Lecture 1 Flashcards
An introduction to neuroscience and the nervous system (15 cards)
What is the overall function of the nervous system?
To receive sensory input, integrate and interpret it in the CNS, and produce a behavioral response via motor output.
What are the three main types of neurons and their roles?
- Sensory (afferent): Carry signals from the periphery to the CNS
- Interneurons: Integrate signals within the CNS
- Motor (efferent): Carry signals from the CNS to muscles/glands
What is the role of interneurons in neural circuits?
They act as intermediaries between sensory and motor neurons, enabling regulation.
What structures make up the CNS?
Brain and spinal cord, encased in the cranium and vertebral canal.
What structures make up the PNS?
Nerves and ganglia (sensory, autonomic, cranial nerve).
What are the two subsystems of the PNS?
- Somatic (voluntary): Controls skeletal muscles
- Autonomic (involuntary): Controls smooth/cardiac muscle and glands (includes sympathetic, parasympathetic, enteric)
What are the two key properties of neurons that enable function?
Connectivity via synapses and communication via action potentials.
Where are ligand-gated and voltage-gated ion channels found in neurons?
- Ligand-gated: Dendrites
- Voltage-gated: Axon and axon hillock
What triggers an action potential?
A change in membrane permeability due to chemical, mechanical, thermal, or sensory stimuli.
What is the role of the myelin sheath?
It insulates axons and increases the speed of electrical impulse conduction (saltatory conduction).
What is the withdrawal reflex?
A simple neural circuit where a painful stimulus triggers a rapid motor response to withdraw from the source.
Describe the pathway of the withdrawal reflex.
Sensory input → spinal interneuron → motor neuron → muscle contraction
Why is the withdrawal reflex fast?
It bypasses the brain and is processed directly in the spinal cord.
What is neuroplasticity?
The ability of synapses to change in shape and function in response to activity or experience.
Name three neurological disorders caused by abnormal neural function.
Alzheimer’s disease, ALS (Motor Neuron Disease), Parkinson’s disease
