Autonomic Nervous System

Question 1

chief goals of the autonomic nervous sytem

Answer 1

• maintain homeostasis
• allostasis
• adjustments sometimes, but rarely, require voluntary actions and awareness of internal state sometimes comes to consciousness via emotional experience

Question 2

homeostasis

Answer 2

-steady state of bodily function centered around a set point

Question 3

allostasis

Answer 3

-stability through change

Question 4

multi-units

Answer 4

• involve large numbers of postganglionic fibers, each in close contact with smooth muscle fibers
• this arrangement provides independent and more precise control of contraction

Question 5

single units

Answer 5

• involve small numbers of postgangionic fibers, which only contact a small number of muscle fibers
• the smooth muscle fibers not in direct contract either receive transmitter via diffusion or are activated via gap junctions
• the fibers contract in synchrony

Question 6

Sympathetic effect on pupil: ciliary muscle

Answer 6

dilation!: increases light

-ciliary relaxation leads to far vision

Question 7

parasympathetic effect on pupil and ciliary muscles

Answer 7

pupil: contracts (sphincter)—> decreases light

ciliary muscle contracts –> near vision

Question 8

sympathetic effects on lacrimal, salivary glands

Answer 8

-vasoconsriction, slight secretions and decreased digestions! This allows blood to flow to muscles

Question 9

parasympathetic effects on lacrimal, salivary glands

Answer 9

• vasodilation; copious- this cleans the cornea

- watery secretions- increase digestion

Question 10

sympathetic effects on the heart

Answer 10

• increased heart rate, increased force of contraction, and ouput; coronary vasodilation (B)
• these all seek to enhance cardiovascular performance

Question 11

parasympathetic effects on the heart

Answer 11

• decreased heart and cardiac output

- heart is at rest

Question 12

sympathetic effects on bronchi and lungs

Answer 12

-bronchodilation (B), decreased secretions, and increased respirations

Question 13

parasympathetic effect on the bronchi and lungs

Answer 13

• bronchoconstriction and increased secretions

- this helps remove contaminants

Question 14

sympathetic effects on the stomach, pancreas, and intestines

Answer 14

decreased peristalsis, decreased secretion, and vasocconstriction

Question 15

parasympathetic effects on the stomach, pancreas, and intestines

Answer 15

-increased peristalsis and secretion; vasodilation

Question 16

sympathetic effects on urinary bladder

Answer 16

-constriction of internal sphincter; urinary retention

Question 17

parasympathetic effects on the urinary bladder

Answer 17

-contraction of detrusor muscle; relaxation of internal sphincter

Question 18

sympathetic effects on extremities

Answer 18

• sweat secretion, vasoconstriction, piloerection, vasodilation in muscles (B)
• this redistributes blood flow to the muscles and it decreases temperatures

Question 19

sympathetic effects on the face

Answer 19

-vasodilation and blushing

Question 20

mydriasis

Answer 20

-dilation of the pupil

Question 21

superior cervical ganglion

Answer 21

-gives out sympathetic dilatory fibers

Question 22

ciliary ganglion

Answer 22

-gives out parasympathetic fibers

Question 23

pupillary light reflex is mediated by

Answer 23

-parasympathetic system

Question 24

accessory oculomotor nucleus is also called the

Answer 24

-Edinger-Westphal

Question 25

how will the pupillary light reflex show unilateral optic nerve damage?

Answer 25

-the reflex will be abolished in both eyes, but only when light is shown into the ipsilateral eye

Question 26

how will unilateral oculomotor nerve damage affect the pupillary light reflex?

Answer 26

-will abolish then reflex in the ipsilateral eye, regardless of where light is shown

Question 27

a patient with fixed and dilated eyes may be suspected of having

Answer 27

-damage to the midbrain

Question 28

What drug can suppress the pupillary light reflex?

Answer 28

-atropine

Question 29

what is the main pacemaker of the heart? What is its backup?

Answer 29

• the sinatrial node is the main pacemaker of the heart (SA node)
• the atriventricular node (AV) can operate as pacemaker if the SA node is disabled

Question 30

sympathetic innervation to the heart comes from the

Answer 30

-paravertebral chain and extends beyond the nodes to the cardiac muscle itself

Question 31

do many autonomic nerves carry sensory fibers and motor fibers?

Answer 31

-YES!

Question 32

sensory cells of the autonomic nervous system

Answer 32

• typically pseudounipolar
• soma typically in cranial or dorsal root ganglia
• most are thin Ad or c fibers
• can be nociceptors, chemoreceptors, and mechanoreceptors

Question 33

where do chemoreceptors of blood gases lie in the body?

Answer 33

-carotid body: between the internal and external branches of the carotid artery

Question 34

chemoreceptor cells release transmitter onto afferents of which cranial nerve?

Answer 34

glossopharyngeal nerve

Question 35

where does the glossopharyngeal project to after it receives transmitter from the chemoreceptors

Answer 35

nucleus of the solitary tracts

Question 36

the nucleus of the solitary tracts will alter the activity of the

Answer 36

-reticulospinal neurons and increase respiratory rate and increase blood flow to the brain

Question 37

where do stretch receptors lie? what do they do?

Answer 37

-stretch receptors detect blood pressure and lie within the carotid sinus of the carotid artery

Question 38

the caudal nucleus of solitary tract (NTS) receives

Answer 38

visceral afferents signals from the vagus and glossopharyngeal nerves

Question 39

the efferents of the NTS include

Answer 39

ascending inputs to other nuclei that regulate autonomic function like the hypothalamus and the limbic system

Question 40

Horner’s syndrome

Answer 40

associated with interruption of the sympathetic input to the head, usually as a result of a tumor to the superior cervical ganglion

• unilateral
• face is warm due to lack of sympathetic input
• drooping eyelids
• maybe caused by internal carotid dissection which could lead to massive strokes