Nervous System Flashcards
What does CNS stand for
Central nervous system
What does the CNS consist of, and what are the 2 general cell classes that they are composed of ?
Consists of brain and spinal cord
Composed of neurons and glia
What does PNS stand for
Peripheral Nervous System
What is the PNS consisted of and what are the 2 general cell classes that they are composed of ?
Consisted of peripheral nerves and ganglia
Composed of neurons and glia
What are the 2 general fractures of Neurons ?
- cells specialised for transmission of information
- 4 morphological types
What are the 3 general features of Glia ?
- support neurons
- 5 basic types —> 4 in CNS, 1 in PNS
- each type has specific functions
What are the 2 features of dendrites ?
- receive input
- send info to the cell body
What are the 2 features of the cell body ?
- contain nucleus and organelles
- sums input
What are the 2 features of the axon ?
- Carries electrical impulses
- may or may not be myelinated
What are the 2 features of the axon terminals ?
- end (terminals) of the axon
- neurotransmitter release
What is a bundle of axons called
Tract
In the CNS, What is a group of cell bodies called ?
Nucleus (nuclei)
In the CNS, what do you call a group of cell bodies in the cerebral cortex or spinal cord ?
Grey matter
In the CNS, what do you call a bundle of axons in the cerebral cortex or spinal cord ?
White matter
In the white matter, is the axons myelinated or not
They are
In the PNS, what do you call a group of cell bodies ?
Ganglion (ganglia)
In the PNS, what do you call a bundle of axons ?
Nerve
What components from the neuron are in the input zone ?
Dendrites and cell body
What is the functional components of the input zone ?
Receives CHEMICAL SIGNALS from other neurons
What components from the neuron are in the summation zone ?
Axon Hillock
What is the functional component of the summation zone
Summation of inputs
What components from the neuron are in the conduction zone ?
Axon (may be very long)
What is the functional component of the conduction zone?
Carry ELECTRICAL SIGNALS (ACTION POTENTIAL) between brain areas to and from the spinal cord or from Peripheral sensory receptors to effector cells
What components from the neuron are in the output zone?
- Axon terminals
what is the functional components of the output zone?
- Contact with input zone of other neurons or effectors
- release of neurotransmitters = CHEMICAL SIGNALS
what is the axon hillock
- is an anatomical location where inputs are summated before action potential
- in the summation zone
how many processes emanate from a Multipolar cell body
multiple processes
how many processes emanate from a Bipolar cell body
2 processes
how many processes emanate from a unipolar cell body
1 process, it then branches into dendrite and axon
What is different in Anaxonic processes
has no distinct axon,
all processes look alike
what are the 4 CNS Glia
1) Astrocytes
2) Microglia
3) ependymal cells
4) oligodendrocytes
what are the 3 features of Astrocytes
- supply nutrients to neurons
- ensheath blood capillaries
- injury response
what are the 2 features of Microglia
- immune cells of the CNS
- Engulf microorganisms and debris
what are the 2 features of Ependymal cells
- line fluid-filled spaces of brain and spinal cord
- have cilia (hair-like processes) to circulate CSF
what are the 2 features of Oligodendrocytes
- support nerve fibres
- ensheath them with myelin
what is the name of the PNS Glia
Schwann cells
what are the 3 features of the schwann cells
- support peripheral nerve fibres
- ensheath them with myelin
- similar to oligodendrocytes (CNS)
what is the Myelin Sheath
- is a lipid (fat) wrapped around the axon
- it increases conduction velocity
what are Nodes of Ranvier and their functions
- are gaps between myelin
- it increases conduction velocity
how do neurons communicate with one another
- occurs through a junction called a SYNAPSE
during the synapse, what happens with the information
it need it change form when it moves to on thing to the next
- electrical –> chemical –> electrical
what is the word for when information goes INTO the brain
afferent
or
ascending
what is the name of the response that come OUT of the brain
efferent
or
descending
