• Autonomic Nervous System (ANS)

urpose of performing the valsalva maneuver?

-clearing the ears when scuba diving or a change in altitude increases pressure -increasing colonic pressure to induce a bowel movement -treat people with supraventricular tachycardia

Whenever dysfunction of the ANS is suspected, it is essential to question the patient fully. Possible symptoms can be grouped by system:

1.Cardiovascular=dizziness/fainting 2.Skin=changes in sweating 3.Gastrointestinal=anorexia, s, nausea, vomiting, diarrhea, constipation, or decreased salivation (dry mouth) 4. Genito-urinary and reproductive=urinary issues/problems with erection 5.Eyes=loss of accommodation and impaired near vision can occur/drooping eyelids (ptosis)

Explain why the heart rate and finger pulse change during a Valsalva maneuver. Include in your explanation how changes in arterial blood pressure, peripheral resistance, and autonomic nervous activity bring about these responses.

1st- intrathoracic pressure raises pressure and drives blood from lungs into left atrium 2. increases stroke volume and small raise in systolic bp small decrease in heart rate 3. decreases veins return and systolic bp falls 4. the fall in systolic bp is detected by carotid sinus and aortic arch baroreceptors activating baroreflex 5. baroreflex increases sympathetic tone and heart rate 6. pressure is released has a small fall in stroke volume ad thoracic vessels fill with blood and stroke volume increases w/ bp returning to normal value

In assessing autonomic nervous system function in a healthy person, which of the following may the Valsalva maneuver result in?

An appreciable increase in heart rate.

How would you expect the latencies and amplitudes in the skin of the hand and the foot compare? Explain any differences in the latencies.

C fibers have unmyelinated slow conduction velocities and are supplied by the postganlionic sympathetic nerves. The foot has greater latency bc nerve impulses have to travel further

Tissue that is only supplied by the parasympathetic division

Ciliary muscle in the eye

Valsalva maneuver has on the cardiovascular system in relation to ANS/What do we expect to see? Medical applications?

Expect to see initial decrease of the heart rate, increase in blood pressure. Can be used to arrest supraventricular tachycardia, or abnormally fast heart rhythm.

T/F the sympathetic nervous system Reduces heart rate and blood pressure

F- parasympathetic typically slows down processes (except digestion and urinary REST AND DIGEST)

Explain the RR interval and what it demonstrates

Heart rate increases = rr interval increases

T/F gut function is part of the autonomic nervous system

Note that the system regulating gut function is often referred to as the enteric nervous system and not everyone includes this as a part of the autonomic nervous system.

constricts pupils, slows heartbeat, constrict airways, stimulate intestines, promote erection, constrict bladdar REST and DIGEST

Parasympathetic

In the parasympathetic system, which of the following is the preganglionic and postganglionic neurotransmitter? In the sympathetic what is the pre and post neurotransmitter?

Parasympathetic is always acetylcholine. sympathetic: preganglionic =acetylcholine, post-ganglionic sympathetic=norepinephrine

ANS Disorders

Parkinson's Disease/Diabetes

Describe the various neuropathies that can potentially be encountered by people with diabetes.

Peripheral: arm weakness/ walking issues/ loss of senses in feet Autonomic: dry skin/ blurry vision/ dizziness/ urination issues

Do the mean RR intervals differ between quiet and deep breathing? How do the SDs differ? Explain these observations.

SD is greater for deep breathing and greater spread of data

In measuring the autonomic nervous system skin potentials, which of the following is true for stimulation of the median nerve?

Stimulation can be on either side.

sweat glands are only supplied by

Sympathetic nervous system

How can you explain the change in potential across the hand that follows peripheral nerve stimulation?

The peripheral nerve stimulation send signals to the brain activating sympathetic nervous system. Sweat is the result of the sympathetic stimulation

4 phases of valsalva maneuver

There are four phases during the Valsalva maneuver. Phase one is the onset of straining with increased intrathoracic pressure. The heart rate does not change but blood pressure rises. Phase two is marked by the decreased venous return and consequent reduction of stroke volume and pulse pressure as straining continues. The heart rate increases and blood pressure drops. Phase three is the release of straining with decreased intrathoracic pressure and normalization of pulmonary blood flow. Phase four marks the blood pressure overshoot (in the normal heart) with return of the heart rate to baseline.

T/F Most organs have nerves from both the sympathetic and parasympathetic nervous systems

True

Moderately forceful attempted exhalation against a closed airway

Valsalva Maneuver

You may observe a change in the skin potential even before the stimulus is delivered. How can you explain this?

a tap, sound in the environment, or movement in cords could show a change in skin potential before the stimulus

It acts to regulate visceral functions that are largely outside of conscious control. It affects cardiac function, digestion, respiration, salivation, sweating, pupil diameter, urination, and sexual arousal

autonomic nervous system

Was there greater heart rate variability during quiet breathing or during deep breathing? Explain your findings.

deep bc an increase happens in tidal volume activates lungs stretch receptors that send impulses to the vagus nerve. Then that info is processed in the brain and an increase in sympathetic and a decrease in parasympathetic is conveyed to the heart.

parasympathetic outflow comes

from the cranial and sacral regions of the spinal cord

sympathetic outflow comes

from the thoraco-lumbar region

ANS controls

heart rate, temperature, breathing rate and digestion

The primary sensory neurons synapse on neurons in a region of the brain called the

medulla, in the nucleus solitarius (nucleus of the solitary tract

acetylcholine (ACh)

parasympathetic system (Exceptions are that ACh is the neurotransmitter for sympathetic postganglionic innervation of sweat glands)

Be able to describe the differences between the sympathetic nervous system and the parasympathetic nervous system

parasympathetic=cranial and sacral regions of the spinal cord, sympathetic outflow =throaco-lumbar region

The ANS is part of the ___ and has both sensory ___ and motor ___ components

peripheral nervous system/(afferent)/(efferent)

The autonomic motor neurons are described as

preganglionic or postganglionic

Describe the volunteer's skin potential response after the startle and gasp stimuli. How can you explain these findings?

sweating from the SNS from stressful stimuli and the gasp occurs by activating the SNS by stimulating stretch receptors in the lung that send impulses on fibers of the vagus nerve

dilate pupils, salivation, heartbeat increased, relaxed airways, inhibit stomach activity, secrete epi and norepi, relax bladdar, promote ejaculation FIGHT OR FLIGHT

sympathetic

norepinephrine

sympathetic system

Short preganglionic axon, long postganglionic axon vs Long preganglionic axon, short postganglionic axon

sympathetic vs parasympathetic

Identify the components that make up the ANS

sympathetic: found in the lateral horn of the grey matter in the thoracic and lumbar regions of the spinal cord parasympathetic

Explain the change in potential in the hand that would follow peripheral nerve stimulation

the stimulation is conveyed to the brain that activates sympathetic nervous system activating sweat glands.