BSC 3096 Chapter 11
Appropriate site of release Somatic motor neuron
Acetylcholine (Ach)
Neurons that secrete acetylcholine are described as neurons, whereas those that secrete norepinephrine are called either or neurons.
Cholinergic—acetylcholine, adrenergic or noradrenergic—norepinephrine.
Match the following with its description. A. acetylcholine B. norepinephrine C. cholinergic nicotinic receptor D. adrenergic receptor E. cholinergic muscarinic receptor sympathetic tissue receptor
D. adrenergic receptor
A location outside of the central nervous system where autonomic signals can synapse
Ganglion
Which statements apply to the parasympathetic division of the nervous system? Epinephrine is the primary neurotransmitter of the parasympathetic division. Its ganglia are nearby, on or near their target organs. It is dominant during "resting and digesting." It is dominant during "resting and digesting" and its ganglia are nearby, on or near their target organs. All of the statements apply.
It is dominant during "resting and digesting" and its ganglia are nearby, on or near their target organs.
Appropriate site of release Postganglionic neuron from the sympathetic nervous system
Norepinephrine (NE)
A receptor potential is a(n) __________ potential. resting graded threshold action
graded
Increased parasympathetic stimulation causes sweat glands to release sweat. causes the pupils to dilate. increases heart rate. increases gastric motility. causes blood vessels in the skin to dilate.
increases gastric motility.
A neuron that receives an action potential from another neuron and then delivers that action potential to a smooth muscle
postganglionic autonomic neuron
Which of the following has its cell body in the ganglion? preganglionic neuron and postganglionic neuron preganglionic neuron somatic motor neuron preganglionic neuron, postganglionic neuron, and somatic motor neuron postganglionic neuron
postganglionic neuron
A neuron that delivers an action potential from the central nervous system to another neuron in the peripheral nervous system
preganglionic autonomic neuron
Neurons in the parasympathetic pathway use which of the following neurotransmitters? norepinephrine norepinephrine (preganglionic) and acetylcholine (postganglionic) acetylcholine acetylcholine (preganglionic) and norepinephrine (postganglionic)
acetylcholine
Somatic motor neurons secrete the neurotransmitter ________ onto ________ receptors at the target tissue. norepinephrine; adrenergic acetylcholine; muscarinic norepinephrine; nicotinic acetylcholine; nicotinic
acetylcholine; nicotinic
The two varieties of adrenergic receptors are beta and cholinergic. nicotinic and muscarinic. nicotinic and cholinergic. alpha and beta.
alpha and beta.
Antagonistic control of efferent output is typical of the ________ division. somatic and autonomic somatic and sensory autonomic somatic sensory
autonomic
The division of the efferent nervous system that controls smooth and cardiac muscles and many glands is the ________ division. sympathetic autonomic parasympathetic somatic
autonomic
Which functions are controlled through the autonomic nervous system? 1. blood pressure 2. heart rate 3. water balance 4. temperature regulation
1,2,3,4
Applying Your Knowledge of Neurotransmitter and Receptor RelationshipsPart complete Muscarine, a chemical produced by certain mushrooms, binds to muscarinic receptors mimicking the effect of acetylcholine. How do you think administering this chemical would change body function? The drug would _____________. Check all that apply. change the functionality of the smooth muscles within the digestive system change the functionality of the heart change the rate at which action potentials are propagated from the preganglionic neurons to the postganglionic neurons of the autonomic nervous system change the functionality of certain exocrine and endocrine glands change the functionality of skeletal muscles
change the functionality of the smooth muscles within the digestive system change the functionality of the heart change the functionality of certain exocrine and endocrine glands
Which of the following are components of the efferent nervous system? Check all that apply. parasympathetic neurons spinal cord sympathetic neurons somatic motor neurons brain
parasympathetic neurons sympathetic neurons somatic motor neurons
The target tissue(s) of somatic motor neurons is/are ________. skeletal muscle cardiac and smooth muscles skeletal and cardiac muscles skeletal, cardiac, and smooth muscles
skeletal muscle
Which of the following is/are targets of the efferent nervous system? Check all that apply thalamus smooth muscle medulla oblongata skeletal muscle glands cerebral cortex cardiac muscle
smooth muscle skeletal muscle glands cardiac muscle
A single neuron is stimulated at the central nervous system; this signal travels all the way to the target tissue, where the neurotransmitter acetylcholine is released onto the target tissue. The acetylcholine binds to a nicotinic receptor to induce skeletal muscle contraction. These steps describe the function of which branch of the efferent nervous system? Choose the best answer. parasympathetic somatic afferent sympathetic none of the listed answers
somatic
A neuron that delivers an action potential from the central nervous system to a skeletal muscle
somatic motor neuron
The autonomic nervous system includes
sympathetic pathways parasympathetic pathways adrenal sympathetic pathways
Somatic motor pathways are excitatory or inhibitory? are composed of a single neuron or a preganglionic and a postganglionic neuron? synapse with glands or with smooth, cardiac, or skeletal muscle?
(a) excitatory (b) single neuron (c) synapse with skeletal muscle
If a target cell's receptor is (use items in left column), the neuron(s) releasing neurotransmitter onto the receptor must be (use all appropriate items from the right column). A. nicotinic cholinergic B. adrenergic α C.muscarinic cholinergic D. adrenergic β 1. somatic motor neuron 2. autonomic preganglionic neuron 3. sympathetic postganglionic neuron 4. parasympathetic postganglionic neuron
A. 1,2 B. 3 C. 4 D. 3
Acetylcholinesterase (AChE) inhibitor administration is a common treatment for myasthenia gravis. Why does this help alleviate some of the symptoms of this autoimmune disease? AChE inhibition increases ACh in the synaptic cleft to bind remaining ACh receptors. AChE inhibition increases the breakdown of ACh. AChE inhibition stimulates muscle cells to produce ACh receptors. AChE inhibitors bind to the remaining ACh receptors.
AChE inhibition increases ACh in the synaptic cleft to bind remaining ACh receptors.
Appropriate site of release Postganglionic neuron from the parasympathetic nervous system
Acetylcholine (Ach)
Appropriate site of release Preganglionic neuron from the parasympathetic nervous system
Acetylcholine (Ach)
Appropriate site of release Preganglionic neuron from the sympathetic nervous system
Acetylcholine (Ach)
Which neurosecretory endocrine gland is closely allied to the sympathetic branch?
Adrenal medulla.
What kind of receptor is found on the postsynaptic cell in a neuromuscular junction?
nicotinic cholinergic receptors
What is the trigger for ACh release into the synaptic cleft of a neuromuscular junction? Acetylcholinesterase opens vesicles, allowing ACh to diffuse into the cleft. Contraction of nearby muscle cells stimulates the release of ACh from surrounding neurons of the same motor unit. An action potential at the axon terminal opens voltage-gated Ca2+ channels. Stimulation of the presynaptic membrane releases ACh via a cAMP second messenger system.
An action potential at the axon terminal opens voltage-gated Ca2+ channels.
Sometimes the effects of sympathetic stimulation can be contradictory in the same types of tissue. For example, in the arterioles of the GI tract, sympathetic stimulation causes constriction while arterioles of skeletal muscle can dilate in response to sympathetic stimulation. What mechanism explains these opposite effects? Two different types of sympathetic neurons carry signals to tissues. The nature of the effect is due to the type of neuron used. The effect will reflect the "needs" of the tissue at the time. Different neurotransmitters binding to the same receptors Different receptors for the same neurotransmitter
Different receptors for the same neurotransmitter
What is the advantage of divergence of neural pathways in the autonomic nervous system?
Divergence allows one signal to affect multiple targets.
Match the following with its description. A. acetylcholine B. norepinephrine C. cholinergic nicotinic receptor D. adrenergic receptor E. cholinergic muscarinic receptor parasympathetic tissue receptor
E. cholinergic muscarinic receptor
What would be the effect of ACh binding to its receptor on the postsynaptic muscle cell? Ca2+ would leak out of the cell as Na+ flowed into the cell. Na+ would flow into the cell and K+ would flow out of the cell. Ca2+ would flow into the cell as Na+ flowed out of the cell. Only Na+ would flow into the cell.
Na+ would flow into the cell and K+ would flow out of the cell.
Part H - Comparing and Contrasting the Somatic Pathways with Parasympathetic PathwaysPart complete The somatic nervous system and the parasympathetic nervous system both release acetylcholine (ACh) onto their target tissues. Do you predict that this would indicate that these two pathways carry out the same effects? Why or why not? Choose the best answer. View Available Hint(s) Yes, because the two pathways terminate at the same target tissues. No, because each pathway releases a different type of acetylcholine onto its target tissue. Yes, because the neurotransmitter is the same. No, because the receptors found on the target tissue for each pathway are different. Yes, because the receptors at the target tissues of the somatic nervous system and the parasympathetic branch of the autonomic nervous system are the same.
No, because the receptors found on the target tissue for each pathway are different.
Which of these characteristics is the same in both the sympathetic and parasympathetic branches for the vast majority of neurons? Preganglionic neurotransmitter Site of origin of the nerves Postganglionic neurotransmitter Receptor type at the target tissues
Preganglionic neurotransmitter
Name the two efferent divisions of the peripheral nervous system. What type of effectors does each control?
Somatic motor—skeletal muscles. Autonomic—smooth and cardiac muscle, glands, some adipose tissue.
The Huaorani Indians of South America use blowguns to shoot darts poisoned with curare at monkeys. Curare is a plant toxin that binds to and inactivates nicotinic ACh receptors. What happens to a monkey struck by one of these darts?
Skeletal muscles would become paralyzed. Monkey could not flee.
What are the two branches of the autonomic nervous system? How are these branches distinguished from each other anatomically and physiologically?
Sympathetic and parasympathetic divisions. Sympathetic neurons exit the spinal cord in the thoracic and lumbar regions; ganglia are close to the spinal cord. Parasympathetic exit from the brain stem or sacral region; ganglia on or close to their targets. Sympathetic—fight-or-flight; parasympathetic—rest-and-digest.
If nicotinic receptor channels allow both Na+ and K+ to flow through, why does Na+ influx exceed K+ efflux?
The electrochemical gradient for Na+ is greater than that for K+.
The autonomic nervous system is sometimes called the nervous system. Why is this an appropriate name? List some functions controlled by the autonomic nervous system.
Visceral nervous system because it controls internal organs (viscera) and functions such as heart rate and digestion.
Which of the following best describes the direction and function of efferent signals? away from the central nervous system, cause motor effects in glands or muscles away from the central nervous system, to provide sensation to all parts of the body toward the central nervous system, in order to cause the movement of glands and muscles toward the central nervous system, in order to deliver sensory information from all parts of the body
away from the central nervous system, cause motor effects in glands or muscles
The adrenal medulla is important to the sympathetic branch of the autonomic nervous system because it is considered a modified sympathetic ganglion. it is a source of catecholamines and it is considered a modified sympathetic ganglion. it is a source of catecholamines. it is a source of catecholamines, it is considered a modified sympathetic ganglion, and it releases epinephrine and norepinephrine directly into the blood. it releases epinephrine and norepinephrine directly into the blood.
it is a source of catecholamines, it is considered a modified sympathetic ganglion, and it releases epinephrine and norepinephrine directly into the blood.