Neuropsych Flashcards
Neurons
- The cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between
- 10 billion in human body
Cell body*
- Contains nucleus of the cell
- Where chemical signals are converted to electrical signals
- Soma
Dendrites*
Pick up incoming neurotransmitters
Myelin sheath*
Increases speed of signals transmitted between neurons
Axon*
- Sends the neural message from dendrites to terminal buttons
- Can be covered by the mylin sheath which speeds the message
- Inside and outside there are charged ions (electricity)
Terminal buttons*
Contains neurotransmitters which send the message to other neurons
Neural messages
- Can originate in response to external stimuli
- Special receptors exist in your sense organs (nose, tongue, eyes, ears, skin)
- Can also originate in our brain
- Messages can get sent from body to brain, from brain to body, and just within the body or brain
- Process of moving a message along a neuron is electrical
Polarization
In a resting state, there are negative ions inside the neuron and positive on the outside
Depolarization
- When the dendrites pick up a strong enough message (from special receptors or from internal chemicals)
- The ions switch (negative move outside, positive move inside)
- Like a zipper
Neural impulse
- Movement down axon
- Goes faster when the neuron has a myelin sheath
- We say the neuron is firing
Neurotransmitter chain reaction
- Neurotransmitters flow across the tiny synaptic space and into their receptor sites on the dendrites of other neurons
- The message goes into the dendrites as a chemical, down the axon as an electrical impulse, out the terminal buttons as a chemical
- Fit like lock + key
Neurotransmitters
- At the end of the axon, there are the terminal buttons
- When the neuron fires, the terminal button swells and releases chemicals kept in the synaptic vesicles in the terminal button
Synaptic space*
- The space between neurons (neurons don’t touch)
- (synapse)
- The dendrites of one neuron are close to the axon of another
- 10,000 in human body
Threshold of excitation
- Neurons have to meet this to fire
- They have to pick up enough neurotransmitters
All-or-none law
States that either it fires or not
Absolute refractory period
The 1/1000 of a second that the neuron cannot fire again no matter what
Reuptake
- Much of the extra neurotransmitter is then sucked back up into the sending neuron in this process
- In your brain, glial cells clean up a lot of the “excess” neurotransmitter that ends up floating around
- Happening in your body and brain
Medulla
Sends messages between the spinal cord and the brain and regulates involuntary functions such as heart rate and breathing
Thalamus
Filters and sends signals related to sensory information to the cerebral cortex and the medulla
Cerebellum
- Coordinates voluntary movement and balance
- Helps us judge time, modulate our emotions, discriminate sounds and textures
Amygdala
Helps form and process emotional memories and processes fear and aggression
Hypothalamus
- Controls many basic survival needs such as body temperature, hunger, thirst, and sleep regulation
- Connects and sends signals to endocrine system (via pituitary gland)
- Monitors blood chemistry and takes orders from other parts of the brain
- Linked to emotion and reward
Frontal lobe
- Speaking and muscle movements
- Making plans and judgement
- Helps with motor control and plays a role in personality
Parietal lobe
Processes sensory information from touch sensations and helps with spatial awareness and body position
Occipital lobe
Receives and interprets visual input from the retinas in the eyes.
Temporal lobe
Receives auditory input from the ears. It helps interpret language and recognize objects and people.
Motor cortex
Controls voluntary movements
Sensory cortex
Registers and processes body touch and movement sensations
Nervous system diagram
