Chapter 7 questions Flashcards
(13 cards)
What are the divisions of the nervous system?
Central Nervous System (CNS) — the brain and spinal cord.
Peripheral Nervous System (PNS) — outside the CNS; includes cranial nerves, spinal nerves, and associated ganglia1.)
somatic (conscious control)- CNS to skeletal muscle(motor nerves), cranial nerves, spinal nerves2.) autonomic (involuntary functions)- Three components; sympathetic (fight or flight), parasympathetic (calm, exocrine glands), and enteric.
Know the parts of a neuronal cell, how do their composition and functions differ?
Cell body
(perikaryon or soma)• in CNS typically polygonal; in PNS round
Dendrites
• several per cell body; generally multi-branched
• can receive signals from many neurons simultaneously
•Can also form dendrodendritic synapses with other neurons
Axon
• varying diameter and up to 100 cm long
• conduct impulses away from soma
• terminate in end-bulbs and form synapses with other neurons, muscle, or glands•can synapse with another neuron at 3 locations: axosomatic, axodendritic,axoaxonic
What are the differences between an oligodendrocyte and a Schwann cell?
Oligodendrocyte function in electrical insulation by producing myelin in the CNS. A single Schwann cell can only myelinate a single node of an axon on the PNS.
Know the different types of neuroglial cells and their functions?
exclusive to the CNS are astrocytes, oligodendrocytes, microglial cells, and ependymal cells.
Schwann cells and capsule cells in the PNS.
What is the function of astrocytes?
- act as scavengers of ions and neurotransmitters (K+, glutamate, GABA)- histological hallmark: bundles of intermediate filaments (glial fibrillar acidic protein)- may contribute to the blood-brain barrier.
What is the function of microglial cells?
•Members of the mononuclear phagocyte system (derived from bone marrow)• Act as phagocytes, as well as APC’s and produce cytokines• Darkly staining•Secretions VERY toxic to neurons!
What is the function of ependymal cells?
•Low columnar or cuboidal epithelial cells • Some are ciliated - thought to aid in the movement of cerebrospinal fluid• Line the ventricles of the brain and central canal of spinal cord• Function in the modification of CSF
How is an action potential initiated, propagated, and re-equilibrated (brought to resting potential)? What ensures that the action potential will move in one direction down the axon?
- neurons and other cells are electrically polarized at -40 to -90mV- change in membrane potential primarily controlled by 3 channels and a pump-action potential - the cycle of depolarization, hyperpolarization, and return to RMP- refractory period.
Know the chart of neurotransmitters and some basic principles that apply to neurotransmitter function.
1) Single transmitter can cause different actions
2) The postsynaptic receptor determines the effect
3) Usually multiple transmitters released at a time
4) Volume transmission is possible—one release affects several cells.
What is the difference between salutatory and continuous conductance?
The key difference between saltatory and continuous conduction is that saltatory conduction is the propagation of action potential along myelinated axons while continuous conduction is the propagation of action potential along unmyelinated axons.
What are the differences between gray and white matter
White Matter- myelinated & unmyelinated fibers- color due to abundance of myelin- spinal cord vs. brain locations
Gray Matter- aggregates of cell bodies, dendrites, unmyelinated axons, neuroglial cells- located in periphery cortex of cerebrum and cerebellum- located deep in the spinal cord forms an H shape in cross section, the central canal lined with ependymal cells is the crossbar- Dorsal (sensory; unipolar), ventral (motor; multipolar), and lateral horns.
Where is CSF produced and what is its purpose?
Produced in the choroid plexus.
functions of CSF include: buoyancy, chemical stability, and protection.
Know the layers of the cerebrum and the cerebellum.
cerebrum= - 6 layers: molecular layer, external granular layer, external pyramidal layer,Internal granular layer, internal pyramidal layer, and multiform layer Cerebellum= - molecular layer (stellate and basket cells)- Purkinje cell layer (uses GABA)- granular layer (granular cells and glomeruli)
