Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
52 Cards in this Set
- Front
- Back
Nerves
|
Bundles of axons and their sheaths which extend from the CNS
|
|
Ganglia
|
Collections of neuron cell bodies which are outside of the CNS
|
|
central nervous system (CNS)
|
brain and the spinal cord
|
|
peripheral nervous system (PNS)
|
nerves and ganglia
|
|
Spinal nerves
|
Nerves which originate from the spinal cord
|
|
Cranial nerves
|
Nerves which originate from the brain
|
|
Afferent neurons
|
Neurons which transmit action potentials from the sensory organs to the CNS
|
|
Efferent neurons
|
Neurons which transmit action potentials from the CNS to the effector organs
|
|
action potential
|
is an electrical signal that travels along a neuron
|
|
Somatic motor nervous system
|
The system that transmits action potentials from the CNS to the skeletal muscles
|
|
Autonomic nervous system
|
The system that transmits action potentials from the CNS to the smooth muscles, cardiac muscles, and glands
|
|
Sympathetic division
|
Division of the ANS that generally prepares the body for physical activity
|
|
When you touch a hot stove, you immediately pull your hand away to avoid being seriously burned. Which system of the PNS (efferent or afferent) is utilized first in this situation?
|
afferent
|
|
When you flex your forearm, which division of the PNS (efferent or afferent) is being used?
|
efferent
|
|
What would be the most specific way to describe the part of the PNS that is being used when you flex your forearm?
|
somatic motor nervous system (SMNS).
|
|
soma
|
cell body houses the cell nucleus.
|
|
Dendrites
|
are receptive to stimuli and bring stimuli from the environment (sensory epithelial cells or other neurons) to the cell body. There are usually several dendrites per neuron.
|
|
Perikaryon
|
(cell body) is also receptive to stimuli, but also serves as the trophic or synthesizing center for the whole nerve
|
|
Axon hillock
|
Where the action potential begins and the area that marks the end of the cell body and the beginning of the axon. Once an action potential begins here, it will be conducted all the way down to the far end of the axon.
|
|
myelin sheath
|
which is a fatty wrapping that actually speeds up the transmission of the action potential down the axon.
|
|
neuroglia
|
specialized cells that produce myelin sheaths.
|
|
Schwann cells
|
neuroglia in the PNS
|
|
oligodendrocytes
|
neuroglia in the CNS
|
|
nodes of Ranvier
|
gaps in the myelin sheath
|
|
Collaterals with telodendria
|
Axons can split into collateral axons, and they end by branching into presynaptic terminals, which are also called terminal boutons
|
|
unipolar neuron
|
it really has only one process, and the cell body “hangs” off of that process
|
|
pseudo dendrite
|
it does what a dendrite does (sends signals towards the cell body), it sends signals the way that an axon does.
|
|
bipolar neuron
|
have two processes: an axon and a single dendrite split into many branches
|
|
multipolar neuron
|
has many processes: several dendrites but only one axon
|
|
Association neuron
|
A neuron that conducts action potentials from one neuron to another neuron within the CNS
|
|
A signal is traveling down the process of a neuron. It is traveling in the same direction as another signal in another process of that same neuron. Is this signal traveling towards or away from the cell body?
|
to the cell body
|
|
An axon has a myelin sheath produced by a Schwann cells. Is this neuron in the PNS or CNS?
|
PNS
|
|
what are the four types of neuroglia in the CNS?
|
Ependymal cells
Related to cerebrospinal fluid Astrocytes Largest and most numerous Oligodendrocytes Myelination of CNS axons Microglia Phagocytic cells |
|
What are two types of neuroglia in the PNS?
|
Satellite cells
Surround neuron cell bodies within ganglia Schwann cells Ensheath axons in the PNS |
|
Ependymal cells (function)
|
1. Line venticles (brain)& central canal (spinal cord)
2. Assist in producing, circulating & monitoring of cerebrospinal fluid. |
|
Astrocytes (function)
|
1. Maintain blood brain barrier.
2. Provide structural support. 3. Regulate ion, nutrient & dissolved gas caoncentration. 4. Absorb & re-cycle neurotransmitters. 5. Form scar tissue after injury. |
|
Oligodendrocytes (function)
|
1. Mylenate CNS axons.
2. Provide structural framework. |
|
Microglia (function)
|
1. Remove wastes, cell debris, and pathogens via phagocytosis.
|
|
Satellite cells (function)
|
1. Surround neuron cell bosies in ganglia.
2. Regulate O2, CO2, nutrient and neurotransmitter levels around neurons in ganglia. |
|
Schwann Cells (function)
|
1. Surround axons in PNS.
2. Mylenate peripheral axons. 3. Participate in repair process after injury. |
|
Endoneurium
|
a thin connective tissue layer surrounding each individual fiber
|
|
Epineurium
|
is a more extensive connective tissue layer between the bundles and extending to the most peripheral parts of the nerve.
|
|
Perineurium
|
Fibers are grouped in bundles, which are also surrounded by a connective tissue layer.
|
|
Sensory nerves
|
Nerves possessing only sensory fibers.
|
|
Motor nerves
|
nerves possessing only motor fibers.
|
|
Mixed nerves
|
Nerves that possess both sensory and motor fibers.
|
|
A group of axons bundled together is severed and does not heal. There are two possible reasons. What are they?
|
the axons are in the CNS or the two severed ends were not lined up well
|
|
Carpal tunnel syndrome is a problem resulting from pressure in the flexor retinaculum which compresses the median nerve, a nerve that is about the thickness of a shoestring and is found in the wrist. When that nerve doesn't function properly, the grip gets weak and the hand goes numb. Is the median nerve a motor nerve, a sensory nerve, or a mixed nerve?
|
mixed nerve
|
|
Suppose the membrane suddenly became very permeable to sodium ions. What would happen to the potential difference between the inside and outside of the axon?
|
The potential difference would become less negative
|
|
Excitability
|
The ability to create an action potential in response to a stimulus
|
|
Potential difference
|
A measure of the charge difference across the cell membrane
|
|
These simple rules create the resting potential:
|
1) Concentration gradient moves ions from high to low concentration
2) Electrical force moves ions with same charge away from each other and ions with opposite charge towards each other. 3) Na+/K+ pump moves Na+ to the extracellular space. It can't get back in because the membrane is impermeable to Na+. 4) The membrane is permeable to K+ (i.e., it flows either way) 5) Large negatively charged proteins (A-) are stuck inside the neuron Na+ and K+ are driven intracellularly to A- by the electrical force. The concentration gradient is going to push Na+ intracellularly and K+ extracellularly. The Na+/K+ pump is going to move Na+ extracellularly. |