Nervous system Flashcards
Functions of the nervous system
Sensory input, Integration, Controls of muscles and glands, Homeostasis, Center for mental activities.
detects external and internal stimuli
sensory input
processes and responds to sensory input
integration
___ is maintained by regulating other systems
Homeostasis
Two anatomical divisions of the nervous system
Central nervous system(CNS), Peripheral Nervous System(PNS)
Detects stimuli and transmits information TO the CNS and receives information FROM the CNS
Peripheral nervous system (PNS)
processes, integrates, stores, and responds information FROM the PNS
Central nervous system (CNS)
PNS has two divisions
Sensory division and Motor division
TRANSMITS action potentials FROM sensory receptors TO the CNS
Sensory division
CARRIES action potentials away FROM the CNS in cranial or spinal nerves
Motor division
innervervates skeletal muscle
Somatic nervous system
Innervates cardiac muscle, smooth muscle, and glands (three divisions)
Autonomic nervous system
three divisions of autonomic nervous system
Sympathetic, Parasympathetic, and Enteric division
is most active during PHYSICAL ACTIVITY
Sympathetic division
regulates RESTING FUNCTION
Parasympathetic division
controls the DIGESTIVE SYSTEM
Enteric nervous system
Two principal cell types
Neurons, Non-Neural cells (glial cells)
EXCITABLE cells that TRANSMITS electrical signal
Neurons
cells that SORROUND neurons. Account for over half the brains weight
Non-Neural Cells (glial cells)
Neurons have three compartments
cell body (soma), Dendrites, and Axon.
primary site of protein synthesis
cell body (soma)
are short, branched cytoplasmic extensions of the cell body that usually CONDUCT electric signals toward the cell body
Dendrites
a CYTOPLASMIC extension of the cell body that TRANSMITS action potentials to OTHER CELLS
Axon
Clusters of cell bodies in the CNS are called
Nuclei
Clusters of cell bodies in the PNS are called
ganglia
the part of the neuron where the axon originates
Trigger zone
branched terminus of an axon
Presynaptic terminal
junction between a nerve cell and another cell
Synapse
Bundles of PROCESSES are called ___ in the CNS
nerve tracts
Bundles of PROCESSES are called ___ in the PNS
Nerves
TYPES OF NEURON
Multipolar, bipolar, unipolar
have several dendrites and a single axon
Multipolar Neurons
have a single axon AND dendrite
Bipolar Neurons
have a SINGLE AXON
Unipolar neurons
supporting cells
Glial cells
Glial cells of the CNS
A.M.Ep.O ( Astrocytes, Microglial, Epyndemal, Oligodendrocytes)
Glial cells of the PNS
Satellite cells and Schwann cells
Most abundant, versatile, and highly branched
Astrocytes
Range in shape from squamous to columnar and many are ciliated.
Epyndemal cells
Small, ovoid cells. Phaagocytes that monitor the health of neurons
Microglia
form MYELIN SHEATHS around the axons of several CNS neurons
Oligodendrocytes
Form a MYELIN SHEATH around part of the axon of a PNS neuron
Schwann cells
Support and nourish neuron cell bodies within ganglia
Satellite cells
plasma membrane of Schwann/oligodendroctyes
Myelinated axons
Gaps in the myelin sheath
Nodes of ranvier
Rest in invaginations of Schwann cells and Oligodendrocytes
Unmyelinated axons
Nervous tissue can be grouped into __ and __
white matter and gray matter
consists of myelinated axons, forms nerve tracts in the CNS and nerves in the PNS
White matter
collection of neuron cell bodies or unmyelinated axons.
Gray matter
Electric signals are produced by cells are called
action potentials
transmits signal towards a synapse
presynaptic cell
receives the signal of a synapse
postsynaptic cell
two types of synapses
electrical, and chemical
Neuronal pathways and circuits
Convergent pathway, divergent pathway, and oscillating circuit
have many neurons synapsing with a FEW neurons
Convergent pathways
have many neurons synapsing with a MANY neurons
divergent pathways
Have COLLATERAL branches of postsynaptic neurons synapsing with presynaptic neurons
Oscillating circuits
