U1L4: Biological Bases of Behavior

Genetic predisposition

Inherited genetic traits that influence susceptibility to certain diseases or behaviors.

Neurons

Specialized cells that transmit information throughout the nervous system.

Multiple sclerosis

A disease where the immune system attacks the protective covering of nerves, disrupting communication between the brain and body.

Neural transmission

The process by which neurons send electrical and chemical signals to communicate.

Resting potential

The state of a neuron when it is inactive, maintaining a slight negative charge.

Threshold

The minimum stimulus required to trigger an action potential in a neuron.

Action potential

A brief electrical charge that travels down a neuron, initiating communication.

All-or-none principle

Once a neuron reaches the threshold, it fires completely; it does not fire partially.

Depolarization

A shift in the neuron's charge, making it less negative and triggering an action potential.

Excitatory neurotransmitters

Chemicals that increase the likelihood of a neuron firing.

Inhibitory neurotransmitters

Chemicals that decrease the likelihood of a neuron firing.

Dopamine

Involved in reward, pleasure, and motor control; associated with Parkinson's disease and addiction.

Serotonin

Regulates mood, appetite, and sleep; linked to depression and anxiety.

Norepinephrine

Enhances alertness, arousal, and fight-or-flight response.

Glutamate

The brain's primary excitatory neurotransmitter, crucial for learning and memory.

GABA

The brain's main inhibitory neurotransmitter, preventing excessive neural activity.

Endorphins

Natural painkillers that also produce feelings of pleasure.

Substance P

Involved in transmitting pain signals.

Acetylcholine

Essential for memory, learning, and muscle movement.

Alzheimer's disease

A degenerative brain disorder characterized by memory loss and cognitive decline.

Myasthenia gravis

A condition where the immune system attacks receptors needed for muscle contraction, leading to weakness.

Sensory neurons

Transmit sensory information from the body to the brain.

Interneurons

Connect neurons within the brain and spinal cord.

Motor neurons

Relay commands from the brain to muscles for movement.

Central nervous system (CNS)

Composed of the brain and spinal cord, it controls bodily functions.

Peripheral nervous system (PNS)

Includes all nerves outside the CNS, linking the brain to the body.

Reflex arcs

Automatic responses to stimuli, processed by the spinal cord without brain involvement.

Somatic nervous system

Controls voluntary muscle movements.

Autonomic nervous system

Regulates involuntary functions like heart rate and digestion.

Sympathetic nervous system

Activates the body's fight-or-flight response.

Parasympathetic nervous system

Promotes rest and digestion.

Endocrine system

Produces and releases hormones that regulate body processes.

Hormones

Chemical messengers that influence bodily functions and behaviors.

Adrenaline

Increases heart rate and energy in response to stress.

Leptin

Regulates hunger and metabolism.

Ghrelin

Stimulates hunger.

Melatonin

Regulates sleep cycles.

Oxytocin

Known as the 'bonding hormone,' affecting social connections and trust.

Lesioning

Damaging brain tissue to study its function.

Electroencephalogram (EEG)

Measures brain wave activity.

Functional MRI (fMRI)

Tracks blood flow in the brain to identify active areas.

Medulla

Regulates breathing and heart rate.

Cerebellum

Coordinates movement and balance.

Reticular formation

Controls alertness and arousal.

Thalamus

Serves as a sensory relay center.

Hypothalamus

Regulates hunger, thirst, body temperature, and hormonal balance.

Amygdala

Processes emotions, especially fear and aggression.

Hippocampus

Essential for memory formation.

Brain stem

Regulates basic life functions.

Cerebral cortex

The outer layer of the brain responsible for higher cognitive functions.

Limbic system

Governs emotions and memory.

Contralateral hemispheric organization

One hemisphere controls the opposite side of the body.

Hemispheric specialization

The left hemisphere is dominant for language, and the right for spatial abilities.

Split-brain patients

Individuals who have had their corpus callosum severed to reduce seizures.

Corpus callosum

Connects the brain's hemispheres for communication.

Lobes

Distinct regions of the cerebral cortex responsible for different functions.

Association area

Brain regions that integrate sensory and motor information.

Frontal lobes

Involved in decision-making, problem-solving, and personality.

Prefrontal cortex

Essential for reasoning, planning, and impulse control.

Central executive

Controls attention and coordinates cognitive tasks.

Broca's area

Involved in speech production; damage leads to aphasia.

Aphasia

A language disorder affecting speech or comprehension.

Wernicke's area

Responsible for language comprehension.

Motor cortex

Controls voluntary movements.

Parietal lobes

Process sensory information like touch and spatial awareness.

Somatosensory cortex

Registers tactile sensations.

Phantom limb syndrome

Sensations felt in a missing limb.

Occipital lobes

Process visual information.

Temporal lobes

Handle auditory processing and memory.

Linguistic processing

The brain's method of understanding and producing language.