Biology of Behavior Notes

Biological/Neuroscientific Perspective: Focuses on how physical systems, such as the brain, influence behavior, feelings, and thoughts.
Evolutionary Perspective: Emphasizes natural selection of traits and their impact on behavior.
Behavior Genetics Perspective: Examines the contributions of genes and the environment to behavior.
Psychoanalytic/Psychodynamic Perspective: Deals with unconscious dynamics within the individual.
Behavioral Perspective: Focuses on learning through reinforcements and punishments.
Cognitive Perspective: Studies how people reason, remember, and interpret information.
Sociocultural Perspective: Explores how social and cultural forces shape an individual's behavior.

Thoughts, feelings, and behaviors are traceable to electrical and chemical signals traveling through the brain and body.

Neuron: A specialized cell that transmits neural messages to other neurons, glands, and muscles.
- Dendrite: Receives neural messages from other neurons.
- Cell Body (Soma): Houses DNA.
- Axon: A thin tube that transmits messages.
Glial Cells (Glia):
- Provide structure for neurons.
- Some form the blood-brain barrier, preventing some toxins from entering the brain.
- Some form the myelin sheath, which wraps around the axon to help transmit messages.

Dendrites: Receive messages from other cells.
Cell Body: The cell's life-support center.
Axon: Passes messages away from the cell body to other neurons, muscles, or glands.
Terminal Branches of Axon: Form junctions with other cells.
Neural Impulse: Electrical signal traveling down the axon.
Myelin Sheath: Covers the axon of some neurons and helps speed neural impulses.

Neurons communicate in two steps:
- Electrical signal within a neuron (action potential).
- Chemical signal between neurons (neurotransmitters).

Action Potential: An electrical impulse that travels from the cell body down to the end of the axon (neural firing).
Threshold: The level of electric charge needed to stimulate an action potential.
All-or-None Response: Once the electric charge of the neuron reaches a certain threshold, it fires an action potential.

Synapse: The junction between two neurons.
Messages are transmitted across the synapse via neurotransmitters.
Neurotransmitters: Chemical messengers that travel across the synapse from the sending neuron to receptors on the receiving neuron.
Reuptake: The sending neuron reabsorbs excess neurotransmitters.

1. Electrical impulses (action potentials) travel down a neuron's axon until reaching a tiny junction known as a synapse.
2. When an action potential reaches an axon terminal, it stimulates the release of neurotransmitter molecules. These molecules cross the synaptic gap and bind to receptor sites on the receiving neuron. This allows electrically charged atoms to enter the receiving neuron and excite or inhibit a new action potential.
3. The sending neuron normally reabsorbs excess neurotransmitter molecules, a process called reuptake.

Central Nervous System (CNS): Brain and spinal cord.
Peripheral Nervous System (PNS): All of the nervous system outside the brain and spinal cord.
- Autonomic: Controls Self-Regulated Action of Internal Organs and Glands.
  - Sympathetic: Arousing.
  - Parasympathetic: Calming.
- Somatic: Controls voluntary movements of skeletal muscles.

Motor Neurons: Carry signals from the brain or spinal cord to muscles, skin, and glands.
Sensory Neurons: Carry messages from receptors to the spinal cord and brain.

Central Nervous System: Brain and spinal cord.
- Responds to sensory information.
- Sends messages to muscles, glands, and organs.
Spinal Cord: Extension of the brain.
- Handles both incoming and outgoing messages.
- Acts as a bridge between the brain and body below the neck.
Spinal Reflexes: Automatic responses that occur without any brain involvement.

Peripheral Nervous System: All of the nervous system outside the brain and spinal cord.
- Allows communication between the CNS and sensory systems.
Contains somatic and autonomic nervous systems.

Somatic Nervous System (Voluntary):
- Sensory and motor pathways.
Autonomic Nervous System (Automatic):
- Sympathetic Nervous System: Increases physiological arousal (Fight or Flight).
- Parasympathetic Nervous System: Decreases arousal (Rest & Digest).