Lo mila blok 5 up 2

19
INDIVIDUAL ASSIGNMENT BLOCK 5 STUDY UNIT 2 Peripheral Nervous System By: Istianah Maryam Jamilah 2011/315747/KH/7098 Faculty of Veterinary Medicine Gadjah Mada University Yogyakarta

Transcript of Lo mila blok 5 up 2

Page 1: Lo mila blok 5 up 2

INDIVIDUAL ASSIGNMENT

BLOCK 5 STUDY UNIT 2

Peripheral Nervous System

By: Istianah Maryam Jamilah

2011/315747/KH/7098

Faculty of Veterinary Medicine

Gadjah Mada University

Yogyakarta

2012

Page 2: Lo mila blok 5 up 2

I. Learning Objectives1. What are neurotransmitter components (type) and function?2. How is the impulse transmitted trough synapse?3. How the reflex happen?4. Complete definition of PNS and its nerve?

II. Explanation1. Neurotransmitter components and function

Neurotransmitters are substances that are produced by neurons, stored in the synapses and released in to the synaptic reflect in response to a stimulus. At the post synaptic membrane, they bind to special receptors and affect their activity (Koolman and Roehm, 2005). Neurotransmitters are the chemicals which allow the transmission of signals from one neuron to the next across synapses (Boeree, 2009).

(Campbell, 2007)

Page 3: Lo mila blok 5 up 2

EXCITATORY INHIBITORYAcetylcholine (Ach) GABAAspartat Glisin Dopamine DopamineHistamineNorepinephrine Epinephrine Glutamat Serotonine

A. Small molecule neurotransmitter a. Acetylcholine (C7H16O2N/ CH3COOCH2CH2N)

The Acetic acid ester of the cationic alcohol choline acts at neuromuscular junctions, where its triggers muscle contraction and in certain parts of the brain and the autonomous nervous system (Koolman and Roehm, 2005).

Proteinogenic Amino Acid Neurotransmitter

b. GlutamateIt is acts as a stimulatory transmitter in the CNS. More than

half of synapses in the brain are glutaminergic.The amine GABA also synthetized from it.

c. Glycine Glycine is an inhibitory neurotransmitter with effects in the

spinal cord and in parts of the brain (Koolman and Roehm, 2005). A neurotransmitter used mainly by neurons in the spinal cord. It probably always acts as an inhibitory neurotransmitter.

Biogenic aminesArise from amino acid by decarboxylation.

d. 4-aminobutyrate (γ-aminobutyric acid/ GABA)Formed from glutamate and is the most important inhibitory

transmitter in CNS (Koolman and Roehm, 2005). Inhibits excretory neurotransmitters; decreases anxiety and paranoia; maintains proper firing of nerve impulses. GABA acts like a brake to the excitatory neurotransmitters that lead to anxiety.  People with too little GABA

Page 4: Lo mila blok 5 up 2

tend to suffer from anxiety disorders, and drugs like Valium work by enhancing the effects of GABA.  Lots of other drugs influence GABA receptors, including alcohol and barbituates.  If GABA is lacking in certain parts of the brain, epilepsy results (Boeree, 2009).

e. NorephinephrineNorepinephrine is strongly associated with bringing our nervous

systems into "high alert."  It is prevalent in the sympathetic nervous system, and it increases our heart rate and our blood pressure.  Our adrenal glands release it into the blood stream, along with its close relative epinephrine (aka adrenalin).  It is also important for forming memories (Baroore, 2009). Norepinephrine acts as a neurotransmitter and a hormone. In the peripheral nervous system, it is part of the flight-or-flight response. In the brain, it acts as a neurotransmitter regulating normal brain processes. Norepinephrine is usually excitatory, but is inhibitory in a few brain areas.

f. SerotoninSerotonin is an inhibitory neurotransmitter that has been found to

be intimately involved in emotion and mood.  Too little serotonin has been shown to lead to depression, problems with anger control, obsessive-compulsive disorder, and suicide.  Too little also leads to an increased appetite for carbohydrates (starchy foods) and trouble sleeping, which are also associated with depression and other emotional disorders.  It has also been tied to migraines, irritable bowel syndrome, and fibromyalgia ( Baroore, 2009). 

g. DopamineThe neurotransmitter that produces feelings of pleasure when released by the brain reward system. Dopamine has multiple functions depending on where in the brain it acts. It is usually inhibitory.Inhibits prolactine release. Feelings of happiness, pleasure and content; increased social behavior; muscle movement control ( Baroore, 2009).

Function summary

Neurotransmitter Role in the Body

Acetylcholine A neurotransmitter used by the spinal cord neurons to control muscles and by many neurons in the brain to regulate memory. In most instances, acetylcholine is excitatory.

Dopamine The neurotransmitter that produces feelings of pleasure when released by the brain reward system. Dopamine has multiple functions depending on where in the brain it acts. It is usually inhibitory.

Page 5: Lo mila blok 5 up 2

GABA(gamma-aminobutyric acid)

The major inhibitory neurotransmitter in the brain.

Glutamate The most common excitatory neurotransmitter in the brain.

Glycine A neurotransmitter used mainly by neurons in the spinal cord. It probably always acts as an inhibitory neurotransmitter.

Norepinephrine Norepinephrine acts as a neurotransmitter and a hormone. In the peripheral nervous system, it is part of the flight-or-flight response. In the brain, it acts as a neurotransmitter regulating normal brain processes. Norepinephrine is usually excitatory, but is inhibitory in a few brain areas.

Serotonin A neurotransmitter involved in many functions including mood, appetite, and sensory perception. In the spinal cord, serotonin is inhibitory in pain pathways.

NIH Publication No. 00-4871http://outreach.mcb.harvard.edu/teachers/Summer05/RaymondBroadhead/Synapses_and_Drugs.pdf

2. Impuls transmitted trough synapse

(Campbell, 2007)Synapses is a unique junction that controls the communication between

one neuron to another cell. Cells that conduct signals called prasimpatic cells and cells that received the cell called the parasympathetic. Synapses are of two types: electrical synapses and chemical synapses. Electrical synapses allow action potentials propagate directly from cell to cell prasinanptik post-synaptic. These

Page 6: Lo mila blok 5 up 2

cells are loosely connected by junction channels between cells that is the local action potential ion stream to flow between neurons. This allows the impulses travel from one neuron to another neuron without delay and without loss of signal strength. (Campbell, 2007).

Page 7: Lo mila blok 5 up 2

(Campbell, 2007)

Chemical synapses, the synaptic cleft separating the cells post-synaptic prasinaptik of cells, causing the cells can not be matched electrically and action potentials that occur in the cells can not be slowed prasinaptik directly to the post-synaptic cell membrane. Inside the bag there are many chemical synapses (synaptic vesicles) that contain thousands of neurotransmitter molecules, which are substances that were released as a messenger between cells into the synaptic cleft. (Campbell, 2007)

3. How Reflex Happen

Page 8: Lo mila blok 5 up 2

(Campbell, 2007)

Reflex have five primary components:

a. Reflex is start with receptor. Receptor transduce some environment energy into action potrentiol along the sensory nerve. For example:

-Receptor at the retina that transduce light energy.-Skin that transduce heat, cold, pressure, and other cutaneuos stimule. -Muscle spindle receptor that tranduce stretch

In transduction, action potential are genetrated along sensory nerves at a frequency proportional to the intensity with which the receptor is stimulated and and the frequency os the resulting sensory nerve action potoential is called

Page 9: Lo mila blok 5 up 2

frequency codingand its how the receptor comunicates to the CNS the instensity of light, heat, stretch, and so forth its transduced (Cunningham, 2002).

b. Sensory nerve (afferent nerve) that carry action potential from the receptor to the CNS which entered the spinal cord by way of the dorsal roots

c. Synapse in CNS. Actually most reflex arcs, more than one synapse occurs. However, a few reflex arcs, such as those that come from the muscle spindle, are monosynaptic.

d. Motor nerve (efferent nerve), which carries action potential from the CNS to the target (effector) organ. Motor nerve leave the spinal cord depart by way of the ventral root.

e. The targeted organ(effector organ) that causes the reflex response. These usually a muscle, such as skeletal muscle of the quadriceps muscle of the leg, in the case of knee jerk(muuscle stretch) reflex, or the smooth muscle of the iris, in the case of pupillary light reflex (Cunningham, 2002).

Reflex arcs are either segmental or intersegmental

Segmental reflex is a reflex in which the reflex arc through only a small segment of CNS. For example are the muscle stretch reflex and the pappilary light reflex because they are only use a small segment of either the spinla cord or the brain stem. In the intersegmental reflex, multiple segments of the CNS are used. Concious proprioceptions response is a good example of this type. Because of the sensory action potential may enter as far away as the lumbar spinal cord and yet travel all the way to the cerebral cortex before the motor response is generted. The motor response returns along roughly the same intersegmenteal route (Cunningham, 2002).

4. Peripheral Nervous System

Page 10: Lo mila blok 5 up 2

Peripheral nervous system or peripheral nervous system is the nervous system includes the cranial nerves and spinal nervous. Peripheral nervous system (PNS) is divided into two subsystems, namely the motor (efferent) and sensory (afferent). The motor component of the nervous cranial and spinal nervous that the motor neurons and autonomic somatic motor neurons.

a.) Somatic motor neurons (axons of somatic efferent neurons) bring an action potential command and central nervous system to the sympathetic junction in skeletal muscle.

b.) Autonomic motor neurons (axons visceral efferent neurons) bring an action potential, through synaps intermediates, to synaps in smooth muscle, cardiac muscle and exocrine glands.

Peripheral sensory nerves carry messages to the action potential of the central nervous system peripheral receptors. This receptor is responsible for converting environmental energy (light, noise, muscle activity) to the action potential moves toward the central nervous system. Nervous bring an action potential of sensory receptors such as the photoreceptor in the eye, ear or auditory receptors in the stretch receptors in skeletal muscle. Nervous and sensory components of cranial nervous spinal afferent neurons are somatic and visceral afferent neurons.

Page 11: Lo mila blok 5 up 2

a.) Somatic afferent neurons carry action potentials result from stimulation of receptors such as the photoreceptor in the eye, ear or auditory receptors in the stretch receptors in skeletal muscle.

b.) Visceral afferent neurons carry action potential that occurs due to muscle stretch or chemoresptor located in the thorax and abdominal visceral organs to the central nervous system.

Visceral efferent and afferent axons are part of the autonomic nervous system, part of the central nervous system and peripheral nervous system responsible for involuntary control of smooth muscle, cardiac muscle and some endocrine glands.

(Cunningham, 2007)

A.) Cranial Nervous

Cranial Nervous in mammals there are 12 pairs. Cranial nerve roots close to the braincase. Overall 12 pairs of nerves given the name and numbering with Roman numerals ranging from anterior to posterior.

The twelve cranial nerves of the posterior antaerior are as follows:

I. Olfactory Nerve

Is related to the sensory nervous smelling / smells. Tues olfactorius from the olfactory mucous membrane sac. A short axon connecting each cell to the olfactory bulbus. Each axon consists of an olfactory fibers. Overall, the fibers form the olfactory nervous olfactorius short.

II. Optic Nerve

According to Kardong (2012), not a nervous optic nerve but a sensory tract. It is said that because gathered axon optic nerve is not a peripheral, but a collection of fibers in the central nervous system.

Optic tract to the caudal and lateral to the lateral face of Chiasma in the cerebellum. Then across the pars anterior tractus pedenculi cerebri and turned in the dorsal lateral fissure. This tract ends in the posterior pars thalamus. Fibersin the thalamus and midbrain is synaptic.

III. Oculomotorius Nerve

Plays an important role to supply working muscles outside the eye (superior rectus, medial rectus, inferior rectus and inferior oblique). A nervous little motor that also carries visceral motor fibers to the iris and ciliary body of the eye. The fibers emerging from the nucleus occulomotor in the midbrain floor.

IV. Nerve Trochealis

Is the motor that supplies the nervous exterior, superior oblique. The fibers appear in the midbrain trochlear nucleus.

Page 12: Lo mila blok 5 up 2

V. Trigeminal nerve

N.Trigeminus divided into three main branches:

l. N. Ophtalmicus is sensory. Login orbital fossa and gives 3 branches namely N. cornualis, N. Iacrimalis, and N. frontalis. And continue as N. nasociliaris.

2. N. Characteristically sensory Maxilaris. It is the largest branch. Leave the cavum cranii through the foramen ventral pars orbitorotundum, and into the fossa pterygopalatina. Divided into N. Infra-orbital and N. Spheno palatine.

3. N. The mandibular branch of the posterior and ventral N. Trigeminal. Leave the cavum cranii through the foramen ovale of the temporalis allae os sphenoidale. On m. pterigoideus the lateral nerves are divided into several branches, namely: N. Buccinatorius, N. Temporalis Profundus, N. Massetericus, N.Temporalis superficial, N. Pterygoid, N. Lingual, N. Mandibular alveolar.

VI. Abducent nerve

Nervous is nervous to the three who helped the movement of the eyeball. Is the motor nervous that supplies the outside (extrinsic), lateral rectus muscle. The fibers appear in the abducens nucleus is located in the medulla. Innervates m. retractor oculi and m. lateral rectus

VII. The facial nerve

A nervous mix (Sensory and motor), in which there are sensory fibers from taste buds (papillae) and the motor fibers that arch menderivate second (hyoid).

Divided in: N. Buccalis dorsalis, N. Buccalis ventral, chorda tympani, N. Posterior auricular, N. Auricular internus / Profundus, N. Digastricus, N. Auriculopalpebralis

VIII. Nerve octavus / acusticus

Is the sensory nervous that carry sensory fibers from the inner ear, which serves to balance and hearing. Nervous synapse in some regions of the medulla.

IX. Nerve glossopharyhgeus

A mixture of nervous supply to the third branchial arch. Contains sensory fibers from the papilla. Motor fibers to the third branchial arch muscle innervates.

X. Vagus Nerve

A nervous mix. Branched out into the mouth, pharynx and most of the visceral.

XI. Spinal nerve accesorius

Page 13: Lo mila blok 5 up 2

Motoric nerve. Radix and radix spinalis has medullaris. Radix is formed by a fiber cord in the cervical vertebrae are the 5 and 6. And radix medullaris from the medulla oblongata. Nerves leave the cavum cranii through the foramen lacerum posterior. The fibers emerging from several nuclei in the medulla.

(Kardong, 2012)

XII. Hypoglossus nerve

Is the motor nervous, innervates muscle and genio-hyoideus tongue. Root fibers-fibers arise from the ventral medulla facies.(Sisson, 1971)

Dog Cranial Nerve Lateral View

(Kardong, 2012)

2.) Spinal Nervous

Naming of the nervous (nerves) and spinal grounded by separate chain with the number of assosiai vertebrae (cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacral vertebrae, caudal vertebrae). Except for the nerves and the caudal cervical region, a pair of spinal nerve (one right and one left) appears on the back of the vertebrae, so there is equal number of pairs of nerve thoracic, lumbar, and sacral, as vertebrae sections.

The first pair of cervical nerves emerge through the foramen present in the first cervical vertebrae, and a second pair of cervical vertebrae are the first and second. Therefore, there are always eight pairs of cervical nerves to 7 vertebrae, for example. In general, caudal neural pair is considerably less than the segment vertebraenya. (Frandson, 1993)

In the spinal canal, peripheral sensory and motor peripheral nervous nervous separately. Nervous sensory, conduct afferent impulses, into the spinal cord via the dorsal roots, whereas Nervous motor, deliver efferent impulses, out of the spinal cord through ventral roots (Campbell, 2002) Near the intervertebral foramen, dorsal root ventral root meet, forming a major part of the spinal nerves. Thus, the spinal nerve trunk contains both sensory and motor nerve fibers, so-called mixed nerves.

Page 14: Lo mila blok 5 up 2

Dorsal branches of spinal nerves inverse structures located in the dorsal position of a process of the vertebrae. Ventralnya branch in charge of the inverse of the structure located ventral process of the transverses and most of the structure of the tool back and forward motion. (Frandson, 1993)

Tend to innervatess spinal nerve fibers to the sensory and motor areas of the body in the emergence of the nerve fibers of the spinal cord. However, other parts of the fibers innervates by the motor and sensory arrangement resembles a plait, known as the plexus. There are two types of brachial plexus the plexus and lumbosacral plexus.

Brachial plexus is a network of nerves that originate from the nerve-sraf last third or fourth cervical and thoracic nerves the first or second. Innervates plexus nerve fibers to learn the front foot. In this section, the size of the spinal cord has wider part known as the cervical enlargement.

a.) Horses: Nerves: 3 last cervical and first two thoracic

b.) Cattle: Nerves: 3 last cervical and first thoracic 1

Right and left lumbosacral plexus nerve fibers innervates into both hind legs. Plexus is composed of several sections of the lumbar and sacral recent first, second and third.

a.) Horses: Nerves: 3 last lumbar and first sacral 2.

b.) Dogs: Nerves: lumbar last 5 and 3 sacred. (Frandson, 1993)

ReferenceBoeree, G. 2009. General Psychology: Neurotransmitter. Shippensburg University :

webspace.ship.edu

Campbell, N.A,dkk. 2007. Biology. Benjamin Cumming : San Francisco.

Page 15: Lo mila blok 5 up 2

Cunningham,J.G.2002.Textbook of Veterinary Physiology. Penerbit EGC:Jakarta.

Frandson,R.,D.1993.Anatomi dan Fisiologi Ternak.Edisi ke 4.Gadjah Mada University Press:Yogyakarta.

Kardong,K.V. 2012. Comparative Anatomy, Function, Evolution Sixth Edition. Mc Graw Hill: USA

Koolman, J and Roehm, 2005. Color Atlas of Biochemistry. Stuttgart: Thieme

Sisson, S. dan James, D. G. 1971. The Anatomy of the Domestic Animals. W. B. Saunders CO : Philadelphia and London.

Sites:

http://outreach.mcb.harvard.edu/teachers/Summer05/RaymondBroadhead/Synapses_and_Drugs.pdf