Physio Nervous System 6

True

(T/F): A depolarizing graded potential can cause an action potential.

False

(T/F): At resting membrane potential, voltage-gated potassium ion channels are open.

True

(T/F): During the transmission of action potential along a myelinated axon, as one neurofibril node is depolarizing, the pervious node is repolarizing.

False

(T/F): Ganglia are clusters of neuron cell bodies located within the CNS.

False

(T/F): Glial cells help neurons by generating action potentials.

True

(T/F): Grade potentials can result from voltage across the plasma membrane.

True

(T/F): Graded potentials can result from mechanical stimulation or temperature changes.

True

(T/F): If extracellular concentration of potassium are increased dramatically, a neuron may be able to repolarize during an action potential.

True

(T/F): In neurons, protein pumps allow substances to move passively down their concentration gradients.

True

(T/F): Increased permeability of the membrane to sodium results in depolarization.

False

(T/F): Individual EPSPs and IPSPs determine whether or not a neuron fires and the rate of firing by stimulating or inhibiting the production of more action potentials.

True

(T/F): Inhibitory postsynaptic potentials (IPSPs) may be caused by the opening of either chemically gated potassium channels or chemically gated chloride channels.

False

(T/F): Neurons are unique in that they do not require glucose or oxygen to function.

True

(T/F): On a typical neuron, the axon is usually longer in length than the dendrites.

True

(T/F): Postsynaptic neurons can generate both inhibitory and excitatory postsynaptic potentials simultaneously.

True

(T/F): Sodium has a higher concentration outside the cell than within.

True

(T/F): The effects produced by one graded potential can be added onto the effects of another graded potential.

False

(T/F): The endoneurium wraps around groups of fascicles to form a nerve.

True

(T/F): The entry of sodium ions into the postsynaptic neuron causes depolarization.

True

(T/F): The leakage of potassium plays a more significant tole in the resting membrane potential than the leakage of sodium.

True

(T/F): The potential change can vary from small to large depending on the stimulus strength or summation.

Temporal Summation

-A single presynaptic neuron releases neurotransmitter. -The same location of neuron is exposed to neurotransmitter in a very short period of time.

Microglia

-Cells of the lymphatic system. -Macrophages of the CNS.

Ependymal and CNS

-Line the ventricles of the brain. -Form the choroid plexuses. -Have cilia that help move cerebrospinal fluid.

Astrocytes

-Most abundant CNS glial cells. -Involved with neurogenesis, scar formation, and blood-brain barrier maintenance. -starlike in shape and helps form the blood-brain barrier

Spatial Summation

-Various locations of recpetive segment are exposed to neurotransmitter. -Multiple presynaptic neurons releasing neurotransmitter. -Can generate an EPSP, IPSP, or both.

Astrocytes and CNS

-Vital for synapse formation. -Take up neurotransmitters. -Play an energy supporting role.

Multipolar Neuron

-many dendrites and a single axon -most common type; innervate muscles and glands

Bipolar Neurons

-one dendrite and one axon -special senses

Unipolar Neuron

-one process with two branches; one extending to the CNS, one extending to the periphery -most neurons in the PNS

Absolute refractory period.

A recently depolarized area of a cell membrane cannot generate an action potential because of the...?

Synaptic Cleft

A typical synapse in the CNS consists of a presynaptic neuron and a post synaptic neuron, separated by a narrow space called the?

Extracellular fluid.

Activation gates in the cell membrane for voltage-gated sodium ion channels open into the...?

Faster

An axon with a large diameter transmits an impulse ______ than an axon with a smaller diameter.

The postsynaptic neuron's membrane potential to become more positive.

An excitatory postsynaptic potential (EPSP) causes...?

Will make it more difficult for the postsynaptic neuron to reach threshold.

An inhibitory postsynaptic potential (IPSP)...?

Sodium ions enter the cell.

As a result of a neurotransmitter opening up chemically gated sodium channels on the postsynaptic membrane...?

Central Nervous System

Consists of the brain and spinal cord.

More positive.

Depolarization is initiated by a stimulus that makes the membrane potential...?

Cerebrospinal fluid

Ependymal cells help produce...?

Oligodendrocytes and CNS

Form myelin sheaths around several axons.

Oligodendrocytes

Form the myelin sheath in the CNS.

Neurolemmocytes

Form the myelin sheath in the PNS.

Ependymal Cells

Function in the production and circulation of the cerebrospinal fluid.

The membrane potential would be about -90 millivolts.

If all the sodium leakage channels were removed from the cell membrane of a neuron...?

Vesicles containing neurotransmitters would not merge with the plasma membrane.

If extracellular calcium was absent, which would likely be true?

Peripheral Nervous System

Includes cranial nerves, spinal nerves, and ganglia.

Plasma Membrane

Myelin sheaths mainly consist of which part of glial cells that form them?

Peripheral

Neurolemmocytes produce myelin in the _______ nervous system.

Efferent

Neurons that carry signals from the CNS to skeletal muscle for contraction would be classified as ________ neurons.

Excitatory Postsynaptic Potentials (EPSPs)

On a graph of an action potential, the small depolarizations that leads to threshold are from...?

1. Depolarization 2. Repolarization 3. Hyperpolarizationn

Order action potential travels.

Satellite Cells

PNS cells that surround an insulate the somas.

Afferent

Pain receptors in the skin send signals to the CNS for processing, These pain receptors are an example of _________ neurons.

Microglia and CNS

Phagocytize miuoorganisms.

More Abundant in Cytosol.

Phosphate, Negatively Charged Proteins, and Potassium

More Abundant in ISF.

Sodium and Potassium

Absolute Refractory Period

The ________ is a period when a membrane cannot respond to another stimulus (no matter how strong).

Sensory, Motor

The __________ nervous system transmits information from receptors to the CNS, while the ___________ nervous system transmits information from the CNS to the rest of the body.

Multipolar

The most common type of neuron contains many dendrites and a single axon. Structurally, this is classified as a(n) __________ neuron.

There are more negatively charges particles on the inside of the membrane that on the outside.

The negative value of the resting membrane potential means that?

1. Dendrites 2. Soma 3. Axon Hillock 4. Neurofibril Node 5. Synaptic Knobs

The order in which an electrical impulse through structures beginning with the postsynaptic membrane.

Mixed

The vagus nerve contains afferent and efferent neurons; therefore it is an example of a ______ neuron.

3, 5, 1, 4, 2

What is the correct order for events of neurotransmitters release from the synaptic terminal? 1. Extracellular Ca2+ enters terminal and binds to sensor protein in the cytoplasm. 2. Exocytosis of neurotransmitters into synaptic cleft. 3. Action potential reaches axon terminal. 4. Ca2+ protein complex stimulates fusion of the docked synaptic vesicle with the plasma membrane. 5. Voltage-gated Ca2+ channels open.

Oligondendrocytes

What types of cells produce the myelin sheath in the central nervous system (CNS)?

Chemically Gated Sodium Channel

When a neurotransmitter binds a protein channel, it opens and lets sodium diffuse down its concentration gradient. This is an example of a?

Positive

When sodium enters the neuron via chemically gated sodium channels, the membrane will depolarize. Therefore, the membrane potential will become more...?

Microglial Cells

Which glial cell acts as a phagocytes?

Synaptic Bulbs

Which part of a neuron contains calcium pumps and channels?