Peripheral Nervous System

Somatic

Consists of the cranial and spinal nerve fibers that connect the CNS to the skin and skeletal muscles, so it oversees conscious activities.

Abducens (VI)

Controls the extrinsic eye muscle that abducts (turns laterally) the eye. (Lateral Rectus Muscle) Motor Function

What are the muscles of the Musculocutaneous Nerve?

Coroco Brachialis, Biceps Brachii, Braciallis (2).

What are the muscles of the Axillary Nerve?

Deltoid Teres Minor

A Nerve cell body is composed of...

Dendrites and an Axon.

What forms a spinal nerve?

Dorsal and Ventral roots of the spinal cord.

What does a nerve cell body do?

It receives all this information and sends it down an axon.

Trigeminal Nerves (V)

Largest Cranial Nerves. They arise from the pons. Each sensory component includes 3 large branch divisions. All Three are Sensory and has Motor

What eye muscle(s) are innervated by CN VI?

Lateral Rectus Muscle

Optic Nerves (II)

Lead from the eyes to the brain, and are associated with vision. Sensory Function

What is the difference between Dorsal and Ventral roots and ramus?

The roots form a spinal nerve, the ramus are branches of the roots.

Ganglia

The sensory fibers in the cranial nerves that attach to the neuron cell bodies that are located outside the brain. They are arranges in bundles called ganglia (Ganglion). Neuron Cell Bodies Outside brain.

Parasympathetic Spinal Cord Distribution

CN III, VII, IX, X. Ventral Rami of S2,3,4.

What forms the Radial Nerve?

The Ventral Rami from C5 to T1

What are the 4 branches of the Spinal Nerve?

1. Recurrent Meningeal 2. Visceral (White and Grey Rami Communicate). 3. Dorsal Ramus 4. Ventral Ramus T1 to L2 there are 5 Branches.

Cranial Nerves

12 Pairs. They arrise from the underside of the brain. Most are mixed nerves.

Spinal Nerves

31 Pairs of Nerves Mixed nerves; provide two way communication between the spinal cord and parts of the upper and lower limbs, neck, and trunk.

Spinal Nerve Groups

8 Pairs in Cervical (C1 to C8) C7 has two. 12 pairs of Thoracic (T1 to T12 5 Pairs of Lumbar (L1 to L5) 5 Pairs of Sacral (S1 to S5) 1 Pair of tiny coccygeal (C0)

Filum Terminale

A central structure that is a continuation of the pema mater from the surface of the brain and the spinal cord and attached in the sacral region. Keeps the spinal cord tight so it does not move very much.

Accessory Nerve (XI)

And Spinal Nerves C2,3,4. Originate in the medulla oblongata and the spinal cord; thus, they have both cranial and spinal branches. They are considered accessory to the vagus nerve. Cranial Branch - Joins vagus and carries impulses to muscles of the soft palate, pharynx, and larynx. Spinal Branch Motor functions to Trapezius and Sternocleidmastoid muscles. Motor Function

Facial Nerve (VII)

Arise from the lower part of the pons and emerge on the sides of the face. For Facial Expression. Sensory - sense of taste on 2/3 of the tongue and impulses of facial expression. Motor - Autonomic motor function through tear glands and salivary glands.

Oculomotor Nerves (III)

Arise from the midbrain and pass into the orbits of the eyes. Moves the eyes in their orbits. Motor Function

Compare Spinal Cord Exiting at Birth and as and Adult.

As we age, the column grows faster then the cord. Thus, the spinal cord ends around the inferior border of L2.

Olfactory Nerves (I)

Associated with the sense of smell and contain only sensory.

White Matter of Brain

Axons that have been myelinated.

What composes the Cervical plexus?

C1 to C4 (C5) - Forms the phrenic Nerve. Keep

Phrenic Nerve

C3 to C5 - Keep the diaphragm alive!

What composes the Brachial Plexus?

C5 to T1

Cranial Nerve Origination

Except for the first pair, which begins in the cerebrum, these nerves originate from the brain stem. They pass from their sites of origin through foramina of the skull and lead to areas of the head, neck, and trunk.

Under Parasympathetic affect, do your pupils dilate or constrict?

Eyes Constricted which is called Miosis. So drug dilate your eyes.

What are the muscles of the Ulnar Nerve?

Flexor Carpi Ulnaris Flexor Digitorum Profundus (2)

Vestibulocochlear Nerves (VIII)

For Hearing and Balance. Sensory Function Vestibular Branch - Maintain Equilibrium Cochlear Branch - Ganglion near the hearing receptors.

What do we call a nerve cell body outside the central nervous system?

Ganglia

What is the Dorsal Ramus of C2 become?

Greater Occipital

Autonomic

Includes fibers that connect the CNS to viscera such as the heart, stomach, intestines, and various organs. Thus, it controls unconscious actions. Also includes Sympathetic (Fight or Flight) and Parasympathetic (Rest digest) divisions.

Labyrinthitis

Inflammation of the VIII nerve. Patients experience varying degrees of "vertigo" or a feeling of falling from high places.

What do the ventral rami form of a spinal nerve from T1 to T12?

Intercostal Nerves

What is the Parasympathetic affect of CN III?

It causes Miosis or constriction of the pupil.

Perineurium

Loose connective tissue sleeve that surrounds fascicles (bundles of fibers)

Endoneurium

Loose connective tissue that surrounds individual nerve fibers.

What makes up the medial and lateral branches of Dorsal Rami of T7 to T12?

Medial - Motor Lateral - Sensory

What makes up the medial and lateral branches of Dorsal Rami of T1 to T6?

Medial - Sensory Lateral - Motor

What branches does the Dorsal Rami of T1 to T12 have?

Medial and Lateral Branches

Gray Matter of Brain

Motor neuron cell bodies or nerve cell bodies. On the Outside

Ventral Root

Motor or Efferent Root - EXITING the CNS Efferent go out the front door. Each spinal nerve consists of axons from the motor neurons whose cell bodies are located within the gray matter of the cord.

What nerves create the Brachial Plexus?

Musculocutaneous Nerve (57) Ulnar Nerve (81) Median Nerve (51) Radial Nerves Axillary Nerves

Hypoglossal nerves (XII)

Name means "Under the Tongue" This nerve runs inferior to the tongue and innervates some tongue-moving muscles. Motor Function - Moves the tongue.

Vagus Nerve (X)

Name means "wonderer" Goes through chest and into abdominal cavity. Somatic - Speech and Swallowing. Autonomic - supplies peristalsis (involuntary contractions) of smooth muscle. Autonomic - Heart Contractions can slow it down.

What is a mass of nerve cells inside the CNS?

Nucleus

Epineurium

Outermost layer of the connective tissue, it is dense and includes many collagen fibers

What muscles that are not located on the face are innervated by the facial nerve?

Platysma Digastric (Posterior Belly) Stylohyoid

What do the ventral rami form of a spinal nerve from L1 to S4?

Plexi Lumbar (14) and Sacral (44)

What do the ventral rami form of a spinal nerve from C1 to T1?

Plexi Both the Cervical (14) and Brachial (51)

What are the muscles of the Medial Nerve?

Pronator Teres Pronator Quadratus Flexor Carpi Radialis Palmaris Longus Flexor Digitorum Superficialis Flexor Digitorum Profundus (2) Flexor Digitorum Longus

What 5 Eye Muscles are innervated by CN III

SMIIL!!! 1. SR - Superior Rectus 2. MR - Medial Rectus 3. IR - Inferior Rectus 4. IO - Inferior Oblique 5. LPS - Levator Palpebrae Superioris

What eye muscle(s) are innervated by CN IV?

SO - Superior Oblique

Dorsal Root

Sensory or Afferent Root - APPROACHING the CNS Afferent tracks always come in the back door. Therefore, sensory come through the back door. Dorsal Root is pregnant or it has a ganglion.

Trochlear Nerves (IV)

Smallest Cranial Nerves. They arrise from the midbrain and carry motor impulses to a pair of external eye muscles. Motor Functions

Median Nerve

Spinal Nerve Roots C5 to T1 (51)

Radial Nerve

Spinal Nerve Roots C5 to T1 (51)

Axillary Nerve

Spinal Nerve Roots C5,6 (56)

Ulnar Nerve

Spinal Nerve Roots C8, T1 (81)

Musculocutaneous Nerve

Spinal nerve roots C5,6,7 (57)

What is the Dorsal Ramus of C1 become?

Suboccipital Nerve

What are the nerves involved with the flight or flight response?

T1 to L2. All Ventral Ramas.

Sympathetic Spinal Cord Distribution

T1 to L2. Ventral Rama of T1 to Ventral Rama of Lumbar L2. Thoracolumbar Distribution

What composes the brachial plexus?

THe brachial plexus is composed of the spinal nerve roots C5 to T1.

Lateral Horns on the Spinal Cord

The sympathetic distribution of the spinal cord. Therefore, we only find the lateral horns from T1 to L2.

What is the Dorsal Ramus of C3 become?

Third (or Lesser) Occipital

Glossopharyngeal Nerve (IX)

Tongue and Pharynx Sensory - Posterior taste of tongue. Motor - Swallowing

What are the three branches of the Trigeminal Nerves?

V1 - Ophthalmic Division (Sensory) V2 - Maxillary Division (Sensory) V3 - Mandibular Division (Sensory and Motor)

Ophthalmic Division

V1 - Sensory Sensory fibers that bring impulses to the brain from the surface of the eye, tear gland, and the skin of the anterior scalp, forehead, and upper eyelid.

Maxillary Division

V2 - Sensory Carry sensory impulses from the upper teeth, upper gum, and the upper lip, as well as from the mucous lining of the palate and facial skin.

Mandibular Division

V3 - Sensory and Motor The sensory branches transmit impulses from the scalp behind the ears, the skin of the jaw, the lower teeth, the lower gum, and the lower lip. The Motor branches supply the muscles of mastication and certain muscles in the floor of the mouth.

What are the C5 to T1 root system form from?

Ventral Rami

What forms the roots of the Plexus?

Ventral Rami. Spinal (Ventral and Dorsal) Roots form a spinal nerve, a spinal nerve has 5 branches, the ventral branch of the spinal nerve forms a plexus, and the plexus has it roots system.

What is the difference between the White and Grey Rami?

White Rami - T1 to L2 of Spinal Cord Grey Rami - Throughout Spinal Cord Create a loop. Exits with the White and enters with the Grey. When it exits, it can synapse with a ganglia (just outside or at another level) Then it re-enters via the grey.

What are the muscles of the Radial Nerve?

brachialis (2) brachioradialis triceps brachii (Long, Lateral, and Medial Heads) anconeus extensor carpi radialis longus extensor carpi radialis brevis extensor carpi ulnaris extensor digitorum communis extensor digiti minimi extensor indicis extensor pollicis longus extensor pollicis brevis abductor pollicis longus