Neuron Structure Flashcards
Action potential
A process where an excitation that travels along an axon is at a constant strength, no matter how far it travels
It is an impulse that flows down an axon by movement of chemical ions
Mechanism: an action potential depends on the entry of sodium into the axon. Anything that blocks this flow stops the action potential
All-or-none law
The fact that an axon cannot vary the strength or velocity of its action potentials
Axon
A single, long, thin, straight fibre with branches near its tip
Cell body
contains the nucleus of the cell
dendrite
They are widely branching structures that receive input from other neurons
Dopamine
Dopamine is a neurotransmitter, a chemical messenger in the brain that plays a crucial role in various functions, including motivation, reward, movement, and the regulation of mood. It’s often referred to as the “feel-good” neurotransmitter because it is associated with feelings of pleasure and satisfaction, particularly in response to rewarding activities.
Gila
It support the neurons in many ways such as by insulating them, synchronising activity among neighbouring neurons, and removing waste products
Myelin
An insulating sheath that speeds up the transmission of impulses along an axon
Neuron
It is an enormous number of separate cells in our brain
Neurotransmitter
A chemical that activates receptors on other neurons
Each neurotransmitter can attach to several types of receptors with different properties
The duration of its effects varies from one synapse to another
Parkinson’s Disease
A condition that affects 1-2% of people over the age of 65 in western nations
Main symptoms: difficulty in initiating voluntary movement, slow movement, tremors, rigidity, and depressed moods
Postsynaptic Neuron
The neuron on the receiving end of the synapse
Resting potential
An electrical polarisation across the membrane (or covering) of an axon
Synapse
The specialised junction between one neuron and another, a neuron releases a chemical that either excites or inhibits the next neuron
Terminal Bouton
It is a little bulge, which ends at the branches of a typical axon
Neuron structure
a neuron, or nerve cell, consists of a cell body, dendrites, and an axon. The axon conveys information to other neurons
How do neuron communicate?
a neuron communicates with another neuron by releasing a chemical called a neurotransmitter at a specialised junction called a synapse. A neurotransmitter can either excite or inhibit the next neuron, with varying durations of effect
what about neurotransmitters and causes behavioural disorders
an excess or deficit of a particular neurotransmitter can lead to abnormal behaviour, such as that exhibited by people with Parkinson’s disease
Amygdala
it responds strongly to emotional situations
autonomic nervous system
it controls the heart, digestive system, and other organs
binding problem
The question of how separate brain areas combine forces to produce a unified perception of a single object
blindsight
It is the ability to point to or otherwise indicate the direction to a visual stimulus, without any conscious perception of seeing anything at all
central nervous system
Consists of the brain and the spinal cord, and communicates with the rest of the body through the peripheral nervous system
cerebellum
it is part of the hindbrain
cerebral cortex
it is the outer covering of the forebrain
corpus callosum
It is a set of axons that connect the left and right hemispheres of the cerebral cortex
Electroencephalograph
It uses electrodes on the scalp to record rapid changes in the brain electrical activity
Endocrine system
Glands that produce hormones and release them into the blood
Epilepsy
A condition in which cells somewhere in the brain emit abnormal rhythmic, spontaneous impulses
frontal lobe
It is at the forward part of the brain, and includes the primary motor cortex
Functional magnetic resonance imaging
uses magnetic detectors outside the head to compare the amounts of haemoglobin with and without oxygen in different brain areas
hemisphere
the left and right halves of the forebrain
hormone
Chemicals released by glands and conveyed by the blood to alter activity in various organs
hypothalamus
Located just below the thalamus and it is important for hunger, thirst, temperature regulation, sex, and other motivated behaviours
interpreter
The left hemisphere has this function which makes up a story to explain what it sees happening, even if the behaviours actually happens for a different reason
Magnetoencephalography
it records magnetic changes
medulla
It is at the bottom-most part of your brain. Its location means it’s where your brain and spinal cord connect, making it a key conduit for nerve signals to and from your body. It also helps control vital processes like your heartbeat, breathing and blood pressure
mirror neurons
Found in several parts of the brain, especially the frontal cortex and they are active. imitation
monism
The idea that mental activity and brain activity are inseparable
occipital lobe
it is at the rear of the head and is specialised for vision
oxytocin
love hormone
parietal lobe
It is forward from the occipital lobe, and is specialised for the body senses, including touch, pain, temperature, and awareness of the location of body parts in space
plasticity
change as a result of experience
pons
It is a part of your brainstem, a structure that links your brain to your spinal cord. It handles unconscious processes and jobs, such as your sleep-wake cycle and breathing
positron-emission tomography
it records radioactivity of various brain areas emitted from injected chemicals
prefrontal cortex
It is at the anterior sections of the frontal lobe, and is important for memory of what has just happened and what you are planning to do next
primary motor cortex
it is important for controlling fine movements
primary somatosensory
It is a strip in the anterior portion of the parietal lobe, and has cells sensitive to touch in various body areas
Its largest areas are devoted to touch at the most sensitive areas
reflex
it is a rapid, automatic response to a stimulus
social neuroscience
it is the study of the biological bases of social behaviour
spinal cord
it controls the muscles from the neck down and is responsible for reflexes
stem cells
undifferentiated cells
temporal lobe
It is located towards the left and right sides of the head, and it the main area for hearing and certain aspects of vision
What is the action potential process like?
- When an action potential reaches the terminal button, it releases a neurotransmitter into the synaptic cleft
- The neurotransmitter molecules in the synaptic cleft will then bind with receptor sites on the membrane of the neighbouring neuron
- Various neurons use dozens of chemicals as neurotransmitters, but a given neuron releases inly one or few of them
- The neurotransmitter molecules diffuse across a narrow gap to receptors on the postsynaptic neuron
- A neurotransmitter fits into its receptor, and it either excites or inhibits the postsynaptic neuron
- After a neurotransmitter excites or inhibits a receptor, it separates from the receptor, ending the message
What are the lobes in the brain?
occipital, temporal, frontal, parietal lobe
What are the subcortical structures under the cerebral cortex?
thalamus, hypothalamus, hippocampus, amygdala
What are used to measure brain activity?
electroencephalograph, magnetoencephalograph, positron-emission tomography, functional magnetic resonance imaging
sympathetic nervous system
it prepares the organs for brief periods of vigour activities that expand energy
parasympathetic nervous system
it works to conserve energy and works when the body is at rest, or when the fight or flight situation is over
How does the cerebral cortex communicate with the rest of the body?
information from the cerebral cortex passes to the medulla and then into the spinal cord. The medulla and spinal cord receive sensory input from the periphery and send output to the muscles and glands.
what are split-brain patients like?
After damage to the corpus callosum, people can describe information only if it enters the left hemi-sphere. Such people in some ways act as if they have separate fields of consciousness, and in some ways they act as if they are unified.
