What is neuroanatomy?
Neuroanatomy relates to the parts and functions of individual nerve cells, known as neurons.
What is a neuron?
A neuron is an individual nerve cell.
Name the seven parts of a neuron.
Dendrites are branch-like arms attached to the cell body that receive information from other neurons.
The cell body/soma is the "brain" of the neuron, containing the nucleus.
Axons are tube-like structures that transmit information from the cell body to the terminal buttons.
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).
Terminal buttons are where information from the axon ends up, and contain neurotransmitters.
What are synonyms for "terminal buttons"?
terminal branches of axons
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.
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.
Chemicals travel within the cells, but are transmitted to other neurons electrically.
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.
Can a neuron fire at different magnitudes?
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.
How is an action potential created?
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.
Some __________ are excitatory, prodding the cell body to fire, and others are __________, which prevent the creation of a cell's action potential.
Describe the path of information within a neuron from beginning to end.
Dendrite (chemical signals)⇒cell body (become electrical signals)⇒axon⇒axon terminal (become chemical signals)⇒synapse⇒dendrite of next neuron
When neurotransmitters from the axon terminal are released, they attempt to connect with __________ on the postsynaptic dendrite.
The threshold is the level of depolarization a cell body must reach to produce an action potential.
Function: motor movement
Problem: Alzheimer's disease linked to acetylcholine deficit
Function: motor movement and alertness
Problems: Parkinson's disease (dopamine deficiency) and schizophrenia (excessive dopamine)
Function: pain control
Problem: endorphins are released when pleasure areas of the brain are stimulated, so addictions are linked to endorphins
Function: mood control
Problem: deficiency linked to clinical depression
What is the difference between afferent and efferent neurons?
Afferent neurons, or sensory neurons, carry information to the brain.
Efferent neurons, or motor neurons, carry information from the brain to the body.
What are the subdivisions of the nervous system?
central nervous system
brain and spinal cord
peripheral nervous system
- brain and spinal cord
What is the difference between the central nervous system and the peripheral nervous system?
The central nervous system includes the nerves in bones. The peripheral nervous system includes the nerves not encased in bone.
When you want to answer a question in class, what part of the nervous system controls your ability to raise your hand?
The somatic nervous system controls voluntary muscle movements.
When your stomach begins to growl before lunch, what part of the nervous system is activated?
The autonomic nervous system is activated, which controls the parts of our bodies that work automatically, like heart beats, breathing, and digestive muscles.
What does the sympathetic nervous system do?
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.
What is the function of the parasympathetic nervous system?
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."
How did Phineas Gage contribute to the field of psychology?
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.
What are ways in which psychologists study the functions of different brain areas?
Computerized Axial Tomography (CAT or CT)
Magnetic Resonance Imaging (MRI)
Positron Emisson Tomography (PET)
Functional MRI (fMRI)
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.
Used largely in sleep research, the electroencephalogram (EEG) detects brain waves during different states of consciousness.
Computerized Axial Tomography
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.
Magnetic Resonance Imaging
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.
Positron Emission Tomography
The PET allows psychologists to see activity in the brain by monitoring how much of a chemical different parts of the brain are using.
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.
What parts of the brain are located in the hindbrain?
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.
The pons connects the forebrain, midbrain, and hindbrain, and helps control facial expression.
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.
Located in the midbrain, the reticular formation controls bodily arousal and our ability to focus.
Where are the thalamus, hypothalamus, amygdala, and hippocampus located in the brain?
What are the four parts of the brain known as the limbic system, and what function does the limbic system serve?
The limbic system is involved in memory and emotion.
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.
The hypothalamus controls the endocrine system, as well as metabolic functions like libido, body temperature, hunger, and thirst.
The hippocampus is responsible for converting short-term memories to long-term memories.
The amygdala controls emotion and fear.
Why are our brains wrinkled?
The surface of the brain is covered with neurons, and wrinkles (or fissures) increase the surface area so more neurons can connect with one another to transmit more information.
If you want to kick a soccer ball with your right foot, which hemisphere of the brain controls this, and what principle explains it?
The left hemisphere controls the motor function on the right half of the body and vice versa. This is called contralateral control.
Split-brain patients have had their __________ severed, usually to treat epilepsy. What two doctors pioneered this surgical procedure?
Roger Sperry and Michael Gazzinga pioneered this procedure.
The corpus callosum is the nerve bundle that runs through the middle of the brain, separating the hemispheres.
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?
brain lateralization and hemispheric specialization
There are four lobes in the brain. Name them.
What is the area in the anterior frontal lobe called, and what is it responsible for?
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.
What area of the brain allows us to move our muscles to produce speech?
Broca's area, which is located in the left frontal lobe in most right-handers
The top of the motor cortex controls voluntary muscle movements in what area of the body?
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.
Located in the parietal lobe behind the motor cortex, the __________ receives touch sensations from the body.
sensory cortex, or somato-sensory cortex
Why is the area where vision is processed counterintuitive?
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).
Damage to what area of the temporal lobe would result in an inability to understand written or spoken language?
What sensory modality is the temporal lobe responsible for processing?
Unlike vision, hearing is not lateralized. Sound coming in one ear is processed by both hemispheres of the brain.
Explain brain plasticity.
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.
Why is the endocrine system important to the field of psychology?
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
Who was Thomas Bouchard and why was his research important?
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