ANATOMY OF SOMATIC NERVOUS SYSTEM Flashcards
What does the EFFERENT nervous system do?
Carries information away from the CNS to the effectors- it is a motor system
What does the AFFERENT nervous system do?
Carries information from the periphery to the CNS - it is a sensory system
Which cells make up the nervous system and in what proportions?
- Neurones - 10%
- Glial cells - 90%
Glial cells assist neurones in their functions
What are the 3 types of neurones?
Draw them
- Motor
- Bipolar (special sense)
- Pseudo Unipolar
What are the 4 types of glial cells?
- Astrocytes - most common
- Oligodendrocytes
- Microglia
- Ependymal
What is the function of an astrocyte?
- Maintain synapses by removing old ones
- Provide structural and metabolic support
Function of an oligodendrocyte?
- Myelinates axons in the CNS - allows for saltatory conduction
- Metabolic and structural support - provide nutrients
Function of microglia? (3)
- Prevent pathogens going to the CNS
- Immune cells
- maintain homeostasis
Function of Ependymal?
- CSF synthesis
- Ciliated cells that regulate the flow of CSF
Describe the structure of ependymal cells
Small ciliated epithelial cells
Which cells myelinated axons in the PNS?
Schwann cells - only one axon at a time
Where are the afferent sensory cell bodies found?
Dorsal root ganglion
Whivh muscle types are effectors of somatic and autonomic systems?
Somatic - skeletal muscle
Autonomic - Cardiac or smooth muscle
What is a nerve made from?
Multiple neurones/ axons bundled together form a fascicle. Bundles of fascicles form a nerve.
What are the
- Endoneurium
- Perineurium
- Epineurium
Connective tissue that holds together;
- Bundles of axons
- Entire fascicle
- Multiple fascicle
