The Nervous System: Organization, Cells, Membrane Potential-Lecture 8 Exam 2 Flashcards
What does the Central Nervous System include?
Brain & Spinal Cord
What does the Peripheral Nervous System include?
Sensory (afferent) & Efferent neurons
Components of Sensory (afferent) & Efferent Neurons
-Sensory: none specific listed
-Efferent: Somatic Motor Neurons & Autonomic Neurons
Components of Somatic Motor Neurons & Autonomic Neurons
-Somatic: none specific listed
-Autonomic: Sympathetic & Parasympathetic
**Identify/draw and describe the major components of a typical neuron (e.g., cell body,
nucleus, dendrites, axon hillock, axon proper, axon terminal) and indicate which parts receive
input signals and which parts transmit output signals. **
LOOK AT NOTES!!!
Sensory (afferent) Neurons
-Transmit information from receptors in skin or internal organs (PNS) toward the CNS for processing
-Multiple dendrites & single axon
-Located in PNS
Interneurons (association neurons)
-Integrate sensory & motor information
-Several branching dendrites, a cell body (soma), & an axon
-Mostly in the CNS
Motor (efferent) Neurons
-Transmit information away from the CNS to effectors
-Cell body (soma), axon, & dendrites
-Located in PNS: muscles & glands
Types of Glial Cells
PNS & CNS
PNS Glial Cells
Development, maintenance, function, & regeneration of peripheral nerves
CNS Glial Cells
Regulate neurotransmission & help form the blood-brain barrier
Satellite Cells
-PNS glial cell
-Provide support for ganglia (clusters of neuron cell bodies)
Neurolemmocyte/Schwann cell
-PNS glial cell
-Myelinate axons in the PNS
Microglia
-CNS glial cell
-Immune cells of the CNS
-Phagocytize debris
Ependymal Cells
-CNS glial cell
-Make and secrete cerebrospinal fluid (CSF)
Astrocytes
-CNS glial cell
-Forms the blood brain barrier (BBB)
with capillaries (tight junctions)
-Regulates chemical content (ions,
glucose, NTs) in ECF
Oligodendrocytes
-CNS glial cell
-Myelinate axons in the CNS
Myelination
Formation of the myelin sheath around a nerve to allow for improved conduction
Myelination in PNS & CNS
-Neurolemmocyte/Schwann cell (PNS): Single cell forms myelin around a segment of one axon
-Oligodendrocyte (CNS): A single cell can myelinate many axons
Concentration/Chemical Gradient
Ions diffuse from regions of high concentration to regions of low concentration
Electrical Gradient
Ions move toward regions of opposite charge
Electrochemical Gradient
When both concentration and electrical gradients determine which direction ions move
When does Equilibrium occur?
When concentration & electrical gradients for an ion balance
Gradient
A slope that guides how things move from one place to another
