AP- Biological Bases of Behavior

Neuroanatomy

The study of the parts and functions of neurons.

Neurons

Individual nerve cells.

Dendrites

Rootlike parts of the cell that stretch out from the cell body; grow to make synaptic connections with other neurons.

Cell body/soma

Contains the nucleus and other parts of the cell needed to sustain its life.

Axon

Wirelike structure ending in the terminal buttons that extends from the cell body.

Myelin sheath

A fatty covering around the axon of some neurons that speeds neural impulses.

Terminal buttons

The branched end of the axon that contains neurotransmitters.

Synapse

The space between the terminal buttons of one neuron and the dendrites of the next neuron.

Action potential

The electric message firing of neurons.

All-or-none principle

States that a neuron must either fire completely or not at all; a neuron cannot fire a little or a lot - the impulse is the same every time.

Acetylcholine

Neurotransmitter that controls motor movement; a lack of it is associated with Alzheimer's disease.

Dopamine

Neurotransmitter that controls motor movement and alertness; a lack of it is associated with Parkinson's disease while an overabundance is associated with schizophrenia.

Endorphins

Neurotransmitters that act as pain control; excess or deficits of endorphins are involved in addictions.

Serotonin

Neurotransmitter that act as mood control; a lack of it is associated with clinical depression.

Afferent/sensory neuron

Takes information from the senses to the brain.

Interneuron

Takes the messages from afferent neurons in the brain or spinal cord and sends them elsewhere in the brain or on to efferent neurons.

Efferent/motor neuron

Takes information from the brain to the rest of the body.

Central nervous system (CNS)

Consists of our brain and spinal cord (all the nerves housed within bone); transmits information from the rest of the body to the brain.

Peripheral nervous system (PNS)

Consists of all the nerves not encased in bone; divided into the somatic and autonomic nervous systems.

Somatic nervous system

Controls our voluntary muscle movements.

Autonomic nervous system

Controls the automatic functions of our body; divided into the sympathetic and parasympathetic nervous systems.

Sympathetic nervous system

Mobilizes our body to respond to stress.

Parasympathetic nervous system

Responsible for slowing down our body after a stress response.

Lesioning

The removal or destruction of part of the brain.

Electroencephalogram (EEG)

Detects brain waves; shows researchers the types of brain waves produced during different stages of consciousness.

Computerized axial tomography (CAT/CT) scan

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

Magnetic resonance imaging (MRI)

Uses magnetic fields to measure the density and location of brain material and creates a detailed image of the brain.

Position emission tomography (PET) scan

Lets researchers see what areas of the brain are most active during certain tasks; measures how much of a certain chemical parts of the brain are using.

Functional MRI (fMRI)

Combines elements of the MRI and PET scans to show details of brain structure with information about blood flow in the brain, tying brain structure to brain activity during cognitive tasks.

Hindbrain

Consists of structures in the top of the spinal cord; the life support system; controls the basic biological functions that keep us alive; consists of the medulla, pons, and cerebellum.

Medulla

Involved in the control of our blood pressure, heart rate, and breathing; located above the spinal cord; part of the hindbrain.

Pons

Connects the hindbrain with the midbrain and the forebrain; also involved in the control of facial expressions; located just above the medulla and toward the front; part of the hindbrain.

Cerebellum

Coordinates some habitual muscle movements; located on the bottom rear of the brain; part of the hindbrain.

Midbrain

Consists of structures just above the spinal cord but still below areas categorized as the forebrain; in general, coordinates simple movements with sensory information; most important part is the reticular formation.

Reticular formation

A netlike collection of cells throughout the midbrain that controls general body arousal and the ability to focus our attention; if this does not function, we fall into a deep coma; part of the midbrain.

Forebrain

Control what we think of as thought and reason; consists of the thalamus, hypothalamus, amygdala, and hippocampus.

Thalamus

Responsible for receiving the sensory signals coming up the spinal cord and sending them to the appropriate areas in the rest of the forebrain; located on top of the brain stem; part of the forebrain.

Hypothalamus

Controls several metabolic functions including body temperature, sexual arousal (libido), hunger, thirst, and the endocrine system; located right next to the thalamus; part of the forebrain.

Amygdala

Vital to our experiences of emotion; located near the end of each hippocampal arm; part of the forebrain.

Hippocampus

Vital to our memory system - memories are processed through this area and then sent to other locations in the cerebral cortex for permanent storage; consists of two arms surrounding the thalamus; part of the forebrain.

LImbic system

Consists of the thalamus, hypothalamus, hippocampus, and amygdala; deals with aspects of emotion and memory.

Cerebral cortex

The gray wrinkled surface of the brain which is actually a thin (1 mm) layer of densely packed neurons; covers the rest of the brain.

Fissures

Wrinkles in the brain.

Contralateral control

Describes the ability of the right hemisphere to control the left side of the body and vice versa.

Brain lateralization

The specialization of function in each hemisphere of the brain.

Hemispheric specialization

The specialization of function in each hemisphere of the brain.

Split-brain patients

Patients whose corpus callosum has been cut to treat severe epilepsy; cannot orally report information only presented to the right hemisphere since the spoken language centers of the brain are usually located in the left hemisphere.

Cerebral cortex

The collection of the frontal, parietal, temporal, and occipital lobes.

Association area

Any area of the cerebral cortex that is not associated with receiving sensory information or controlling muscle movements.

Frontal lobes

Large areas of the cerebral cortex located at the top front part of the brain behind the eyes.

Prefrontal cortex

The anterior or front of the frontal lobe that is thought to play a critical role in directing thought processes; 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 the frontal lobe and is responsible for controlling the muscles involved in producing speech; damage to in might leave us unable to make the muscle movements needed for speech.

Motor cortex

Thin vertical strip at the back of the frontal lobe; sends signals to our muscles, controlling our voluntary movements.

Parietal lobes

Located behind the frontal lobe but still on the top of the brain.

Sensory cortex

Thin vertical strip that receives incoming touch sensations from the rest of our body; located behind the motor cortex in the parietal lobe.

Occipital lobes

Located at the very back of the brain, farthest from the eyes; interpret messages from our eyes in our visual cortex.

Temporal lobes

Process sound sensed by our ears.

Wernicke's area

Located in the temporal lobe and is responsible for interpreting both written and spoken speech; damage to it would affect our ability to understand language.

Endocrine system

System of glands that secrete hormones that affect many different biological processes in our body; controlled by the hypothalamus.

Adrenal glands

Produce adrenaline, which signals the rest of the body to prepare for fight or flight.

Turner's syndrome

People born with only a single X chromosome in the spot usually occupied by the twenty-third pair; causes some physical characteristics, lie shortness, webbed necks, and differences in physical sexual development.

Klinefelter's syndrome

People born with an extra X chromosome, resulting in an XXY patter; causes minimal sexual development and personality traits.

Down syndrome

People born with an extra chromosome on the twenty-first pair; causes some physical characteristics like a rounded face, shorter fingers and toes, slanted eyes set far apart, and some degree of mental retardation.