A + P II: ANS

What are the divisions of the autonomic nervous system?

- Sympathetic division - Parasympathetic division

In the brain, vision originates in the rods and cones in the retina. Separate regions of the brain decode basic information, like color, shapes, intensity of light, and there are other regions that decode information like position in space, and awareness of patterns. As you use your visual system, all of these regions are working simultaneously. This simultaneous awareness of all regions working at the same time is due to which processing pattern listed below? A. Oscillative processing B. Reflexive processing C. Parallel processing D. Serial processing

C; In parallel processing, inputs are segregated into many pathways, and different parts of the neural circuitry deal simultaneously with the information delivered by each pathway. This helps us understand all of the different types of information in our visual fields simultaneously.

Which of the following is responsible for the overall integration of the autonomic nervous system (ANS)? A. Peripheral ganglia B. Cerebral cortex C. Hypothalamus D. Brain stem

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

What do the cholinergic fibers release?

Norepinephrine

The sympathetic division promotes metabolic effects that are ____ _______ by the parasympathetic division

Not reversed

What is the sympathetic division also known as?

"Fight or Flight"

What is the parasympathetic division also known as?

"Resting + Digesting"

What are catecholamines?

- 85% epinephrine (adrenaline) - 15% norepinephrine (noradrenaline)

What body parts does the sympathetic division control?

- Adrenal glands - Sweat glands - Arrector pili muscles - Kidneys - Blood vessels

What are the divisions of the motor division?

- Autonomic nervous system - Somatic nervous system

What are the functions of the ANS?

- Blood pressure - Digestion - Secretion - Respiration

How does the parasympathetic division work when a person is relaxing after a meal?

- Blood pressure, heart rate, and respiratory rates are low - Gastrointestinal tract activity is high - The skin is warm + the pupils are CONSTRICTED

What does the sympathetic tone do?

- Constricts blood vessels + causes blood pressure to rise as needed - Prompts vessels to dilate if blood pressure is to be decreased

What are the 3 D's of the parasympathetic division?

- Digestion - Defecation - Diuresis

What are the sympathetic outcomes?

- Dilate pupils and irises, inhibit salivary glands, stimulate lifting of eyelid - Increase heart + breathing rate - Shut down digestion- inhibits visceral organ activities - Ejaculation + uterine contractions - Can synapse in adrenal gland, stimulating adrenaline (nor/epinephrine) release**

What are the 4 E's of the sympathetic division?

- Exercise - Excitability - Emergency - Embarrassment

How does the sympathetic division work when a person is threatened?

- Heart rate increases - Breathing is rapid + deep - The skin is cold + sweaty - Pupils DILATE

How does the sympathetic division effect metabolism?

- Increases the metabolic rate of body cells - Raises blood glucose levels - Mobilizes fat as a food source - Stimulates the reticular activating system (RAS) of the brain, increasing mental alertness

How does the sympathetic division work during exercise?

- It promotes adjustments during exercise - The blood flow to organs is reduced, flow to the muscles is increased

What are the functions of the sympathetic division?

- Mobilizes the body during extreme situations - Increases heart rate - Increases blood pressure - Increases airflow - Increases blood glucose

What are the functions of the parasympathetic division?

- Performs maintenance activities - Conserves body energy - Decreases heart rate - Decreases blood pressure - Decreases airflow - Decreases blood glucose

What are the parasympathetic outcomes?

- Pupils constrict, lenses to bulge - Stimulate salivary glands - Slow heart + breathing rates - innervate and activate major digestive organs - Sacral outflow: large intestine, urinary bladder, reproductive organs - Shunts blood to reproductive organs

What does the adrenal medulla do?

- Secretes a mixture of hormones into bloodstream - (essentially a sympathetic ganglion)

What are the divisions of the PNS?

- Sensory division - Motor division

What does the parasympathetic tone do?

- Slows the heart - Dictates normal activity levels of the digestive + urinary systems

What do the motor neurons in the ANS innervate?

- Smooth muscle - Cardiac muscle - Glands

What does the sympathetic division control?

- Thermoregulatory responses to heat - Release of renin from the kidneys to increase blood pressure - Metabolic effects - Stimulate release of adrenaline

In which of the following structures would you expect to see afferent ganglia? A. Glossopharyngeal nerve B. Spinal cord C. Adrenal gland D. Neuromuscular junction

A

Which target organ is NOT affected by the parasympathetic division of the autonomic nervous system (ANS)? A. Adrenal medulla B. Liver C. Heart D. Lungs

A; 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 reflex is triggered when a stranger suddenly grasps your arm? A. Crossed-extensor reflex B. Plantar reflex C. Tendon reflex D. Stretch reflex

A; The grasped arm is withdrawn (via the flexor reflex) as the opposite arm pushes you away from the attacker (via crossed-extensor reflex). As in this scenario, the crossed-extensor reflex often accompanies the flexor reflex.

Which division of the nervous system has long preganglionic neurons? A. Parasympathetic B. Sympathetic C. Somatic sensory D. Somatic neuron

A; The sympathetic division has short preganglionic fibers and long postganglionic fibers. The parasympathetic division has long preganglionic fibers and short postganglionic fibers. The somatic division has a single lower motor fiber (no preganglionic or postganglionic fibers).

Which description is NOT consistent with the sympathetic division? A. Most innervation from the vagus nerve B. Ganglia close to the spinal cord C. Thoracolumbar D. Long postganglionic fibers

A; The vagus nerve innervates most of the parasympathetic division.

What do the nicotinic fibers release?

Acetylcholine

What are the two main neurotransmitters of the ANS?

Acetylcholine + norepinephrine

Which is the outer layer of the adrenal glands?

Adrenal cortex

What is the inner layer of the adrenal glands?

Adrenal medulla

Which drugs interfere with vasomotor fibers + are used to treat hypertension?

Alpha-blockers

What is Renin?

An enzyme that promotes increased blood pressure

Outflow of the sympathetic division occurs from which regions of the CNS? A. Cranial + sacral B. Thoracic + lumbar C. Cervical + lumbar D. Cranial only

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

Which of the following is characteristic of the parasympathetic division? A. Dilated airways B. Stimulates secretory activity C. Increased heart rate D. Inhibited digestion and elimination

B; Secretory activity is controlled by the parasympathetic division of the autonomic nervous system

Which of the following is NOT associated with the parasympathetic division of the autonomic nervous system (ANS)? A. Resting B. Emergency action C. Digesting D. Energy conservation

B; The activity of the sympathetic division, often called the "fight-or-flight" system, is evident when we are excited, exercising, or find ourselves in emergency situations.

Which of the following is an effect of norepinephrine binding to beta 2 adrenergic receptors? A. Vasoconstriction B. Vasodilation C. An increase in heart rate D. Lipolysis

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

A knee-jerk reflex that is unusually strong may be caused by ______. A. Inhibition of reciprocal inhibition B. Transmission of excitatory signals from the brain to the neurons that form the femoral nerve C. Suppression of muscle spindle activity in the lower limb D. Enhancement of activity in the antagonistic muscles

B; The femoral nerve innervates all of the muscles that act to extend the knee (quadriceps).

Which reflex requires gamma motor neurons to set the length of the muscle? A. Tendon reflex B. Stretch reflex C. Flexor reflex D. Crossed-extensor reflex

B; The gamma motor neurons signal the intrafusal muscle fibers, which stretch with the skeletal muscle. If the intrafusal fiber is stretched, sensory receptors initiate the stretch reflex

Which of the following lists the hierarchy of motor control from lowest to highest level of control? A. Segmental level, precommand level, projection level B. Segmental level, projection level, precommand level C. Precommand level, projection level, segmental level D. Projection level, precommand level, segmental level

B; The hierarchy of motor control from lowest to highest level of control is segmental level, projection level, and precommand level.

Which plexus does NOT receive innervation from the vagus nerve? A. Abdominal aortic plexus B. Inferior hypogastric plexus C. Cardiac plexuses D. Pulmonary plexuses

B; The inferior hypogastric plexus receives nerve fibers from the pelvic splanchnic (spinal) nerves, not the vagus (cranial) nerve. As the vagus nerves pass into the thorax, they send branches to the cardiac, pulmonary, and esophageal plexuses. In the abdominal cavity, they send fibers through the large abdominal aortic plexus.

When removing a hot sheet of cookies from the oven, you feel heat coming through the pot holder. What mechanism momentarily overrides your reflexive action to immediately drop the hot cookie sheet? A. Temporary suppression of sensory input to the spinal reflex center B. Intervention by the limbic system to inhibit the fear of being burned C. Modulation of descending motor pathways by brainstem + cortex D. Modification of outgoing efferent signals by spinal cord gray matter interneurons

C

Which of the following target organs/systems is affected by the sympathetic nervous system but is NOT affected by the parasympathetic nervous system? A. Lungs B. Salivary glands C. Cellular metabolism D. Gallbladder

C; 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).

Which of the following best demonstrates an example of cooperation of the parasympathetic + sympathetic nervous systems? A. Sympathetic stimulation causes vasodilation of blood vessels in the clitoris, leading to erection; parasympathetic stimulation then causes reflex contractions of the vagina. B. Parasympathetic stimulation causes copious sweating; sympathetic stimulation causes epidermal pores to dilate. C. Parasympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; sympathetic stimulation then causes ejaculation. D. Sympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; parasympathetic stimulation then causes ejaculation.

C; The best example of cooperative autonomic effects is seen in controls of the external genitalia. Parasympathetic stimulation causes vasodilation of blood vessels in the external genitalia, and is responsible for erection of the male penis or female clitoris during sexual excitement. Sympathetic stimulation then causes the ejaculation of semen by the penis or reflex contractions of the vagina during an orgasm.

Part complete Which of the following is NOT an autonomic nervous system (ANS) function? A. Emptying the bladder B. Gland secretion C. Reflex of skeletal muscle D. Increasing heart rate

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

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

C; There is no separate receptor for epinephrine. It enhances the sympathetic pathways because it binds to the same receptors as norepinephrine.

Which receptor paring below is correct? A. Nicotinic: norepinephrine B. Alpha 1: acetylcholine C. Muscarinic: norepinephrine D. Nicotinic; acetylchline

D; Nicotinic receptors are one of two acetylcholine receptors.

Which of the following is NOT a designation for sympathetic ganglia? A. Collateral ganglia B. Trunk ganglia C. Prevertebral ganglia D. Terminal ganglia

D; Parasympathetic ganglia are also called terminal ganglia because they lie close to or within the target organs.

Which of these activities is most likely driven by parasympathetic innervation? A. Sweating + dilating pupils B. Fight or flight responses C. Vigorous physical activity D. Resting + digesting

D; 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 organ receives major input from the sympathetic, but not parasympathetic, division? A. Salivary glands B. Heart C. Bladder D. Skin

D; The smooth muscle of dermal blood vessels and arrector pili are innervated by the sympathetic, but not parasympathetic, division.

What differentiates an autonomic reflex from a somatic reflex? A. An integration center B. Presence of a sensory receptor C. A single sensory neuron in the sensory pathway D. A two-neuron motor pathway

D; 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 is a way in which the somatic and autonomic nervous systems are similar? A. Both systems share common effectors. B. Both systems share common efferent pathways. C. Both systems have ganglia in their motor pathways. D. Both systems elicit the same target organ responses to their neurotransmitters. E. None of the listed responses is correct.

E; Each of the factors is different in the somatic + autonomic efferent pathways

True or False: The major anatomic difference in autonomic reflex arcs is that there are two sensory afferents.

False; The major anatomical difference in autonomic reflex pathways is that there are two motor neurons, the pre- and postganglionic motor neurons.

What is the main integration center of ANS activity?

Hypothalamus

The sympathetic division controls blood pressure + keeps the blood vessels in a continual state of ________ _______.

Partial constriction

ACh is released by all ___ganglionic axons and all parasympathetic ___ganglionic axons.

Pre;post

What does applying heat to the skin do to the blood vessels?

Reflex dilation

What does the adrenal cortex do?

Secretes steroid hormones

Where are the adrenal glands?

Superior poles of the kidneys

(Parasympathetic/Sympathetic) impulses activate the kidneys to release renin.

Sympathetic

What kind of axons are with cholinergic fibers?

Sympathetic postganglionic axons

True or False: Dilation brings warm blood to the surface + activates sweat glands to cool the body

True

True or False: Systemic body temperature elevation results in widespread dilation of blood vessels

True

True or False: The sympathetic + parasympathetic division counterbalance each other.

True

True or False: Part complete The sympathetic division innervates targets with nerves that all originate from the thoracolumbar region.

True; The sympathetic division is also called the thoracolumbar division of the autonomic nervous system because the thoracic and upper lumbar spinal segments contain the cell bodies of all preganglionic sympathetic neurons.

What is the sympathetic tone also known as?

Vasomotor tone

What kind of reflexes are in the ANS?

Visceral

When is a time where the parasympathetic division would come in?

When a person is relaxing after a meal

When is a time where the sympathetic division would come in?

When a person is threatened

Can the sympathetic division override the effects of the parasympathetic tone during times of stress?

Yes