Biological Psychology Flashcards
What is a neuron?
A nerve cell specialised for communication
How many neurons does the human brain contain?
Around 85 billion neurons
What is the neuronal membrane?
A barrier that separates the inside of the neuron from the outside, which in cases the entire neuron
What is the cell body of a neuron?
The central region of the neuron that manufactures new cell components, consisting of small and large molecules
What are dendrites?
Portions of neurons that extend out from the cell body region and receive signals by making synapses with the axon terminals of other neurons or with other body cells (I.e. Neuromuscular junctions)
What are axon terminals?
Portions of neurons that send signals. This area of the neuron creates neurotransmitter-filled synaptic vesicles which are released into the synapse when prompted by an electrical impulse.
What are axons?
The normally long part of a neuron that the electrical impulse travels along towards the axon terminals. The axon is often surrounded by myelin which speeds up the impulse.
What are synaptic vesicles?
Spherical sacs containing neurotransmitters produced by the neuron
What are neurotransmitters?
Chemical messengers specialised for communication and released into the synapse when prompted by an electrical impulse
What is a synapse?
Space between two connecting neurons where neurotransmitters are released
What are glial cells?
Support cells in the nervous system that play a role in the formation of myelin and the blood-brain barrier, respond to injury and remove debris (I.e. Neurotoxins)
What is a threshold?
Minimum membrane potential necessary to trigger an action potential
What is an action potential?
An electrical impulse that travels down the axon and allows neurons to communicate.
What is he absolute refractory period?
Time during which another action potential is impossible which limits the maximal firing rate.
What is the name of the longest neuron in the body?
Sciatic nerve (runs the length of the leg)
What are neuron receptor sites?
Locations on a dendrite that uniquely recognise a neurotransmitter
What is neurotransmitter reuptake?
Recycling of neurotransmitters, a process by which the synaptic vesicle engulfs the neurotransmitter.
What are the three steps in neurotransmission?
- Release of the neurotransmitter from the axon terminal into the synaptic cleft
- Binding of the neurotransmitter to its receptor site
- Halting neurotransmission by either the chemical breakdown of the neurotransmitter of by reuptake of the neurotransmitter back into the axon terminal
What are the two most common neurotransmitters in the CNS?
Glutamate and GABA
What are endorphins?
Chemicals in the brain that play a specialised role in pain reduction
What are astrocytes?
The most abundant type of glial cell which can interact with between 300,000 and 1,000,000 neurons. They communicate closely with neurons, increase the reliability of their transmission, control blood flow in the brain and play a vital role in the development of the embryo.
What is the blood-brain barrier?
A protective shield that insulates the brain from infection by bacteria and other intruders.
What is an oligodendrocyte?
A type of glial cell that promotes new connections among nerve cells and releases chemical to aid helping. Oligodendrocytes also produces the myelin that surrounds the axons of neurons
What is the myelin sheath?
An insulation layer around the axon of neurons produced by glial cells that speed up action potentials
What is resting potential?
Electrical charge difference (-60 millivolts) across the neuronal membrane, when the neuron is not being stimulated or inhibited.
What are graded potentials?
Postsynaptic potentials that can be excitatory or inhibitory, depending on whether positively or negatively charged particles flow across the neuronal membrane and in which direction they flow.
At rest, is a neuron positively or negatively charged?
Negative
What is neural plasticity?
The ability of the nervous system to change. This can be drastic during early development or subtle when you learn something new. Plasticity can potential allow a person with brain damage to use a different part of their brain to perform tasks that were affected by injury
What are the four primary ways that the network of neurons in the brain changes over the course of development?
- Growth of dendrites and axons
- Synaptogenesis, or the formation of new synapses
- Pruning, consisting of the death of Crain neurons and the retraction of axons that make connections that are not useful
- Myelination, or the insulation of axons with myelin sheath
What is neurogenesis?
The creation of new neurons in the adult brain
What are stem cells?
Unspecialised cells that retain the ability to become a wide variety of specialised cells
True or false: dendrites are the sending portions of neurons
False
True or false: positive ions flowing into the neuron inhibit its action
False
True or false: neurotransmitters send messages between neurons
True
True or false: some antidepressants block the reuptake of serotonin into the axon terminal
True
True or false: neurogenesis is equivalent to pruning
False
What is the central nervous system?
The part of the nervous system comprising of the brain and the spinal cord that controls mind and behaviour.
What is the peripheral nervous system?
The nerves in the body that extend outside the CNS
What are the six distinct sections of the CNS?
- Cortex
- Basal Ganglia
- Limbic System
- Cerebellum
- Brain Stem
- Spinal Cord
What is cerebrospinal fluid?
A clear liquid that runs through cerebral ventricles and bathes our brain and spinal cord, providing nutrients and cushioning us against injury.
What is the cerebral cortex?
Outermost part of the forebrain/cerebrum, responsible for analysing sensory processing and higher brain functions. This is broken up into two hemispheres and four lobes (per hemisphere)
What is the forebrain?
Forward part of the brain that allows advanced intellectual abilities; also known as the cerebrum