The brain and behaviour Flashcards
Describe neurons
Neurons are the basic building blocks of the nervous system
Describe dendrites
Dendrites are specialised receiving units, like antennae, that collect messages from neighbouring neurons and send them onto the cell body
Describe axons
Axons conduct, electrical impulses away from the cell body to other neurons, muscles or glands
Describe glial cells
Glial cells do not send or receive nerve impulses. They manufacture, chemicals that provide nutrients neurons, need and absorb toxins and waste materials that can damage neurons.
Describe resting potential
Resting potential is the uneven distribution of positive and negative ions that make the interior of the cell negative compared to the outside. This internal difference of around 70 mV is the neurons resting potential
Describe action potential
Action potential is an electrical shift within the neuron that lasts a millisecond that creates a nerve impulse
Describe absolute refractory period
The membrane is not excitable and cannot discharge another impulse
Define the all or non law
Action potentials occur at a uniform and maximum intensity, or they do not occur at all
Define graded potentials
Changes in the negative resting potential that do not reach the -50 mV action potential threshold
Describe the Myelin sheath
A white fatty insulation layer derived from glial cells during development
Describe synaptic space
A tiny gap between the axon terminal and the dendrites, or cell body of the next neuron
Describe neurotransmitters
Chemical substances that carry messages across the synaptic space to other neurons, muscles or glands
What are synaptic vesicles?
Chambers within the axon terminals used to store synthesised neurotransmitters
Explain receptor sites
Large protein molecules embedded in the receiving neurons cell membrane. Each site has a specifically shaped surface that fits a specific transmitter molecule
Explain reuptake
Reuptake is, when the transmitter molecules are taken back into the presynaptic, axon terminals
What is acetylcholine?
A neurotransmitter involved in muscle activity and memory
Describe the function of a neuro modulator?
Neuro modulators have a more widespread and generalised influence on synaptic transmission
Describe the three primary effects of an agonist drug
An agonist drug increases the activity of a neurotransmitter by enhancing a neurons ability to synthesise store, or release neurotransmitters; mimic the action of a neurotransmitter, by binding, with and stimulating, postsynaptic receptor sites; or making it more difficult for neurotransmitters to be deactivated, such as by inhibiting reuptake
What are the primary effects of an antagonist drug?
Antagonist drugs inhibit, or decrease the action of a neurotransmitter. And antagonist may reduce a neurons ability to synthesise store or release neurotransmitters; or prevent a neurotransmitter from binding with the postsynaptic neuron by fitting into and blocking receptor sites on the postsynaptic neuron.
Describe the function of sensory neurons
Sensory neurons carry input messages from the sense organs to the spinal-cord and brain.
Describe the function of motor neurons
Motor neurons transmit output impulses from the brain and spinal cord to the bodies, muscles and organs
Describe the function of interneurons
Interneurons outnumber sensory and motor neurons and perform connective or associative functions within the nervous system
Describe the peripheral nervous system
The peripheral nervous system contains all of the neural structures that lie outside of the brain and spinal cord
Describe the somatic nervous system
The somatic nervous system consists of sensory neurons that are specialised to transmit messages from the eyes, ears and other sensory receptors to the brain and motor neurons that send messages from the brain and spinal cord to the muscles that control voluntary movements
Describe the autonomic nervous system
The autonomic nervous system senses the bodies internal functions and controls the glands and involuntary muscles that form the heart, the blood vessels in the lining of the stomach and intestines
Explain the sympathetic nervous system
The sympathetic nervous system has an activation or arousal function and it tends to act as a total unit
Explain the parasympathetic nervous system
The parasympathetic nervous system is far more specific in its opposing actions, affecting one or a few organs at a time. It slows down body processes and maintains a state of tranquility.
Describe the enteric nervous system
The enteric nervous system is a unique system that acts exclusively on the gastrointestinal tract
What is homeostasis?
Homeostasis is a delicately, balanced or constant internal state
What is contained in the central nervous system?
The central nervous system contains the brain and the spinal cord which connects most parts of the peripheral nervous system with the brain
What does an electroencephalograph do?
An electroencephalograph measures the activity of large groups of neurons through a series of large electrodes placed on the scalp
What does computerised axial tomography scans do?
Computerised axial tomography uses x-ray technology to study brain structures
How does magnetic resonance imaging work?
Magnetic resonance imaging creates images, based on how atoms in living tissue respond to a magnetic pulse delivered by the device
What do positron emission tomography scans measure?
Positron emission tomography scans, measure brain activity, including metabolism, bloodflow, and neurotransmitter activity
What does a functional MRI do?
Functional MRIs can produce pictures of bloodflow in the brain taken within seconds of one another and also measures brain activity
Describe the endocrine system
The endocrine system consists of numerous hormones, secreting glands distributed throughout the body
What are hormones?
Hormones are chemical messengers that are secreted from glands into the bloodstream
What does the motor cortex do?
The motor cortex controls 600 or more muscles involved in voluntary body movements
What does the somatic sensory cortex do?
The somatic sensory cortex receives sensory input that contributes to our sensations of heat touch and to our senses of balance in the body movement
What does the association cortex do?
The association cortex constitutes most of the human cerebral cortex, and is involved in many important, mental functions, including perception, language, and thought
Describe the pre-frontal cortex
The pre-frontal cortex is located in the forward section of the frontal lobe and is associated with executive functions
What does the thalamus do?
The Thalumus is like a switchboard that organises inputs from sensory organs and routes them to appropriate areas of the brain
What does the hypothalamus do?
The hypothalamus plays a major role in many aspects of motivation and emotion, including sexual behaviour, temperature regulation, sleeping appetite and aggression
What are the core functions of the limbic system?
The limbic system is involved in the processing of emotion, motivation, learning, and memory
What is the purpose of the hippocampus?
The hippocampus is involved in forming and retrieving memories
What is the purpose of the amygdala?
The amygdala organises motivational and emotional response patterns, particularly those linked to aggression and fear
Describe the reticular formation
The reticular formation acts as a sentry, both alerting higher centres of the brain that messages are coming, and then either blocking those messages, or allowing them to proceed to the fore brain
What is the Pons responsible for?
The Pons lies at the top of the brain stem and carries nerve impulses between higher and lower levels of the nervous system. The pons also helps to regulate vital functions such as respiration and sleep
What does the medulla do?
The medulla plays an important role, vital body functions, such as heart rate and respiration
What does the cerebellum do?
The cerebellum is concerned, primarily with muscular movement, coordination and maintaining balance and posture, but also plays a role in learning and memory
Describe the corpus callosum
The corpus callosum is a broad band of White myelinated nerve fibres that connect the left and right cerebral hemispheres aiding communication between the 2 halves of the brain
What does lateralisation refer to?
Lateralisation refers to the relatively greater localisation of a function in one hemisphere or the other
What is the Wernicke‘s area responsible for?
The Wernicke’s area is located in the left temporal lobe and is primarily involved in speech comprehension
What is the broca’s area responsible for?
The Broca’s area is in the left frontal lobe, and is mainly involved in the production of speech through its connections with the motor cortex region that controls the muscles used in speech
What is neural plasticity
Neural plasticity refers to the ability of neurons to change in structure and function as a result of exposure and experience to the surrounding environment
What is neurogenesis?
Neurogenesis is the production of new neurons in the nervous system
Describe neural stem cells
Neural stem cells are immature, ‘uncommitted’ cells that can mature into any type of neuron or glial cell needed by the brain
