1. Dr/Nahla Yacout 2015/2016 Physiology 232 BMS

2. Is the part of the nervous system that consists of the nerves outside the brain & spinal cords It’s main function: is to connect CNS to the limbs & organs & so acts for communication between the brain & the extremeties Anatomical classification Cranial nervesSpinal nerves They are nerves that emerge directly from the brain & the brainstem reaching head & neck They are nerves that connect the spinal cord to other parts of the body

3. Are cluster of neurons that transmit sensory signals Sympathetic Parasympathetic  Are the ganglia of Are the ganglia of sympathetic nervous system parasympathetic NS  They deliver information to the body Are small terminal about stress & danger (Fight & Flight) ganglia lying near the organs they innervate

4. Synaptic cleft: Is a small gap at the end of a neuron that allows information to pass from one neuron to the next Pre-ganglionic neuron: Neuron lying before the ganglia Post-ganglionic neuron Neurons lying after the ganglia

6. Ach is a neurotransmitter which is released at preganglionic neurons in both sympathetic & parasympathetic stimulation & released at postganglionic neurons in parasympathetic stimulation only

7. 1.Muscarinic (On all organs with parasympathetic nerves) M1M2M3 ActionsIncreases secretion from salivary glands & stomach Reduces heart rate & force of contraction Bronchoconstri ction AgonistsMuscarine - ACh ACh AntagonistsAtropine

8. 2. Nicotinic (In ganglia of both sympathetic & parasympathetic) Are stimulated by Nicotine & Ach

9. Noradrenaline is a neurotransmitter of most sympathetic postganglionic neurons & is present also in adrenal medulla Actions Vasoconstriction Increase in the heart rate Elevation in blood pressure Pupil dilatation Decreases peristalsis in GIT Decreases the contraction of urinary bladder & rectum

10.  Alpha 1 ---- In GIT & urinary bladder  Alpha 2 ---- In parts of GIT  Beta 1 ---- In the heart  Beta 2 ---- In the bronchioles of the lung

13. SympatheticParasympathetic Stress, Fight & Flight responseRest & digest response There are two kinds of neurons involved in the transmission of any signal through this system: Pre & Postganglionic neurons Preganglionic fibers: Short Postganglionic fibers: Long Two kinds of neurons involved in the transmission of any signal through this system: Pre & Postganglionic neurons Preganglionic fibers: Long Postganglionic fibers: Short

14. Pre-ganglionic neurons release acetylcholine which activates nicotinic acetylcholine (Ach) receptors on postganglionic neurons ---- in response to this stimulus post-ganglionic neurons will release norepinephrine which activates adrenergic receptors on the target tissues Parasympathetic system uses Acetylcholine as it’s neurotransmitter. Preganglionic neurons release Ach which acts on nicotinic receptors of postganglionic neurons ---- in response postganglionic neurons will release Ach to stimulate the muscarinic receptors of the target organ

15. SympatheticParasympathetic Rate & force increase HeartRate & force decrease Bronchial muscles relaxed – widening of bronchioles (Allowing more O2 & CO2 exchange) LungsBronchial muscles contracted Pupil dilatation (Allowing more light) EyePupil constriction

16. SympatheticParasympathetic Motility is reducedIntestineDigestion is increased Sphincter closesUrinary bladderSphincter relaxes Urine secretion is decreased KidneysUrine secretion is increased

17.  Nervous system: Central Peripheral  Neuron: Is the basic unit of nervous system  Neurons consist of: Dendrites, Soma, Axon, Presynaptic terminals  Functional classification of neurons: Sensory, Motor & Interneurons  Brain consists of 3 parts: Forebrain (Cerebrum, Thalamus, Hypothalamus), Midbrain (Tectum & Tagmentum) & Hindbrain (Cerebellum, Pons, Medulla oblongata)  Spinal cord: is the main pathway for information connecting the brain & peripheral nervous system

18.  It consists of 31 nerve segments which are arranged from above as 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, & 1 coccygeal  Peripheral nervous system : is the part of the nervous system that consists of the nerves outside the brain & spinal cords  It consists of 3 types of nerves: Cranial, Spinal & Autonomic nerves  Autonomic ganglia: are cluster of neurons that transmit sensory signals

19.  Acetyl choline (Ach): is a neurotransmitter which is released at preganglionic neurons in both sympathetic & parasympathetic stimulation & released at postganglionic neurons in parasympathetic stimulation only  It’s receptors: Muscarinic – Nicotinic  Noradrenaline (NA): is the neurotransmitter of most sympathetic postganglionic neurons  It’s receptors: Alpha1, Alpha2, Beta1 & Beta2