chapter 9 - 9.15 - 9.16 TEST

The somatic nerve fibers of the PNS connect cranial and spinal nerves to skeletal muscles and autonomic nerve fibers of the PNS connect cranial and spinal nerves to viscera and glands. Autonomic nerves are under:

• conscious control (we can think about it and make it happen) Ex: bicep curl in the gym.

• autonomic control (we can NOT control it) Ex: heart beating and food digesting

From where do the spinal nerves project outwards?

• From the brain

• From the space between each vertebrae

• From the heart

• From the muscles

How many pairs of spinal nerves are there?

• 21 pairs

• 31 pairs

• 41 pairs

• 51 pairs

The Auerbach's plexus is located in the Gastrointestinal (GI) tract.

• TRUE

• FALSE

The somatic branch of the PNS is VOLUNTARY, & connects motor neurons from the brain to the:

• skin & skeletal muscles

• viscera and glands

• cardiac muscle

• smooth muscles

What parts of the brain controls autonomic activity?

• medulla oblongata for cardiac, vasomotor, and respiratory activities

• hypothalamus helps regulate body temperature, hunger, thirst, & water and electrolyte balance

• specific centers of the brain, including the limbic system & cerebral cortex = salivating when you are hungry

• ALL OF THE ABOVE

What is the termination point of the spinal cord called?

(see picture)

• Lumbar enlargement

• Cervical enlargement

• Conus medullaris

• Cauda equina

What is is function of the ventral root? DAVE

• Carries motor or efferent output

• Carries sensory or afferent output

The autonomic nervous system includes three divisions -- the sympathetic, parasympathetic & enteric divisions. The functions of the autonomic division are mixed; that is, each activates some organs and inhibits others, (or the divisions work antagonistically, alternately activating or inhibiting the actions of effectors) .

However, the division have important functional differences. What does the enteric division do?

• prepares the body for energy-expending, stressful, or emergency situations, as part of the fight or flight response --- increasing heart & breathing rates

• most active under ordinary, restful conditions, such as after a meal. Restores the body to a resting state after a stressful experience ---- decreases heart & breathing rates

• controls the digestive system. Often communicates with the brain & spinal cord, but it doesn't have to. Receives messages about the food in your stomach, controls contraction of smooth muscles along the digestive tract, & controls the release of hormones along the digestive tract.

Autonomic _________ in both the sympathetic & parasympathic divisions secrete acetylcholine & are therfore called cholinergic fibers. Most sympathetic postganglionic neurons secrete norepinephrine (noradrenalin) and are called adrenergic fibers. The different postganglionic neurotransmitters cause the different effects that the sympathetic and parasympathetic divisions have on their effector organs

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