3.1.2 Spinal cord and reflexes Flashcards
(23 cards)
What are the main structures of a neuron?
- Dendrites
- Cell body
- Axon
- Nodes of Ranvier
- Axon Terminal
- Myelin sheath
- Nucleus
- Schwann Cell
These structures are essential for neuron function and communication.
What is the function of dendrites?
Receives information from communicating neurons
Dendrites are often referred to as ‘dendron’ which means tree, due to their branching structure.
What is the role of the cell body (soma) in a neuron?
Controls metabolism and maintenance of the neuron; receives messages from other neurons
It is the largest part of the neuron.
What does the nucleus of a neuron contain?
Genetic material (chromosomes) for cell development and protein synthesis
The nucleus is covered by a membrane.
What is the primary function of an axon?
To propagate information (as an electrical impulse) from soma to communicating neuron
Axons can be very long, up to 1-1.5m in the peripheral nervous system.
What is the purpose of the myelin sheath?
Protects and insulates axons, enhances transmission of electrical impulses
The myelin sheath is a white fatty coating around axons.
What do Schwann cells do?
Insulate neurons by producing myelin in the peripheral nervous system
In the central nervous system, oligodendrocytes serve a similar function.
What are Nodes of Ranvier?
Periodic gaps in the myelin sheath that facilitate rapid conduction of nerve impulses
These nodes are crucial for saltatory conduction.
What is the function of axon terminals?
Transmit information as neurotransmitters across the synapse to the next neuron
Axon terminals have terminal buttons that contain sacs for neurotransmitter secretion.
What are the two main types of neurons in the spinal cord?
- Motor Neurons
- Sensory Neurons
- Interneurons
Each type plays a distinct role in the nervous system.
What is the role of motor neurons?
Communicate messages from the CNS to muscles for movement
They are essential for executing motor commands.
What do sensory neurons do?
Carry sensory information from the body and environment to the CNS
Sensory neurons are generally very long cells.
Define a reflex.
A fast, automatic, unplanned sequence of actions in response to a stimulus
Reflexes enhance safety and survival.
What is a spinal reflex?
A reflex action occurring within the spinal cord without involving the brain
This allows for quicker responses to stimuli.
What are the five main components of a spinal reflex arc?
- Receptor
- Sensory afferent neurons
- Integration center (interneuron)
- Motor (efferent) neuron
- Effectors (muscle or gland)
Each component plays a crucial role in the reflex action.
Differentiate between monosynaptic and polysynaptic reflex arcs.
- Monosynaptic: Involves only one synapse
- Polysynaptic: Involves interneurons and at least two synapses
Monosynaptic reflexes are simpler and faster.
What is the role of the cerebral cortex?
Can be divided into discrete areas with specific functions
Includes frontal, occipital, parietal, and temporal lobes.
Where does language processing occur in the brain?
Within Broca’s area, Wernicke’s area, and Geschwind’s territory
These areas are critical for language comprehension and production.
Where is voluntary movement coordinated in the brain?
From the primary motor cortex, cerebellum, and basal ganglia
These regions work together for effective motor control.
What brain structures are involved in emotion?
- Limbic system
- Amygdala
- Prefrontal cortex
These areas are important for emotional processing and regulation.
Identify two types of neurotransmitters.
- Excitatory
- Inhibitory
Glutamate is an example of an excitatory neurotransmitter, while GABA is an inhibitory neurotransmitter.
Compare the functions of dopamine and serotonin.
- Dopamine: Involved in reward and motivation
- Serotonin: Regulates mood and anxiety
Both neurotransmitters have significant psychological functions.
What is the impact of interference in neurotransmitter function?
Can lead to symptoms and treatments related to conditions like Parkinson’s disease and Alzheimer’s disease
These diseases are characterized by specific neurotransmitter imbalances.
