Bio Psychology 02 Flashcards
(38 cards)
What are the two main types of cells focused on in this lesson?
Neurons, which handle brain activity, and glial cells, which primarily act as support cells.
What is the approximate number of neurons in the human brain?
The brain has approximately 100 billion neurons.
What is an ‘action potential’?
It is the firing of a neuron, the primary way neurons communicate through neurochemical messaging.
What are the dendrites of a neuron?
Branch-like structures that receive messages from neighbouring neurons.
What is the soma (cell body)?
The ‘core’ of the neuron, containing the nucleus with its genetic information.
What is the axon and its function?
A long projection where an electrical signal (action potential) is sent or propagated.
What does the myelin sheath do?
It acts as insulation around the axon, allowing the signal to travel much faster.
What is a synapse?
The small gap between the axon terminal of one neuron (presynaptic) and the dendrite of another (postsynaptic).
What are neurotransmitters?
Chemicals released from the axon terminal into the synapse to transmit signals to the next neuron.
What are sensory (afferent) neurons?
Neurons that carry messages from sensory organs (like skin) to the brain and spinal cord.
What are motor (efferent) neurons?
Neurons that carry messages from the spinal cord to muscles and glands to initiate movement.
What are interneurons?
Neurons primarily found in the brain and spinal cord that connect sensory, motor, and other interneurons.
What is a reflex arc?
A rapid motor response to a stimulus, processed via the spinal cord (sensory to motor neuron, often via an interneuron) without immediate brain involvement.
What are the four types of glial cells mentioned?
Oligodendrocytes, Schwann cells, Microglia, and Astrocytes.
Differentiate between Oligodendrocytes and Schwann cells.
Both form the myelin sheath, but Oligodendrocytes are in the central nervous system, while Schwann cells are in the peripheral nervous system.
What is the role of Microglia?
They act as the brain’s immune cells, cleaning up debris, managing inflammation, and playing a role in cell death and synapse formation/breakdown.
What are Astrocytes and their functions?
The largest, star-shaped glial cells that regulate blood flow, manage molecular movement, and can communicate with neurons and other astrocytes.
What is synaptic transmission?
The process of transmitting a message across a synapse from one neuron to another.
What is the resting potential of a neuron?
The electrical charge difference across the neuron’s membrane when it’s not firing, typically around -70mV, meaning it’s polarised.
What are sodium-potassium pumps?
Mechanisms in the cell membrane that actively transport ions to maintain the -70mV resting potential.
What is depolarisation?
When the neuron becomes less negative inside (e.g., moves from -70mV to -67mV), increasing the chance of firing.
What is hyperpolarisation?
When the neuron becomes more negative inside (e.g., moves from -70mV to -72mV), decreasing the chance of firing.
What are EPSPs and IPSPs?
EPSPs (Excitatory Postsynaptic Potentials) increase the likelihood of firing, while IPSPs (Inhibitory Postsynaptic Potentials) decrease it.
What is the threshold of excitation?
The level of depolarisation (around -65mV) that must be reached for an action potential (firing) to occur.
