AP Psychology Unit 1 Vocabularuy

Biological Bases of Behavior

Central Nervous System (CNS)

Brain and spinal cord

Nervous system

Body’s speedy, electrochemical communication network — consisting of all of the nerve cells of the peripheral and CNS.

Peripheral nervous system

Sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundled axons that form neural cables connecting the CNS with muscles, glands, and sense organs.

Sensory (afferent) neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord. “APPROACHES”

Motor (efferent) neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands. “EXITS”

Interneurons

Neurons within the brain and spinal cord (CNS) that intervene between the sensory inputs and motor outputs.

Somatic nervous system

Division of the peripheral nervous system that controls the body’s skeletal muscles. Voluntary actions.

Autonomic nervous system

Division of the peripheral nervous system that controls the glands and the muscles of the internal organs. Involuntary actions.

Sympathetic nervous system

Arouses the body, mobilizes its energy in stressful situations. “Flight or fight”

Parasympathetic nervous system

Calms the body, conserves its energy. “Rest and digest”

Glial cells (glia)

They hold neurons in place — support, nourish, and protect them. May also play a role in learning and thinking.

Reflex

The action itself. An involuntary, rapid, and automatic response to a stimulus.

Reflex arc

The pathway that makes it happen.

5 components of a reflex arc?

receptor (picks up the stimulus) —> sensory —> integration center —> motor neuron —> effector (muscle reacts)

Neural transmission

the electrochemical process by which neurons (nerve cells) send and receive information throughout the nervous system

Action potential

A neural impulse; brief electrical charge that travels down an axon.

All-or-none response

A neuron’s reaction of either firing (with a full-strength response) or not firing.

Resting potential

The inactive, polarized state of a neuron before it fires (-70 mV internal charge).

Concentration of ions in resting potential:

High concentration of Na+ ions outside the axon, inside K+ ions and negative proteins.

Threshold

The minimum level of stimulation required to trigger a neural impulse (an action potential). (-55 mV)

Depolarization

If stimulation hits the threshold (approx. -55 mV), voltage-gated sodium channels burst open.The internal charge is flipped from negative to positive.

What does a stronger stimulus cause?

More frequency, not a stronger “action potential.”

Refractory period

Reset — Brief resting pause after the action potential in which the neuron can not fire again. The sodium-potassium pump uses energy (ATP) to clean up the mess, swapping 3 Na+ ions out for every 2 K+ ions in; essentially, the original chemical balance is restored.

Reuptake

Clean-up — The recycling process of extra chemical messengers. The sending neuron's terminal buttons reabsorb excess, unbound neurotransmitters from the synapse.

Myasthenia gravis

Autoimmune disorder involving the damage of ACh receptor sites, preventing muscle cells from receiving chemical signals of ACh. Leads to severe, progressive muscle weakness and mul.

Multiple sclerosis

The degeneration of the myelin sheath, causing communication to the muscles to slow down, thus leading to the eventual loss of muscle control.

Excitatory neurotransmitters

Pushes the neuron closer to the threshold (brings charge from -70 mV up toward -55 mV). “FIRE” Associated with depolarization (more positive —> pushes closer to threshold).

Inhibitory neurotransmitters

Pushes the neuron further from the threshold (drops charge below -70 mV). “STOP” Associated with hyperpolarization.

Examples of excitatory neurotransmitters

Glutamate, ACh, Epinephrine (Adrenaline)

Examples of inhibitory neurotransmitters

GABA, Endorphins

Acetylcholine (ACh)

Muscle action, learning, assistance with memory.

Substance P

Helps with the transmission of pain signals from sensory (afferent) nerves to the CNS.

Dopamine

Movement, learning, attention, and emotions, Helps drive our motivation and reward system.

Serotonin

Impacts an individual’s hunger, sleep, arousal, and mood.

Endorphins

Pain control, pain tolerance — associated with “runner’s high.”

Norepinephrine

Increases your body’s blood pressure, heart rate, alertness, and helps with the body’s “flight-or-fight” response.

Glutamate

Long-term memory and learning. Excitatory neurotransmitter, master switch.

GABA

Sleep, movement, and calms/slows down our bodies. Inhibitory neurotransmitter, master switch.

Hormones

Chemical messengers that are manufactured by the endocrine glands that travel through the bloodstream and affect other tissues.