Fundamentals of the Nervous System Flashcards
The master controlling and communicating system of the body
Nervous System
Functions of the nervous system:
- Sensory Input
- Integration
- Motor Output
The two principle cell types of the nervous system are:
- Neurons
2. Supporting Cells (Neuroglial Cells)
Smaller cells that work with/ support neurons
Neuroglial
Part of neuron that receives information:
Dendrite
List the sequence of the nervous system
Sensory input–> Integration–> Motor Output
Has myelinated axons
White matter
Has unmyelinated axons or structures
-Includes cell body and dendrites
Gray Matter
Structural units of the nervous system
composed of body, axon, and dendrites
Characteristics of Neurons:
- long-lived
- amniotic
- Have a high metabolic rate
Function in:
- Electrical Signaling
- Cell-to-cell signaling during development
Neural Plasma Membrane
Nerve cell body is also known as:
Perikaryon or soma
Characteristics of nerve cell body:
- Has no centrioles (thus amniotic)
- Has well-developed Nissl Bodies
- Contains an axon hillock
Rough ER
-Appears to make the neurotransmitters of the neuron
Nissl Bodies
Slender processes branching form the hillock
Axon
Long axons are called:
Nerve Fibers
Secretory component of neuron
end of axon tail
Axon Terminal
Usually ___ unbranched axon per neuron
One
Functions of axons:
- Generate and transmit action potential
- Secrete neurotransmitters from the axonal terminals
- Neurotransmitters initiate a neural impulse in the next neuron to excite particular muscles or glands
A neural impulse in the next neuron or excite a particular muscle or gland
Neurotransmitters
CNS
- Brain
- Spinal Cord
PNS
- Crainial Nerves
- Spinal Nerves
The supporting cells (neuroglia) have:
Many different types with specific functions
- Produce myelin on peripheral myelinated neurons
- Increase neurotransmission
*Not found in brain or spinal cord
Schwann Cells
Support clusters of neuron cell bodies (ganglia)
Satellite Cells
- Most abundant, versatile, and highly branched glial cells
- Mop up excess ions
- Induce synapse formation
- Connect neurons to blood vessels
*Found in CNS
Astrocyte
*Starburst
- Found in CNS
- Are myelin-forming cells
Oligodendrocytes
- Small, ovid cells with spiny processes
- Phagocytic cells of the CNS
Microglia
- Range in shape from squamous to columnar
- Ciliated cells of CNS
- Line the central canal of the spinal cord and ventricles of the brian
Ependyma
Einstein has more ____ in his brain
More neuroglial (not more neurons)
- Whitish, fatty (protein-lipoid), segmented sheath around most long axons
- It functions to insulate the axon of a neuron
- Make sure the neuron impulses run down the axon and stimulates the next cell
Myelin Sheath
___ is formed by Schwann cells in the PNS
Myelin
Remaining nucleus and cytoplasm of a Schwann Cell
Neurilemma
- Gaps in the myelin sheath between adjacent Schwann cells
- They are sites where axon collaterals can emerge
Nodes of Ranvier (Neuorfibral Nodes)
In _____, there is no regeneration if you cut the axon
in spinal cord
*B/c oligodendrocytes do not divide
Both myelinated and unmyelinated fibers are present
Axons of the CNS
When myelin sheaths are formed in the CNS, they are formed by:
Oligodendrocytes
Two divisions of the Nervous System:
- Sensory (afferent) division
- Motor (efferent) division
Two main systems in the Motor Division:
- Somatic Nervous System
- Automatic Nervous System
Picks up sensory information and delivers it to CNS
Sensory (afferent division)
Carries info to skeletal muscle
Motor (efferent) division
Carries info to smooth muscle, cardiac muscle, and glands
Autonomic nervous system
Sensory Functions:
Sensory receptors gather info and info is carried to the CNS
Integrative Functions:
Sensory information used to create:
- Sensations
- Memories
- Thoughts
- Decisions
Motor Functions:
- Decisions are acted upon
- Impulses are carried to effectors
What are effectors?
Muscles or glands
Structural differences of neurons:
- Bipolar
- Unipolar
- Multipolar
- Two processes
- In eyes, nose, and ears
Bipolar
- One process
- Neural Ganglia
Unipolar
- Many processes
- Significant component of the CNS
Multipolar
Functional differences of neurons:
- Sensory Neurons
- Interneurons
- Motor neurons
- Afferent neurons
- Carry impulses to the CNS
- Most are unipolar (some bipolar)
Sensory Neurons
- Link neurons
- Multipolar
- Park of CNS (brain and spinal cord)
Interneurons
- Multipolar
- Carry impulses away from the CNS to effectors (muscles and glands)
Motor Neurons
Neurons are highly _____
irritable
Action potentials, or nerve impulses, are generated from:
neurotransmitters
Neurotransmitters are released from:
synaptic bulb when stimulated by a neural impulse
Measure of electrical potential difference in energy
Voltage (V)
Voltage measured between two points
Potential Difference