Neurons in the parasympathetic pathway use which of the following neurotransmitters? |
acetylcholine |
Which of the following is the type of adrenergic receptor found in most sympathetic target tissues? |
alpha 1 |
What would be the effect of ACh binding to its receptor on the postsynaptic muscle cell? |
Na+ would flow into the cell and K+ would flow out of the cell |
The diameter of blood vessels varies under the control of ________ neurons, which cause the diameter to ________. |
sympathetic; either increase or decrease, depending upon the type of receptor present |
The division of the efferent nervous system that controls smooth and cardiac muscles and many glands is the ________ division. |
autonomic |
These neurons secrete the neurotransmitter acetylcholine onto their targets: |
somatic motor and parasympathetic motor |
The two main types of acetylcholine receptor are known as |
nicotinic and muscarinic |
The neurotransmitter that controls skeletal muscle causes which of the following? |
muscle contraction |
The target tissue(s) of somatic motor neurons is/are ________. |
skeletal muscle |
What is an appropriate classification for the ACh receptor found in the neuromuscular junction? |
ligand-gated, nonspecific, cation channel |
What type of acetylcholine receptor is present in the postganglionic neurons and on the target tissue in autonomic pathways? |
nicotinic on the postganglionic neurons and muscarinic on the target tissue |
Which nervous system division has parasympathetic and sympathetic branches? |
the autonomic division of the efferent nervous system |
Which statements apply to the parasympathetic division of the nervous system? |
It is dominant during "resting and digesting" and its ganglia are nearby, on or near their target organs |
The presence of two peripheral efferent neurons in a pathway is typical of the ________ division. |
autonomic |
The adrenal medulla is important to the sympathetic branch of the autonomic nervous system because |
it is a source of catecholamines, it is considered a modified sympathetic ganglion, and it releases epinephrine and norepinephrine directly into the blood |
Which area(s) of the brain exert(s) control over the autonomic nervous system? |
1, 3, 4, 5 |
Which functions are controlled through the autonomic nervous system? |
1, 2, 3, 4 |
"Dual innervation" refers to an organ receiving |
both sympathetic and parasympathetic nerves |
The neural pathway from the spinal cord to the target tissue has two neurons, the preganglionic neuron and the postganglionic neuron. |
true for the sympathetic & parasympathetic division |
The neurotransmitter acetylcholine is released by neurons at the neuroeffector synapse. |
true only for the parasympathetic division |
It releases norepinephrine at the neuroeffector synapse. |
true only for the sympathetic division |
The adrenal medulla is closely allied with this system. |
true only for the sympathetic division |
On average, one preganglionic neuron synapses with eight or nine postganglionic neurons, each innervating a different target. |
true for the sympathetic & parasympathetic division |
It is important during stress or emergencies (fight-or-flight). |
true only for the sympathetic division |
It dominates during resting-and-digesting activities. |
true only for the parasympathetic division |
The two types of cholinergic receptors are |
nicotinic and muscarinic |
Cholinergic muscarinic receptors are found at the ________ in the ANS. |
parasympathetic neuroeffector junctions |
Cholinergic nicotinic receptors are found in the ________ of the ANS. |
autonomic ganglia |
The two varieties of adrenergic receptors are |
alpha and beta |
Epinephrine and norepinephrine that are released from the adrenal glands affect target tissue for a longer period of time than the same substances released from neurons at their peripheral receptors. Why? |
There are no enzymes to break down epinephrine and norepinephrine in the blood and very little in peripheral tissues |
Somatic motor neurons secrete the neurotransmitter ________ onto ________ receptors at the target tissue. |
acetylcholine; nicotinic |
How do the synapses of the autonomic nervous system differ from a neuromuscular junction (NMJ)? |
Neurotransmitter receptors are concentrated on the postsynaptic membrane in the NMJ but diffusely arranged across the tissue in a varicosity |
Which type of receptor is found in the neuromuscular junction? |
nicotinic |
What is the trigger for ACh release into the synaptic cleft of a neuromuscular junction? |
An action potential at the axon terminal opens voltage-gated Ca2+ channels |
How many molecules of ACh are necessary to completely activate the cholinergic nicotinic receptor? |
2 |
The motor end plate is |
a folded area of muscle cell membrane with ACh receptors clustered at the top of each fold |
What is the main enzyme responsible for the breakdown of catecholamines? |
Monoamine oxidase |
Why is the parasympathetic nervous system also called the cranio-sacral division? |
Its nerves arise in the head and sacrum |
The effects of the sympathetic nervous system are divergent, meaning that a single stimulus can have an effect on a large number of targets. In other words, when the SNS is activated, all of the organs it innervates are stimulated. This does not occur in the parasympathetic system. Why? |
The sympathetic ganglia spreads the stimulus to all postganglionic sympathetic neurons |