Chapter 12: Nervous Tissue
- The nervous system includes all nervous tissue in the body -Neural tissue contains two types of cells: 1) neurons (10% of all neurons, conduct nerve impulses) 2) neuroglia (support neurons) -We have 100 billion neurons
-Organs of the nervous system: brain, spinal cord, sensory receptors of sense organs (eyes, ears, etc.), and nerves (connects the nervous system with other systems, bundle of neurons that relay information) -Functions of the nervous system: 1) sensory input- everything coming in (smells, tastes, sounds, thoughts) 2) integration- processing, happens in the CNS 3) motor output- commands/directions leave and go to all cells in the body -We are only aware of 1% of our sensory input
-Somatic/voluntary structures: refers to skeletal muscle and skin -Autonomic/Visceral structures: structures under involuntary control (cardiac muscle, smooth muscle, glands) -Afferent: carrying impulse towards the CNS
-Efferent: carrying impulse away from the CNS
-CNS: the control center/headquarters, consists of brain and spinal cord -PNS (peripheral nervous system): cranial and spinal nerves, communication lines between the CNS and the rest of the body, broken down into 2 divisions: 1) sensory/afferent division- somatic and visceral sensory nerve fibers, conducts impulses from receptors to the CNS 2) motor/efferent division- motor nerve fibers, conducts impulses from the CNS to effectors (muscles and glands), broken down into two systems 1) somatic nervous system- somatic motor/voluntary, conducts impulse from CNS to skeletal muscle 2) autonomic nervous system (ANS)- visceral motor/involuntary, conducts impulses from CNS to autonomic structures, divided into two categories 1) sympathetic division- mobilizes body systems during activities 2) parasympathetic- conserves energy, promotes housekeeping functions during rest -ENS (enteric nervous system): a separate nervous system in your digestive organs (gut) -Information flow through the...
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