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Set 22 - Organ Systems - The Nervous System

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celine's version from 2018-03-22 15:54

Section

Question Answer
The two major divisions of the nervous system are the _________ and the _________.central nervous system (CNS), peripheral nervous system (PNS)
The central nervous system (CNS) includes the _________ and _________.neurons of the brain and spinal cord
The peripheral nervous system (PNS), includes all other neurons and originates in the _________ and _________.cranium and between the vertebrae
The peripheral nervous system (PNS) is further divided into _________ and _________ systems.somatic and autonomic systems
The somatic system links the skeletal muscles to the _________.central nervous system (CNS)
The autonomic system regulates _________ and _________.involuntary muscles and endocrine glands
The autonomic system consists of 3 divisions:Sympathetic, Parasympathetic, and Enteric
Sympathetic nervous systemThis division results in arousal and alertness, stimulating production of the “fight or flight” hormones (epinephrine and norepinephrine), increasing heart rate, and easing breathing.
Parasympathetic nervous systemThis division promotes “rest and digest” activities. It slows the heart rate, constricts the lungs, and stimulates the digestive organs.
Enteric nervous systemThis division controls the digestive organs and can be regulated by the other two autonomic divisions.
Basic units of nervous systemneurons
A neuron consists of _________, which receive signals from other neurons; a _________ that contains the nucleus; and an _________ that transmits a signal down its length and through the terminal branches.dendrites, cell body, axon
Cells called _________ form myelin, which wraps around and insulates the axons of some cells. The long axons of neurons make up _________, and clusters of neuron cell bodies constitute _________.glia, nerve fibers, ganglia
Electrical signals called _________ travel through neurons. An action potential results from a temporary shift in the balance of positively and negatively charged ions inside and outside the cell membrane. Action potentials are initiated when _________ are opened, allowing sodium into the cytoplasm. The balance is restored when _________ exit the cytoplasm.action potentials, sodium ion (Na+) channels, potassium ions (K+)
Besides action potentials, the nervous system uses chemical messengers called _________. When an action potential reaches the terminal axon branches, neurotransmitter molecules are released into a space called a _________. Here, they bind to receptor proteins on the membrane of the adjacent cell’s dendrites. Neurotransmitters affect the sodium and potassium channels of the cell and can create a new action potential.neurotransmitters, synapse
Examples of neurotransmittersSerotonin, acetylcholine, and dopamine
Almost all animals are capable of motion due to the existence of a nervous system, whether simple or complex. The simplest type of nervous system is the nerve net of _________. The next level of complexity features _________ that coordinate the movements of multiple body parts. Still more complex nervous systems feature a brain, nerve cord (CNS), and ganglia (neuron clusters) that innervate specific sections of the body.cnidarians (jellyfish, anemones, and hydras), nerve nets
Which precedes an action potential traveling down the axon of a neuron?Neurotransmitters bind to receptors on the dendrite of the neuron. (Action potentials are transmitted from input at the dendrites of a neuron, travel down the axon, and release neurotransmitters into the synapse between adjacent cells. These neurotransmitters bind to receptors on the dendrite of the second neuron, helping to produce a new action potential. Action potentials cannot travel through synapses)
A nerve leading to the small intestine causes the rate of digestion to increase. This nerve MOST LIKELY belongs to which of the following systems and divisions? I. Autonomic II. Sympathetic III. Peripheral IV. EntericD. I, III, and IV (The nerve is outside the CNS and so belongs to the peripheral nervous system (PNS). Because it is not under voluntary control, it must belong to the autonomic system. Because it promotes “rest and digest” functions, it must belong to the parasympathetic (rather than sympathetic) nervous system. Finally, because it innervates the intestines, it is likely part of the enteric nervous system)
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