PSYCH 111: Introduction to Psychology: Week 7: Chapter 3 Quizzes: Biopsychology

The Correct Answer is:

d. brain and spinal cord

The central nervous system (CNS) consists of the brain and spinal cord, which serve as the body’s primary control center. The brain processes, integrates, and interprets information, while the spinal cord transmits signals between the brain and the rest of the body. Together, they regulate thoughts, emotions, sensations, and voluntary and involuntary actions. The CNS works closely with the peripheral nervous system to coordinate responses and maintain overall body function.

Why the other options are incorrect:

a. sympathetic and parasympathetic nervous systems

This is incorrect because these are subdivisions of the autonomic nervous system, which is part of the peripheral nervous system (PNS), not the CNS.

b. organs and glands

This is incorrect because organs and glands are regulated by the nervous and endocrine systems but are not components of the CNS itself.

c. somatic and autonomic nervous systems

This is incorrect because both the somatic and autonomic systems belong to the peripheral nervous system, which connects the CNS to the rest of the body but is separate from it.

The Correct Answer is:

B. It shows changes in metabolic activity over time by tracking blood flow in the brain

Functional magnetic resonance imaging (fMRI) is a non-invasive brain imaging technique that measures changes in blood oxygen levels to track metabolic activity over time. When a specific brain region becomes active, it requires more oxygen, increasing blood flow to that area. The fMRI detects these changes, allowing researchers to create real-time maps of brain activity during different tasks. Unlike PET scans, fMRI does not involve radiation and provides better resolution and timing accuracy.

Why the other options are incorrect:

A. It measures electrical activity in the brain by detecting neuron firing patterns

This is incorrect because measuring electrical activity is the role of electroencephalography (EEG), not fMRI. While fMRI detects blood flow linked to activity, it does not directly measure neuron firing.

C. It uses radioactive tracers to map active and inactive brain regions

This is incorrect because the use of radioactive tracers is a feature of positron emission tomography (PET) scans. fMRI, on the other hand, measures oxygenated blood flow without exposing the brain to radiation.

D. It captures static images of brain structures without showing brain function

This is incorrect because static structural imaging is the function of a traditional MRI, not fMRI. While both techniques use magnetic resonance, fMRI specifically shows dynamic changes in brain activity over time rather than just capturing anatomical images.

The Correct Answer is:

a. inside; outside

During an action potential, sodium ions (Na+) rapidly move inside the neuron through voltage-gated sodium channels, causing depolarization of the membrane. Afterward, potassium ions (K+) flow outside the cell through potassium channels, leading to repolarization and restoring the resting membrane potential. This coordinated movement of Na+ and K+ ions generates the electrical signal that travels down the axon, allowing neurons to communicate effectively within the nervous system.

Why the other options are incorrect:

b. outside; inside

This is incorrect because sodium ions do not move outside during an action potential. They enter the cell first, while potassium moves out afterward to restore balance.

c. inside; inside

This is incorrect because both ions do not move into the neuron simultaneously. Sodium flows inward, but potassium flows outward during the repolarization phase.

d. outside; outside

This is incorrect because sodium ions move inside the cell, not outside, during the initial depolarization. Potassium moves outward later, meaning both ions do not leave the cell at the same time.

The Correct Answer is:

B. His injury demonstrated that the frontal lobe is involved in personality, decision-making, and emotional regulation

Phineas Gage’s case became one of the most famous in neuroscience after an iron rod passed through his frontal lobe on September 13, 1848. Although he survived, his personality changed drastically, becoming impulsive, irritable, and unreliable. This provided critical evidence that the frontal lobe plays a key role in regulating behavior, decision-making, social interactions, and emotional control, laying the foundation for our modern understanding of brain-behavior relationships.

Why the other options are incorrect:

A. His accident proved that the frontal lobe only controls motor movements

This is incorrect because the frontal lobe is responsible for much more than motor control. While it assists with voluntary movement, Gage’s dramatic personality and behavioral changes revealed its deeper role in higher cognitive functions and emotional regulation.

C. His case showed that damage to the frontal lobe does not affect behavior or personality

This is incorrect because Gage’s personality changed significantly after his injury. Before the accident, he was responsible and well-liked; afterward, he became aggressive and had difficulty controlling impulses. This demonstrates a strong link between the frontal lobe and personality.

D. His recovery proved that the brain cannot adapt after severe injury

This is incorrect because Phineas Gage did show some adaptation over time. While his personality never fully returned to normal, modern research suggests that neuroplasticity allows the brain to reorganize after injury, meaning the brain can adapt, even if recovery is incomplete

The Correct Answer is:

B. It involves injecting a mildly radioactive tracer to monitor blood flow and brain activity

A PET scan is a brain imaging technique that uses a mildly radioactive substance called a tracer, which is either injected or consumed. As brain regions become active, blood flow to those areas increases, carrying more tracer. A computer detects these changes and creates a rough map of active and less active areas of the brain during specific tasks. PET scans provide insight into brain function but have lower spatial resolution compared to fMRI and expose the brain to mild radiation.

Why the other options are incorrect:

A. It measures electrical signals in the brain to track neuron activity

This is incorrect because measuring electrical activity is the role of an EEG (electroencephalogram), not a PET scan. PET focuses on blood flow and metabolic activity, not direct electrical signals.

C. It produces static images of brain structures without showing functional activity

This is incorrect because structural imaging is done using MRI or CT scans. PET scans provide functional imaging, allowing researchers to observe which brain regions are active during different tasks.

D. It uses magnetic fields to measure changes in oxygen levels during brain tasks

This is incorrect because this describes fMRI, not PET scans. Unlike fMRI, PET uses radioactive tracers to monitor changes in blood flow and metabolic activity, making the techniques fundamentally different.

The Correct Answer is:

b. MRI

An MRI (Magnetic Resonance Imaging) uses powerful magnetic fields and radio waves to create detailed images of internal tissues and structures, including the brain. Unlike imaging techniques that rely on radiation, MRI is non-invasive and provides high-resolution images, making it especially useful for detecting tumors, injuries, and structural abnormalities. It can capture soft tissue contrast better than CT scans and is widely used in medical and neurological diagnostics.

Why the other options are incorrect:

a. EEG

This is incorrect because an electroencephalogram (EEG) measures electrical activity in the brain using electrodes placed on the scalp. It does not create images of brain structures or tissues.

c. PET scan

This is incorrect because a positron emission tomography (PET) scan uses a mildly radioactive tracer to track metabolic activity and blood flow in the brain, not magnetic fields. PET scans focus on brain function rather than detailed anatomical imaging.

d. CT scan

This is incorrect because a computed tomography (CT) scan uses X-rays to produce cross-sectional images of internal structures. While it provides useful anatomical details, it does not use magnetic fields and typically offers less soft tissue contrast compared to MRI.

The Correct Answer is:

D. Dendrites

Dendrites are branch-like extensions of the neuron that receive incoming signals from other neurons. They are specialized to detect chemical messages, called neurotransmitters, released into the synaptic cleft and convert them into small electrical impulses. These impulses are then transmitted to the soma (cell body) for processing. Dendrites play a critical role in communication within the nervous system by enabling neurons to integrate information from multiple sources.

Why the other options are incorrect:

A. Soma

This is incorrect because the soma, or cell body, processes incoming signals but does not primarily receive them. Its main role is to integrate signals from dendrites and generate an action potential when the threshold is reached.

B. Terminal buttons

This is incorrect because terminal buttons are located at the ends of the axon and are responsible for sending signals, not receiving them. They release neurotransmitters into the synaptic cleft to communicate with neighboring neurons.

C. Myelin sheath

This is incorrect because the myelin sheath is an insulating layer that covers the axon, helping speed up the transmission of electrical impulses. It does not participate in receiving signals but enhances how fast signals travel along the axon.

The Correct Answer is:

d. glucagon and insulin

The pancreas plays a vital role in regulating blood sugar levels by secreting two key hormones: insulin and glucagon. Insulin lowers blood glucose by promoting its uptake into cells for energy or storage, while glucagon raises blood glucose by stimulating the liver to release stored glucose. Together, they maintain homeostasis of blood sugar levels, ensuring the body has a stable energy supply necessary for proper functioning.

Why the other options are incorrect:

a. estrogen and progesterone

This is incorrect because these hormones are secreted by the ovaries in females, not the pancreas. They regulate female reproductive functions, including the menstrual cycle and pregnancy.

b. norepinephrine and epinephrine

This is incorrect because these hormones are secreted by the adrenal glands, not the pancreas. They prepare the body for fight-or-flight responses during stress by increasing heart rate, blood pressure, and energy release.

c. thyroxine and oxytocin

This is incorrect because thyroxine is secreted by the thyroid gland to regulate metabolism, while oxytocin is produced by the hypothalamus and released by the pituitary gland to influence childbirth, bonding, and social behaviors.

The Correct Answer is:

B. Our genes set the boundaries for potential traits, but the environment influences where within that range we fall

The range of reaction concept explains that genes establish a set of possible outcomes for a particular trait, but environmental factors determine the individual’s actual expression within those limits. For example, two people might have genes for above-average intelligence, but differences in nutrition, education, and life experiences could lead one to reach a higher potential than the other. Genes provide the framework, but the environment determines where someone falls within that framework.

Why the other options are incorrect:

A. Our environment fully determines our traits, and genes play no role

This is incorrect because genetics set biological boundaries that environmental factors cannot override. Environment influences expression, but it does not replace genetic influence.

C. Our genes alone decide exactly how our traits will be expressed, regardless of environmental factors

This is incorrect because genes do not act in isolation. Even with strong genetic potential, environmental conditions like healthcare, nutrition, or learning opportunities shape the final outcome.

D. Environmental influences can force traits to develop outside the genetic limits set by our DNA

This is incorrect because the environment cannot push traits beyond genetic possibilities. It can maximize or minimize expression, but it cannot create outcomes beyond what genes allow.