chapter 14 physiology

two types of reflex arc

-autonomic reflex arc... affecting inner organs -somatic reflex arc... muscles

norepinephrine

Blood pressure support It can treat low blood pressure and heart failure.

Which pathway(s) compose the autonomic nervous system?

Efferent pathways of the ANS are characterized by a two-neuron chain from the CNS to the effector organ. Both B and C show such an arrangement consisting of both pre- and postganglionic neurons.

In which of the following structures would you expect to see afferent ganglia?

Glossopharyngeal nerve

epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline. Blood pressure support and vasoconstrictor It can treat severe asthma attacks and allergic reactions (including anaphylaxis) in an emergency situation.

The adrenal medulla secretes epinephrine during sympathetic stimulation. Which of the following statements describes why epinephrine would increase the sympathetic response? 1. Epinephrine increases the action of pre- and postganglionic axons. 2. Epinephrine has no effect on sympathetic targets. 3. The same receptors that respond to norepinephrine also respond to epinephrine, increasing the action of both. 4. Epinephrine binds to a separate receptor than norepinephrine, which increases the sympathetic response.

The same receptors that respond to norepinephrine also respond to epinephrine, increasing the action of both. There is no separate receptor for epinephrine. It enhances the sympathetic pathways because it binds to the same receptors as norepinephrine.

vagus nerve

The vagus nerve (cranial nerve X) is a component of the parasympathetic cranial outflow. It controls normal function of organs of the thoracic and upper abdominal cavities.

white rami communicantes

The white rami communicantes connect preganglionic fibers from the spinal cord to the sympathetic trunk.

What differentiates an autonomic reflex from a somatic reflex? 1. a single sensory neuron in the sensory pathway 2. a two-neuron motor pathway 3. an integration center 4. presence of a sensory receptor

a two neuron motor pathway Visceral reflex arcs have essentially the same components as somatic reflex arcs--receptor, sensory neuron, integration center, motor neuron, and effector. A key difference is that a visceral reflex arc has two neurons in its (autonomic) motor component, whereas the somatic reflex arc has a single (somatic) motor neuron.

Which of the following would not be an example of autonomic neuropathy? 1. diarrhea 2. constipation 3. abnormal stretch reflex responses 4. hyposecretion by sudoriferous glands

abnormal stretch reflex responses The stretch reflex is controlled by a somatic reflex arc which includes afferent input from stretch receptors and output along somatic motor neurons to skeletal muscle.

Which target organ is not affected by the parasympathetic division of the autonomic nervous system (ANS) 1. adrenal medulla 2. heart 3. lungs 4. liver

adrenal medulla The adrenal medulla is not innervated (thus not affected) by the parasympathetic division of the ANS. Preganglionic sympathetic fibers stimulate the adrenal medulla to secrete epinephrine and norepinephrine (hormones that contribute to the overall fight-or-flight response mediated by the sympathetic division of the ANS) into the bloodstream.

Which of the following target organs/systems is affected by the sympathetic nervous system but is NOT affected by the parasympathetic nervous system? 1. gallbladder 2. lungs 3. salivary glands 4. cellular metabolism

cellular metabolism Preganglionic sympathetic fibers stimulate the adrenal medulla to secrete epinephrine into the bloodstream during "fight-or-flight" situations (such as exercise). In turn, epinephrine increases cellular metabolism (metabolic rate).

autonomic neuropathy

damage to nerves supplying the internal body structures that regulate functions such as blood pressure, heart rate, bowel and bladder emptying, and digestion

Your patient is recovering after a severe allergic reaction to a bee sting. You are instructing him on the use of the epinephrine auto-injection device that has been prescribed for him. Which of the following groups of side effects would NOT be expected after self-injection with epinephrine? 1. Pupillary dilation and increased blood pressure 2. Dry mouth and pallor 3. Excessive salivation and pupillary constriction 4. Rapid heartbeat and tremors

excessive salivation and pupillary constriction These effects are caused by activation of the parasympathetic autonomic nervous system and are mediated by acetylcholine.

Which receptor paring below is correct? 1. muscarinic: norepinephrine 2. alpha 1: acetylcholine 3. nicotinic; acetylchline 4. nicotinic: norepinephrine

nicotinic; acetylchline Nicotinic receptors are one of two acetylcholine receptors.

Which division of the nervous system has long preganglionic neurons? 1. somatic motor 2. somatic sensory 3. parasympathetic 4. sympathetic

parasympathetic The parasympathetic division has long preganglionic fibers and short postganglionic fibers.

Which of these activities is most likely driven by parasympathetic innervation? 1. sweating and dilating pupils 2. vigorous physical activity 3. fight-or-flight responses 4. resting and digesting

resting and digesting The parasympathetic division, sometimes called the "rest and digest" system, keeps body energy use as low as possible, even as it directs vital housekeeping activities like digesting food and eliminating feces and urine.

Which set of details correctly identifies a series of events in a sympathetic pathway? 1. thoracolumbar origin, long preganglionic fiber, NE release at ganglion, short postganglionic fiber, NE release at effector 2. craniosacral origin, short preganglionic fiber, ACh release at ganglion, long postganglionic fiber, ACh release at effector 3. thoracolumbar origin, short preganglionic fiber, ACh release at ganglion, long postganglionic fiber, NE release at effector 4. craniosacral origin, long preganglionic fiber, ACh release at ganglion, short postganglionic fiber, ACh release at effector

thoracolumbar origin, short preganglionic fiber, ACh release at ganglion, long postganglionic fiber, NE release at effector

Which of the following is an effect of norepinephrine binding to beta 2 adrenergic receptors? 1. an increase in heart rate 2. vasoconstriction 3. vasodilation 4. lipolysis

vasodilation The binding of norepinephrine to the beta 2 adrenergic receptors in blood vessels causes vasodilation.

vasodilation

widening of blood vessels

Part complete Assume that the triangular and circular molecules shown in the illustration represent specific neurotransmitters. Which of the following best describes the effect on the heart of neurotransmitters released from the postganglionic neurons of B and C?

Sympathetic stimulation would increase heart rate when under stress, while parasympathetic stimulation would decrease heart rate during "rest and digest." Parasympathetic ganglia are within or near effector organs, while sympathetic ganglia lie nearer to the CNS. Sympathetic postganglionic neurons secrete a different neurotransmitter than somatic and parasympathetic neurons.

Once a preganglionic axon reaches a trunk ganglion, one of three things can happen to the axon. Which of the following is NOT one of these three things? 1. The axon can ascend or descend the sympathetic trunk to synapse in another trunk ganglion. 2. The axon can course back into the spinal cord to synapse with preganglionic neurons in a different spinal segment. 3. The axon can pass through the trunk ganglion and emerge from the sympathetic trunk without synapsing. 4. The axon can synapse with a ganglionic neuron in the same trunk ganglion.

The axon can course back into the spinal cord to synapse with preganglionic neurons in a different spinal segment. Preganglionic axons do not pass back into the spinal cord.

Organophosphate insecticides work by blocking acetylcholinesterase. Which symptom would NOT be typical of poisoning with these agents? 1. Dilated pupils 2. Excessive salivation 3. Muscle cramps 4. High blood pressure

dilated pupils If acetylcholinesterase is blocked, the patient should exhibit "too much" acetylcholine, the neurotransmitter that relays information to skeletal muscles and parasympathetic receptors. In other words, the parasympathetic portion of the autonomic nervous system would exert greater influence. Sympathetic activity dilates pupils, whereas parasympathetic activity constricts them.

Which of the following is responsible for the overall integration of the autonomic nervous system (ANS)? 1. cerebral cortex 2. hypothalamus 3. brain stem 4. peripheral ganglia

hypothalamus The hypothalamus stands at the top of the control hierarchy as the integrator of ANS activity

Which of the following is not an autonomic nervous system (ANS) function? 1. emptying the bladder 2. gland secretion 3. skeletal muscle reflex 4. increasing heart rate

skeletal muscle reflex The somatic nervous system stimulates skeletal muscle, whereas the ANS innervates cardiac muscle, smooth muscle, and glands.

Which of the following releases the neurotransmitter norepinephrine?

terminus of a sympathetic postganglionic neuron. In cases of dual innervation, release of norepinephrine at synapses within effector organs is characteristic of the sympathetic division (B). Sympathetic postganglionic neurons release acetylcholine in areas that receive only sympathetic fibers.

autonomic nervous system (ANS)

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms. -sympathetic -parasympathetic

Outflow of the sympathetic division occurs from which regions of the CNS?

thoracic and lumbar Preganglionic fibers of the sympathetic division arise from the thoracic and upper lumbar regions (T1 to L2) of the spinal cord.