MIDTERM 1 Flashcards
What are the divisions of the nervous system?
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
What does the CNS consist of?
Brain and Spinal Cord
What does the PNS consist of?
Cranial Nerves
Spinal Nerves
Sensory Receptors in Skin
What are the functions of the Nervous System?
Sensory
Integration
Motor
What does the Sensory function do?
There are sensory receptors the detect internal and external stimuli and relay the sensory information to the brain and the spinal cord for integration.
What does the Integration function do?
The Central Nervous System analyzes the sensory information and makes decisions for appropriate responses.
What does the Motor Function do?
The motor information is conveyed from the Central Nervous System through the cranial and spinal nerves in the Peripheral Nervous System which is then relayed to the appropriate effectors (muscles and glands).
What is the difference between plasticity and repair
Plasticity refers to the ability to change throughout life. Repair refers to regeneration of a neuron after damage.
How does regeneration in the PNS occur.
It works through the aid of Schwann cells because the cells contribute in the formation of the regeneration tube which stimulate the regrowth of an axon. (If an individual injures the nerve in their upper limb has a good chance of regaining nerve function).
How does regeneration in the CNS occur?
There is little to no repair of an axon after injury. Due to absence of growth-stimulating cues that were present during fetal development and/or inhibitory proteins secreted by neuroglia.
What two ways doe neurons/muscle fibers communicate?
- Graded Potentials (short-distance communication)
- Action Potentials (long-distance communication)
How is the action potential different in the nerve versus the muscle?
Nerve action potentials/impulses causes the release of neurotransmitters. Muscle action potentials causes the muscles to contract.
Provide an example of how the functions of graded potential and action potentials are understood.
- As you touch a pen, a graded potential develops in a sensory receptor in the skin of the fingers.
- The graded potential triggers the axon of the sensory neuron to form a nerve action potential, which travels along the axon into the CNS and ultimately causes the release of neurotransmitter at a synapse with an interneuron.
- The neurotransmitter stimulates the interneuron to form a graded potential in its dendrites and cell body.
- In response to the graded potential, the axon of the interneuron forms a nerve action potential. The nerve action potential travels along the axon, which results in neurotransmitter release at the next synapse with another interneuron.
- This process of neurotransmitter release at a synapse followed by the formation of a graded potential and then a nerve action potential occurs over and over as interneurons in higher parts of the brain (such as the thalamus and cerebral cortex) are activated. Once interneurons in the cerebral cortex, the outer part of
the brain, are activated, perception occurs and you are able to feel the smooth surface of the pen touch your fingers. As you will learn
What are the four types of ion channels important to neuron function?
- Leak Channels
- Ligand-Gated Channels
- Mechanically Gated Channels
- Voltage Gated Channels
Leak Channels
These are gated channels that randomly open and close. They are found in nearly all cells, including dendrites, cell bodies and axons of all types of neurons. They are important for establishing membrane potential.
