BIOL 324: Nervous Tissue 2
gray matter middle layer of the cerebellum that consists of a certain type of large, multipolar cells
Purkinje (neuron layer)
cells that compose the myelin sheath in the PNS, the nuclei of which stain darker purple than axons and can sometimes be seen
Schwann cells (white arrow heads in image)
non-vascular meningeal layer lining the dura consisting of fine white and yellow fibers (loose CT) that form columns elevating this layer from the brain surface; covered throughout with simple squamous epithelium (mesothelium)
arachnoid
type of macroglial star-shaped cells (most numerous glial cells) with many cytoplasmic processes, can be protoplasmic or fibrous; responsible for repair and scarring cells of sclerosis, regulating interstitial fluid environment, and maintaining the blood brain barrier
astrocytes
series of ganglia connected together parallel to the spinal cord composed of multipolar neurons, deep in the body cavity
autonomic ganglia
refers to the capillaries in the central nervous system being exceedingly tight, meaning they aren't very permeable to solutes in the blood plasma
blood brain barrier
The dura mater has lots of what kind of fibers?
cartilage
Is gray matter on the surface or center of the spinal cord?
center
Is white matter on the surface or center part of the brain?
center
fluid secreted by choroid plexi into ventricles and in the central canal of the spinal cord that circulates around the subarachnoid space
cerebrospinal fluid
substance found within the hollow central canal of the spinal cord, in the middle of the gray matter
cerebrospinal fluid
Which major region of the brain consists of multiple layers of pyramidal neurons in its gray matter?
cerebrum
region of the brain responsible for sensory functions, thought, consciousness, memory, and gross motor control, has multiple layers of pyramidal neurons in gray matter
cerebrum
Where do sympathetic nervous system fibers originate? (3)
cervical, thoracic, lumbar spinal nerves
What secretes cerebrospinal fluid?
choroid plexus
cluster of modified ependymal cells that actively secrete cerebrospinal fluid
choroid plexus
Where do parasympathetic nervous system fibers originate? (2)
cranial nerves, sacral spinal nerves
sensory ganglia in the dorsal root of all spinal nerves composed of pseudounipolar neurons
dorsal root ganglia
meningeal layer that is actually two layers around the brain, consisting of an outer, periosteal layer of DICT next to skull bones and a less vascular fibrous layer next to the arachnoid layer
dura mater (tough mother)
area of connective tissue immediately surrounding a neuron
endoneurium
tall, columnar-shaped neuroglial lining cells of the CNS central canal; ciliated when younger, brush border in adult stage
ependyma
area of connective tissue surrounding a whole nerve
epineurium
True or false: Neuroglia are found in both the central and peripheral nervous system, though mostly central.
false (ONLY central)
refers to a group of axons (also a group of muscle fibers)
fascicle
The imaging of different cells in the brain can be clearly visualized with what technique?
fluorescent microscopy
refers to a collection of nerve cell bodies in the peripheral nervous system
ganglion
The small nuclei surrounding multipolar neurons in the spinal cord belong to what kind of cells?
glial cells
Silver staining in the cerebrum can be used to clearly visualize what two kinds of cells?
glial cells, pyramidal neurons
gray matter inner layer of the cerebellum that consists of many small granulated multipolar neurons with small nerve cell bodies
granular (neuron layer)
Which type of matter has large multipolar neurons: white or gray?
gray
Capillaries are adjacent to neurons only in what part of the brain?
hypothalamus
Why is white matter so light in appearance?
includes myelinated axons of nerves
Do parasympathetic nerves have short or long preganglionic fibers? Short or long postganglionic fibers?
long preganglionic, short postganglionic
procedure in which a needle is inserted between the L3 and L4 vertebrae in order to extract cerebrospinal fluid via positive pressure Normally, there shouldn't be much protein or WBCs in CSF, so any abnormalities can be detected with this procedure.
lumbar puncture
Astrocytes and oligodendrocytes are two types of what kind of nerve cell?
macroglia
What are the three categories of neuroglia?
macroglia, ependyma, microglia
three protective membranes that surround the brain and spinal cord
meninges
What is the only nerve cell of mesodermal origin?
microglia
type of neuroglia that are the only nerve cells of mesodermal origin, similar to fibroblasts; found along blood vessels and around nerve cell bodies in gray matter as satellite cells **least numerous neuroglial cells, phagocytic
microglia
gray matter outer layer of the cerebellum that consists of small, multipolar neurons with small nerve cell bodies and many non-myelinated neurons
molecular (layer)
What are the three layers of the gray matter of the cerebellum from outer to inner?
molecular, Purkinje, granular
Are autonomic ganglia nerve cell bodies unipolar or multipolar?
multipolar
fairly large neurons found in gray matter, can be sympathetic motor or somatic motor
multipolar neurons
Most, but not all, axons of a neuron are surrounded by what?
myelin sheath
refers to a collection of neurons (axons) in the peripheral nervous system
nerve
Blood vessels do NOT come into contact with neurons in the central nervous system; only what kind of cells?
neuroglia
cells that bind and support neurons and shape the central nervous system
neuroglia
What three components make up ganglia?
neuron cell bodies, glial cells, reticular fibers
refers to a collection of nerve cell bodies in the central nervous system
nuclei
type of macroglial cells with few cytoplasmic processes, typically found in white matter in rows enveloping myelinated neurons; in gray matter, they are found around nerve cell bodies as satellite cells **1 cell produces myelin for several neurons
oligodendrocytes
Autonomic ganglia on the surface of or in target organs are part of what division of the nervous system?
parasympathetic
area of connective tissue surrounding a fascicle of neurons
perineurium
meningeal layer consisting of delicate loose CT (with many blood vessels) over the brain and spinal cord surface, follows the contours of the brain
pia mater (intimate mother)
What are the three meninges in order from inner to outer?
pia, arachnoid, dura
The cerebrum consists of multiple layers of what kind of characteristic cells in gray matter?
pyramidal neurons
What are the three main functions of astrocytes?
regulate interstitial fluid environment, maintain blood brain barrier, tissue repair and scarring
The dark staining areas surrounding the nuclei of multipolar neurons have a high density of what organelles? What are they called?
ribosomes, Nissl bodies
What is the histological structure of dorsal root ganglia?
round nerve cell bodies clumped to one side, prominent fiber bundles in between
Do sympathetic nerves have short or long preganglionic fibers? Short or long postganglionic fibers?
short preganglionic, long postganglionic
The arachnoid meningeal layer is covered throughout with what kind of tissue?
simple squamous epithelium (mesothelium)
space beneath the arachnoid meningeal layer filled with cerebrospinal fluid, highly vascularized
subarachnoid space
Is gray matter on the surface or center part of the brain?
surface
Is white matter on the surface or center part of the spinal cord?
surface
Autonomic ganglia in the deep body cavity are part of what division of the nervous system?
sympathetic
refers to a collection of neurons (axons) in the central nervous system
tract (white matter)
How many pairs of cranial nerves are there?
12
How many pairs of spinal nerves are there?
31
If the average brain weighs 1500 g, how much of that is CSF?
50 g
Anything over about what size isn't permeable in CNS capillaries?
500 Da
About how much cerebrospinal fluid is secreted a day? However, how much exists at any given time in our body?
500 mL, 150 mL
Are dorsal root ganglia nerve cell bodies unipolar or multipolar?
unipolar