Lab 10

The odd tingling sensation that you experiences when you hit the funny bone is due to trauma to the ________ nerve. - axillary - ulnar - radial - median

- ulnar

Sensory or afferent neurons are typically of this type. - unipolar - multipolar - bipolar

- unipolar

How many pairs of spinal nerves do humans have? - 10 - 12 - 31 - 47

- 31

Neurons can be classified according to function. __________ or motor neurons carry electrical signals from the central nervous system primarily to muscles or glands. - Afferent - Efferent

- Efferent

The cell bodies of sensory neurons are found in an enlarged area of the dorsal root called the gray commissure. - True or False

- False

The femoral nerve is the largest nerve from the sacral plexus. - True or False

- False

Neurons can be classified according to structure. __________ neurons have many processes that issue from the cell body. - Bipolar - Unipolar - Multipolar

- Multipolar

__________ are the functional units of nervous tissue.

- Neurons

The formation of myelin in the peripheral nervous system is accomplished by these cells. - Schwann cells - satellite cells - astrocytes -oligodendrocytes

- Schwann cells

Axons are the neuron processes that generate and conduct nerve impulses. - True or false

- True

Because the spinal nerves arise from fusion of the ventral and dorsal roots of the spinal cord, and contain motor and sensory fibers, all spinal nerves are considered mixed nerves. - True or False

- True

You have lost the sensation, but not movement, in one of your hands due to a problem with your spinal cord neurons. Based upon these symptoms, what type of neuron was most likely affected? - motor and sensory neurons - afferent neuron - motor neuron - efferent neuron

- afferent neuron

This part of the neuron generates and conducts action potentials. - axon - dendrite - cell body

- axon

The ________ forms synapses, or junctions, with other neurons or effector cells. - synaptic cleft - axon hillock - initial segment - axon terminal

- axon terminal

This type of sensory neuron is quite rare. - bipolar - multipolar - unipolar

- bipolar

The following represents a collection of spinal nerve roots hanging from the inferior end of the spinal cord. - denticulate ligament - filum terminale - cauda equina - dorsal roots

- cauda equina

At an axon terminal, the electrical signal from one cell ________. - is transmitted directly to the next cell by strands of membrane - jumps from the axon terminal to the next cell - causes the release of chemical neurotransmitter molecules that cause an electrical signal in the next cell - ends and the signal it carried is not transmitted to another cell

- causes the release of chemical neurotransmitter molecules that cause an electrical signal in the next cell

Axons give rise to branches called ________. - axon terminals - collaterals - initial segments - dendrites

- collaterals

The sciatic nerve divides into the tibial and __________ nerves. - posterior femoral cutaneous - common fibular

- common fibular

A nerve ________. - consists of entire neurons - dendrites, cell bodies, and axons - is found only in the CNS - consists of axons wrapped in connective tissue in the PNS

- consists of axons wrapped in connective tissue in the PNS

In addition to its role in spinal reflex activity, the spinal cord also ________. - controls movement of the limbs - perceives sensation - contains sensory and motor tracts traveling to and from higher nervous centers - is associated with consciousness

- contains sensory and motor tracts traveling to and from higher nervous centers

At the level of the first or second lumbar vertebra the spinal cord terminates in a structure called the ________. - denticulate ligament - dura mater - filum terminale - conus medullaris

- conus medullaris

The spinal cord extends from the foramen magnum of the skull to the first or second lumbar vertebra, where it terminates in the __________. - gray matter - denticulate ligament - conus medullaris - filum terminale

- conus medullaris

These branching neuron processes serve as receptive regions and transmit electrical signals toward the cell body. They are __________. - collaterals - dendrites - axons - neuroglia

- dendrites

Somatosensory functions are carried out in this part of the spinal cord. - dorsal white columns and dorsal horns - ventral fiber tracts and ventral horns -lateral fiber tracts and lateral horns - lateral and ventral fiber tracts and ventral horns

- dorsal white columns and dorsal horns

The meninges that cover the spinal cord from outermost to innermost are ________. - dura mater, pia mater, arachnoid mater - pia mater, arachnoid mater, dura mater - dura mater, arachnoid mater, pia mater - arachnoid mater, dura mater, pia mater

- dura mater, arachnoid mater, pia mater

Within a nerve, each axon is surrounded by a covering called the __________. - endoneurium - epineurium - perineurium

- endoneurium

The outermost connective tissue covering of a nerve is called the ________. - epineurium - perineurium - endoneurium

- epineurium

This extension of one of the meninges covering the spinal cord attaches it to the coccyx. - dura mater - conus medullaris - filum terminale - denticulate ligament

- filum terminale

A cluster of neurons in the peripheral nervous system is called a ________. - fasciculus - nucleus - ganglion - pod

- ganglion

In cross section, the __________ matter of the spinal cord looks like a butterfly or the letter H. - white - gray

- gray

Myelin is important in ________. - allowing electrical signals to be transferred from one axon to another adjacent axon - maintaining the ionic balance in the environment surrounding the axon - absorbing damaged tissue or invading organisms - insulating axons and increasing the conduction velocity of action potentials

- insulating axons and increasing the conduction velocity of action potentials

Which of the following is NOT required for a reflex arc? - interneurons - motor neurons - receptors - sensory neurons

- interneurons

These horns of the spinal cord are present only in the thoracic and lumbar regions. - dorsal - ventral - lateral

- lateral

Nerves serving the lower limb issue from this enlargement of the spinal cord. - sacral - cervical - thoracic - lumbar

- lumbar

The spinal nerves are ________ nerves. - sensory - motor - mixed

- mixed

Ventral roots of spinal nerves are purely or primarily ________. - motor -mixed sensory and motor - sensory

- motor

These neurons transmit impulses from CNS to effectors. - sensory neurons - motor neurons - interneurons

- motor neurons

Most axons are covered with a fatty material called __________ , which insulates the fibers and increases the speed of neurotransmission.

- myelin

The gaps in the sheath that insulates axons are called ________. - gaps of Schwann - outer collar of perinuclear cytoplasm - myelin sheath gaps - myelinated fibers

- myelin sheath gaps

These nervous system cells are highly specialized to transmit messages throughout the body. - microglial cells - neurons - oligodendrocytes - astrocytes

- neurons

Vesicles in the axon terminal contain ________. - neurotransmitters - chromatophilic substance - Ca2+ - digestive enzymes

- neurotransmitters

This nerve, arising from the cervical plexus, is essential for normal breathing. - transverse cervical - greater auricular - lesser occipital - phrenic

- phrenic

The ventral rami of all spinal nerves except T2 through T12 form complex networks of nerves known as __________. - ganglia - plexuses - sulci - fissures

- plexuses

This nerve of the brachial plexus supplies all the extensor muscles of the upper limb. - ulnar - radial - median - musculocutaneous

- radial

Neuroglia of the peripheral nervous system include __________. - ependymal cells and satellite cells - oligodendrocytes and astrocytes - satellite cells and Schwann cells

- satellite cells and Schwann cells

Fiber tracts conducting impulses to the brain are called ascending or __________ tracts. - sensory or motor

- sensory

What functional type of neuron is found in the dorsal root ganglion? - both sensory and motor - motor - sensory - There are only interneurons in the dorsa root ganglion.

- sensory

Cell bodies of these neurons lie in ganglia in the peripheral nervous system (PNS). - interneurons - motor neurons - sensory neurons

- sensory neurons

The dorsal rami of spinal nerves ________. - serve the muscles of the intercostal spaces and skin and muscles of the anterior trunk - form nerve plexuses that serve the limbs - serve the skin and muscles of the posterior body trunk

- serve the skin and muscles of the posterior body trunk

Neuron fibers (axons) running through the central nervous system form __________ of white matter. - nerves - tracts

- tracts

Functional classification of neurons is based on ________. - the length of the axon - the shape of the neuron - whether the signal carried is traveling toward or away from the CNS - the number of processes coming off the cell body

- whether the signal carried is traveling toward or away from the CNS