Nervous system Flashcards
Which system consists of the brain and spinal cord?
central nervous system (CNS)
Whats a common neurological disorder characterized by unprovoked seizures?
Epilepsy
What are the functions fo the somatic nervous system?
- Stimulate skeletal muscles
- Under voluntary control
- Consists of single neurons or nerve cels
What is the minimum level of a stimulus required to activate a neuron?
Threshold
What does the diencephalon consist of?
thalamus
subthalamus
epithalamus
hypothalamus
What are the two sections of the nervous system?
Peripheral and central nervous system
What does the PNS do?
- Consists of sensory receptors, nerves, ganglia, and plexuses
- Senses stimuli, sends info. to and from the CNS
What does the CNS do?
- Contains the brain and spinal cord
- Processes, stores and responds to info. from the PNS
- largest part of the NS
- within the dorsal cavity
What are the two divisions of the PNS?
- Sensory - transmits action potential to CNS
- Motor- Carries action potential & is divided into somatic and autonomic systems
What does the somatic nervous system do?
- stimulates skeletal muscles
- voluntary
What does the autonomic nervous system do?
- stimulates cardiac, smooth muscles, and glands
What are neurons?
- nerve cells
- receive stimuli
- transmit action potential
- consists of soma, dendrites, and axons
What are glial cells?
major support cells of the NS
What is nervous tissue?
- Gray and white matter
What is white matter?
- consists of myelinated (sheathed) axons & spreads action potential
- on the inside of the brain
- on the outside of the spinal cord
What is gray matter?
- includes neuron cell bodies
- outside the brain
- inside the spinal cord
Explain action potentials.
- Electric signals produced by the cells
- the main way cells transfer info.
What is resting potential?
- no active membrane
- negative value
What is moving potential?
- a neuron being stimulated by another neuron
- impulses travel away from the dendrites toward the end of the axon through the protein channels allowing ions to pass
What is the synapse and what does it do?
- located between where neurons transfer impulses between cells
- the gap separating the axon from the dendrites
- action potential arrives at the axon terminal neurotransmitters fill the gap between the axon and dendrites
How many pairs of cranial nerves are there?
12
How many pairs of spinal nerves are there?
31
What does the brainstem do?
connects spinal cord to the brain
What is amyotrophic lateral sclerosis (ALS)?
- a progressive fatal neurodegenerative disease caused by the degeneration of motor neurons
- causes muscle weakness and atrophy
- no cure
