-or-flight response. Specifically, when the entire SNS is activated, there is a cascade of reactions from all the organ systems of the body, which prepare the individual to deal with an emergency. This includes an increase in heart rate, bronchial dilation, increase in cardiac output, and dilation of pupils, all of which are directed towards heightened awareness and preparation to combat danger. The SNS consists of two sets of neurons – those that have their cell bodies within the spinal cord, and those whose soma resides in ganglia outside the central nervous system. The first set, called presynaptic neurons, has its cell bodies within the thoracic and lumbar sections of the spinal cord, and release a neurotransmitter called acetylcholine at synapses within ganglia. Acetylcholine is taken up by receptors on postsynaptic neurons. The activation of postsynaptic neurons leads to the transmission of an electrochemical impulse along the length of their axons, till there is a release of noradrenalin at the synapses with peripheral tissues. Among the many targets for presynaptic neurons, is the adrenal medulla. Prolonged systemic activation of the SNS leads to the release of adrenaline and noradrenaline from the adrenal medulla. The Sympathetic Nervous System is also known for regulating the body temperature, both by mobilizing fat reserves to enhance heat production and by changing blood flow to the skin. The SNS can also stimulate sweat glands to cool the body down. It can initiate a long-term response to prolonged cold periods by controlling some cells of adipose tissues and stimulating the release of fatty acids from them. At the same time, heat is lost from peripheral extremities through sweat, even when the body is at rest. Additionally, the sympathetic nervous system regulates minute changes to the cardiovascular system. When there is a change in posture, from sitting to standing, for example, cardiac output needs to change to accommodate this alteration. In people suffering from disorders of the SNS, one of the first signs of an ailment is postural dizziness. Similarly, during intense exercise, the body needs to focus on delivering nutrients and oxygen to skeletal muscle and quickly removing the metabolic waste generated in the tissue. This is also mediated by the sympathetic nervous system.      Source

 

L Phrenic Nerve

The phrenic nerve is a bilateral, mixed nerve that originates in the neck and descends through the thorax to reach the diaphragm. As the only source of motor innervation to the diaphragm, this nerve has an important role in breathing. The phrenic nerve mainly originates from the C4 spinal root, but it also receives contributions from C3 and C5. It also receives some communicating fibres from the cervical plexus.      Source

 

L Recurrent Laryngeal Nerve

R Recurrent Laryngeal Nerve: is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and left, in the human body. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery then traveling upwards. They both travel alongside of the trachea. Additionally, the nerves are one of few nerves that follow a recurrent course, moving in the opposite direction to the nerve they branch from, a fact from which they gain their name. The recurrent laryngeal nerves supply sensation to the larynx below the vocal cords, gives cardiac branches to the deep cardiac plexus, and branches to the trachea, esophagus and the inferior constrictor muscles. The posterior cricoarytenoid muscles, the only muscles that can open the vocal cords, are innervated by this nerve. Inconclusion, the recurrent laryngeal nerves control all intrinsic muscles of the larynx except for the cricothyroid muscle. These muscles act to open, close, and adjust the tension of the vocal cords, and include the posterior cricoarytenoid muscles, the only muscle to open the vocal cords. The nerves supply muscles on the same side of the body, with the exception of the interarytenoid muscle, which is innervated from both sides. The nerves also carry sensory information from the mucous membranes of the larynx below the lower surface of the vocal fold, as well as sensory, secretory and motor fibers to the cervical segments of the esophagus and the trachea.

 

L Intercostal Nerve 2

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The second intercostal nerve: Its lateral cutaneous branch is named intercostobrachial nerve. It lessons around the axilla and joins the medial cutaneous branch of the arm. The intercostobrachial nerve supplies the skin of the floor of the axilla and upper part of the medial side of the arm. In coronary arterial disease, the cardiac pain is attributed along this nerve to the medial side of the arm. The lateral cutaneous branch of the second intercostal nerve does not divide, like the others, into an anterior and a posterior branch, it is named the intercostobrachial nerve. It pierces the Intercostalis externus and the Serratus anterior, crosses the axilla to the medial side of the arm, and joins with a filament from the medial brachial cutaneous nerve. It then pierces the fascia, and supplies the skin of the upper half of the medial and posterior part of the arm, communicating with the posterior brachial cutaneous branch of the radial nerve. It is often the source of referred cardiac pain. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. first two intercostal nerves (T1 and T2) in addition to supplying the thorax also give branches to the brachial plexus.      Source 

 

L Intercostal Nerve 3

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.      Source

 

L Intercostal Nerve 4

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The fourth intercostal nerve is enervated by cutaneous slowly-adapting and rapidly-adapting mechanoreceptors, especially by ones densly-packed under the areola, enervation subsequently triggers oxytocin release, which, when in the peripheral bloodstream, causes myoepithelial cell contraction and lactation: this is an example of a non-nerve-innervation muscular reflex. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.      Source

 

L Intercostal Nerve 5

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.      Source

 

L Intercostal Nerve 6

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the second, third, fourth, fifth, and sixth thoracic nerves, and the small branch from the first thoracic, are confined to the walls of the thorax, and are named thoracic intercostal nerves. The intercostal nerves (T3-T6) supply only the thoracic wall.      Source  

 

L Intercostal Nerve 7

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. Seventh to eleventh intercostal nerves: These nerves leave the corresponding intercostal spaces to goes into the abdominal wall, for this reason they’re termed thoraco abdominal nerves. These nerves supply intercostal muscles of the corresponding intercostal spaces. T7 – T11 also supply the muscles of the anterior abdominal wall (e.g. the obliques, rectus abdominis). The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.      Source 

 

L Intercostal Nerve 8

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscle.  All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.    Source

 

L Intercostal Nerve 9

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. T7 – T9 nerves run all the way around to the anterior aspect of the thorax. They then dive deep to the costal cartilages of the ribs and travel inferiorly, to the abdominal wall. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) also supply the abdomen and peritoneum.      Source 

 

L Intercostal Nerve 10

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. T10 – T11 nerves enter the anterior abdominal wall directly because they are floating ribs and have no costal cartilage. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.       Source

 

L Intercostal Nerve 11

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura. Seventh to eleventh intercostal nerves: These nerves leave the corresponding intercostal spaces to goes into the abdominal wall, for this reason they’re termed thoraco abdominal nerves. These nerves supply intercostal muscles of the corresponding intercostal spaces. The anterior divisions of the seventh, eighth, ninth, tenth, and eleventh thoracic intercostal nerves are continued anteriorly from the intercostal spaces into the abdominal wall, hence they are named thoraco-abdominal nerves. The lowest five intercostal nerves (T7-T11) supply the abdomen and peritoneum.       Source 

 

L Intercostal Nerve 12

The intercostal muscles are a grouping of solidified muscles situated between the ribs. These muscles as well help in a cause to expand and shrink the dimensions of the chest cavity to facilitate breathing. The intercostal nerves are technically T1 – T11. T12 is not ‘intercostal’ because it lies below the twelfth rib only. The intercostal nerves have a variety of functions – they do more than just provide motor innervation to the intercostal muscles… All intercostal nerves give off cutaneous branches to provide sensory innervation to the skin, branches to provide motor innervation to the intercostal muscles and branches to the costal pleura.  T12, also called the subcostal nerve, runs along the inferior border of the twelfth rib and then directly enters the anterior abdominal wall to supply the muscles there. It communicates with the iliohypogastric nerve of the lumbar plexus, and gives a branch to the Pyramidalis. It also gives off a lateral cutaneous branch that supplies sensory innervation to the skin over the hip.       Source