Two types of cells in the peripheral nervous system * SENSORY NERVOUS CELLS *MOTOR NERVOUS CELLS

Nervous System Central Nervous System Peripheral Nervous System

Consists of brain and spinal cord Interprets incoming sensory information and issues instructions Consists of nerves that extend from spinal cord and brain Serve as the communication lines, linking parts of the body by carrying impulses from the sensory receptors to the CNS and to the appropriate glands or muscles Central Nervous System Peripheral Nervous System

Nervous System CNSPNS Efferent (motor division) Afferent (sensory divison)

Divisions of the Peripheral Nervous System.  Sensory Nervous System-Sends information to the cns from internal organs and external stimuli.  Motor Nervous System- Sends information from the CNS to organs, muscles and glands

Nervous System CNSPNS Efferent (Motor) division SomaticAutonomic Afferent (Sensory division)

Types of Nerves in the Peripheral Nervous System Spinal Nerves  31 pairs  Formed by the combination of the ventral and dorsal roots of the spinal cord  Named according to region of cord from which they arise Cranial Nerves  12 pairs  Serve head and neck  Numbered in order  Described by name, number, and major function

Peripheral Nervous System Consists of cranial and spinal nerves  A. Twelve pairs and their branches  Some are responsible for the special senses  (what are the special senses)  Other receive general sensation such as  Touch  Pressure  Pain  Temperature  They also send out impulses for involuntary and voluntary muscle control

Autonomic Nervous System (ANS) Helps maintain a balance in the involuntary functions of the body but allows the body to react in times of an emergency. Two divisions  Sympathetic nervous system  Parasympathetic nervous system Usually the two systems work together to maintain a balanced state or homoeostasis Control involuntary body functions at proper rates

Sympathetic Nervous system Acts in emergencies such as fight or flight Prepares the body to act Raises blood pressure Increases heart rate and respirations Slows the digestive tract.

Parasympathetic Nervous System Counteracts the actions of the sympathetic nervous systems after an emergency Slows the heart rate and respirations Lowers blood pressure Increases activity in the digestive tract. Video

The Somatic Nervous System This is part of the PNS and is responsible for carrying motor and sensory information to and from the CNS. It is responsible for all voluntary muscle movement with one exception. (The reflex arc) It is responsible for processing sensory information.

Deep tendon reflexes An immediate contraction when a tendon is tapped quickly. Involuntary- Reflex arcs Voluntary- Happen without even thinking about it or pain is felt. An example would be touching a hot stove. You would automatically pull your hand away before your brain senses pain.

Techniques It is best to get a patient to relax when testing reflexes. Try changing the position of the patient. Have the patient put slight tension on a muscle not being tested If testing a lower extremity have the patient hook the fingers of each hand so they can pull against each other. Right before you elicit the reflex tell them to pull.

Note features of the reflex: How much hammer force was required to obtain a contraction The strength of the contraction The duration of the contraction The duration of the relaxation phase The response of other muscles (Hyperactive)

Abnormal results Weak or absent response may indicate damage to nerves outside the spinal cord. (peripheral Neuropathy) Damage to motor neurons before or after they leave the spinal cord (motor neuron disease or muscle disease) Excessive response may indicate damage above the level controlling the response. Different responses when compared bilaterally may be related to a disease, localized nerve damage or trauma. A positive Babinski test may indicate brain trauma or a spinal lesion.

Motor Exam: (Myotome) This is where you will be testing movement or motor function. This is usually going to test major muscle groups of the upper and lower extremities. The muscles are tested for mass muscle tone strength

Sensory Exam: (Dermatome) The sensory part of the exam evaluates the sensation what they can feel This includes touch (deep and superficial) pain and temperature sensation

Dermatomes Test for changes in sensation. Can use your finger, reflex hammer, pin wheel. All tests should be done with eyes closed All tests should be compared bilaterally Myotomes Tests for difference is strength and movement All tests should be done bilaterally

Upper extremity dermatomes C1Top of head C2Temporal & occipital regions of head C3Neck and posterior cheek C4Superior shoulder and clavicle C5Deltoid patch & lateral arm C6Lateral forearm, thumb and index finger C7Posterior lateral forearm & middle finger C8Medial forearm, ulna border, ring & little fingers T1Medial side of forearm & upper arm

Lower Extremity Myotome (motor)Reflex L1-L2 tested with resisted hip flexion No reflex L3 tested with resisted knee extensionPatellar reflex L4 tested with resisted foot dorsi flexion Patellar reflex L5 tested with resisted great toe extensionNo reflex S1/S2 tested with plantar flexionAchilles reflex