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BIOL 235 Human Anatomy and Physiology > Chapter 15: The Autonomic Nervous System > Flashcards

Chapter 15: The Autonomic Nervous System Flashcards

1
Q

What is the primary role of the autonomic nervous system (ANS)?

A

The ANS contributes to homeostasis by conveying motor output from the CNS to smooth muscle, cardiac muscle, and glands for appropriate responses to integrated sensory information.

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2
Q

What are the two main branches of the autonomic nervous system?

A

The two main branches of the ANS are the sympathetic nervous system and the parasympathetic nervous system.

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3
Q

What is the primary function of the somatic nervous system (SNS)?

A

The SNS controls voluntary movements by innervating skeletal muscles, with motor neurons causing muscle contractions.

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4
Q

How does the somatic nervous system operate in terms of control?

A

The somatic nervous system usually operates under voluntary (conscious) control, but some involuntary movements, such as posture and reflexes, are controlled by integrating centers in the brainstem and spinal cord.

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5
Q

How does the autonomic nervous system (ANS) differ from the somatic nervous system (SNS)?

A

The ANS regulates involuntary processes, such as the function of smooth muscle, cardiac muscle, and glands, while the SNS controls voluntary movements of skeletal muscles.

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6
Q

What are visceral effectors in the context of the autonomic nervous system?

A

Visceral effectors are tissues such as cardiac muscle, smooth muscle, and glands that are regulated by the ANS.

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7
Q

What is dual innervation in the autonomic nervous system?

A

Dual innervation refers to the fact that most organs receive input from both the sympathetic and parasympathetic divisions of the ANS.

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8
Q

What is the function of the sympathetic nervous system?

A

The sympathetic nervous system prepares the body for emergency situations, often referred to as the fight-or-flight response.

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9
Q

What is the function of the parasympathetic nervous system?

A

The parasympathetic nervous system enhances rest-and-digest activities, promoting body energy conservation and restoration during rest or digestion.

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10
Q

How does the enteric nervous system (ENS) function?

A

The ENS regulates the gastrointestinal tract, with sensory neurons monitoring chemical changes and stretching, and motor neurons controlling smooth muscle contractions and gland secretions.

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11
Q

What is the role of preganglionic and postganglionic neurons in the autonomic nervous system?

A

In the ANS, the preganglionic neuron extends from the CNS to an autonomic ganglion, and the postganglionic neuron extends from the ganglion to the effector tissue (smooth muscle, cardiac muscle, or a gland).

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12
Q

What is the difference between somatic and autonomic motor neurons in terms of neurotransmitter release?

A

Somatic motor neurons release acetylcholine (ACh) only, while autonomic motor neurons release either ACh or norepinephrine (NE).

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13
Q

What is the role of chromaffin cells in the autonomic nervous system?

A

Chromaffin cells, found in the adrenal medulla, secrete the neurotransmitters epinephrine and norepinephrine.

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14
Q

What is the key difference between the motor pathways in the somatic and autonomic nervous systems?

A

The somatic nervous system has a single motor neuron extending directly to the effector, while the autonomic nervous system typically involves two motor neurons in series.

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15
Q

What type of sensory input does the Somatic Nervous System (SNS) receive?

A

The SNS receives sensory input from somatic senses and special senses.

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16
Q

What type of sensory input does the Autonomic Nervous System (ANS) receive?

A

The ANS mainly receives sensory input from interoceptors, with some input from somatic senses and special senses.

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17
Q

What is the control of motor output in the Somatic Nervous System?

A

Motor output in the SNS is under voluntary control from the cerebral cortex, with contributions from the basal ganglia, cerebellum, brainstem, and spinal cord.

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18
Q

What is the control of motor output in the Autonomic Nervous System?

A

The ANS is under involuntary control from the hypothalamus, limbic system, brainstem, and spinal cord, with limited control from the cerebral cortex.

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19
Q

What is the motor neuron pathway in the Somatic Nervous System?

A

The SNS has a one-neuron pathway: Somatic motor neurons extend from the CNS and synapse directly with the effector.

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20
Q

What is the motor neuron pathway in the Autonomic Nervous System?

A

The ANS usually follows a two-neuron pathway: Preganglionic neurons extend from the CNS to an autonomic ganglion, and postganglionic neurons extend from the ganglion to the effector. Alternatively, preganglionic neurons may synapse with chromaffin cells in the adrenal medullae.

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21
Q

What neurotransmitters are released in the Somatic Nervous System?

A

All somatic motor neurons release only acetylcholine (ACh).

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22
Q

What neurotransmitters are released in the Autonomic Nervous System?

A

All sympathetic and parasympathetic preganglionic neurons release ACh. Most sympathetic postganglionic neurons release norepinephrine (NE); those to most sweat glands release ACh. All parasympathetic postganglionic neurons release ACh. Chromaffin cells of the adrenal medullae release epinephrine and norepinephrine (NE).

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23
Q

What are the effectors of the Somatic Nervous System?

A

The effectors of the SNS are skeletal muscles.

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24
Q

What are the effectors of the Autonomic Nervous System?

A

The effectors of the ANS are smooth muscle, cardiac muscle, and glands.

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25
Q

What is the response to motor output in the Somatic Nervous System?

A

The response in the SNS is the contraction of skeletal muscles.

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26
Q

What is the response to motor output in the Autonomic Nervous System?

A

The response in the ANS includes contraction or relaxation of smooth muscle, increased or decreased rate and force of contraction of cardiac muscle, and increased or decreased secretions of glands.

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27
Q

What are the two motor neurons in any autonomic motor pathway called?

A

The two motor neurons are called the preganglionic neuron and the postganglionic neuron.

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28
Q

Where is the cell body of a preganglionic neuron located?

A

The cell body of a preganglionic neuron is in the brain or spinal cord.

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29
Q

What is the axon of a preganglionic neuron like?

A

The axon of a preganglionic neuron is a small-diameter, myelinated type B fiber.

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30
Q

Where does the preganglionic neuron synapse?

A

The preganglionic neuron synapses with a postganglionic neuron in an autonomic ganglion.

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31
Q

What is the axon of a postganglionic neuron like?

A

The axon of a postganglionic neuron is a small-diameter, unmyelinated type C fiber.

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32
Q

Where does the axon of a postganglionic neuron terminate?

A

The axon of a postganglionic neuron terminates in a visceral effector.

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33
Q

What are the two divisions of the autonomic nervous system based on the location of preganglionic neurons?

A

The two divisions are the sympathetic division (thoracolumbar division) and the parasympathetic division (craniosacral division).

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34
Q

Where are the preganglionic neurons of the sympathetic division located?

A

The preganglionic neurons of the sympathetic division are located in the lateral horns of the gray matter in the 12 thoracic segments and the first two lumbar segments of the spinal cord.

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35
Q

Where are the preganglionic neurons of the parasympathetic division located?

A

The preganglionic neurons of the parasympathetic division are located in the nuclei of four cranial nerves (III, VII, IX, and X) in the brainstem and in the lateral gray matter of the second through fourth sacral segments of the spinal cord.

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36
Q

What are the two major types of sympathetic ganglia?

A

The two major types of sympathetic ganglia are sympathetic trunk ganglia and prevertebral ganglia.

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37
Q

Where are sympathetic trunk ganglia located?

A

Sympathetic trunk ganglia are located in a vertical row on either side of the vertebral column, extending from the base of the skull to the coccyx.

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38
Q

Where are prevertebral ganglia located?

A

Prevertebral ganglia are located anterior to the vertebral column, close to large abdominal arteries.

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39
Q

Where do preganglionic axons of the parasympathetic division synapse?

A

Preganglionic axons of the parasympathetic division synapse with postganglionic neurons in terminal (intramural) ganglia, located close to or within the wall of a visceral organ.

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40
Q

How many postganglionic neurons may a single sympathetic preganglionic fiber synapse with?

A

A single sympathetic preganglionic fiber may synapse with 20 or more postganglionic neurons.

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41
Q

What are the types of connections between sympathetic preganglionic neurons and postganglionic neurons?

A
  1. Synapse with postganglionic neurons in the same ganglion. 2. Ascend or descend to a higher or lower ganglion before synapsing. 3. Continue without synapsing to a prevertebral ganglion. 4. Pass through ganglia and synapse with chromaffin cells in the adrenal medullae.
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42
Q

How does the parasympathetic division affect its effectors?

A

The parasympathetic division usually causes localized responses, with each postganglionic neuron synapsing with only four or five postsynaptic neurons that supply a single visceral effector.

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43
Q

What are autonomic plexuses?

A

Autonomic plexuses are tangled networks of both sympathetic and parasympathetic neurons in the thorax, abdomen, and pelvis, often along major arteries, sometimes containing sympathetic ganglia.

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44
Q

What are the major autonomic plexuses in the thorax?

A

The major autonomic plexuses in the thorax are the cardiac plexus, which supplies the heart, and the pulmonary plexus, which supplies the bronchial tree.

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45
Q

What is the celiac (solar) plexus?

A

The celiac (solar) plexus is the largest autonomic plexus, surrounding the celiac trunk, and it supplies organs such as the stomach, spleen, pancreas, liver, gallbladder, kidneys, adrenal medullae, testes, and ovaries.

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46
Q

What organs are supplied by the superior mesenteric plexus?

A

The superior mesenteric plexus supplies the small and large intestines.

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47
Q

What organs are supplied by the inferior mesenteric plexus?

A

The inferior mesenteric plexus supplies the large intestine.

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48
Q

What is the role of the renal plexus?

A

The renal plexus supplies the renal arteries within the kidneys and ureters.

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49
Q

Where are the sympathetic preganglionic neurons located?

A

The cell bodies of sympathetic preganglionic neurons are located in the lateral gray horns of all thoracic segments and the first two lumbar segments of the spinal cord.

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50
Q

How do sympathetic preganglionic axons travel to the sympathetic trunk?

A

The preganglionic axons travel through the anterior root of a spinal nerve, enter a white ramus, and then pass to the nearest sympathetic trunk ganglion.

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51
Q

What is the function of white rami communicantes?

A

White rami communicantes contain myelinated sympathetic preganglionic axons and connect the anterior ramus of a spinal nerve with the ganglia of the sympathetic trunk.

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52
Q

How many sympathetic trunk ganglia are there?

A

There are 3 cervical, 11 or 12 thoracic, 4 or 5 lumbar, 4 or 5 sacral sympathetic trunk ganglia, and 1 coccygeal ganglion.

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53
Q

What do the postganglionic neurons of the superior cervical ganglion innervate?

A

Postganglionic neurons from the superior cervical ganglion innervate the sweat glands, smooth muscles of the eye, blood vessels of the face, lacrimal glands, pineal gland, nasal mucosa, salivary glands, and the heart.

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54
Q

What is the sympathetic innervation of the heart?

A

Sympathetic innervation of the heart consists of postganglionic neurons from the cervical and thoracic ganglia that enter the cardiac plexus to supply the heart.

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55
Q

What is the sympathetic innervation of the lungs?

A

Sympathetic innervation of the lungs involves postganglionic neurons from the thoracic ganglia that enter the pulmonary plexus to supply the smooth muscle of the bronchi and bronchioles.

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56
Q

What are splanchnic nerves?

A

Splanchnic nerves are formed by sympathetic preganglionic axons that pass through the sympathetic trunk and extend to prevertebral ganglia, supplying the organs of the abdominopelvic cavity.

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57
Q

What is the role of splanchnic nerves to the suprarenal medulla?

A

Splanchnic nerves to the suprarenal medulla stimulate chromaffin cells in the adrenal glands to release hormones, mainly epinephrine, norepinephrine, and a trace of dopamine.

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58
Q

Where are parasympathetic preganglionic neurons located?

A

Parasympathetic preganglionic neurons are found in the nuclei in the brainstem and the lateral gray matter of the second through fourth sacral segments of the spinal cord.

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59
Q

What is the cranial parasympathetic outflow?

A

The cranial parasympathetic outflow consists of preganglionic axons that extend from the brainstem in four cranial nerves.

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60
Q

What are the four pairs of cranial parasympathetic ganglia?

A

The four pairs of cranial parasympathetic ganglia are the ciliary, pterygopalatine, submandibular, and otic ganglia.

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61
Q

Where is the ciliary ganglion located, and what does it innervate?

A

The ciliary ganglion is located lateral to the optic nerve near the posterior orbit. It innervates smooth muscle fibers in the eyeball.

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62
Q

Where is the pterygopalatine ganglion located, and what does it innervate?

A

The pterygopalatine ganglion is located lateral to the sphenopalatine foramen, between the sphenoid and palatine bones. It innervates structures in the head such as the lacrimal glands and mucosal glands.

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63
Q

What are the two classifications of autonomic neurons based on the neurotransmitter they produce and release?

A

Autonomic neurons are classified as cholinergic or adrenergic based on the neurotransmitter they produce and release.

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64
Q

What neurotransmitter do cholinergic neurons release?

A

Cholinergic neurons release acetylcholine (ACh).

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65
Q

Which autonomic neurons are cholinergic?

A

Cholinergic neurons include: 1) all sympathetic and parasympathetic preganglionic neurons, 2) sympathetic postganglionic neurons that innervate sweat glands, and 3) all parasympathetic postganglionic neurons.

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66
Q

What are the two types of cholinergic receptors?

A

The two types of cholinergic receptors are nicotinic receptors and muscarinic receptors.

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67
Q

Where are nicotinic receptors located?

A

Nicotinic receptors are located in the plasma membrane of dendrites and cell bodies of sympathetic and parasympathetic postganglionic neurons, chromaffin cells of the adrenal medullae, and the motor end plate at the neuromuscular junction.

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68
Q

Where are muscarinic receptors located?

A

Muscarinic receptors are located in the plasma membranes of effector cells (smooth muscle, cardiac muscle, and glands) innervated by parasympathetic postganglionic axons and in sweat glands innervated by cholinergic sympathetic postganglionic neurons.

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69
Q

What effect does ACh have on nicotinic receptors?

A

Activation of nicotinic receptors by ACh causes depolarization and excitation of the postsynaptic cell.

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70
Q

What effect does ACh have on muscarinic receptors?

A

Activation of muscarinic receptors by ACh can cause either depolarization (excitation) or hyperpolarization (inhibition), depending on the cell.

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71
Q

What enzyme inactivates acetylcholine (ACh)?

A

Acetylcholine is inactivated by the enzyme acetylcholinesterase (AChE).

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72
Q

What neurotransmitter do adrenergic neurons release?

A

Adrenergic neurons release norepinephrine (NE), also known as noradrenaline.

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73
Q

What are the two main types of adrenergic receptors?

A

The two main types of adrenergic receptors are alpha (α) receptors and beta (β) receptors.

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74
Q

What are the subtypes of adrenergic receptors?

A

The subtypes of adrenergic receptors are α1, α2, β1, β2, and β3.

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75
Q

What is the typical effect of activation of α1 and β1 receptors?

A

Activation of α1 and β1 receptors generally produces excitation.

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76
Q

What is the typical effect of activation of α2 and β2 receptors?

A

Activation of α2 and β2 receptors generally causes inhibition of effector tissues.

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77
Q

Where are β3 receptors found, and what do they do when activated?

A

β3 receptors are found on cells of brown adipose tissue, and their activation causes thermogenesis (heat production).

78
Q

How does norepinephrine affect alpha and beta receptors?

A

Norepinephrine stimulates alpha receptors more strongly than beta receptors.

79
Q

What neurotransmitter is released by the adrenal medulla?

A

The adrenal medulla releases epinephrine as a hormone.

80
Q

How is the activity of norepinephrine terminated?

A

The activity of norepinephrine is terminated either by reuptake by the releasing neuron or enzymatic inactivation by catechol-O-methyltransferase (COMT) or monoamine oxidase (MAO).

81
Q

How does the duration of the effect of norepinephrine compare to acetylcholine?

A

Norepinephrine lingers in the synaptic cleft longer than acetylcholine, causing longer-lasting effects.

82
Q

What is the major location of nicotinic receptors?

A

Plasma membrane of postganglionic sympathetic and parasympathetic neurons, chromaffin cells of adrenal medullae, and sarcolemma of skeletal muscle fibers (motor end plate).

83
Q

What is the effect of activating nicotinic receptors?

A

Excitation → impulses in postganglionic neurons, epinephrine and norepinephrine secretion, and excitation → contraction in skeletal muscle.

84
Q

Where are muscarinic receptors located?

A

Effectors innervated by parasympathetic postganglionic neurons, sweat glands innervated by cholinergic sympathetic postganglionic neurons, and skeletal muscle blood vessels innervated by cholinergic sympathetic postganglionic neurons.

85
Q

What happens when muscarinic receptors are activated?

A

In some receptors, excitation; in others, inhibition. Increased sweating in sweat glands, and inhibition → relaxation → vasodilation in skeletal muscle blood vessels.

86
Q

What is the major location of 𝛼1 adrenergic receptors?

A

Smooth muscle fibers in blood vessels serving salivary glands, skin, mucosal membranes, kidneys, and abdominal viscera; radial muscle in iris of eye; sphincter muscles of stomach and urinary bladder.

87
Q

What effect does activation of 𝛼1 adrenergic receptors have?

A

Excitation → contraction, causing vasoconstriction, pupil dilation, and closing of sphincters.

88
Q

Where are 𝛼1 adrenergic receptors also located, and what do they do?

A

Salivary gland cells (secretion of K+ and water) and sweat glands on palms and soles (increased sweating).

89
Q

Where are 𝛼2 adrenergic receptors located?

A

Smooth muscle fibers in some blood vessels, cells of pancreatic islets (beta cells), pancreatic exocrine acinar cells, and platelets in blood.

90
Q

What happens when 𝛼2 adrenergic receptors are activated?

A

Inhibition → relaxation → vasodilation in smooth muscle, decreased insulin secretion, inhibition of digestive enzyme secretion, and platelet aggregation to form a plug.

91
Q

What is the major location of 𝛽1 adrenergic receptors?

A

Smooth muscle in walls of airways, blood vessels serving heart, skeletal muscle, adipose tissue, liver, and walls of visceral organs (e.g., urinary bladder).

92
Q

What effects occur when 𝛽1 adrenergic receptors are activated?

A

Inhibition → relaxation, causing dilation of airways, vasodilation, and relaxation of organ walls, including the ciliary muscle in the eye.

93
Q

What happens in the liver when 𝛽1 adrenergic receptors are activated?

A

Glycogenolysis (breakdown of glycogen into glucose).

94
Q

Where are 𝛽3 adrenergic receptors located?

A

Brown adipose tissue.

95
Q

What effect occurs when 𝛽3 adrenergic receptors are activated?

A

Thermogenesis (heat production).

96
Q

What is an agonist?

A

An agonist is a substance that binds to and activates a receptor, mimicking the effect of a natural neurotransmitter or hormone.

97
Q

What is an example of an adrenergic agonist and its effect?

A

Phenylephrine is an adrenergic agonist at 𝛼1 receptors. It constricts blood vessels in the nasal mucosa, reducing mucus production and relieving nasal congestion.

98
Q

What is an antagonist?

A

An antagonist is a substance that binds to and blocks a receptor, preventing a natural neurotransmitter or hormone from exerting its effect.

99
Q

What is an example of a muscarinic receptor antagonist and its effects?

A

Atropine is an antagonist that blocks muscarinic ACh receptors. It dilates the pupils, reduces glandular secretions, and relaxes smooth muscle in the gastrointestinal tract.

100
Q

What are some uses of atropine?

A

Atropine is used to dilate pupils during eye exams, treat smooth muscle disorders like iritis and intestinal hypermotility, and as an antidote for chemical warfare agents that inactivate acetylcholinesterase.

101
Q

What is autonomic tone?

A

Autonomic tone is the balance between sympathetic and parasympathetic activity, regulated by the hypothalamus, where the sympathetic and parasympathetic divisions typically work in opposition.

102
Q

What structures receive only sympathetic innervation?

A

Structures that receive only sympathetic innervation include sweat glands, arrector pili muscles, kidneys, spleen, most blood vessels, and adrenal medullae.

103
Q

What happens during high sympathetic tone?

A

High sympathetic tone favors body functions that support vigorous physical activity, increases heart rate and blood pressure, dilates airways, and reduces energy storage processes.

104
Q

What is the fight-or-flight response?

A

The fight-or-flight response includes physiological changes like pupil dilation, increased heart rate and blood pressure, airway dilation, blood vessel constriction to non-essential organs, blood vessel dilation to muscles and vital organs, glycogenolysis in the liver, lipolysis in adipose tissue, and inhibition of non-essential processes.

105
Q

Why do sympathetic effects last longer than parasympathetic effects?

A

Sympathetic effects last longer because sympathetic axons diverge more extensively, norepinephrine lingers in the synaptic cleft longer than acetylcholine, and epinephrine and norepinephrine from the adrenal medullae prolong the response by circulating in the blood.

106
Q

What is the role of the parasympathetic division?

A

The parasympathetic division enhances rest-and-digest activities, conserving and restoring body energy during rest and recovery.

107
Q

What is the acronym SLUDD used to remember?

A

SLUDD stands for salivation (S), lacrimation (L), urination (U), digestion (D), and defecation (D), which are all parasympathetic responses.

108
Q

What are the “three decreases” in parasympathetic responses?

A

The “three decreases” in parasympathetic responses are decreased heart rate, decreased diameter of airways (bronchoconstriction), and decreased diameter of pupils (pupil constriction).

109
Q

What is the distribution of the sympathetic division?

A

The sympathetic division has a wide distribution across the body, including the skin, sweat glands, arrector pili muscles of hair follicles, adipose tissue, and smooth muscle of blood vessels.

110
Q

What is the distribution of the parasympathetic division?

A

The parasympathetic division is limited mainly to the head and the viscera of the thorax, abdomen, and pelvis, with some blood vessels affected.

111
Q

Where are the preganglionic neuron cell bodies located in the sympathetic division?

A

The preganglionic neuron cell bodies are located in the lateral gray horns of spinal cord segments T1–L2.

112
Q

Where are the preganglionic neuron cell bodies located in the parasympathetic division?

A

The preganglionic neuron cell bodies are located in the nuclei of cranial nerves III, VII, IX, and X, and in the lateral gray matter of spinal cord segments S2–S4.

113
Q

What are the associated ganglia in the sympathetic division?

A

The sympathetic division has sympathetic trunk ganglia and prevertebral ganglia.

114
Q

What are the associated ganglia in the parasympathetic division?

A

The parasympathetic division has parasympathetic ganglia.

115
Q

Where are the ganglia located in the sympathetic division?

A

The ganglia in the sympathetic division are close to the CNS and distant from visceral effectors.

116
Q

Where are the ganglia located in the parasympathetic division?

A

The ganglia in the parasympathetic division are typically near or within the walls of visceral effectors.

117
Q

How do the axon lengths and divergence compare between the sympathetic and parasympathetic divisions?

A

In the sympathetic division, preganglionic neurons have short axons and synapse with many postganglionic neurons that have long axons, passing to many visceral effectors. In the parasympathetic division, preganglionic neurons have long axons and usually synapse with four to five postganglionic neurons that have short axons, passing to a single visceral effector.

118
Q

What is the role of white and gray communicating rami in the sympathetic division?

A

The sympathetic division has both white and gray communicating rami. The white rami contain myelinated preganglionic axons, and the gray rami contain unmyelinated postganglionic axons.

119
Q

Are white and gray communicating rami present in the parasympathetic division?

A

No, the parasympathetic division does not have white or gray communicating rami.

120
Q

What neurotransmitters are involved in the sympathetic division?

A

In the sympathetic division, preganglionic neurons release acetylcholine (ACh), and most postganglionic neurons release norepinephrine (NE). Postganglionic neurons that innervate most sweat glands and some blood vessels in skeletal muscle release ACh.

121
Q

What neurotransmitters are involved in the parasympathetic division?

A

In the parasympathetic division, preganglionic neurons release acetylcholine (ACh), and postganglionic neurons also release ACh.

122
Q

What physiological effects are associated with the sympathetic division?

A

The sympathetic division is responsible for fight-or-flight responses.

123
Q

What physiological effects are associated with the parasympathetic division?

A

The parasympathetic division is responsible for rest-and-digest activities.

124
Q

What is the effect of sympathetic stimulation on the adrenal medullae?

A

Sympathetic stimulation causes the secretion of epinephrine and norepinephrine (nicotinic ACh receptors).

125
Q

What is the effect of parasympathetic stimulation on the adrenal medullae?

A

There is no known effect.

126
Q

What is the effect of sympathetic stimulation on the lacrimal (tear) glands?

A

Sympathetic stimulation causes slight secretion of tears (𝛼).

127
Q

What is the effect of parasympathetic stimulation on the lacrimal (tear) glands?

A

Parasympathetic stimulation causes secretion of tears.

128
Q

What is the effect of sympathetic stimulation on the pancreas?

A

Sympathetic stimulation inhibits the secretion of digestive enzymes and insulin (𝛼2), while promoting secretion of glucagon (β2).

129
Q

What is the effect of parasympathetic stimulation on the pancreas?

A

Parasympathetic stimulation promotes secretion of digestive enzymes and insulin.

130
Q

What is the effect of sympathetic stimulation on the posterior pituitary?

A

Sympathetic stimulation causes secretion of antidiuretic hormone (ADH) (β1).

131
Q

What is the effect of parasympathetic stimulation on the posterior pituitary?

A

There is no known effect.

132
Q

What is the effect of sympathetic stimulation on the pineal gland?

A

Sympathetic stimulation increases synthesis and release of melatonin (β).

133
Q

What is the effect of parasympathetic stimulation on the pineal gland?

A

There is no known effect.

134
Q

What is the effect of sympathetic stimulation on adipose tissue?

A

Sympathetic stimulation causes lipolysis (breakdown of triglycerides) and release of fatty acids into the blood (β1, β3).

135
Q

What is the effect of parasympathetic stimulation on adipose tissue?

A

There is no known effect.

136
Q

What is the effect of sympathetic stimulation on the liver?

A

Sympathetic stimulation causes glycogenolysis, gluconeogenesis, and decreased bile secretion (𝛼, β2).

137
Q

What is the effect of parasympathetic stimulation on the liver?

A

Parasympathetic stimulation promotes glycogen synthesis and increased bile secretion.

138
Q

What is the effect of sympathetic stimulation on the kidneys (juxtaglomerular cells)?

A

Sympathetic stimulation causes secretion of renin (β1).

139
Q

What is the effect of parasympathetic stimulation on the kidneys (juxtaglomerular cells)?

A

There is no known effect.

140
Q

What is the effect of sympathetic stimulation on cardiac muscle (heart)?

A

Sympathetic stimulation increases heart rate and the force of atrial and ventricular contractions (β1).

141
Q

What is the effect of parasympathetic stimulation on cardiac muscle (heart)?

A

Parasympathetic stimulation decreases heart rate and the force of atrial contraction.

142
Q

What is the effect of sympathetic stimulation on the iris, radial muscle?

A

Sympathetic stimulation causes contraction, resulting in pupil dilation (𝛼1).

143
Q

What is the effect of parasympathetic stimulation on the iris, radial muscle?

A

There is no known effect.

144
Q

What is the effect of sympathetic stimulation on the iris, circular muscle?

A

There is no known effect.

145
Q

What is the effect of parasympathetic stimulation on the iris, circular muscle?

A

Parasympathetic stimulation causes contraction, resulting in pupil constriction.

146
Q

What is the effect of sympathetic stimulation on the ciliary muscle of the eye?

A

Sympathetic stimulation causes relaxation to adjust the shape of the lens for distant vision (β2).

147
Q

What is the effect of parasympathetic stimulation on the ciliary muscle of the eye?

A

Parasympathetic stimulation causes contraction for close vision.

148
Q

What is the effect of sympathetic stimulation on the lungs, bronchial muscle?

A

Sympathetic stimulation causes relaxation, resulting in airway dilation (β2).

149
Q

What is the effect of parasympathetic stimulation on the lungs, bronchial muscle?

A

Parasympathetic stimulation causes contraction, resulting in airway constriction.

150
Q

What is the effect of sympathetic stimulation on the gallbladder and ducts?

A

Sympathetic stimulation causes relaxation, facilitating storage of bile in the gallbladder (β2).

151
Q

What is the effect of parasympathetic stimulation on the gallbladder and ducts?

A

Parasympathetic stimulation causes contraction, resulting in the release of bile into the small intestine.

152
Q

What is the effect of sympathetic stimulation on the stomach and intestines?

A

Sympathetic stimulation decreases motility and tone (𝛼1, 𝛼2, β2) and contracts sphincters (𝛼1).

153
Q

What is the effect of parasympathetic stimulation on the stomach and intestines?

A

Parasympathetic stimulation increases motility and tone and relaxes sphincters.

154
Q

What is the effect of sympathetic stimulation on the spleen?

A

Sympathetic stimulation causes contraction and discharge of stored blood into the general circulation (𝛼1).

155
Q

What is the effect of parasympathetic stimulation on the spleen?

A

There is no known effect.

156
Q

What is the effect of sympathetic stimulation on the ureter?

A

Sympathetic stimulation increases motility (𝛼1).

157
Q

What is the effect of parasympathetic stimulation on the ureter?

A

Parasympathetic stimulation increases motility.

158
Q

What is the effect of sympathetic stimulation on sex organs in males?

A

Sympathetic stimulation causes contraction of smooth muscle in the ductus deferens, prostate, and seminal glands, resulting in ejaculation (𝛼1).

159
Q

What is the effect of parasympathetic stimulation on sex organs in males?

A

Parasympathetic stimulation causes vasodilation and erection of the penis.

160
Q

What is the effect of sympathetic stimulation on sex organs in females?

A

Sympathetic stimulation causes contraction of smooth muscle in the ductus deferens, prostate, and seminal glands, resulting in ejaculation (𝛼1).

161
Q

What is the effect of parasympathetic stimulation on sex organs in females?

A

Parasympathetic stimulation causes vasodilation and erection of the clitoris.

162
Q

What is the effect of sympathetic stimulation on arrector muscles of hair?

A

Sympathetic stimulation causes contraction, resulting in the erection of hairs and goosebumps (𝛼1).

163
Q

What is the effect of parasympathetic stimulation on arrector muscles of hair?

A

There is no known effect.

164
Q

What is the effect of sympathetic stimulation on salivary gland arterioles?

A

Sympathetic stimulation causes vasoconstriction, which decreases saliva secretion (𝛼1).

165
Q

What is the effect of parasympathetic stimulation on salivary gland arterioles?

A

Parasympathetic stimulation causes vasodilation, which increases saliva secretion.

166
Q

What is the effect of sympathetic stimulation on gastric gland arterioles?

A

Sympathetic stimulation causes vasoconstriction, inhibiting secretion (𝛼1).

167
Q

What is the effect of parasympathetic stimulation on gastric gland arterioles?

A

Parasympathetic stimulation causes secretion of gastric juice.

168
Q

What is the effect of sympathetic stimulation on intestinal gland arterioles?

A

Sympathetic stimulation causes vasoconstriction, inhibiting secretion (𝛼1).

169
Q

What is the effect of parasympathetic stimulation on intestinal gland arterioles?

A

Parasympathetic stimulation causes secretion of intestinal juice.

170
Q

What is the effect of sympathetic stimulation on coronary (heart) arterioles?

A

Sympathetic stimulation causes relaxation (vasodilation) (β2) and contraction (vasoconstriction) (𝛼1, 𝛼2).

171
Q

What is the effect of parasympathetic stimulation on coronary (heart) arterioles?

A

There is no known effect.

172
Q

What is the effect of sympathetic stimulation on skin and mucosal arterioles?

A

Sympathetic stimulation causes contraction (vasoconstriction) (𝛼1).

173
Q

What is the effect of parasympathetic stimulation on skin and mucosal arterioles?

A

Parasympathetic stimulation causes vasodilation, which may not be physiologically significant.

174
Q

What is the effect of sympathetic stimulation on skeletal muscle arterioles?

A

Sympathetic stimulation causes contraction (vasoconstriction) (𝛼1) and relaxation (vasodilation) (β2).

175
Q

What is the effect of parasympathetic stimulation on skeletal muscle arterioles?

A

There is no known effect.

176
Q

What is the effect of sympathetic stimulation on brain arterioles?

A

Sympathetic stimulation causes slight contraction (vasoconstriction) (𝛼1).

177
Q

What is the effect of parasympathetic stimulation on brain arterioles?

A

There is no known effect.

178
Q

What is the effect of sympathetic stimulation on kidney arterioles?

A

Sympathetic stimulation causes constriction of blood vessels, decreasing urine volume (𝛼1).

179
Q

What is the effect of parasympathetic stimulation on kidney arterioles?

A

There is no known effect.

180
Q

What are autonomic (visceral) reflexes?

A

Autonomic (visceral) reflexes are responses that occur when nerve impulses pass through an autonomic reflex arc, regulating conditions like blood pressure, digestion, defecation, and urination.

181
Q

What are the key functions of autonomic reflexes?

A

Autonomic reflexes regulate blood pressure, heart rate, force of ventricular contraction, blood vessel diameter, digestion, motility and muscle tone of the gastrointestinal tract, and sphincter control for defecation and urination.

182
Q

What are the components of an autonomic reflex arc?

A

The components are: sensory receptor, sensory neuron, integrating center, motor neurons, and effector.

183
Q

What is the role of sensory receptors in autonomic reflexes?

A

Sensory receptors detect stimuli (such as stretching or chemical composition) and produce a change that triggers nerve impulses. They are usually associated with interoceptors.

184
Q

What is the function of sensory neurons in an autonomic reflex arc?

A

Sensory neurons conduct nerve impulses from receptors to the CNS.

185
Q

Where are the integrating centers for most autonomic reflexes located?

A

The integrating centers are mainly in the hypothalamus and brainstem, with some autonomic reflexes (e.g., urination and defecation) involving centers in the spinal cord.

186
Q

What are motor neurons in the autonomic reflex arc?

A

Motor neurons transmit nerve impulses from the integrating center to an effector, with preganglionic and postganglionic neurons connecting the CNS to the effector.

187
Q

What are effectors in autonomic reflexes?

A

Effectors are smooth muscle, cardiac muscle, and glands.

188
Q

How does the hypothalamus control autonomic functions?

A

The hypothalamus receives sensory input from visceral functions, olfaction, gustation, temperature, and emotional input. It influences autonomic centers in the brainstem and spinal cord, regulating functions like heart rate and blood pressure.

189
Q

How is the hypothalamus anatomically connected to the ANS?

A

The hypothalamus is connected to the sympathetic and parasympathetic divisions of the ANS through axons of neurons that form tracts to nuclei in the brainstem and spinal cord.

190
Q

Which areas of the hypothalamus control the sympathetic division?

A

The posterior and lateral parts of the hypothalamus control the sympathetic division, increasing heart rate, blood pressure, body temperature, pupil dilation, and inhibiting the gastrointestinal tract.

191
Q

Which areas of the hypothalamus control the parasympathetic division?

A

The anterior and medial parts of the hypothalamus control the parasympathetic division, decreasing heart rate, blood pressure, constricting pupils, and increasing gastrointestinal secretion and motility.

BIOL 235 Human Anatomy and Physiology (5 decks)

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