psych unit 2 part 2

Neuron

Neuron

A nerve cell; the basic building block of the nervous system

Action potential

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

threshold

The level of stimulation required to trigger a neural impulse.

Refractory period

In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state

all-or-none response

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

synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.

neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

Nervous system

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

Central nervous system (CNS)

The brain and spinal cord

Peripheral nervous system (PNS)

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Sensory (afferent) neurons

Neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord

Motor (efferent) neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles.

Autonomic nervous system (ANS)

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs. Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic nervous system

The division of the autonomic nervous system that arouses the body, mobilizing its energy

Parasympathetic nervous system

The division of the autonomic nervous system that calms the body, conserving its energy.

Endocrine system

The body's slow "chemical" communications system; a set of glands that secrete hormones into the bloodstream

Adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that helps around the body in times of stress

Pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

plasticity

The brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

neurogenesis

The formation of new neurons

Sequential processing

Processing one aspect of a problem at a time; generally used to process new information or to solve difficult problems.

chromosomes

Threadlike structures made of DNA molecules that constrain the genes

Molecular genetics

The subfield of biology that studies the molecular structure and functions of genes

mutation

A random error in gene replication that leads to a change