Chapter 10 Flashcards
Master regulatory system, sends and receives information, maintains homeostasis, acts as center for thought, learning, and memory
Nervous system
Main cell types of nervous system
Neurons(nerve cells)
Neuroglia
detects changes
Sensory input
Makes decisions
Integration and processing
Stimulates muscle and glands to respond
Motor output
Responds quickly to change/stimuli, conducts electrical impulses via neurotransmitters
Neurons
Protects, supports, insulates, and nourishes neurons; does not conduct electrical impulses
Neuroglia
Only the brain and spinal cord makes up
Central nervous system
Connects CNS to other body parts, consists of cranial and spinal nerves
Peripheral nervous system (PNS)
Two subdivisions of PNS
Afferent (sensory)
Efferent (motor)
Afferent
Sensory
Efferent
Motor
Two divisions of motor
Somatic
Autonomic
Transmits voluntary commands to skeletal muscles
Somatic
Transmits involuntary commands to viscera
Autonomic
Three parts of neuron
Cell body( soma, perikaryon)
Dendrite
Axon
Contains nucleus, cytoplasm, organelles, neurofilaments, chromatophillic substance (Nissl Bodies)
Cell body (soma or perikaryon)
Branched receptive surfaces; a neuron may have many
Dendrites
Transmits impulses and releases neurotransmitters to another neuron or effector(another neuron, a muscle cell, or a gland cell); a neuron may have only one axon
Axon
Neuroglia of the PNS that wrap around some axons in layers
Schwann cells
Mixture of fats and proteins that fill layers made by Schwann cell membranes
Myelin
A wrapped coating around some PNS axons, composed of layers of Schwann cell membranes and myelin; acts as electrical insulator
Myelin sheath
Gaps in myelin sheath between Schwann cells
Nodes of raniver
Myelinated axons in PNS produced by
Schwann cells
Myelinated axons in CNS produced by
Oligondendrocytes
Comprise white matter
Only brain and spinal cord
Encased by Schwann cells cytoplasm in PNS, but there is no wrapped coating of myelin surrounding the axons
Groups of this in CNS comprise grey matter
Unmyelinated axons
Many processes extend from cell body
99% of neurons
Most neurons of CNS, some in autonomic NS
(Classification of neuron)
Multipolar neurons
Two processes extend from cell body(1 dendrite, 1 axon)
Not that common
Eyes, ears, nose
(Classification of neurons )
Bipolar neurons
Three classifications of neurons
Multipolar
Bipolar
Unipolar (pseudounipolar)
Four neuroglia of the CNS
Astrocytes
Oligondendrocytes
Microglia
Ependyma or ependymal cells
Form scar tissue, aid metabolism of certain substances, regulate ion concentrations, as k+, part of blood brain barrier
Astrocytes
Myelinate CNS axons, also provide structural support
Oligodendrocytes
Phagocytic cells; also provide structural support
Microglia
Line central canal of spinal cord & ventricles of brain, cover choroid plexuses
Help regulate composition of cerebrospinal fluid
Ciliated cuboidal or columnar cells
Ependyma or ependymal cells
Support clusters of neuron cell bodies (ganglia)
Nourish and balance ionic concentrations
Satellite cells
Neurons communicate with each other at
Synapse
(Synapse). Neuron sends impulse
Presynaptic
(Synapse). Neuron receives impulse
Postsynaptic
Produced in the rough ER or cytoplasm
Neurotransmitter
Increase permeability to Na+ ions, bring membrane closer to threshold; increase likelihood of generating impulses (neurotransmitter)
Excitatory neurotransmitter
Move membrane farther from threshold, decrease likelihood of generating impulses (neurotransmitter)
Inhibitory neurotransmitters
Groups of interneurons that make synaptic connections with each other, and are located completely within the CNS
Interneurons work together to perform a common function
Each pool receives input from other neurons and generates output to other neurons
Neuronal pools
One neuron receives input from several neurons
Convergence
One neuron sends impulses to several neurons, via branching of its axon, can amplify impulse
Divergence
