Biology chapter 49

Emotion, motivation, olfaction, behavior, and memory, in humans, are mediated by the _____.

temporal lobes of the cerebral cortex
occipital lobes of the cerebral cortex
cerebellum
limbic system
frontal lobe of the cerebral cortex

The peripheral nervous system (PNS) transmits information to and from the central nervous system (CNS) and plays a role in regulating an animal’s movements and internal environment.
Determine which of the following statements about the PNS are true.
Select the four statements that are true.

The sympathetic division amplifies the effects of the parasympathetic division.
The sympathetic division of the PNS prepares the body for physical exertion in stressful situations.
Neurons in the parasympathetic division release neurotransmitters that act on receptors that slow heart rate.
Parasympathetic nerves are associated with the cranial and sacral regions of the spinal cord, whereas sympathetic nerves are associated with the thoracic and lumbar regions.
Stimulating the organs of digestion is a parasympathetic response.
The autonomic nervous system controls the action of skeletal muscle.
The sympathetic and parasympathetic divisions consist of afferent neurons.

As vertebrates evolved, the increasingly complex structure of the brain conferred increasingly complex function, especially apparent in the _____.

sleep-wake cycles of birds and mammals
cerebral cortex, which is greatly expanded in nonhuman primates and cetaceans
forebrain, which is a small brain region that arises early in development
medulla oblongata, which controls automatic functions
brainstem, which in most vertebrates, controls homeostasis and basic bodily function

Motor cortex and somatosensory cortex are _____.

organized in similar manner adjacent to each other, and are anatomically similar from one person to the next
located in the thalamus and hypothalamus, respectively
located in the hypothalamus and hippocampus, respectively
located on the left and right sides, respectively, of the cerebellum
dispersed along the ventral and dorsal, respectively

In adult humans, short-term memory relies on connections in the _____ whereas long-term memories appear to be based in the _____.

thalamus … hypothalamus
hippocampus … cerebral cortex
selective addition of synapses … selective addition of neurons
addition of new neurons … addition of new neurons
hypothalamus … cerebellum

Addiction onset by cocaine and amphetamines is characterized by increased _____.

release of serotonin
destruction of dopamine neurons
hormone secretion from the hypothalamus
persistence of dopamine in the brain’s synapses
motor paralysis

Parkinsonism is characterized by the loss of _____.

serotonin neurons
stem cells in the adult brain
dopaminergic neurons
cholinergic neurons
adrenergic neurons

In a controlled experiment, researchers manipulate one variable at a time.
What was the experimental variable in this study?

the genotype of the transplanted tissue
whether the SCN was part of the transplanted tissue
the genotype of the host tissue
whether the hamster’s original SCN was removed

Why did the researchers use more than one hamster for each procedure?

to assess whether the differences in cycle period before and after transplant were greater than the variation in cycle period from animal to animal
to assess the variability of circadian rhythms across different individuals
to determine whether the results were consistent regardless of the sex of the animals
to assess whether the SCN or some other part of the hypothalamus is responsible for circadian rhythm

What traits of the individual hamsters would likely have been controlled across the treatment groups?

genotype
sex only
age and sex
age only

For the wild-type hamsters that received τ SCN transplants, what would have been an appropriate control?

surgically expose the brain of a τ hamster without removing the SCN
transplant the SCN from one τ hamster to another τ hamster
transplant the entire hypothalamus from a τ hamster to a wild-type hamster
transplant the SCN from one wild-type hamster to another wild-type hamster

What general trends does the graph reveal about the period of the circadian rhythm in transplant recipients?

It was similar to that of the donor in wild-type hamsters but similar to that of the recipient in τ hamsters.
It was similar to that of the donor, whether the recipient was wild-type or τ mutant.
It was similar to that of the donor in τ hamsters but similar to that of the recipient in wild-type hamsters.
It was determined by the genotype of the recipient.

What can you conclude about the role of the SCN in determining the period of the circadian rhythm?

The SCN determines the period of the circadian rhythm.
The SCN determines the period of the circadian rhythm in τ hamsters but not wild-type hamsters.
The SCN determines the period of the circadian rhythm in wild-type hamsters but not τ hamsters.
The SCN does not determine the period of the circadian rhythm.

In 20% of the hamsters, there was no restoration of rhythmic activity following the SCN transplant.
Can you be confident of your conclusion about the role of the SCN based on data from 80% of the hamsters? Why or why not?

No. The most likely explanation is that the SCN does not control the circadian rhythm in hamsters.
No. A failure rate of 20% is much too high in any experiment.
Yes. Because 80% is much higher than 20%, the result is reliable.
Yes. The data from 80% of the hamsters are very consistent. In the other 20%, the transplanted SCN may not have established functional connections with the recipient’s brain.

Suppose researchers identified a mutation that caused hamsters to have no rhythmic activity. Also suppose you transplanted the SCN of wild-type hamsters into hamsters with this mutation.
What result would you expect from this experiment, assuming that the SCN determines the period of the circadian rhythm?

The recipients would have rhythmic activity with a period of about 24 hours.
The recipients would have rhythmic activity with a period of about 20 hours.
The recipients would have no rhythmic activity.
The recipients would have rhythmic activity with a variety of periods ranging from 20 to 24 hours.

What result would you expect if you transplanted the SCN of τ hamsters into no-rhythmic-activity mutants?

The recipients would have no rhythmic activity.
The recipients would have rhythmic activity with a variety of periods ranging from 20 to 24 hours.
The recipients would have rhythmic activity with a period of about 24 hours.
The recipients would have rhythmic activity with a period of about 20 hours.

What is the likelihood of a person developing schizophrenia if the disorder affects his or her fraternal twin?

8%
13%
17%
48%

How would the likelihood change if DNA sequencing revealed that the fraternal twins shared the genetic variants that contribute to the disorder?

It would decrease to 8%.
It would remain at 17%.
It would increase to 48%.
It would increase to 100%.

The knee-jerk reflex has sensory neurons arising in the _____, interneurons in the _____, and efferent neurons that stimulate contraction in the _____.

bone … stretch receptors … quadriceps muscle
patella … brain … gastrocnemius
autonomic nervous system … peripheral nervous system … smooth muscles in the leg
biceps … olecranon process … the cervical ganglion
quadriceps muscle … spinal cord … quadriceps muscle

An organism that lacks integration centers _____.

can be expected to lack myelinated neurons
will not be able to interpret stimuli
cannot receive stimuli
will not have a nervous system

In the human knee-jerk reflex of a seated individual, as the calf is raised from a vertical position to a horizontal position, the muscles of the quadriceps (on the front of the thighs) and the muscles of the hamstring (on the back side of the thighs) are _____.

inhibited and excited, respectively
both excited and contracting
both inhibited and relaxed
excited and inhibited, respectively

The stretch sensors of the sensory neurons in the human knee-jerk reflex are located in the _____.

brain, the sensorimotor relay
hamstring muscles on the back side of the thighs
quadriceps muscles on the front side of the thighs
cartilage of the knee

Choose the correct match of glial cell type and function.

astrocytes – metabolize neurotransmitters and modulate synaptic effectiveness
oligodendrocytes – produce the myelin sheaths of myelinated neurons in the peripheral nervous system
Schwann cells – provide nutritional support to non-myelinated neurons
radial glia – the source of immunoprotection against pathogens

The cerebrospinal fluid is _____.

a filtrate of the blood
a secretion of glial cells
secreted by the hypothalamus
cytosol secreted from ependymal cells

The human knee-jerk reflex requires an intact _____.

spinal cord
corpus callosum
cerebellum
medulla

Myelinated neurons are especially abundant in the _____.

white matter of the brain and the gray matter of the spinal cord
white matter in the brain and the white matter in the spinal cord
gray matter of the brain and the white matter of the spinal cord
gray matter of the brain and the gray matter of the spinal cord

Cerebrospinal fluid can be described as which of the following?
I) functioning in transport of nutrients and hormones through the brain
II) a product of the filtration of blood in the brain
III) functioning to cushion the brain
IV) filling spaces between glial cells and neurons in the gray matter

only II and IV
only I and III
only I, II, and III
only II, III, and IV

The divisions of the nervous system that have antagonistic, or opposing, actions are _____.

motor and sensory systems
presynaptic and postsynaptic membranes
central nervous system and peripheral nervous system
sympathetic and parasympathetic systems

Preparation for the fight-or-flight response includes activation of the _____ nervous system

parasympathetic
sympathetic
central
somatic

Exercise and emergency reactions include _____.

increased activity in the sympathetic, and decreased activity in the parasympathetic divisions
decreased activity in the sympathetic, and increased activity in the parasympathetic divisions
increased activity in the enteric nervous system
increased activity in all parts of the peripheral nervous system

Increased activity in the sympathetic nervous system leads to _____.

increased secretion by the pancreas
decreased heart rate
relaxation of the airways in the lungs
increased contractions of the stomach

The activation of the parasympathetic branch of the autonomic nervous system is associated with _____.

release of epinephrine into the blood
resting and digesting
intensive aerobic exercise
increased metabolic rate

In a cephalized invertebrate, the system that transmits “efferent” impulses from the anterior ganglion to distal segments is the _____.

peripheral nervous system
central nervous system
autonomic nervous system
parasympathetic nervous system

Imagine you are resting comfortably on a sofa after dinner. This could be described as a state with _____.

decreased activity in the sympathetic nervous system, and increased activity in the parasympathetic and enteric nervous systems
increased activity in the sympathetic, parasympathetic, and enteric nervous systems
decreased activity in the sympathetic, parasympathetic, and enteric nervous systems
increased activity in the sympathetic nervous system, and decreased activity in the parasympathetic and enteric nervous systems

If a doctor attempts to trigger the patellar tendon reflex and a lack of response occurs, what are potential regions where pathology might exist?
I) the brain
II) the knee
III) the spinal cord

only III
only II
only II and III
only I

Upon witnessing a robber hold up a convenience store at gunpoint, which of the following reactions would your nervous system initiate?

increased heartbeat
decreased heartbeat
constriction of pupils
constriction of airways

After eating a large meal, which nerves are most active in your digestive system?
I) parasympathetic nerves
II) somatic (motor) nerves
III) sympathetic nerves

only I
only II
only III
only II and III

The central nervous system is lacking in animals that have _____.

a closed circulatory system
a complete gut
radial symmetry
bilateral symmetry

Cephalization, the clustering of neurons and interneurons in the anterior part of the animal, is apparent in _____.

sea stars
cnidarians
invertebrate animals with radial symmetry
Planaria

C.elegans is a model organism and was the first eukaryotic organism to have its genome sequenced. The free-living nematode is often used in laboratories investigating nervous system development with all 302 of its neurons and their effectors categorized. Interesting control mechanisms have been investigated with reproduction, particularly with egg-laying in the nematode. There are 16 muscles, 2 types of neurons, and multiple receptors involved in the process of laying eggs in C.elegans, and there are mutations in all of those structures for the study of the process. One particular mutation that prevents the laying of eggs by the worm is rescued by the neurotransmitter, serotonin. That rescue suggests that the mutation is most likely in which of the following?

one of the muscles needed for egg-laying
a receptor for serotonin on cells needed for egg-laying
a pre-synaptic neuron involved in egg-laying
a post-synaptic neuron involved in egg-laying

Which of the following structures or regions is correctly paired with its function?

limbic system – motor control of speech
cerebellum – homeostatic control
medulla oblongata – emotional memory
corpus callosum – communication between the left and right cerebral cortices

Calculation, contemplation, and cognition are human activities associated with increased activity in the _____.

cerebrum
spinal cord
cerebellum
hypothalamus

Central coordination of vertebrate biological rhythms in physiology and behavior reside in the _____.

thalamus
hypothalamus
pituitary gland
cerebrum

Biological rhythms in animals isolated from light and dark cues _____.

continue to have cycles of approximately twenty-four hours duration; some more rapid, some slower
cease having any rhythms
continue to have cycles of exactly twenty-four hours’ duration
synchronize activity with whatever lighting cycle is imposed on them

Bottlenose dolphins breathe air but can sleep in the ocean because _____.

they move to shallow water to sleep, so they do not need to swim to keep their blowholes above the surface of the water
they alternate which half of their brain is asleep and which half is awake
they sleep for only thirty minutes at a time, which is the maximum interval they can cease breathing
they fill their swim bladder with air to keep their blowholes above the surface of the water while they sleep

The limbic system in the central nervous system sustains many vegetative functions in mammals and is closely associated with structures that process cues about _____.

olfaction
vision
audition
mechanosensation

Increases and decreases of the heart rate result from changes in the activity of the _____.

thalamus
cerebellum
medulla oblongata
pituitary

The unconscious control of respiration and circulation are associated with the _____.

cerebrum
thalamus
medulla oblongata
cerebellum

Which of the following structures are correctly paired?

midbrain – cerebrum
brainstem – anterior pituitary gland
forebrain – cerebellum
hindbrain – cerebellum

Hormones secreted by the posterior pituitary gland are made in the _____.

thalamus
hypothalamus
cerebellum
cerebrum

The coordination of groups of skeletal muscles is driven by activity in the _____.

cerebellum
cerebrum
thalamus
medulla oblongata

The regulation of body temperature derives from the activity of the _____.

thalamus
cerebellum
cerebrum
hypothalamus

The regulatory centers for the respiratory and circulatory systems are found in the _____.

cerebrum
cerebellum
thalamus
medulla oblongata

Food and water appetites are under the regulatory influence of the _____.

hypothalamus
medulla oblongata
thalamus
cerebrum

The suprachiasmatic nuclei are found in the _____.

Broca’s area
hypothalamus
amygdala
epithalamus

Wakefulness is regulated by the reticular formation, which is present in the _____.

cerebral cortex
limbic system
basal nuclei
brainstem

If a patient has an injury in the brain stem, which of the following would be observed?

auditory hallucinations
an inability to regulate body temperature
an inability to regulate heart function
visual hallucinations

The telencephalon region of the developing brain of a mammal _____.

gives rise to the cerebrum
is the brain region most like that of ancestral vertebrates
divides further into the metencephalon and myelencephalon
develops from the midbrain