Ch. 13 Nervous Tissue Flashcards
Nervous system Functions
- Sensory input
- Integration of information
- Motor output
- Homeostasis
- Mental activity
Central Nervous System
Brain and spinal cord
Peripheral Nervous System
Sensory and motor
Motor Nervous System
Somatic and autonomic
Autonomic Nervous System
Sympathetic and parasympathetic
Sensory Pathway
Touch receptor, sensory neuron, spinal nerve, ganglion, dorsal root
Motor Pathway
Cell body in spinal cord, axon goes all the way out to the muscle
Autonomic Nervous System
Two nerves: body in the spinal cord, with an axon going out to a ganglion, where we have a second cell body with an axon going out to an organ
(Pre and post ganglionic neuron)
The Neuron (Structure)
Cell body with dendrites, an axon, trigger zone, schwann cells, myelin sheath, nodes of ranvier, and end plates
The dendrites and cell body (Functions)
Dendrites and cell body are stimulated by environmental input or other neurons
This causes small electric currents in the cell membrane
Summary of input may cause the trigger zone to fire
If this happens, the signal will travel down the axon
Axons and end plates (Functions)
The electrical signal (action potential) travels down to the end of the axon. All or nothing
The action potential stimulates vacuoles in the end plates to release chemicals (neurotransmitters)
Neurotransmitters diffuse to the target (nerve, muscle, gland) and either stimulate or inhibit an action
Chemical synapses
ACh, and other neurotransmitters, are released into the chemical synapse.
Types of neurons
Multipolar: Cell body with many projections
Bipolar: Cell body in the middle with two projections
Unipolar: Cell body with one projection
i.e. - One, Two, Many (projections)
Types of Neurons
Motor neurons (away from the CNS) Sensory neurons (toward the CNS) Interneurons
Neoroglia
Support cells
- Oligodendrocyte
- Astrocytes
- Microglia
- Ependymal cells
