C8 - How do we control ourselves? Flashcards
(41 cards)
What are the functions of the nervous system?
- Receive sensory input
- Integrating information
- Controlling muscles and glands
- Maintaining homeostasis
- Establishing and maintaining mental activity
These functions highlight the nervous system’s role in processing information and regulating bodily activities.
List the 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 includes all neural elements outside the CNS.
Differentiate between the somatic and autonomic nervous systems.
Somatic nervous system controls voluntary movements; autonomic nervous system regulates involuntary functions.
The autonomic system is further divided into sympathetic and parasympathetic systems.
What are the general functions of the CNS and PNS?
- CNS: processes sensory information and initiates responses
- PNS: transmits information to and from the CNS
The CNS is the control center, while the PNS connects the CNS to the rest of the body.
What are the three parts of a neuron?
- Cell body
- Dendrites
- Axon
Each part plays a crucial role in the transmission of electrical signals.
What are sensory, motor, and interneurons?
- Sensory neurons: transmit information towards the CNS
- Motor neurons: transmit information away from the CNS
- Interneurons: connect sensory and motor neurons within the CNS
Interneurons are responsible for processing information and reflexes.
List the neuroglial cells in the CNS and their functions.
- Astrocytes: support and nourish neurons
- Oligodendrocytes: produce myelin in the CNS
- Ependymal cells: line brain cavities and produce cerebrospinal fluid
- Microglia: act as immune cells in the CNS
Neuroglia support and protect neurons, playing a critical role in maintaining homeostasis.
What is the resting membrane potential (RMP)?
The difference in charge across the cell membrane of a resting neuron, typically around -70mV.
RMP is essential for the generation of action potentials.
What changes occur in the RMP when a neuron is stimulated?
The RMP becomes less negative (depolarization) and may reach a threshold to trigger an action potential.
The threshold is usually around -55mV.
What is the effect of myelination on action potential conduction?
Myelination increases the speed of action potential conduction through saltatory conduction.
Saltatory conduction allows the impulse to jump between nodes of Ranvier, speeding up transmission.
Describe the structure and function of a synapse.
A synapse consists of a presynaptic terminal, synaptic cleft, and postsynaptic membrane; it facilitates communication between neurons.
Neurotransmitters are released into the synaptic cleft to transmit signals.
What is the difference between a reflex and a reaction?
A reflex is an automatic response to a stimulus; a reaction involves conscious thought and decision-making.
Reflexes are faster as they require less processing by the CNS.
What is the role of the enteric nervous system?
It controls the functions of the digestive tract.
It operates independently but can be influenced by the autonomic nervous system.
What are the main parts of a reflex arc?
- Sensory receptor
- Sensory neuron
- Interneuron
- Motor neuron
- Effector
Reflex arcs enable quick responses to stimuli.
Fill in the blank: Neuroglia are cells other than neurons found within the _______.
[nervous system]
True or False: The CNS is responsible for integrating information and initiating responses.
True
Fill in the blank: The _______ nervous system is responsible for voluntary movements.
[somatic]
What is the primary function of dendrites?
To receive input from other neurons and conduct impulses towards the cell body
Dendrites increase the neuron’s ability to connect with other neurons.
What type of neurons are primarily involved in sensory input?
Unipolar neurons
Unipolar neurons are often found in sensory pathways.
What is the primary role of Schwann cells?
To produce myelin which wraps around the axons of neurons in the PNS.
Myelination increases the speed of signal transmission.
What are the charges (voltage) either side of the cell membrane in a resting cell?
Typically around -70mV inside the cell and 0mV outside.
This polarization is crucial for action potential generation.
What initiates the response to a stimulus in the spinal cord?
The response is initiated at the lumbar region of the spinal cord
The brain becomes conscious of the stimulus only after initial processing in the spinal cord.
What is the light reflex an example of?
An autonomic reflex
It involves involuntary muscle responses.
What happens to the right pupil when light is shone into it?
Constricts – gets smaller
This is called the direct reflex.
