nervous system Flashcards
What are the three overlapping functions of the nervous system?
- Sensory input
- Integration
- Motor output
These functions are essential for the nervous system to control body actions and responses.
What does sensory input involve?
Gathering information from sensory receptors and sending it to the nervous system
Example: Seeing a red light.
What is the function of integration in the nervous system?
Processing and interpreting sensory information
This leads to appropriate responses or actions.
What is motor output?
The process of sending signals to muscles or glands to elicit a response
Example: Muscles breaking in response to a signal.
List broader functions of the nervous system.
- Sensations (e.g., touch, hearing)
- Perception
- Thought and emotions
- Learning and memory
- Movement, balance, and coordination
- Sleep
These functions highlight the complexity of the nervous system.
What are the main divisions of the nervous system?
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
The CNS consists of the brain and spinal cord, while the PNS connects the CNS to the rest of the body.
What are the functional subdivisions of the PNS?
- Somatic Nervous System (SNS)
- Autonomic Nervous System (ANS)
- Enteric Nervous System (ENS)
Each subdivision has distinct roles in controlling bodily functions.
What are neurons?
Specialized cells for signal reception, propagation, and processing
Neurons are the structural units of the nervous system.
What role do neuroglia cells play in the nervous system?
Support, nourish, and protect neurons
Neuroglia are critical for maintaining homeostasis around neurons.
What is the typical structure of a motor neuron?
- Cell body
- Dendrites
- Axon
- Terminal branches with axon terminals
- Myelin sheath
Each part has a specific function in transmitting neural signals.
What is the function of the myelin sheath?
Insulates axons and increases the speed of nerve conduction
Myelin is crucial for efficient signal transmission.
What are the types of neurons based on structural classification?
- Multipolar neurons
- Bipolar neurons
- Unipolar neurons
Each type has unique structural characteristics and locations within the nervous system.
What are sensory (afferent) neurons?
Mostly unipolar neurons located in sensory ganglia outside the CNS
They carry impulses towards the CNS.
What are motor (efferent) neurons?
Multipolar neurons whose cell bodies are mostly in the CNS
They carry impulses away from the CNS.
What are interneurons?
Mostly multipolar neurons confined within the CNS
They make up 99% of the neurons in the body.
What is the role of astrocytes?
Connect to neurons and capillaries, guide neuron migration, and control the chemical environment
They are crucial for maintaining the homeostasis of the nervous system.
What do microglial cells do?
Monitor health of neurons and can acquire an immune function
They play a role in the defense of the nervous system.
What is the function of ependymal cells?
Line the cerebral and spinal cavities and form a barrier between cerebrospinal fluid and extracellular fluid
Some are involved in the production and circulation of cerebrospinal fluid.
What do oligodendrocytes do?
Wrap around nerve fibers forming myelin sheath in the CNS
They are affected in diseases like multiple sclerosis.
What are Schwann cells?
Similar to oligodendrocytes but found in the PNS
They also form myelin sheaths around peripheral nerves.
