Nervous Tissue Flashcards
parts of CNS rich in cell bodies but limited numbers of myelinated axons
Grey Matter
region rich in myelinated axons
White Matter
Components of the CNS with ectodermal origin.
What are these cells sensitive to?
Neurons
Astrocytes
Oligodendrocytes
Hypoxia
Components of the CNS with mesodermal origin.
How do these cells differ from those of ectodermal origin?
Microglia
Vascular endothelium
Not sensitive to hypoxia
Cell bodies in the PNS
Ganglia
Cell bodies in the CNS
Nuclei
How can you tell the approx. age of a neuron?
By the amount of the wear and tear pigment lipofuscin
Other names for a neuron’s cell body
perikaryon, soma
Neuron soma characteristics
Euchromatic nucleus
prominent nucleolus
Basophilic cytoplasm
What are the three shapes that a perikaryon (cell body) can have and where would you find each type?
1) Round or oval (pyriform) – pseudounipolar neurons – Purkinje cells in cerebellum 2)Pyramidal (pyramid shaped) – in brain cortex 3)Stellate – multipolar motor neurons in spinal cord
The distal branch of a neuronal axon that can further branch into multiple axon terminals
Telodendron
a synapse between the axon of one neuron and the cell body of another.
axosomatic
synapse between the axon of one neuron and the dendrites of another.
axodentritic
synapse between the axon of one neuron and the axon of another.
axoaxonic
Synaptic vesicles that are small, pale and round contain what neurotransmitter?
acetylcholine
Synaptic vesicles that are pale and oval contain what neurotransmitter?
GABA or glycine
Synaptic vesicles that are large with a dense core contain what neurotransmitter?
norepinephrine & epinephrine
2 receptors with free (naked) nerve endings
Nociceptors
thermoreceptors
5 receptors with encapsulated nerve endings
MEISSNER’S CORPUSCLE KRAUSE CORPUSCLE PACINIAN CORPUSCLE GOLGI ORGAN MUSCLE SPINDLE
Encapsulated mechanoreceptor
for deep pressure.
What appearance will these have?
Pacinian corpuscle
onion appearance
Proprioceptive sensory receptor organ/senses stretching
Located at the insertion of skeletal muscle fibers into the tendons
Golgi tendon organ, neurotendinous organ or neurotendinous spindle
specialized sensory receptor for muscle stretch and position sense, unconscious maintenance of skeletal muscle tone and proper balance of postural muscle activity
muscle spindle
functions of an astrocyte
Transport of Nutrients Maintenance of extracellular matrix ion content Neurotransmitter uptake Part of blood brain barrier Antigen presentation
2 types of astrocytes and where they’re found
Protoplasmic (grey matter)
Fibrillar (white matter)
Small dark nuclei (between myelin sheaths or around neurons)
Develop and maintain myelin in CNS
Can be destroyed by viruses/toxins resulting in primary demyleination
Oligodendrocytes
_________ is derived from blood-borne monocyte
Resident macrophage of CNS
When activated during necrosis or inflammation, they are called _________.
Microglia (microgliocytes)
Gitter Cells
Ciliated cubodial cells lining neural canal, ventricles, choroid plexus
Formation of CSF
Ependymal Cells
Capillaries with overlying ependymal cells form ___________ and produce ___________.
choroid plexus
cerebrospinal fluid
Myelin is snthesized by _________ in the CNS, and ____________ in the PNS.
What is the positional difference between the two?
oligodendrocytes
Schwann cells
Oligos connect to multiple internodes, Schwann cells to 1
White matter contains myelinated ______ and ________, and is located _______ in the spinal cord and _______ in the brain.
myelinated axons and glial cells
peripheral in spinal cord
central in brain
Complex phospholipid, lamellar arrangement around axon Galactocerebroside protein
Myelin
_________ contains neurons, glial cells, and axons, is peripheral in brain, central in spinal cord
Grey matter
In the cerebrum elevations are _______, depressions are _______
gyri
sulci
Cerebrum grey matter arises from the _____________
prosencephalon
Layers of the cerebral cortext neo cortex
L. zonalis L. granularis externa L. pyramidalis externa L. granularis interna L. pyramidalis interna L. multiformis
________ is the portion of the brain involved with laying down memory tracks.
Very sensitive to ________ and _________.
Contains numerous ________ receptors
hippocampus and dentate gyrus
hypoxia
hypoglycemia
glutamate
elevations of cerebellar parenchyma
Folia
depressions separating folia
Sulci
3 layers of the cerebellum cortex
Molecular layer
Purkinje cell layer
Granular cell layer
Which part of the brain coordinates body movements
Cerebellum
The ________ is the cerebellar white matter, located deep in the cerebellum. It brings ________ and _______ information to and from the cerebellum.
arbor vitae
sensory
motor
What are the 4 layers of the cortex cerebelli grey matter, and what do they contain?
stratum moleculare-basket cells
stratum gangliosum-Purkinje cells
stratum granulosum-granule cells
White matter core-myelinated nerve fibers
____________ of ___________ are the ONLY nerve fibers leaving cerebellum
Efferent axons
Purkinje cells
_____________ is a disorder where the cerebellum of the brain has not fully formed. There are various causes such as bacterial or viral infections, feline panleukopenia, caused by feline parvovirus, but can also be caused by poisoning, injury or malnutrition.
Cerebellar Hypoplasia
The brain stem contains collections of neurons known as
________ , e.g. “Dorsal and ventral ________________
Nuclei
respiratory groups
____________ is the principal control center of the hypophysis (pituitary gland)
Hypothalamus
Spinal cord grey matter dorsal horns contain __________ and ________.
sensory neurons and glia
Spinal cord intermediate grey matter contains ___________.
autonomic neurons
Spinal cord grey matter ventral horns contain __________ and ________.
motor neurons and glia
__________ - in dorsal horns, axons go in dorsal funicles to brain
Funicular neurons
_____________ – small nerve cells with short axons which do not leave gray matter
Associating neurons
Membranous coverings of brain and spinal cord
meninges
3 layers of the meninges
Dura mater
Arachnoid
Pia mater
outermost layer of the meninges
Dura mater
membrane attached to the dura mater
Arachnoid membrane
Layer of meninges that is highly vascular, adherent to brain and spinal cord
Pia mater
__________ is a transudate, formed by capillaries and ependymal cells, the choroid plexuses of the lateral, 3rd & 4th ventricles of the brain
cerebrospinal fluid
A cluster of arborizing blood vessels covered by a thin connective tissue and ependymal cells
Site of CSF production
Choroid Plexus
The ___________________ are the site of CSF Drainage
arachnoid granulations/villi
The _____________ is a layer of delicate connective tissue around the myelin sheath of each myelinated nerve fiber
endoneurium
Nerve fibers are bundled into groups called nerve fascicles, each fascicle within its own protective sheath called a _____________.
perineurium
In sufficiently large nerves multiple fascicles, each with its blood supply and fatty tissue, may be bundled within yet another sheath, the ___________.
epineurium
