50 terms

A&P chapter 12-13 review

In the spinal cord, white matter is separated into ascending and descending tracts organized as
The outward projections from the central gray matter of the spinal cord are called
The outermost connective tissue covering the nerves is the
The complex, interwoven network formed by contributions from the ventral rami neighboring spinal nerves is termed
Reflexes based on synapses formed during development are the ______ reflexes
The reflex that prevents a muscle from exerting too much tension is the ___ reflex
The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the
Small wandering cells that engulf cell debris and pathogens in the CNS are called
Which of the following is not recognized structural classification for neurons
The most abundant class of neuron in the central nervous system
The cytoplasm that surrounds the nucleus of a neuron is called the
The axon is connected to the soma at the
Axon hillock
Axons terminate in a series of fine extensions known as
Terminal arborization
The site of intercellular communications between neurons is the
The rabies virus travels to the CNS via
Retrograde axopladmic transport
Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called
Neurons that have several dendrites and a single axon are called
Which of the following activities or sensations is not monitored by the interoceptors
At the normal resting potential of a typical neuron, its Na-K ion exchange pump transports
sodium and potassium
Ion channels that are always open are called ____ channels
Passive (leak) channels
The layer of the meninges in direct contact with the spinal cord is the
pia mater
If the dorsal root of a spinal nerve is severed
loss of sensory (organs)
Samples of the CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the
subarachnoid space in the lumbar portion
In which of the following would the delay between stimulus and response be greater?
in an adult, the conus medullaris is found at about
terminal end of the spinal cord, near L1, L2
The posterior horns of the spinal cord contain mainly
somatic and visceral sensory nuclei
The anterior horns of the spinal cord contain maily
somatic motor nuclei
Cerebrospinal fluid flows within the
central canal, subarachnoid
The all-or-nothing principle states that
a given stimulus either triggers a typical action potential or none at all
Which of the following types of nerve fiber possesses the fastest speed of impulse propagation
Type A
The ion that triggers the release of acetylcholine into the synaptic cleft is
When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?
temporary summation
The _____ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament
filum terminale
The spinal cord consists of five regions and ___ segments
Blood vessels that supply the spinal cord run along the surface of the
meninges, pia mater
Axons crossing from one side of the spinal cord to the other within the gray matter are found in the
gray commissures
The dorsal root of a spinal nerve contains
axons of sensory neurons
A dorsal and ventral root of each spinal segment unite to form a
spinal nerve
Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in the lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compresses?
lumbar L1-L5
Bill contracts a viral disease that destroys cells in the posterior gray horns in his spinal cord. As a result, which of the following would you expect?
The ventral rami form four major plexuses, including all of the following except the
1. cervical plexus 2. brachial plexus 3 lumbar plexus 4. sacral plexus
As the _______ nerve approaches the knee, it divides into two branches, the fibular nerve and the tibial nerve
Which of the following is not a function of the nervous system
The part of the peripheral nervous system that carries sensory information to the CNS is designated
afferent division of the PNS carries impulses inward to central organs, and the nerves that conduct impulses from periphery to brain/spinal cord
Functions of astrocytes include all of the following except
1. maintain blood/brain barrier 2 create 3D framework for CNS 3 repair damaged neural tissue
Clusters of RER and free ribosomes in neurons are called
Neurons that have one axon and one dendrite, with the soma in between, are called
The following are the main steps in the generations of an action potential. The proper sequence of these event
1 depolarization of threshold 2 activation of Na channels and rapid depolarization 3 inactivation of Na and activation of K channels 4 closing of K channels
Which of the following is not a function of the neuroglia
1. separate and protect neurons, supportive framework for neural tissue, act as phagocyte, help regulate the composition of the interstitial fluid
The myelin sheath that covers many CNS axons is formed by