Chapter 11 Vocab Flashcards
Spinal nerves
Originate from spinal cord. 31 pairs
Cranial nerves
12 pairs. Originate from brain
Ganglion
Collection of neuron cell bodies located outside CNS
Plexus
Extensive network of axons sometimes neuron cell bodies outside CNS
Subdivisions of PNS
Sensory division and motor division
Sensory division
Afferent -toward brain
Motor division
Efferent. Away from brain to organs
Motor division subcategories
Somatic and autonomic
Autonomic nervous system (ANS) subcategories
Sympathetic and parasympathetic division
Sympathetic division
Active during physical activity
Parasympathetic division
Regulates resting functions. Digestion empty urine
Enteric nervous system
Plexus within digestive tract. Control independently from CNS
Neuroglia
Supportive cells, protect neurons. Accounts for more than half brains weight.
Axons
Nerve fibers
Nissl bodies
Primary site of protein synthesis in neurons.
Dendritic spines
Receive input from other neurons axons and environment
Axon hillock
Most neurons; single axon arises from a cone shaped area of. Neuron cell body
Initial segment
Beginning of the axon
Trigger zone
Action potentials generated
Axoplasm
Cytoplasm of an axon
Axolemma
Axon plasma membrane
Types of neurons
Sensory, motor, interneurons, bipolar neurons, multipolar neurons, pseudo-unipolar neuron
Interneurons
Conduct action potentials within CNS
Multipolar neurons
Many dendrites and single axon. Most in CNS and motor
Bipolar neurons
Two processes; one dendrite one axon. Received stimulus– retina and nasal cavity
Pseudo-Unipolar neurons
Single process extends from cell body. Sensory receptors
Neuroglia of CNS
Astrocytes, ependymal cells, microglia, oligodendrocytes
Neuroglia of the PNS
Schwann cells, satellite cells
Astrocytes
Star shaped. Cytoplasmic processes extend to form foot processes
Foot processes
Astrocytes. Spread out and cover blood vessels, neurons and pia matter
Pia matter
Membrane covering outside of brain and spinal cord
Blood brain barrier
Astrocytes release chemicals to form tight gap junctions between endothelial cells of capillaries.
Reactive astrocytes
Injuries to CNS cause astrocytes to wall off damaged area
Ependymal cells
Neuroglia that line the ventricles of brain and central canal of spinal cord.