Biological Bases of Behavior

Question 1

What is neuroanatomy?

Answer 1

Neuroanatomy relates to the parts and functions of individual nerve cells, known as neurons.

Question 2

What is a neuron?

Answer 2

A neuron is an individual nerve cell.

Question 3

Name the seven parts of a neuron.

Answer 3

1) dendrites
2) cell body/soma
3) axon
4) myelin sheath
5) terminal buttons
6) neurotransmitters
7) synapse/synaptic cleft

Question 4

Explain the function of the following part of a neuron:

dendrite

Answer 4

Dendrites are branch-like arms attached to the cell body that receive information from other neurons.

Question 5

Explain the function of the following part of a neuron:

cell body/soma

Answer 5

The cell body/soma is the “brain” of the neuron, containing the nucleus.

Question 6

Explain the function of the following part of a neuron:

axon

Answer 6

Axons are tube-like structures that transmit information from the cell body to the terminal buttons.

Question 7

Explain the function of the following:

myelin sheath

Answer 7

The myelin sheath is the fatty layer around some axons that allows information to travel faster from the cell body to the terminal buttons.

The myelin sheath also acts as insulation so that signals don’t travel to every adjacent neuron, but just to the intended neuron(s).

Question 8

Explain the function of the following part of a neuron:

terminal buttons

Answer 8

Terminal buttons are where information from the axon ends up, and contain neurotransmitters.

Question 9

What are synonyms for “terminal buttons”?

Answer 9

• end buttons
• synaptic knobs
• axon terminals
• terminal branches of axons

Question 10

Explain the function of the following part of a neuron:

neurotransmitters

Answer 10

Neurotransmitters are chemicals in the axon terminals that attempt to communicate with dendrites on other neurons.

Neurotransmitters must “fit” with dendritic receptor sites, like a key in a lock, to continue to the next neuron.

Question 11

Explain the function of the following part of a neuron:

synapse

Answer 11

The synapse, also called the synaptic cleft, is the gap between the axon terminal of one neuron and the information-seeking dendrite of the next neuron. This role as a gap between the terminal buttons and dendrite helps pass chemical or electrical signals from one neuron to the next.

Question 12

True or false:

Chemicals travel within the cells, but are transmitted to other neurons electrically.

Answer 12

false

Within the cells, information is transmitted as an electric signal, but when it reaches the axon terminal, it is converted into chemicals that move between one neuron and the next.

Question 13

Can a neuron fire at different magnitudes?

Answer 13

No, a neuron will fire completely if it reaches or exceeds the depolarization threshold, or not at all, which is called the all-or-none principle.

Question 14

How is an action potential created?

Answer 14

Positively or negatively charged chemical signals enter the dendrite and move to the cell body, which is slightly negatively charged. If these chemical signals depolarize the cell body enough, an action potential will occur, which will fire electrical information down the axon to the axon terminal.

Question 15

Some __________ are excitatory, prodding the cell body to fire, and others are __________, which prevent the creation of a cell’s action potential.

Answer 15

neurotransmitters; inhibitory

Question 16

Describe the path of information within a neuron from beginning to end.

Answer 16

Dendrite (chemical signals)⇒cell body (become electrical signals)⇒axon⇒axon terminal (become chemical signals)⇒synapse⇒dendrite of next neuron

Question 17

When neurotransmitters from the axon terminal are released, they attempt to connect with __________ on the postsynaptic dendrite.

Answer 17

receptor sites

Question 18

Define:

threshold

Answer 18

The threshold is the level of depolarization a cell body must reach to produce an action potential.

Question 19

What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
acetylcholine

Answer 19

Function: motor movement

Problem: Alzheimer’s disease linked to acetylcholine deficit

Question 20

What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
dopamine

Answer 20

Function: motor movement and alertness

Problems: Parkinson’s disease (dopamine deficiency) and schizophrenia (excessive dopamine)

Question 21

What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
endorphins

Answer 21

Function: pain control

Problem: endorphins are released when pleasure areas of the brain are stimulated, so addictions are linked to endorphins

Question 22

What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
serotonin

Answer 22

Function: mood control

Problem: deficiency linked to clinical depression

Question 23

What is the difference between afferent and efferent neurons?

Answer 23

Afferent neurons, or sensory neurons, carry information to the brain.

Efferent neurons, or motor neurons, carry information from the brain to the body

Question 24

What are the subdivisions of the nervous system?

Answer 24

• central nervous system
  - brain and spinal cord
• peripheral nervous system
  - somatic
  - autonomic
  - sympathetic
  - parasympathetic

Question 25

What is the difference between the central nervous system and the peripheral nervous system?

Answer 25

The central nervous system includes the nerves in bones. The peripheral nervous system includes the nerves not encased in bone.

Question 26

When you want to answer a question in class, what part of the nervous system controls your ability to raise your hand?

Answer 26

The somatic nervous system controls voluntary muscle movements.

Question 27

When your stomach begins to growl before lunch, what part of the nervous system is activated?

Answer 27

The autonomic nervous system is activated, which controls the parts of our bodies that work automatically, like heart beats, breathing, and digestive muscles.

Question 28

What does the sympathetic nervous system do?

Answer 28

Like the gas pedal in a car, the sympathetic nervous system accelerates functions needed for responding quickly to stress, like breathing, heart rate, and pupil dilation, and slows functions not immediately necessary, like digestion.

Question 29

What is the function of the parasympathetic nervous system?

Answer 29

The parasympathetic nervous system is like the brake pedal of a car, counteracting the sympathetic nervous system after stress has passed. It is also active during periods of “sex, sleep, and sustenance.”

Question 30

How did Phineas Gage contribute to the field of psychology?

Answer 30

Phineas Gage received frontal lobe damage after an accident, and his personality changed dramatically. This helped researchers conclude that the damaged part of the brain is an area where emotion regulation is controlled.

Since it is unethical to damage a human brain for the purposes of learning about brain function, researchers rely on accidents like Phineas Gage’s to learn what areas of the brain are responsible for different functions.

Question 31

What are ways in which psychologists study the functions of different brain areas?

Answer 31

• accidents
• lesions
• electroencephalogram (EEG)
• Computerized Axial Tomography (CAT or CT)
• Magnetic Resonance Imaging (MRI)
• Positron Emisson Tomography (PET)
• Functional MRI (fMRI)

Question 32

Describe the following method of studying the brain:

lesions

Answer 32

When brain lesions happen through damage or as a byproduct of a surgical procedure (to stop seizures, for example), psychologists are able to see what functions are impaired in a real world setting and glean the way the damaged area of the brain works.

Question 33

Describe the following method of studying the brain:

electroencephalogram (EEG)

Answer 33

Used largely in sleep research, the electroencephalogram (EEG) detects brain waves during different states of consciousness.

Question 34

Describe the following method of studying the brain:

Computerized Axial Tomography

Answer 34

Also known as a CAT or CT, this method can get a three-dimensional X-ray image of the brain, which is helpful for detecting structural problems, like tumors, but does not aid in detecting brain activity.

Question 35

Describe the following method of studying the brain:

Magnetic Resonance Imaging

Answer 35

Similar to a CAT scan, an MRI provides an image of the brain, rather than clues to its activation. Unlike a CAT scan, however, the MRI uses magnetic fields to image brain density and does not expose the patient to potentially harmful radiation.

Question 36

Describe the following method of studying the brain:

Positron Emission Tomography

Answer 36

The PET allows psychologists to see activity in the brain by monitoring how much of a chemical different parts of the brain are using.

Question 37

Describe the following method of studying the brain:

Functional MRI

Answer 37

The fMRI is able to see blood flow in the brain during cognitive tasks, which suggests brain functioning. It also contains elements of the MRI, which gives structural information about the patient’s brain.

Question 38

What parts of the brain are located in the hindbrain?

Answer 38

• medulla
• pons
• cerebellum

Question 39

Describe the part of the brain:

medulla

Answer 39

The medulla (or medulla oblongata) connects the brain to the spinal cord. One of the most primitive parts of the brain, it helps control basic functions of life, like respiration, heart rate, and blood pressure.

Question 40

Describe the part of the brain:

pons

Answer 40

The pons connects the forebrain, midbrain, and hindbrain, and helps control facial expression.

Question 41

Describe the part of the brain:

cerebellum

Answer 41

Meaning “little brain,” the cerebellum looks like a second, smaller brain on the underside of our brain. It is partially responsible for our mind-body connection, particularly in habitual muscle movements.

Question 42

Describe the part of the brain:

reticular formation

Answer 42

Located in the midbrain, the reticular formation controls bodily arousal and our ability to focus.

Question 43

Where are the thalamus, hypothalamus, amygdala, and hippocampus located in the brain?

Answer 43

the forebrain

Question 44

What are the four parts of the brain known as the limbic system, and what function does the limbic system serve?

Answer 44

1) thalamus
2) hypothalamus
3) hippocampus
4) amygdala
The limbic system is involved in memory and emotion.

Question 45

Describe the part of the brain:

thalamus

Answer 45

Known as the “sensory weigh station” of the brain, the thalamus receives information from the spinal cord and routes it to the appropriate part of the forebrain for further processing.

Question 46

Describe the part of the brain:

hypothalamus

Answer 46

The hypothalamus controls the endocrine system, as well as metabolic functions like libido, body temperature, hunger, and thirst.

Question 47

Describe the part of the brain:

hippocampus

Answer 47

The hippocampus is responsible for converting short-term memories to long-term memories.

Question 48

Describe the part of the brain:

amygdala

Answer 48

The amygdala controls emotion and fear.

Question 49

Why are our brains wrinkled?

Answer 49

The surface of the brain is covered with neurons, and wrinkles (or fissures) to increase the surface area so more neurons can connect with one another to transmit more information.

Question 50

If you want to kick a soccer ball with your right foot, which hemisphere of the brain controls this, and what principle explains it?

Answer 50

The left hemisphere controls the motor function on the right half of the body and vice versa. This is called contralateral control.

Question 51

Split-brain patients have had their __________ severed, usually to treat epilepsy. What two doctors pioneered this surgical procedure?

Answer 51

corpus callosum

Roger Sperry and Michael Gazzinga pioneered this procedure.

Question 52

Describe the part of the brain:

corpus callosum

Answer 52

The corpus callosum is the nerve bundle that runs through the middle of the brain, separating the hemispheres.

Question 53

It has been suggested that the right hemisphere of the brain is active during spatial and creative tasks, while the left is activated during logic, spoken language, and sequential tasks. What are the two terms used to describe the differences between the right and left hemispheres?

Answer 53

brain lateralization and hemispheric specialization

Question 54

There are four lobes in the brain. Name them.

Answer 54

1) frontal
2) parietal
3) occipital
4) temporal

Question 55

What is the area in the anterior frontal lobe called, and what is it responsible for?

Answer 55

The prefrontal cortex, and it is the brain’s executive functioning center. It is the part of the brain that is believed to be responsible for reasoning and emotional control. Without the prefrontal cortex (or PFC), we would not be able to make long term plans, regulate our emotions, or consider consequences.

Question 56

What area of the brain allows us to move our muscles to produce speech?

Answer 56

Broca’s area, which is located in the left frontal lobe in most right-handers

Question 57

The top of the motor cortex controls voluntary muscle movements in what area of the body?

Answer 57

The feet and toes are controlled by the top of the motor cortex, located at the back of the frontal lobe. The top of the body is controlled by the bottom of the motor cortex.

Question 58

Located in the parietal lobe behind the motor cortex, the __________ receives touch sensations from the body.

Answer 58

sensory cortex, or somato-sensory cortex

Question 59

Why is the area where vision is processed counterintuitive?

Answer 59

The processing of vision is located in the occipital lobe, which is at the very back of the brain, as far as possible from the eyes themselves. The left and right halves of the visual cortex process information from the same halves of the retinas (meaning processing is lateralized).

Question 60

Damage to what area of the temporal lobe would result in an inability to understand written or spoken language?

Answer 60

Wernicke’s area

Question 61

What sensory modality is the temporal lobe responsible for processing?

Answer 61

hearing/audition

Unlike vision, hearing is not lateralized. Sound coming in one ear is processed by both hemispheres of the brain.

Question 62

Explain brain plasticity.

Answer 62

As our brains develop, there are skills or functions that are more or less important to perform to each individual. Because of this, the neuronal connections in our brains strengthen or weaken to adapt to those needed functions, especially if there is damage to other areas of the brain.

Question 63

Why is the endocrine system important to the field of psychology?

Answer 63

The endocrine system secretes hormones that are part of our psychological processes.

• The adrenal glands secrete adrenaline, which is necessary for the fight-or-flight response of the autonomic nervous system
• Ovaries and testes produce testosterone and estrogen, hormones that can help explain gender differences, which are an important part of developmental psychology

Question 64

Who was Thomas Bouchard and why was his research important?

Answer 64

Thomas Bouchard was a psychologist who studied identical twins raised in different families versus twins raised in the same home. His research was important when considering the nature/nurture argument.

• Twins had enough similarities in personality and IQ to suggest a nature component
• Twins raised in different homes also showed enough differences to suggest that nurture (or environment) was a factor in development of personality and intelligence