F.+Peripheral+Nervous+System

Peripheral Nervous System

__ Application __
==== Meagan- When discussing the peripheral nervous system, PNS, it is important for me as an OTA to understand how it communicates with the CNS. It is important to understand how the cranial nerves and the spinal nerves interact with each other. As an OTA, I will need to know how sensory and motor information is carried throughout the body. If there is a problem with the information being received to the brain, then I know there is a problem in the dorsal root. If there is a problem with information being received by a muscle after being sent to the brain, then there may be a problem in the ventral root. Or there could be a problem with the reflex arc. As an OTA, I will need to know be able to create activities that can help re-create the pathways to and from the brain. ==== ===Kalli- While the central nervous system is one of the most important systems in the body, the peripheral nervous system (PNS) is almost just as important when it comes to being an OTA. I will not always work with patients who have suffered a traumatic brain injury or a stroke, but may sometimes help someone regain their everyday functions which were lost due to a degenerative, congenital, or recently onset disease. The brain and spinal cord communicate with the PNS more often than you see any one person texting (which is alot!) thus would have to mean the communication is important. Without any communication with the PNS, the body would more or less shut down completely. While working as an OTA, I will have to help the patient regain their functions by improving the ability for CNS communication with the PNS.=== ==Christine- As nurses we come across a lot of the drugs that interact or inhibit the peripheral nervous system. We see a lot of beta blockers and epinephrine used in our setting. When I interned last week I had a patient who had asthma and she was prescribed beta blockers to stimulate the beta adrenergic receptors in the airways of the lungs. This allowed my patient to breath deeper and easier. Epinephrine is also used for patients that have hypertension but is also seen in very serious cases such as anaphylactic shock and cardiac arrest. ==

media type="youtube" key="S9C3RWT77Ow" height="315" width="560"
@http://www.youtube.com/watch?v=S9C3RWT77Ow == The knee jerk reflex is a monosynaptic muscle stretch reflex. This basically means that __**one**__ synapse is crossed in the central nervous system during the reflex. During the knee jerk reflex the muscle stimulates the muscle spindles which starts an action potential in the sensory neuron. The sensory neuron then synapses with a particular somatic motor neuron called the alpha motoneuron. This alpha motoneuron then stimulates the muscle to contract and the knee to jerk! == (information found in Fundamentals of Human Physiology pgs137-138)

The Peripheral Nervous System is broken down in to two different nervous systems: The Somatic and Autonomic Nervous System.

 1. __//**Somatic Nervous System**//__
 * stimulate skeletal muscles
 * is a voluntary control
 * only 1 neuron in the efferent pathway from the CNS to the skeletal muscles

 2. __//**Autonomic Nervous System**//__
 * stimulate cardiac muscle, glands, and smooth muscle
 * a involuntary control
 * 2 autonomic neurons in the efferent pathway from the CNS to the involuntary effector cells

The Autonomic Nervous System can be broken down farther into the Sympathetic and Parasympathetic Nervous System which have different effects on the Autonomic Nervous System

__//**1. Sympathetic Nervous System **//__
 * ////heart rate: increased// //
 * Blood Pressure: increased
 * Lungs: dilate the bronchioles
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Pupils: dilate
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Sweat Glands: sweating
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Urinary Bladder: increase sphincter tone so accidents do not occur

__//**<span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">2. Parasympathetic Nervous System **//__ (Fundamentals of Physiology)
 * //<span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">heart rate: decreased //
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Blood Pressure: slightly decreased
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Lungs: conscription of bronchioles
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Pupils: constrict
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Sweat Glands: no effect
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif; font-size: 110%;">Urinary Bladder: decrease sphincter tone for voiding

media type="youtube" key="J968Wco1u0s" height="315" width="420" @http://www.youtube.com/watch?v=J968Wco1u0s

__ Essential Question/ Case Study __
__** 1. Compare and contrast the sympathetic and parasympathetic effects of the peripheral nervous system on physiological functions. **__
 * __Compare-__**
 * Both the sympathetic and parasympathetic have their control centers, which control what is affected and how, in the central nervous system
 * Both the sympathetic and parasympathetic have preganglion and postganglion autonomic neurons in them
 * Both make up a part of the autonomic nervous system

__Sympathetic__
 * __Contrast-__**
 * Increases Heart Rate
 * Dilates Pupils
 * Also known as Thoracolumbar Division
 * Fight or Flight

__Parasympathetic__ > Constricts Pupils
 * Decreases Heart Rate
 * Also known as Craniosacral Division
 * Rest and Digest

__** 2. Do some research....research how five different drugs affect the peripheral nervous system. **__ A. __beta blockers__ 1. block epinephrine and norepinephrine from binding with beta receptors to nerves 2. there are 3 different beta receptors however beta blockers only work for the first two beta receptors 3. beta blockers reduce heart rate, reduce blood pressure, dilate blood vessels, and may constrict air passage 4. used for heart failure, abnormal heart beat, hypertension, tremors, and angina http://www.medicinenet.com/beta_blockers/article.htmA

B. __Atracurium__ 1. the active ingredient atracurium besilate, with the peripheral nervous system by displacing acetylcholine from it receptor sites 2. used as a muscle relaxant along with general anaesthesia to intubate patients and to help with ventilation http://www.drugs.com/uk/atracurium-10mg-ml-solution-for-injection-infusion-spc-10436.html

C. __Nicotine__ 1. mimics acetylcholine in the body 2. chemical structure of nicotine and acetylcholine are very similar 3. activates the cholinergic receptors that are present in your muscles, heart, adrenal glands, brain and other body structures 4. Nicotine can effect respiration, the heart, memory alertness and muscle movement http://clubtnt.org/brain_matters_web/nicotine.htm

D. __Epinephrine__ 1. released during the "fight and flight" response 2. increases heart rate, constricts blood vessels, and increases respirations 3. used when a person goes into cardiac arrest or has a severe allergic reaction @http://en.wikipedia.org/wiki/Epinephrine

E, __Atropine__ 1. opposes the the actions of the vagus nerve and blocks acetylcholine receptors 2. can be used to dilate pupils 3. it can help with the treatment of a low pulse and to treat 2nd & 3rd degree heart blocks 4. antidote for nerve gas poisoning http://en.wikipedia.org/wiki/Atropine