Problem 1 Brain and Body
Motor neuron = from the brain to the muscles (efferent)
Sensory neuron = from sensen to the brain (afferent)
Interneurons = has short or no axon, link within rather than between structures. Sends
messages between neurons.
Afferent nerves= carry information to CNS (approaching)
Efferent nerves= carry signals from CNS (exiting)
Neurons:
- multipolar neuron = neuron with more than two processes extending from its cell
body. (most neurons).
- unipolar neuron = neuron with one process extending from its cell body.
- bipolar neuron = a neuron with two processes extending from its cell body.
- interneurons = integrate neural activity within a single brain structure (not to conduct
signals from one structure to antoher).
Glial cells= other types of cells in NS, provide support to neurons (nutrition, clearing waste,
physical matrix to hold neural circuits together)
Types of glial cells:
- Oligodendrocytes = in the brain and spinal cord
- Schwann cells = in the periphery of the body
- Both: Build the myelin sheaths that surround and insulate certain vertebrate
axons
- Both: Supply nan axon with nutrients necessary for proper functioning
- Microglia = part of the immune system.
- Removing viruses and fungi from the brain.
- Proliferate after brain damage, removing dead or damaged neurons.
- Contribute to learning by removing the weakest synapses.
- Astrocytes = star-shaped.
- Wrap around the synapses of functionally related axons. By surrounding a
connection between neurons, an astrocyte shields it from chemicals
circulating in the surroundings.
- Taking up the ions and transmitters released by axons and then releasing
them back. Helps synchronize closely related neurons, enabling their axons
to send messages in waves.
- Dilate blood vessels > bring more nutrients into brain areas that have
heightened activity.
- Important for: generating rhythms.
- Radial glia
- Guide the migration of neurons and their axons and dendrites during
embryonic development.
Cells of the nervous system:
CNS PNS
Clusters of cell bodies Nuclei (singular: nucleus) Ganglia (singular: ganglion)
, Bundles of axons Tracts Nerves
Nervous system
- Entering dorsal roots (axon bundles) carry sensory information, and the exiting
ventral roots carry motor information.
,Cells definitions
CNS PNS
Tract Nerve
= a set of axons within the CNS. = a set of axons in the periphery, either from
the CNS to a muscle or gland/ from a
sensory organ to the CNS
Nucleus Ganglion
= a cluster of neuron cell bodies = a cluster of neuron cell bodies
Somatic and Autonomic NS
, Sympathetic and parasympathetic NS
Spinal Cord:
= Communicates with all sense organs and muscles, except those of the head
● Segmented structure; Each segment sends sensory information and receives motor
information from the brain. If segment is
● damaged, sensation is lost on the segment and below, also brain loses motor control
Motor neuron = from the brain to the muscles (efferent)
Sensory neuron = from sensen to the brain (afferent)
Interneurons = has short or no axon, link within rather than between structures. Sends
messages between neurons.
Afferent nerves= carry information to CNS (approaching)
Efferent nerves= carry signals from CNS (exiting)
Neurons:
- multipolar neuron = neuron with more than two processes extending from its cell
body. (most neurons).
- unipolar neuron = neuron with one process extending from its cell body.
- bipolar neuron = a neuron with two processes extending from its cell body.
- interneurons = integrate neural activity within a single brain structure (not to conduct
signals from one structure to antoher).
Glial cells= other types of cells in NS, provide support to neurons (nutrition, clearing waste,
physical matrix to hold neural circuits together)
Types of glial cells:
- Oligodendrocytes = in the brain and spinal cord
- Schwann cells = in the periphery of the body
- Both: Build the myelin sheaths that surround and insulate certain vertebrate
axons
- Both: Supply nan axon with nutrients necessary for proper functioning
- Microglia = part of the immune system.
- Removing viruses and fungi from the brain.
- Proliferate after brain damage, removing dead or damaged neurons.
- Contribute to learning by removing the weakest synapses.
- Astrocytes = star-shaped.
- Wrap around the synapses of functionally related axons. By surrounding a
connection between neurons, an astrocyte shields it from chemicals
circulating in the surroundings.
- Taking up the ions and transmitters released by axons and then releasing
them back. Helps synchronize closely related neurons, enabling their axons
to send messages in waves.
- Dilate blood vessels > bring more nutrients into brain areas that have
heightened activity.
- Important for: generating rhythms.
- Radial glia
- Guide the migration of neurons and their axons and dendrites during
embryonic development.
Cells of the nervous system:
CNS PNS
Clusters of cell bodies Nuclei (singular: nucleus) Ganglia (singular: ganglion)
, Bundles of axons Tracts Nerves
Nervous system
- Entering dorsal roots (axon bundles) carry sensory information, and the exiting
ventral roots carry motor information.
,Cells definitions
CNS PNS
Tract Nerve
= a set of axons within the CNS. = a set of axons in the periphery, either from
the CNS to a muscle or gland/ from a
sensory organ to the CNS
Nucleus Ganglion
= a cluster of neuron cell bodies = a cluster of neuron cell bodies
Somatic and Autonomic NS
, Sympathetic and parasympathetic NS
Spinal Cord:
= Communicates with all sense organs and muscles, except those of the head
● Segmented structure; Each segment sends sensory information and receives motor
information from the brain. If segment is
● damaged, sensation is lost on the segment and below, also brain loses motor control
