TOPIC VI: Nervous System IV – MOTOR “OUTPUT”

Question 1

What is the critical role of the motor nervous system?

Answer 1

Controlling most of the organs and physiological processes that keep a person alive and well, including walking, talking, heart rate, digestion and sweating.

Question 2

What is required for coordinated responses to changes in the body’s internal or external environment?

Answer 2

The communication of information from the central nervous system to effectors like skeletal, cardiac, and smooth muscles, as well as many glands.

Question 3

What are the two divisions of the motor nervous system?

Answer 3

Autonomic Nervous System (ANS) and Somatic Nervous System

Question 4

How does the motor nervous system regulate bodily processes?

Answer 4

It regulates involuntary processes through the autonomic nervous system and controls voluntary movements through the somatic nervous system.

Question 5

What is the function of the Autonomic Nervous System (ANS)?

Answer 5

Transmits signals from the CNS to autonomic effectors (smooth muscle, cardiac muscle, glands).

Question 6

How many neurons are in the pathway from the CNS to the effector in the ANS?

Answer 6

Two: preganglionic and postganglionic

Question 7

What are the two types of neurons in the ANS, distinguished by the neurotransmitters they release?

Answer 7

Cholinergic neurons, which release acetylcholine (ACh), and adrenergic neurons, which release norepinephrine (NE).

Question 8

What is the function of the Sympathetic Nervous System (SNS)?

Answer 8

Prepares the body for activity; the “fight or flight” response, and is activated during exercise.

Question 8

What are the two divisions of the Autonomic Nervous System?

Answer 8

Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS).

Question 9

What neurotransmitter does the preganglionic neuron release in the Sympathetic Nervous System (SNS)?

Answer 9

Acetylcholine (ACh); it is cholinergic.

Question 10

What neurotransmitter does the postganglionic neuron typically release in the Sympathetic Nervous System (SNS)? What is the exception?

Answer 10

Typically Norepinephrine (NE); it is adrenergic. The exception is when the effector is a sweat gland.

Question 11

How is acetylcholine (ACh) broken down after stimulating a postsynaptic cell?

Answer 11

By the enzyme acetylcholinesterase (AChE) on the postsynaptic membrane.

Question 12

How is norepinephrine (NE) removed or broken down after stimulating a postsynaptic cell?

Answer 12

It is actively transported back into the synaptic end bulb of the neuron that released it and then broken down by the enzyme monoamine oxidase (MAO).

Question 13

What is the function of the Parasympathetic Nervous System (PSNS)?

Answer 13

“Rest and digest” functions; “housekeeping”.

Question 14

How do the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) typically affect the same organ?

Answer 14

Their effects are usually opposite to one another. For example, SNS increases heart rate, while PSNS decreases heart rate.

Question 15

List the effects of the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) on the pupils of the eyes.

Answer 15

SNS dilates the pupils, while PSNS constricts them.

Question 16

List the effects of the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) on the heart.

Answer 16

SNS increases heart rate and force of contraction, while PSNS decreases heart rate

Question 17

List the effects of the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) on the gastrointestinal tract.

Answer 17

SNS decreases motility, while PSNS increases motility.

Question 18

What is the effect of the Sympathetic Nervous System (SNS) on blood vessels?

Answer 18

Vasoconstriction. However, there is no innervation of blood vessels, except in the penis and clitoris.

Question 19

What is the effect of the Sympathetic Nervous System (SNS) on sweat glands?

Answer 19

Increases secretion (cold sweat)

Question 20

List the effects of the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) on digestive glands.

Answer 20

SNS decreases secretion (except saliva), while PSNS increases secretion (all of them)

Question 21

List the effects of the Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS) on the genitals.

Answer 21

SNS causes ejaculation (male), while PSNS causes erection and lubrication (male and female).

Question 22

What part of the brain has higher control of the ANS?

Answer 22

The hypothalamus.

Question 23

Does the hypothalamus require cerebral input for its ANS functions?

Answer 23

No, there is no conscious control of the effectors. However, emotions can cause autonomic effects.

Question 24

What is the function of the Somatic Nervous System?

Answer 24

Transmits signals from the CNS to skeletal muscle.

Question 25

What are the three types of movement possible through the somatic nervous system?

Answer 25

Reflexes, voluntary, and rhythmic.

Question 26

What are the two types of reflexes?

Answer 26

Spinal reflexes and postural reflexes.

Question 27

What are the levels of motor control?

Answer 27

Planning, signaling directly to lower motor neurons, brain stem nuclei, and spinal cord.

Question 27

What is the role of the cerebellum in motor control?

Answer 27

Planning and initiating movement, storing planned movements, comparing actual movements to the plan, and maintaining balance and muscle tone.

Question 28

What is the role of the basal nuclei in motor control?

Answer 28

Aiding in planning movement, suppressing unwanted motions, and maintaining muscle tone.

Question 28

What are the parts of the Corticospinal (Direct) Pathway?

Answer 28

Upper motor neurons and lower motor neurons.

Question 29

What are the effects of the destruction of upper motor neurons?

Answer 29

Spastic paralysis and exaggerated reflexes, including the Babinski sign.

Question 30

What are the effects of the destruction of lower motor neurons?

Answer 30

Loss of reflex arc and flaccid paralysis with muscle atrophy

Question 31

What is the function of the language implementation system and what areas does it consist of?

Answer 31

Analyzes incoming and produces outgoing word sounds and grammatical structures. Consists of Wernicke’s area, Broca’s area, and basal nuclei.

Question 32

What are the effects of damage to Wernicke’s area?

Answer 32

Poor language comprehension; can speak, but words are meaningless or mixed up.

Question 33

What are the effects of damage to Broca’s area?

Answer 33

Can understand words, but it is difficult to speak or write sensibly (loss of motor control of speech).