Chapter 4: The Brain And Behavior Flashcards
Neurons
The functional building blocks of the nervous system; cells that transmit the electrical activity that underlies psychological processes
Glial cell
From the greek for “glue”; cells surrounding neurons, holding them in place, providing the nutrients neurons need and insulating toxins that would harm the neurons
Synapse
A connection between neurons
Sensory neurons
Carry input messages from the sense organs to the spinal cord and brain
Motor neurons
Transmit output impulses from the brain and spinal cord to the body’s muscles and organs
Interneurons
Perform connective or associative functions within the nervous system
Peripheral nervous system
Contains all the neural structures that lie outside the brain and spinal cord
Somatic nervous system
Consists of sensory neurons that are specialized to transmit messages from the eyes, ears and other sensory receptors, and motor neurons that send messages from the brain and spinal cord to the muscles that control our voluntary movements
Autonomic nervous system
Senses the body’s internal functions and controls the glands and the smooth (involuntary) muscles that form the heart, the blood vessels, and the lining of the stomach and intestines
Sympathetic nervous system
Has an activation or arousal function, and tends to act as a total unit
Parasympathetic nervous system
Is far more specific in its opposing actions than the sympathetic nervous system, affecting one or a few organs at a time; in general, it slows down body processes and maintains a state of tranquility
Homeostasis
A delicately balanced or constant internal state
Central nervous system
Contains the brain and the spinal cord, which connects most parts of the peripheral nervous system with the brain
Dendrites
Specialized receiving units like antennae that collect messages from neighboring neurons and send them on to the cell body
Axon
Conducts electrical impulses away from the cell body to other neurons, muscles or glands
Resting potential
Internal difference of around 70 millivolts (mV)
Action potential
Electrical shift across the neural membrane, which lasts about a millisecond and propagates electrical signals down an axon
Absolute refractory period
Period during which the membrane is not excitable and cannot discharge another impulse
Graded potentials
Changes in the negative resting potential that do not reach the -50 millivolt action potential threshold
Myelin sheath
A whitish, fatty insulation layer derived from glial cells during development
Synaptic cleft
A tiny gap between the axon terminal and the next neuron
Neurotransmitters
Chemicals released by nerve cells that allow them to communicate with one another (example: acetylcholine)
Synaptic vesicles
Chambers within the axon terminals
Receptor sites
Large protein molecules embedded in the receiving neurons cell membrane
Re-uptake
The transmitter molecules are taken back into the presynaptic axon terminals
Acetylcholine (ACh)
A neurotransmitter involved in muscle activity and memory
Botulinum bacteria
Toxin-forming bacteria, a mild form of which is commonly known as botox
Neuromodulators
Chemicals that modulate the activity of diverse populations of neurons in the nervous system
Psychoactive drugs
Chemicals that produce alterations in consciousness, emotion and behavior
Agonist
A drug that increases the activity of a neurotransmitter
Antagonist
A drug that inhibits or decreases the action of a neurotransmitter
Neuropsychology
The study of the function of the brain by investigating the effects of brain damage on mental functions
Vascular brain injury
Disruption of blood flow to the brain (from f.eks. a blockage/stroke, partial blockage/ischaemia, or an enlarged artery/aneurysm)
The loss of function depends on severity of the event and position of damage