ANS INTRO 24.pptx

Nervous System Organization The nervous system functions at conscious and unconscious levels. Central nervous system (CNS). Peripheral nervous system (PNS). Somatic division. Visceral division (autonomic nervous system). © McGraw Hill 1 Autonomi...

Nervous System Organization The nervous system functions at conscious and unconscious levels. Central nervous system (CNS). Peripheral nervous system (PNS). Somatic division. Visceral division (autonomic nervous system). © McGraw Hill 1 Autonomic Nervous System (ANS) 1 Composed of the nerves that travel to smooth and cardiac muscle. Involuntary muscle. Muscle tissues possess autorhythmicity. Regulates the rate at which internal organs work. © McGraw Hill 2 Autonomic Nervous System (ANS) 1 Composed of the nerves that travel to smooth and cardiac muscle. Involuntary muscle. Muscle tissues possess autorhythmicity. Regulates the rate at which internal organs work. © McGraw Hill 3 Autonomic Nervous System (ANS) 2 Segmented into: Sympathetic division. Parasympathetic division. © McGraw Hill 4 Parasympathetic Division Nerves originate from the brain and spinal cord. More active during periods of rest and restoration of body energy stores. Parasympathetic nerves increase body functions such as digestion and elimination of waste products. © McGraw Hill 5 Figure 5.1 - Schematic of the Parasympathetic Nervous System Showing the Origin and Distribution of Parasympathetic Nerves © McGraw Hill Access the text alternative for slide images 6 Sympathetic Division Nerves originate from the thoracic and lumbar spinal nerves. Sympathetic stimulation produces fight or flight reaction. Allows for greater expenditure of energy for physical and mental exertion. All sympathetic nerves are activated when the division is stimulated. © McGraw Hill 7 Figure 5.2 - Schematic of the Sympathetic Nervous System Showing the Origin and Distribution of Sympathetic Nerves © McGraw Hill Access the text alternative for slide images 8 Figure 5.3 - Vasoconstriction and Vasodilation © McGraw Hill Access the text alternative for slide images 9 Table 5.1 - Effects of Sympathetic and Parasympathetic Stimulation © McGraw Hill Access the text alternative for slide images 10 ANS Nerve Fibers and Neurotransmitters 1 Peripheral autonomic nerves. Branches of the cranial and spinal nerves. Travel to the cardiac muscle and smooth muscle of the internal organs. Preganglionic nerve fiber. Formed by neurons that emerge from the central nervous system. © McGraw Hill 11 ANS Nerve Fibers and Neurotransmitters 2 Postganglionic nerve fiber. Formed by neurons that travel from the ganglion to the internal organ. © McGraw Hill 12 Figure 5.4 - Diagrammatic Representation of Pre- and Postganglionic Fibers Synapsing at the Autonomic Ganglion © McGraw Hill Access the text alternative for slide images 13 ANS Nerve Fibers and Neurotransmitters 3 Pharmacological difference between the sympathetic nerves and the parasympathetic nerves. Parasympathetic nerves - Neurotransmitter released at the ganglia and the postganglionic nerve ending is acetylcholine (ACH). © McGraw Hill 14 ANS Nerve Fibers and Neurotransmitters 4 Sympathetic nerves - Norepinephrine (NE) is released at the postganglionic nerve ending and ACH at the ganglia. © McGraw Hill 15 Figure 5.5 – Diagrammatic Representation of Parasympathetic and Sympathetic Fibers Access the text alternative for slide images © McGraw Hill 16 Cholinergic Receptors Muscarinic: Located on the cell membranes of visceral organs and glands. Nicotinic: Nicotinic-nerve (Nn) - Located at parasympathetic and sympathetic ganglia. Nicotinic-muscle (Nm) - Located on cell membranes of skeletal muscle. © McGraw Hill 17 Adrenergic Receptors Alpha: Alpha-1. Alpha- 2. Beta: Beta- 1. Beta- 2. © McGraw Hill 18