Unit 3- Biological Basis of behavior Flashcards
What are the building blocks of the body’s neural information system (nervous system) ?
Neurons or nerve cells
What are dendrites?
Branching extensions of a neuron that receives information from other cells and conducts it toward the cell body
What is the axon?
A neuron extension passing messages from the cell body to other neurons, muscles, or glands
What encases an axon?
Myelin sheath, a layer of fatty tissue that insulates them and speeds their impulses
What is the action potential?
A brief electrical charge that travels down the axon; a neural impulse
What is the refractory period?
A period of inactivity after a neuron has fired.
What does threshold mean?
The level of stimulation required to trigger a neural impulse
The neuron’s action is an ___ ___ _____ response
all or none
What is the synapse?
A tiny gap at the junction between the axon terminal and dendrites of the receiving neuron
What are neurotransmitters?
Chemical messengers that cross the synapses between neurons
What is reuptake?
A neurotransmitter’s reabsorption by the sending neuron neuron
The sending neuron reabsorbs the excess neurotransmitters
What does the neurotransmitter Acetylcholine do? Give an example of a malfunction.
Enables muscle action, learning, and memory.
AC-h producing neurons deteriorate in those with Alzheimer’s disease
What does the neurotransmitter dopamine do? Give an example of a malfunction.
Influences learning, movement, attention, and emotion.
Oversupply is linked to schizophrenia, undersupply is linked to decreased mobility in Parkinson’s disease.
What does the neurotransmitter serotonin do? Give an example of a malfunction.
Affects mood, hunger, sleep, and arousal.
Undersupply linked to depression, some antidepressant drugs raise serotonin levels.
What does the neurotransmitter norepinephrine do? Give an example of a malfunction.
Helps control alertness and arousal.
Undersupply can depress mood.
What does the neurotransmitter GABA do? Give an example of a malfunction.
A major inhibitory neurotransmitter.
Undersupply linked to insomnia, tremors, and seizures.
What does the neurotransmitter Glutamate do? Give an example of a malfunction.
A major excitatory neurotransmitter, involved in memory.
Oversupply can overstimulate the brain, producing migraines or seizures, which is why some avoid foods with MSG.
What are endorphins?
natural neurotransmitters linked to pain control and pleasure.
What is an agonist?
A molecule that mimics the effects of a neurotransmitters
What is an antagonist?
A molecule that inhibits or blocks a neurotransmitter’s functioning.
What is the central nervous system?
Includes the brain and spinal cord, it is the nervous system’s decision maker.
What is the peripheral nervous system?
Connects the CNS to the rest of the body through nerves
What are the two main divisions of the PNS?
-Somatic nervous system; enables voluntary control of the skeletal muscle
-Autonomic nervous system; controls the involuntary muscles and glands by means of the sympathetic and parasympathetic divisions.
What are the three types of neurons?
Sensory- carry info from sense receptors to the brain and spinal cord
Motor- carry info from brain and spinal cord to the muscles and glands
Interneurons- communicate with brain and spinal cord and between sensory and motor neurons
What is the endocrine system?
A set of glands that secrete hormones into the bloodstream where they travel through the body and affect other tissues, including the brain.
What do the adrenal glands do?
Release hormones that trigger the fight or flight response.