Neuroscience Flashcards
(28 cards)
Neurons
A cell in the nervous system whose function is to receive and transmit information
Cell body (neuron)
- soma
- contains the nucleus
- keeps the cell alive
Dendrite
- collects information from other cells
- sends information to the soma
Axon
- transmits information away from the cell body
-sends information to other neurons or to muscles and glands
The Myelin Sheath
- Surrounds the axon of a neuron
- Consists of fatty tissues
allows it to work as an insulator
information moves faster
Terminal end or ‘button’
where the synapse is located
How do neurons send information?
- Relies on the use of an electrochemical process
- Electrical charge moves through the neurons
- Chemicals emitted from the terminal button allow for communication to the next neuron
Action potential
- Electrical signal moves through the neuron due to changes in electrical charge
- Follows the movement of charged particles (ions) from one side of the cell membrane to the other
- Moves from cell body down to the axon of the cell (its end)
- a rapid sequence of changes in the voltage across a membrane
The synapse
synaptic junction or synaptic gap
- The junction between the axon tip (terminal button) of one neuron and the dendrite/cell body of another neuron
Neurotransmitters
- Chemicals used to send a signal across the synaptic gap
- Neurotransmitters bind to receptors on the receiving neuron (this will either inhibit or excite the receiving neuron)
Excitatory neurotransmitters
- Make it more likely for the receiving neuron to change its electrical state
- This means this neuron will fire its own action potential
Inhibitory neurotransmitters
- Make it less likely for the neuron to change its electrical state
- May overcome excitatory neurotransmitters
- Makes it less likely for the receiving neuron to fire its own action potential
Neurotransmitter reuptake
- Neurotransmitters stimulate the receptors of the receiving neurons
- Chemicals are then taken back up into the sending neuron to be used again
Agonist
- Mimics neurotransmitters
- Ex. fentanyl is an agonist for our opiate receptors
Antagonist
- Blocks neurotransmitters from entering sites
- Ex. caffeine is an antagonist for adenosine receptors
Central nervous system
- Brain and spinal cord
- Brain uses nerves to send messages to the rest of the body (the ‘decision maker’)
Peripheral nervous system
- Connects central nervous system to the rest of the body via nerves
sensory neurons: carry messages from IN from the body’s tissues and sensory receptors to the CNS
motor neurons: carry the instructions OUT from the CNS to the body’s tissues
interneurons: only found in the brain and spinal cord, relay signals between sensory and motor cells
Somatic nervous system
(sensory input and motor output)
- Guides voluntary movements
Autonomic nervous system
(sympathetic and parasympathetic)
- Guides unconscious movements
The endocrine system
The message system (this system is slow but sure):
1. Hormones travel through the bloodstream (not synapse)
2. Slower onset of signal
3. Longer distances in the body
4. Slower signal to turn off
Adrenal glands
the sympathetic ‘fight or flight’ nervous system responds to stress by sending a message to the adrenal glands to release hormones like adrenaline and cortisol
Pituitary gland
the ‘master gland’ of the endocrine system
- Controlled by nearby brain area: the hypothalamus
- Pituitary gland produces hormones that regulate other gland such as the thyroid
- Also produces growth hormone and oxytocin (the ‘bonding’ hormone
Computed tomography (CT)
series of x-rays put together to create a 3D image of the brain
allows viewing of : general structure and presence of fluid in the brain
Magnetic resonance imaging (MRI)
magnet moves water molecules in the brain
radio waves (resonances) encourage water molecules to create signals
allows for ‘sliced’ images of the brain (bleeding and tumours)
