Nervous System Flashcards
What are the 2 structural divisions of the nervous system?
- CNS
2. PNS
What does the CNS consist of?
Brain and spinal cord
What is the functional unit of the nervous system?
The neuron
List the major components of a neuron
Dendrite, cell body, nucleus, axon, myelin, nodes of Ranvier
What are the 3 principle functions of the nervous system?
- Sensory input
- Integration
- Sensory output
Which division is the afferent?
Sensory division
Which division is the efferent?
Motor division
What are the 2 divisions of the motor division?
- Somatic
2. Autonomic
What are the 2 divisions of the autonomic nervous system?
- Sympathetic
2. Para-sympathetic
What surrounds the nerve cells?
Glial cells
What are the general functions of glial cells?
Provide support, nutrition, insulation and help with signal transmission
What are the 4 glial cells of the CNS?
- Astrocytes
- Microglial cells
- Ependymal cells
- Oligodendrocytes
Functions of Astrocytes
Regulate ions, exchange materials between neurons and capillaries
Functions of Microglial cells
Immune Defense against invading microbes
Functions of Ependymal cells
Line cavities in the brain and spinal cord. Create, secrete and circulate cerebrospinal fluid
Functions of Oligodendrocytes
Wrap around neurons creating the insulation which is the myelin sheath
What are the 2 types of glial cells of the PNS
- Satellite cells
2. Schwan cells
Functions of the satellite cells
Surround cells and support and facilitate nutrition
Function of Schwan cells
Produce insulating barrier called myelin sheath
Definition of Amitotic
Once neuron takes on given role in nervous system, they lose their ability to divide
What percent of daily caloric intake is used by your brain?
25%
What is the outermost layer of a Schwann cell called?
Neurilemma
What are the 3 functional categories of neurons within the CNS?
- Sensory neurons
- Motor neurons
- Interneurons
Function of interneurons
Relay information from place to place within the CNS
What are white fibers?
Myelinated axons
What is the difference between white and grey matter in the brain?
White matter is myelinated and grey matter isn’t
What are fiber bundles located in the CNS and PNS called, respectively?
Tracts and nerves
Name 4 neuro transmitters
- Norepinephrine
- Seratonin
- Dopamine
- Acetylcholine
Which neurotransmitter is present in the neuromuscular junction
Acetylcholine
4 ways neurotransmitters are removed
- Reuptake
- disolved by Enzymes
- Used by glial cells
- Slow diffusion