Neuron
Biological Bases of Behavior
Why study biology in a psychology class?
“Everything psychological is simultaneously biological.”
Every thought, behavior, emotion, perception, etc. is rooted in our biology, particularly our brain The brain is a “psychological organ” as well as a biological one
Biological psychology: studies the link between our biology and our behaviors and mental processes
a.k.a. biopsychology, neuroscience
Starting small: The Neuron
neuron: a nerve cell; receives signals from other neurons or sensory organs, processes these signals, and sends signals to other neurons, muscles, or bodily organs
the basic unit of the nervous system
The Neuron
3 types of neurons:
1. sensory neurons: respond to input from sensory organs (skin, eyes, etc.) 2. motor neurons: send signals to muscles to control movement 3. interneurons: connect the sensory neurons and motor neurons
most of the neurons in the brain = interneurons
average human brain
100 billion neurons
plus 10x as many glial cells glial cell: a cell that fills the gaps between neurons, facilitate communication between neurons, and help in the care and upkeep of neurons
Structure of the Neuron
Structure of the Neuron
cell body (soma): the central part of the neuron, contains the nucleus
regulates cell functioning
dendrites: the branching part of the neuron that receives messages from other neurons and relays them to the cell body
Structure of the Neuron
axon: the long, cable-like extension that delivers messages to other neurons myelin sheath: layer of fatty tissue that insulates the axon and helps speed up message transmission
multiple sclerosis: deterioration of myelin leads to slowed communication with muscles and impaired sensation in limbs
terminal button: structure at the end of one of the axon’s branches that releases chemicals into the space between neurons, when the neuron is fired
The Neuron in Action
Why study biology in a psychology class?
“Everything psychological is simultaneously biological.”
Every thought, behavior, emotion, perception, etc. is rooted in our biology, particularly our brain The brain is a “psychological organ” as well as a biological one
Biological psychology: studies the link between our biology and our behaviors and mental processes
a.k.a. biopsychology, neuroscience
Starting small: The Neuron
neuron: a nerve cell; receives signals from other neurons or sensory organs, processes these signals, and sends signals to other neurons, muscles, or bodily organs
the basic unit of the nervous system
The Neuron
3 types of neurons:
1. sensory neurons: respond to input from sensory organs (skin, eyes, etc.) 2. motor neurons: send signals to muscles to control movement 3. interneurons: connect the sensory neurons and motor neurons
most of the neurons in the brain = interneurons
average human brain
100 billion neurons
plus 10x as many glial cells glial cell: a cell that fills the gaps between neurons, facilitate communication between neurons, and help in the care and upkeep of neurons
Structure of the Neuron
Structure of the Neuron
cell body (soma): the central part of the neuron, contains the nucleus
regulates cell functioning
dendrites: the branching part of the neuron that receives messages from other neurons and relays them to the cell body
Structure of the Neuron
axon: the long, cable-like extension that delivers messages to other neurons myelin sheath: layer of fatty tissue that insulates the axon and helps speed up message transmission
multiple sclerosis: deterioration of myelin leads to slowed communication with muscles and impaired sensation in limbs
terminal button: structure at the end of one of the axon’s branches that releases chemicals into the space between neurons, when the neuron is fired
The Neuron in Action