Chapter 7 - Quiz 3

Question 1

7.1 Muscles and their movement

What three categories do vertebrate muscles fall into? Describe each (3)

Answer 1

-smooth muscles that control the digestive system + organs
-skeletal or striated muscles that control the skeleton
-cardiac muscles that control the heart

-each muscle is composed of many fibers

Question 2

7.1 Muscles and their movement Stop and Check Pg 226

Why do we move the eye muscles with greater precision than the biceps muscles?

Answer 2

-Each axon to the biceps muscles innervates about a hundred fibers; therefore, it is not possible to change the movement by a small amount. In contrast, an axon to the eye muscles innervates only about three fibers

-Although each muscle fiber receives information from only one axon, a given axon may innervate more than one muscle fiber.

Question 3

7.1 Muscles and their movements

Define neuromuscular junction. In skeletal muscles, what NT does every axon release at this junction? What does it cause the muscle to do? (2)

Answer 3

-synapse between a motor neuron axon and a muscle fiber
-acetylcholine, causing the muscle to contract

-a deficit of acetylcholine or its receptors impairs movement

Question 4

7.1 Muscles and their movement

Can a muscle relax? Can a muscle move in opposite directions? (2)

Answer 4

-no a muscle can only constrict
-moving something back and forth requires opposing sets of muscles (antagonistic muscles)

Question 5

7.1 Muscles and their movement

Define antagonistic muscles and give an example (2)

Answer 5

-muscles that allow you to move something in opposing directions
-for example, you have one muscle that allows you to bring your wrist up to your elbow and another that allows you to straighten your arm

Question 6

7.1 Muscles and their movement

What are flexor and extensor muscles? Give an example. (2)

Answer 6

-flexor muscles usually bend, extensor usually straightens or extends
-example: one muscle that bends arm and another that straightens it

Question 7

7.1 Muscles and their movements: fast and slow muscles

What are the three main types of muscles fibers? (3)

–describe each, including their general function and ability to fatigue, appearance, aerobic or anaerobic, and general activities

Answer 7

-slow-twitch: slow contraction speed and no fatigue, aerobic, red appearance due to high concentration of mitochondria and myoglobin, non-strenous activities (talking)
-fast-twitch oxidative: middle speed of contraction and more fatigue resistant than final type, moderate capacity for aerobic metabolism, moderate amount of mitochondria and myoglobin, activities that require both endurance and strength
-fast-twitch glycolytic: rapid contraction and fatigue quickly, low capacity for aerobic metabolism and primarily rely on anaerobic glycolysis, fewer mitochondria and myoglobin, suited for short-bursts of high-intensity activity

Question 8

7.1 Muscles and their movements: muscle control by propriocepters

Define proprioceptor and give an example (2)

Answer 8

-receptor that detects the position or movement of a part of the body
-example: walking down a bumpy road. you might set your foot down too hard and your body adjusts for this.

Question 9

7.1 Muscles and their movements: muscle control by propriocepters

Define the stretch reflex and give an example. (2)

Answer 9

-when a muscle is stretched, the spinal cord sends a signal to contract it reflexively
-example: you step on a lego brick, the stretch reflex will stop you from putting too much weight on it

-the stretch reflex is caused by a stretch, it does not produce one
-when a physician does the knee tapping thing

Question 10

7.1 Muscles and their movements: muscle control by propriocepters

Define the muscle spindle. Explain how it works and give an example (3)

Answer 10

-type of proprioceptor parallel to the muscle that responds to a stretch
-whenever the muscles is stretched more than the antagonistic muscle, the muscle spindle sends a message to a motor neuron in the spinal cord, which sends a message back to the muscle, causing a contraction
-example: the process by which you can catch a ball someone throws. You extend your arm and are able to contract it because of the muscle spindle detecting the extension

Question 11

7.1 Muscles and their movements: muscle control by propriocepters

Define golgi tendon organs. Where are they located? What do they do? How do they do this (describe the pathway) (4)

Answer 11

-proprioceptors that respond to increases in muscle tension
-located in tendons at opposite ends of a muscle
-act as brake against an excessively vigorous contraction
-golgi tendon organs detect the tension and their impulse travel to the spinal cord, where they excite interneurons that inhibit the motor neurons

-some muscles are so strong that they could damage themselves if too many fibers contracted at once`

Question 12

7.1 Units of movement: voluntary and involuntary movements

Define reflexes.

Answer 12

-consistent automatic responses to stimuli

-often thought of as involuntary

-stretch reflex is an example

Question 13

7.1 Units of movement: movements varying in sensitivity to feedback

Define ballistic movement

Answer 13

-executed as a whole, once it is initiated it cannot be altered

-some behaviors are ballistic movements like a reflex, others can be changed as we observe like threading a needle

Question 14

7.1 Units of movement: sequence of behaviors

Define central pattern generators and give an example (2)

Answer 14

-neural mechanisms in the spinal cord that generate rythymic patterns of motor output
-example: mechanism that generates wing flapping in birds

Question 15

7.1 Units of movements; sequence of behaviors

Define motor program and give an example

Answer 15

-a fixed sequence of movements
-example: cat pandiculating when it gets up from a nap

Question 16

7.2 The Cerebral cortex

Where is the primary motor cortex located? What does direct electrical stimulation do for this? (2)

Answer 16

-along the precentral gyrus of the frontal cortex
-it elicits movement

Question 17

7.2 Cerebral cortex Stop and check Pg 235

What aspect of brain anatomy facilitates communication between body sensations and body movements?

Answer 17

-The motor cortex and the somatosensory cortex are adjacent, and the area of motor cortex devoted to a particular body structure is aligned with the somatosensory cortex area responsive to the same structure.

Question 18

7.2 Cerebral cortex stop and check Pg 235

What evidence indicates that cortical activity represents the “idea” of the movement and not just the muscle contractions?

Answer 18

-Activity in the motor cortex leads to a particular outcome, such as movement of the hand to the mouth, regardless of what muscle contractions are necessary given the hand’s current location.

-these are central pattern generators

Question 19

7.2 The Cerebral cortex

Describe the pathway in which the primary motor cortex sends messages to the muscles.

Answer 19

-axons extend to the brainstem and spinal cord, which generate the impulses that control the muscles, and these structures have axons that extend to the muscles

-some axons go directly from the cerebral cortex to motor neurons, presumably giving humans greater dexterity

Question 20

7.2 The Cerebral cortex (chatgpt)

Which statement best describes the role of the primary motor cortex in motor control?

Answer 20

The primary motor cortex primarily controls involuntary muscle movements and reflexes.

Question 21

7.2: The Cerebral cortex: planning a movement

How does the posterior parietal cortex contribute to movement? The premotor cortex? The supplementary motor cortex? The prefrontal cortex? The primary motor cortex? (5

-it is in order of the structures that reak their peak activity first

Answer 21

-The prefrontal cortex stores sensory information relevant to a movement and considers possible outcomes of a movement.
-The posterior parietal cortex is important for perceiving the location of objects and the position of the body relative to the environment. It is also active for planning of a movement.
-the premotor cortex and supplementary motor cortex are also active in preparing a movement shortly before it occurs.
-The supplementary motor cortex inhibits a habitual action when it is inappropriate.
-the primary motor cortex is the execution of voluntary movements.

Question 22

7.2 The Cerebral cortex: inhibiting a movement

What is the antisaccade task? Describe how it works and list those who struggle more with it. (2)

Answer 22

-a saccade is a voluntary eye movement from one target to another, in this task you will be asked to look at the hand that isnt moving
-children, older people and those with psychiatric disorders and impulsivity issues struggle

Question 23

7.2 The cerebral cortex: mirror neurons

Define mirror neurons and give an example (2)

Answer 23

-neurons that are active both during preparation for a movement and while watching someone else perform the same/similar movement
-example: when someone smiles at us and we automatically smile back

-a huge learning aspect

Question 24

7.2 The cerebral cortex: connections from the brain to the spinal cord

Define the corticospinal tracts. What are the two tracts that make up this? (2)

Answer 24

-paths from the cerebral cortex to the spinal cord
-lateral corticospinal tract and medial corticopsinal tract

Question 25

7.2 The Cerebral cortex: connections from the brain to spinal cord

Define the red nucleus

Answer 25

-midbrain area that controls some aspects of movement

Question 26

7.2: The cerebral cortex: connections from the brain to the spinal cord

Compare the lateral and medial corticospinal tract. Where does it start? Crossing-over? Where do axons travel to? Controls which movement? (7)

Answer 26

Lateral
-origin: axons from primary motor cortex + red nucleus
-crossing over: cross over at pyramids, crosses to the opposite side of spinal cord
-targets: extend directly from motor cortex to target neurons in spinal cord
-movement control: peripheral area, especially the hands and feet

Medial
-origin: axons from many parts of cerebral cortex (not just primary motor cortex), midbrain tectum, reticular formation, vestibular nucleus
-crossing-over: axons go to both sides of the spinal cord
-movement control: mainly muscles of neck, shoulder, and trunk

Question 27

7.2: The cerebral cortex: connections from the brain to the spinal cord

Define the vestibular nucleus

Answer 27

-brain area that recieves input from the vestibular (orientation) system

Question 28

7.2 Summary

What develops gradually in children and adolescents dependent on the maturation of the prefrontal cortex and basal ganglia?

Answer 28

-ability to inhibit an inapropriate behavior

Question 29

7.2 The Cerebellum

What kind of activities is the cerebellum important for? The textbook highlights three different ones (3)

Answer 29

-aim and timing specifically
-responding to sensory stimuli, even without movement
-aspects of attention, need longer to shift attention

-also rythym, clapping hands, pointing at a movign object, speaking, writing, typing or playing a musical instrument
-impaired in almost all athletic activities

Question 30

7.2 The Cerebellum: Cellular Organization

What structures does the cerebellum receive input from?

Answer 30

-spinal cord, from the sensory systems via the cranial nerve nuclei, and from the cerebral cortex

-eventually reaches the cerebellar cortex, the surface of the cerebellum

Question 31

7.2 The Cerebellum: Cellular Organization

Describe how the neurons are arranged in the cerebellar cortex. (3)

Answer 31

-neurons arranged in precise geometric pattern
-have both purkinje cells (vertical)
-and parallel fibers (horizontal)

Question 32

7.2 The Cerebellum: Cellular Organization

Define purkinje cells

Answer 32

-flat (2D) cells in rows

-vertical

Question 33

7.2 The Cerebellum: Cellular Organization

Define parallel fibers

Answer 33

-axons parallel to one another and perpendicular to the vertical Purkinje cells

Question 34

7.2 The Cerebellum: Cellular organization

How do action potentials work in the cerebellar cortex? With the purkinje and parallel cells? (3)

Answer 34

-action potentials in parallel fibers excited one Purkinje cell after another
-each Purkinje cell sends an inhibitory message to cells in the nuclei of the cerebellum and vestibular nuclei in brainstem
-these send information to the midbrain and the thalamus

-Because the parallel fibers’ messages reach Purkinje cells one after another, the greater the number of excited Purkinje cells, the greater their collective duration of response. That is, if the parallel fibers stimulate only the first few Purkinje cells, the result is a brief message to the target cells; if they stimulate more Purkinje cells, the message lasts longer. The sequence of Purkinje cells controls the timing of the output, including both its onset and offset

Question 35

7.2 The Cerebellum: Cellular Organization

Define nuclei of the cerebellum

Answer 35

-clusters of cell bodies in the interior of the cerebellum

Question 36

7.2 The Basal Ganglia

Define the basal ganglia. What structures do all authorities agree are included in it? (2)

Answer 36

-applies to a group of large structures in the brain
-caudate nucleus, putamen, globus pallidus

Question 37

7.2 The Basal Ganglia

Define the striatum or Dorsal striatum

Answer 37

-this is the caudate nucleus and putamen together

-receieves input from cerebral cortex and substantia nigra and sends it output to the globus pallidus, which then sends output to the thalamus and frontal cortex

Question 38

7.2 The Basal Ganglia

Describe the direct pathway. Describe the route, the net effect (excitation or inhibition), what it enhances or controls (3)

Answer 38

-goes from striatum which inhibits globus pallidus, which inhibits part of the thalamus
-net effect is excitation (inhibiting an inhibitor)
-enhances the selected movement, but both direct and indirect pathways are active before a movement and neither is active when the animal is at rest

Question 39

7.2 The Basal Ganglia

Describe what the indirect pathway does and what it is essential for. (2)

Answer 39

-inhibits inappropriate competing movements
-essential for learned performance

-both direct and indirect are active before a movement

Question 40

7.2 The Basal Ganglia Stop and Check

In general, do the basal ganglia have more effect on responses to a stimulus or on self-initiated movements?

Answer 40

-The basal ganglia have more influence on self-initiated movements, which are generally slower.

Question 41

7.2 The Basal Ganglia Stop and Check

Which aspect of movement do the basal ganglia control?

Answer 41

-vigor of movement

Question 42

7.2 Brain Areas and Motor Learning

What two areas, even though all areas are responsible, are highlighted for movement learning? (2)

Answer 42

-neurons in the motor cortex
-basal ganglia are critical for learning new habits

-basal ganglia are specifically important for habits that are difficult to describe in words

Question 43

7.2 Brain areas and Motor Learning

Describe how neurons in the motor cortex adjust their responses as a person/animal learns a motor skill. Discuss the beginning and end (2)

Answer 43

-movement start off slow and as they become faster the relevant neurons in the motor cortex increase their firing rate
-after a while, the movement patterns become more consistent and so do the patterns of activity in the motor cortex

Question 44

7.2 Conscious Decisions and Movement Stop and Check

Explain the evidence suggesting that a conscious decision to move does not cause the movement.

Answer 44

-Researchers recorded responses in people’s cortex that predicted the upcoming response. Those brain responses occurred earlier than the time people reported as “when they made the decision.”

Question 45

7.2 Conscious Decisions and Movement swtop and Check

Why are some researchers skeptical of the evidence that a conscious decision to move is made in advance of the movement?

Answer 45

-The studies assume that people accurately report the times of their intentions. However, people’s reports are influenced by events after the movement, and therefore we cannot be confident of their accuracy. Furthermore, a decision to make a voluntary movement is a gradual process that cannot be pinpointed to a single instant

-like falling in love

Question 46

7.2 End of Module QUiz

When a movement occurs, which of the following brain areas is the last one to reach its peak of activity?

a) the primary motor cortex
b) the posterior parietal cortex
c) the premotor cortex
d) the prefrontal cortex

Answer 46

a) the primary motor cortex

-order goes prefrontal cortex, posterior parietal cortex, premotor cortex, primary motor cortex

Question 47

7.3 Parkinson’s Disease

What is Parkinson’s disease and what is it a result of and what causes it? (3)

Answer 47

-it is a movement disorder characterized by rigidity, muscle tremors, slow movements and difficulty initiating voluntary activity (difficulty activating a movement and difficulty inhibiting inappropriate movements)
-results from the gradual loss of dopamine releasing axons from the substantia nigra to the striatum.
-And genes variants seem to play a role in this as well as lifestyle factors

-with the loss of this input, the striatum decreases its inhibition of the globus pallidus, which therefore increases its inhibitory input to the thalamus
-another common sign is a lack of motivation and pleasure and sometimes cognitive deficits (language, memory, attention)

Question 48

7.2 Parkinson’s disease: cause

How does MPTP exposure influence the likelihood of Parkinson’s disease? What are the effects of cigarette smoking or drinking coffee?

Answer 48

-Exposure to MPTP can induce symptoms of Parkinson’s disease. Cigarette smoking and somewhat coffee drinking is correlated with decreased risk of the disease.

Question 49

7.2 Parkinson’s Disease: L-dopa

What are the limitations to L-dopa? Which is the most common drug used for Parkinson’s today. (4)

-where is it releasing dopamine, when, is dopamine the only neurotransmitter needed, does it stop the onset of the disease, what are the side effects?

Answer 49

-non-specific dopamine release: increase dopamine release in both damaged and functioning axons
-incosistent dopamine levels
-only replaces dopamine, not other depleted neurotransmitters
-no neuroprotection: does not slow down the ongoing loss of neurons
-bad side effects

Question 50

7.2 Parkinson’s Stop and Check

What procedure has improved the effectiveness of brain grafts for treatment of Parkinson’s disease?

Answer 50

-Results improved somewhat after physicians began giving drugs to suppress the immune response.

Question 51

7.2 Parkinson’s: Other treatments

What are some of the other treatments for Parkinson’s? (3)

Answer 51

-other drugs that directly stimulate dopamine receptors or block the breakdown of dopamine
-transplanting fetus tissue or adrenal gland tissue
-stem cells

Question 52

7.3 Huntington’s disease

Describe Huntington’s disease. What causes it? What are its symptoms? What structures break down? (3)

Answer 52

-severe neurological disease with genetic origins
-movement disorder, cognitive decline and psychatric symptoms
-gradual extensive brain damage especially in the basal ganglia but also in cerebral cortex

-because the output from the basal granglia isinhibitory to the thalamus, damage to it leads to increased atcivity in the motor areas of the thalamus. that increase produces the involuntary jerky movements

Question 53

7.3 Summary

How can researchers determine if someone will get Huntingtons? How will they predict when that person will get it?

Answer 53

-examining the genes on chromosome 4 and looking for a repeat of CAG, the more repeats the earlier they’ll get it

Question 54

7.3 Summary

What does the gene responsible for Huntingtons alter?

Answer 54

-the structure of a protein, known as hungingtin.