Peripheral Nervous System Flashcards
Define Neurotransmitter (Ligand)
Chemical that an axon secretes or that we introduce into the system, that stimulates or inhibits an effector (muscle, gland, or other neuron).
Define Receptor
The site within an organism that is available for interaction with chemicals such as drugs. Proteins form the greatest number of drug receptors in the body.
Define Synaptic Cleft
The gap between two neurons where chemical information is transmitted
Define agonist
Binds to a receptor causing activation or “causes things to happen normally”
Define Antagonist
Binds to a receptor blocking activation or “prevents normal function from happening”
Define pre-synaptic
The terminal axon where a neurotransmitter is released
Define post-synaptic
The dendrite where a neurotransmitter attaches to its receptor
What are the two branches of the PNS?
The involuntary (Autonomic) and the voluntary (Somatic)
What are the two branches of the involuntary(Autonomic) nervous system?
The sympathetic and parasympathetic
What are the two branches of the voluntary (Somatic) nervous system and what does the Somatic branch activate?
The motor and sensory; and skeletal muscle.
What are the functions of the Autonomic Nervous system?
Maintain heart rate
Activate cardiac muscle
Regulation of glands
Regulation of smooth muscle
What are the functions of the Parasympathetic Nervous system?
Rest and Digest Slowing the heart rate Reduced MAP Increase gastric secretion Emptying the bladder Emptying of the bowel Focusing the eye for near vision Constriction of the pupil Bronchoconstriction
What are the functions of the Sympathetic Nervous system?
Regulation of the cardiovascular system Increased heart rate Increased MAP Bronchodilation Regulating body temperature Implementing the "fight or flight" response
What symptoms occur during the flight or fight response?
Increased heart rate and blood pressure Shunting blood away from skin and into large muscles Dilation of the bronchi Dilation of the pupils Conversion of stored energy
Define ganglion
A bundle or group of nerves
What are the three neurotransmitters (ligands) of the PNS?
Acetylcholine
Norepinephrine
Epinephrine
What are the three types of Cholinergic receptors?
Nicotinic (n)
Nicotinic (m)
Muscarinic
Define Nicotinic (n) receptor
Nicotinic (n), is a cholinergic neuronal receptor that transmits neuron to neuron.
Define Nicotinic (m) receptor
Nicotinic (m), is a cholinergic receptor that transmits from motor neurons to muscle
Define Muscarinic receptor
A muscarinic cholinergic receptor is attached to various organs and sweats glands
What are the functions of the Muscarinic receptor?
Increased glandular secretion (pulmonary, gastric, intestinal, and sweat glands)
Slows the heart
Contraction of the sphincter of the Iris (Miosis)
Contraction of the ciliary muscle in the eye (Near Vision)
What are the four adrenergic receptors?
Alpha-1, Alpha-2, Beta-1, and Beta-2
What are the functions of the alpha-1 receptor and where is it located?
Located in the eye, blood vessels, male sex organs, and neck of the bladder. It causes mydryasis (Dilation of the pupils), Vasoconstriction, Ejaculation, and Bladder neck constriction.
What is the function and where is the alpha-2 receptor located?
Alpha-2 is located in the nerve terminals, and it’s function is not significant in the peripheral nervous system. However, it is significant in the central nervous system
What are the functions of the beta-1 receptor and where is it located?
The beta-1 receptor is located in the heart and kidneys. In the heart it increases heart rate, force of contraction and velocity of impulse through the AV node. In the kidneys it causes a release of renin.
What are the functions of the beta-2 receptor and where is it located?
Beta-2 is located in the lungs, uterus, muscle (all types, large skeletal muscles), and in the liver. In the lung it causes bronchial dilation. In the uterus it causes relaxation of the uterus. In the muscles it causes vasodilation, and in the liver it causes glycogenelysis (a breakdown of glycogen into glucose).
Define Neuromuscular junction
The gap between a motor neuron and a skeletal muscle fiber. The area on the skeletal muscle fiber that receives the impulse from the motor neuron is called the end-motor plate.
What is glycogenolysis?
The breakdown of glycogen to glucose. This occurs in the liver.
