neuro 2 Flashcards
Ion channel
special protein molecule located in the membrane of a cell; controls the entry/exit of particular ions
Resting potential
membrane potential of a neuron when it is not producing an action potential
Action potential
sudden reversal of the electrical charge across the cell membrane: from the soma to its terminal buttons, causes the release of a neurotransmitter
Neurotransmitter
chemical released by terminal buttons that causes the postsynaptic neuron to be excited or inhibited
Myelin sheath
insulating material that encases most axons
prevents depolarisation and speeds up propagation of AP
Terminal button
the rounded spelling at the end of the axon, releases neurotransmitter
Axon
long thin part of a neuron attached to the soma, divided into a few/many branches ending in terminal buttons
Soma
cell body, largest part of neuron
Dendrite
treelike part of neuron on which other neurons form synapses
Neurons
neural cell that consists of a cell body with dendrites and an axon whose branches end in terminal buttons that synapse with muscle fibres, gland cells or other neurons
Nerves
bundles of many thousands of individual fibres wrapped with tough membrane, transmit messages
Wrinkled cortex
bulges (gyri) and grooves (fissures) - more complex brains require a larger cerebral cortex, these increase surface area
Cerebral cortex
thin layer of tissue (grey matter) which contains billions of neural cells. Where perceptions take place, memories are stored, plans are formulated and executed.
These cells are connected to other parts of the brain through bundles of nerve fibres called white matter
Blood-brain barrier
Capillaries in the brain do not have openings, unlike ones on the rest of the body, to protect the brain from chemical assault
Not perfect, toxic chemicals sometimes still make their way into the brain
Protection of NS
Spinal cord runs through the middle of the spinal column - a stack of hollow bones called the vertebrae
Brain and spinal cord enclosed by a three-layered set of membranes known as the meninges
Brain and spinal cord doesn’t not touch skull/vertebrae: floats in cerebrospinal fluid (CSF)
Cerebrum
More recently evolved
Perception, memories and behaviours
Cerebellum
Attached to back of brain stem
Control and coordinate movements; especially rapid, skilled movements (includes learned ones)
Brain stem
Most primitive region of brain - controls physiological functions and automatic behaviours
Some animals, such as amphibians, only have a brain stem and a simple cerebellum
3 major functions of the brain
- Controlling behaviour
- Processing and retaining the information we receive from the environment
- Regulating the body’s physiological processes
What does the brain control?
muscles, glands and internal organs
How does info from the rest of the body get to the spinal cord and the brain?
spinal nerves
How does info from head/neck region reach the brain?
cranial nerves
Sensory neuron
detects changes in the external/internal environment and sends info about this to CNS
Motor neuron
has terminal buttons that form synapses with muscle fibres.
an action potential that travels down its axon will cause the muscle to twitch
Synapse
junction between the terminal button of one neuron and the membrane of a muscle fibre, gland or other neuron.
neurons communicate using chemical transmission
presynaptic neuron
neuron with terminal buttons that form synapses with and excite/inhibit another neuron
postsynaptic neuron
is excited or inhibited by another neuron’s terminal buttons
Reuptake
molecules of the neurotransmitter that have been released in cleft are quickly taken up again so that it only has a short time to stimulate the postsynaptic receptors
Glutamate
important excitatory neurotransmitter in brain and spinal cord
GABA
important inhibitory neurotransmitter in brain
Acetylcholine
neurotransmitter: responsible for muscular contraction, activates cerebral cortex, controls REM sleep, controls hippocampus
Serotonin
regulation of mood, control of eating/sleep/arousal and regulation of pain, suppresses risky behaviours
CNS
central nervous system - brain and spinal cord
PNS
Peripheral Nervous system - nerves, ANS, ENS
ANS
autonomic NS - controls non-voluntary bodily functions (4Fs etc)
uses acetylcholine and noradrenaline
What are the two branches of the autonomic nervous system?
Sympathetic NS: for action
Parasympathetic NS: for rest and recuperation
ENS
1/2 billion neurons located in the wall of gastrointestinal tract
interacts with brain via symp- and para- NS but can function on its own
control digestive activity
Meninges
flexible sheet made of 3 membranes between bone and nervous tissue
1. Dura mater: tough + thick
2. Arachnoid membrane: spongy, filled wth CSF and blood vessels, cushioning
3. Pia mater: thin membrane against brain
Spinal cord
interface between brain and PNS
* connected to sensory, motor, autonomic nerves
* Controls some movement like spinal reflexes
Thalamus
sensory relay to cortex - smell doesnt go through it
Hypothalamus
hormonal regulation and motivational control
Limbic system
control of emotion and memory
Corpus Callosum
connects the 2 hemispheres of the brain
Resting potential
when a neuron is not actively transmitting a nerve impulse
inside is more negatively charged than the outside, maintained by sodium potassium pumps.
Refractory period
the time after an action potential is generated, it cannot produce a new AP because all sodium channels are already opened/being opening at maximum speed
Frontal lobe
Planning and executive functions (memory selection as well)
Emotional expression
Problem solving
Language
Judgement
Sexual behaviours
Parietal lobe
Sensory experiences are interpreted
Proprioception
Where things are in space, representing space for action
Occipital lobe
Colour, Form, Motion
Temporal lobe
Memory
Encoding
Processes auditory info
Taste
Recognise faces
Language
3 parts of frontal lobe
Prefrontal - higher cognitive functions and personality
Motor
Premotor -
