66 terms

AP Psychology: Biology

- The study of the parts and function of neurons

- These cells make up our entire nervous system
- Neural cell

- Made up of specific structure: dendrites, cell body, axon, and terminal buttons
- Rootlike parts of the cell that stretch out from the cell body

- Dendrites grow to make synaptic connections with other neurons
Cell Body (also called the Soma)
- Contains the nucleus and other parts of the cell needed to sustain its life
- Wirelike structure ending in the terminal buttons that extends from the cell body
Myelin Sheath
- Fatty covering around the axon of some neurons that speeds neural impulses
Terminal Buttons (also called End Buttons, Axon Terminal, Terminal Branches of Axon, and Synaptic Knobs)
- Branched end of the axon that contains neurotransmitters
- Chemicals contained in terminal buttons that enable neurons to communicate

- Neurotransmitters fit into receptor sites on the dendrites of neurons like a key fits into a lock
- Space between the terminal buttons of one neuron and the dendrites of the next neuron
Receptor Sites
- Areas on a dendrite designed to receive a specific neurotransmitter
- Level of neurotransmitters required to "fire" a neuron
Action Potential
- Electric charge that spreads down the length of a neuron after the threshold is achieved

- Travels like a bullet from a gun
All-or-None Principle
- Neuron either fires completely or it does not fire at all

- If the dendrites of a neuron receive enough neurotransmitters to push the neuron past its threshold, the neuron will fire completely every time
Neural Firing
- Electrochemical process

- Electricity travels within the cell (moves from the dendrites to the terminal buttons—called action potential), and chemicals (neurotransmitters) travel between cells in the synapse; electricity does not jump between the neurons
Excitatory Neurotransmitters
- Chemicals released from the terminal buttons of a neuron that excite the next neuron into firing
Inhibitory Neurotransmitters
- Chemicals released from the terminal buttons of a neuron that inhibit the next neuron from firing
- Associated with motor movement

- Lack of acetylcholine is associated with Alzheimer's disease
- Associated with motor movement and alertness

- Lack of dopamine is associated with Parkinson's disease; an overabundance is associated with schizophrenia
- Neurotransmitter associated with pain control

- Also involved in drug addiction
- Neurotransmitter associated with mood control.

- Lack of serotonin is associated with clinical depression.
Afferent Neurons (Sensory Neurons)
- Neurons that take information from the senses to the brain.

- Afferent neurons are responsible for transmitting neural impulses from the rest of the body to the brain.
Efferent Neurons (Motor Neurons)
- Neurons that take information from the brain to the rest of the body.

- Efferent neurons carry information that exits the brain.
Central Nervous System
- Part of the nervous system that consists of our brain and spinal cord.

- All the nerves are housed within bone (the skull and vertebrae).
Spinal Cord
- A bundle of nerves that run through the center of the spine.

- Transmits information from the rest of the body to the brain.
Peripheral Nervous System
- All the nerves in your body other than the brain and spinal cord nerves; all the nerves not encased in bone.

- The peripheral nervous system is divided into two categories: the somatic and the autonomic nervous systems.
Somatic Nervous System
- Controls voluntary muscle movements.

- The motor cortex of the brain sends impulses to the somatic nervous system, which controls the muscles that allow us to move.
Autonomic Nervous System
- Controls the automatic functions of the human body-heart, lungs, internal organs, glands, and so on.

- Controls responses to stress-the fight or flight response that prepares the body to respond to a perceived threat.

- Divided into two categories: the sympathetic and parasympathetic nervous systems.
Sympathetic Nervous System
- Mobilizes our body to respond to stress.

- Part of the nervous system that carries messages to the control systems of the organs, glands, and muscles that direct the body's response to stress.

- The alert system of the human body. It accelerates some functions (such as heart rate, blood pressure, and respiration) but conserves resources needed for a quick response by slowing down other functions (such as digestion).
Parasympathetic Nervous System
- Responsible for slowing down the body after a stress response.

- Carries messages to the stress response system that causes the body to slow down.

- Think of the parasympathetic nervous system as the brake pedal that slows down the body's autonomic nervous system.
- Early psychologists studied accidents as a way to investigate brain function.

- Accidents resulting in injuries to specific brain areas (such as the Phineas Gage case study) helped psychologists get an idea about the function of each part of the brain.
- Removal or destruction of part of the brain.

- Sometimes doctors decide that the best treatment for a certain condition involves surgery that will destroy or incapacitate part of the brain.

- Doctors closely monitor the patient's subsequent behavior for changes.
Electroencephalogram (EEG)
- Device that detects brain waves.

- Researchers can examine what type of waves the brain produces during different stages of consciousness and use this information to generalize about brain function.

- Widely used in sleep research to identify the different stages of sleep and dreaming.
Computerized Axial Tomography (CAT or CT Scan)
- A sophisticated X-ray.

- Uses several X-ray cameras that rotate around the brain and combine all the pictures into a detailed three-dimensional picture of the brain's structure.

- Can show only the structure of the brain, not the functions or the activity of different brain structures.
Cerebral Cortex
- Gray Wrinkled Surface of the brain

- A thin (1-mm) layer of densely packed neurons

- This layer covers the rest of the brain, including most of the structures we have described
- Cerebral cortex is divided into two hemispheres: left and right.

- The hemispheres look like mirror images of one another, but they exert some differences in function.
Left Hemisphere
- Gets sensory messages and controls the motor function of the right half of the body

- Left hemisphere may be more active during spoken language, logic, and sequential tasks
Right Hemisphere
- Gets sensory messages and controls motor function of left half of the body

- Right hemisphere may be more active during spatial and creative tasks
Brain Lateralization (or Hemispheric Specialization)
- Specialization of function in each brain hemisphere

- Right hemisphere may be more active during spatial and creative tasks

- Left hemisphere may be more active during spoken language, logic, and sequential tasks
Corpus Callosum
- Nerve bundle that connects the two brain hemispheres
- Areas of cerebral cortex: frontal, parietal, temporal, and occipital
Association Areas
- Any area of cerebral cortex that is not associated with receiving sensory information or controlling muscle movements
Frontal Lobes
- Located at the top front part of brain behind the eyes

- Anterior or front of the frontal lobe is called the prefrontal cortex and is thought to play a critical role in directing thought processes

- Prefrontal cortex is said to act as the brain's central executive and is believed to be important in foreseeing consequences, pursuing goals, and maintaining emotional control

- Researchers believe this part of the brain is responsible for abstract thought and emotional control
Broca's Area
- Located in frontal lobe and responsible for controlling muscles involved in producing speech

- Damage to Broca's area might leave us unable to make muscle movements needed for speech
Wernicke's Area
- Interprets both written and spoken speech

- Damage to this area would affect our ability to understand language

- Our speech might sound fluent but lack proper syntax and grammatical structure needed for meaningful communication
Motor Cortex
- Thin vertical strip at the back of the frontal lobe

- This part of the cerebral cortex sends signals to our muscles, controlling our voluntary movements

- The top of the body is controlled by the neurons at the bottom of this cortex (by the ears0, progressing down the body as you go up the cortex
Parietal Lobes
- Located behind frontal lobe on the top of the brain

- Contain the sensory cortex (also known as the somato-sensory cortex), which is located right behind the motor cortex in the frontal lobe
Sensory Cortex
- Thin vertical strip of the cerebral cortex that receives incoming touch sensations from the rest of our body

- Organized similarly to the motor cortex

- Top of the sensory cortex receives sensations from the bottom of the body, progressing down the cortex to the bottom, which processes signals from our face and head.
Occipital Lobes
- Located at the very back of the brain, farthest from our eyes. This is somewhat anti-intuitive since one of the major functions of this lobe is to interpret messages from our eyes in our visual cortex

- Impulses from the retinas in our eyes are sent to the visual cortex to be interpreted

- Impulses from the right half of each retina are processes in the visual cortex in the right occipital lobe. Impulses from the left part of each retina are sent to the visual cortex in our left occipital lobe
Temporal Lobes
- Process sound sensed by our ears

- Sound waves are processed by the ears, turned into neural impulses, and interpreted in our auditory cortices

- Auditory cortex is not lateralized like visual cortices are. Sound received by left ear is processed in auditory cortices in both hemispheres
Brain Plasticity
- Parts of brain can adapt themselves to perform other functions if needed

- Cerebral cortex is made up of a complex network of neurons connected by dendrites that grow to make new connections

- Since dendrites grow throughout our lives, if one part of the brain is damaged, dendrites might be able to make new connections in another part of the brain that would be able to take over the functions usually performed by the damaged part of the brain

- Dendrites grow most quickly in younger children. Researchers know that younger brains are more plastic and are more likely to compensate for damage
Endocrine System
- System of glands that secrete hormones

- Affects many different biological processes in our bodies
Magnetic Resonance Imaging (MRI Scan)
- Uses magnetic fields to measure the density and location of brain material

- Doesn't use X-rays as CAT scan does, so patient isn't exposed to carcinogenic radiation

- Like CAT scan, MRI gives doctors information only about structure of brain, not function
Positron Emission Tomography (PET scan)
- Measures how much of a certain chemical (glucose, for example) parts of brain are using - more used, higher activity

- Different types of scans are used for different chemicals such as neurotransmitters, drugs, and oxygen flow
Function MRI (fMRI)
- Combines elements of MRI and PET scans

- Can show details of brain structure with information about blood flow in the brain, tying brain structure to brain activity during cognitive tasks
- Structures in the top part of the spinal cord

- Life support system; controls basic biological functions that keep us alive

- Some important specific structures within are medulla, pons, cerebellum
- Involved in control of blood pressure, heart rate, and breathing

- Medulla oblongata; located above spinal cord
- Located above medulla and toward the front

- Connects hindbrain and midbrain and forebrain

- Involved in control of facial expressions
- Located on the bottom rear of the brain

- Looks like a smaller version of our brain stuck onto the underside of our brain

- Cerebellum means little brain

- Coordinates some habitual muscle movements, such as tracking a target with our eyes or playing saxophone
- Located just above spinal cord

- Controls some very important functions

- Coordinates simple movements with sensory information
Reticular Formation
- Netlike collection of cells throughout midbrain that controls general body arousal and ability to focus attention

- If reticular formation doesn't function, we fall into deep coma
- Controls what we think of as thought and reason

- Size of forebrain makes humans human, most psychological researchers concentrate their efforts in this area of brain

- Specific areas in forebrain are thalamus, hypothalamus, amygdala, and hippocampus
- Located on top of the brain stem

- Responsible for receiving the sensory signals coming up the spinal cord and sending them to the appropriate areas in the rest of the forebrain
- Small structure next to the thalamus

- Small size of the hypothalamus belies the importance of its functions

- Controls several metabolic functions including body temperature, sexual arousal (Libido), hunger, thirst, and endocrine system
- Small area of brain within limbic system

- Vital to our experiences of emotion
- Vital to our memory system

- Memories aren't permanently stored in this area of the brain, however. Memories are processed through this area and then sent to other locations in cerebral cortex for permanent storage
Limbic system
- Name for a group of brain structures: Thalamus, hypothalamus, amygdala, and hippocampus