Neurobiologist and other investigators understand that humans and animals operate similarly when processing information.
The body's information system is build from billions of interconnected cells.
Life support center of the neuron.
Branching extensions at the cell body. Receive messages from other neurons and conducts impulses towards the cell body.
Long single extension of a neuron covered with ____ to insulate and speed up messages through neurons.
Myelin Sheath; Axon
Branched endings of an axon that transmit messages to other neurons.
Terminal Branches of Axon
A brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of the channels in the axon's membrane.
Action potential (neural impulse)
When the neuron is not stimulated, the fluid interior of the axon carries mostly negatively charged atoms (potassium) and outside has mostly positively charged atoms (sodium).
When a neuron is in its' resting state.
Occurs when + (sodium), ions move inside the neuron, making it more prone to firing an action potential (if threshold is reached).
Occurs when - ions enter the neuron, making it less prone to firing an action potential (bringing it back to its resting state).
The point at which there is no holding back. The neuron reaches its' minimum intensity required to fire an action potential.
After a neuron fires an action potential, it pauses for a short period to recharge itself to fire again 9like a resting pause).
Channels in the axon membrane that pump positive sodium and potassium ions in and out of the negatively charged neuron, making the neuron ready for another action potential party.
When the depolarizing current exceeds the threshold, a neuron will fire. If the depolarizing current fails to exceed the threshold, a neuron will not fire. (like a gun)
An action potential remains the same throughout the length of the axon. But a stronger stimulus can elicit more neurons to fire and/or more rapid firing. (i.e. squeezing trigger harder wont make bullet travel faster)
A junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
A knoblike terminals at the terminal branches (end) of an axon that contain chemical messengers.
Chemical messengers that are triggered by an action potential travel across the synapse, and bind to receptor sites on the receiving neuron.
A process in which excess neurotransmitters in the synapse are reabsorbed into the ending neurons.
The neurotransmitter found at every junction between a motor neuron and skeletal muscle that enables muscle contraction, learning, and memory.
The neurotransmitter involved with mood regulation, hunger, sleep and arousal.
The neurotransmitter involved with movement, learning, attention, and emotion. It is also our primary reward/pleasure chemical.
Essentially adrenaline, our "fight or flight" chemical.
Major inhibitory neurotransmitter; undersupply linked to seizures, tremors and insomnia.
GABA (gamma-amminobutyric acid)
Major excitatory neurotransmitter; oversupply can over-stimulate the brain, producing migraines or seizures, which is why some people avoid MSG in foods.
Natural opiate-like neurotransmitters released in response to pain and vigorous exercise.
The brain's natural defense, which protects it from foreign substances, infection and diseases.
Blood-brain barrier (BBB)
Consists of all the nerve cells, It is the body's speedy, electrochemical communication system.
The brain and spinal cord.
Central Nervous System (CNS)
The sensory and motor neurons that connect the central nervous system to the rest of the body.
Peripheral Nervous System
Enables voluntary movement and control of our skeletal muscles.
Somatic Nervous System
A dual system that controls the self-regulating functions of our internal organs; consists of two subdivisions.
Autonomic Nervous System
Division of the ANS that arouses the body, mobilizing its energy in stressful situations.
Sympathetic Nervous System
Division of ANS that calms the body, conserving its energy.
Parasympathetic Nervous System
These bundled axons carry information from the PNS and connect muscles, glands, and sense organs to the CNS.
Carry incoming sensory info from the body's sense receptors to the CNS.
Carry outgoing info from the CNS to the muscles and glands.
CNS neurons that internally process info between sensory and motor neurons.
"Neural nannies" supporting, nourishing and protecting neurons in the nervous system.
Interconnected neurons that form complex networks in the brain.
A simple, automatic, inborn response to a sensory stimulus.
The body's "slow" chemical communication system.
Chemical messengers synthesized by the endocrine glands that are secreted in the bloodstream.
Secretes "fight or flight" hormones during stressful and emotional situations, while the adrenal cortex regulates salt and carbohydrate metabolism.
Regulates the level of sugar in the blood.
The "master gland" is the most influential gland.
The hypothalamus in the brain controls the pituitary gland, which secretes hormones that affect other glands, which secrete more hormones, which affect the brain.
Regulates metabolism (among other things).
Regulates the level of calcium in the body.
Located in different places in men and women. They regulate bodily development and maintain reproductive organs in adults.
Sex Glands (Gonads)
The oldest method of studying the brain. It involves observing and systematically recording the effects of brain diseases and injuries.
_____ (destroying) tiny clusters of normal or defective brain cells in animals in order to study behaviors after tissue destruction.
An amplified recording of the electrical waves sweeping across the brain's surface, which is measured by electrodes placed on the scalp.
Uses computer-aided brain scans to examine the connections between brain, mind and behavior.
Locates, measures and visually depicts radioactive "hotspots" of brain activity while the brain performs certain tasks.
PET (positron emission tomography) Scan
Magnetic fields to align the spinning center of atoms. Releases signals which provide computer-generated images that distinguish among different types of soft brain tissue.
Reveals the brain's changing blood flow (and thus brain function) by comparing successive MRI scans.
Patient's head is in a donut-shaped ring that takes a series of x-ray photos from different angles.