Ch. 4 key terms Flashcards
Acetylcholinesterase
An enzyme that brings about the breakdown of acetylcholine in the synaptic gap.
Acetylcholine
A neurotransmitter that allows a nerve impulse to cross the synaptic junction (gap) between two nerve fibers or between a nerve fiber and an organ (muscle, gland).
Adrenergic
A term used to describe an action of a receptor that is activated by epinephrine or norepinephrine.
Analgesia
Loss of pain sensation (other sensations may be present).
Anesthesia
The loss of all sensation. May be described as local (affecting a small area), regional, or surgical (accompanied by unconsciousness).
Autonomic Nervous System
That portion of the nervous system that controls involuntary activities.
Catalepsy
A state of involuntary muscle rigidity that is accompanied by immobility, amnesia, and variable amounts of analgesia. Some reflexes may be preserved.
Catecholamine
The class of neurotransmitters that includes dopamine, epinephrine, and norepinephrine. When given therapeutically, catecholamines mimic the effects of stimulating the sympathetic nervous system.
Cholinergic
Activated by or transmitted through acetylcholine; also called parasympathomimetic. Cholinergic drugs increase activity in the gastrointestinal tract.
Effector
A gland, organ, or tissue that responds to nerve stimulation with a specific action.
Ganglionic synapse
The site of the synapse between neuron one and neuron two of the autonomic nervous system.
Muscarinic Receptors
Receptors activated by acetylcholine and muscarine that are found in the glands, the heart, and smooth muscle. An acronym for remembering muscarinic effects is “SLUD”= S: salivation; L: lacrimation; U: urination; D: defecation.
Nicotinic receptors
Receptors that are activated by acetylcholine and nicotine found a the neuromuscular junction of the skeletal muscle and the ganglionic synapses.
Parasympathetic Nervous System
That portion of the autonomic nervous system that arises from the craniosacral portion of the spinal cord, is mediated by the neurotransmitter acetylcholine, and is concerned primarily with conserving and restoring a steady state in the body.
Parasympathomimetic
A drug that mimics the effects of stimulating the parasympathetic nervous system.
Sympathetic Nervous System
That portion of the autonomic nervous system that arises from the thoracolumbar spinal cord, is mediated by catecholamines, and is concerned with the flight-or-fight response.
Sympathomimetic
A drug that mimics the effects of stimulating the sympathetic nervous system
