Nervous Tissue Flashcards
Divisions of the nervous system
Central- includes brain and spinal cord
Peripheral: cranial nerves- carry nerve impulses to and from the brain
Divisions of peripheral nervous system
Somatic NS: voluntary, skeletal muscle
Autonomic: involuntary, smooth muscle, cardiac muscle, and glands
Neurons
Highly specialized cells: contain the cell body.
Dentrites
Neurons fibers that conduct impulses to the cell body. Very branched tree like appearance
Axons
Neuron fibers that conduct impulses away from the cell body. Can be delivered to another neuron a muscle or gland
Roles of the nervous system
Market research: sensory receptors
Middle management: spinal cord
Chief executive officer: brain
Factory floor: effectors
Types of neurons
Sensory neuron: conducts impulses to the spinal cord
Types of neurons
Sensory neuron: conducts impulses to the spinal cord and brain
Motor neurons: carry impulses from the CNS out tomuscles and glands
Interneurons: relay information within the CNS
Neuralgia
The cells that glue to and support neurons.
Protect and nourish the nervous tissue
Aid in repair of cells
Central nervous system cells
Oligodendrocytes- produce myelin sheath around axons
Astrocytes- support neurons
Microglia- like phagocytes, remove pathogens
Ependymal- help move fluid around
Peripheral nervous system cells
Schwann- form the myelin sheath and neurolemma around axons
Satellite- support neurons in ganglia
The myelin sheath
Some axons are covered with a fatty material called myelin. It insulates and protects the muscle fiber
Nodes
Small spaces inbetween the individual cells. Speeds nerve impulse conduction
Nerve impulse
Like the spread of an electric current along a wire.
The electrical changes that occur as a resting neuron is stimulated and transmits a nerve impulse.
