Lecture 6 Nervous Tissue Flashcards
Motor neurons and interneurons are examples of _____ neurons
multipolar
Bipolar neurons have 1 dendrite and axon and include retina and _______ receptor neurons
olfactory
______ neurons consist of one branch extending to the CNS and the other to a peripheral ending
Pseudounipolar
the ______ _______ mechanism is the initial segment of an axon (also called axon hillock)
impulse initiating
Nissl bodies are found in cell bodies of neurons and are highly developed ______
rER
The ______ ______ will have a clear appearance near the exit from a soma
axon hillock
Plasma membrane of the axon is the _____. The cytoplasm of an axon is called _____
axolemma
axoplasm
_____ can transport enzymes, proteins, and NTs in the orthograde direction of an axon
Kinesin
____ can transport organelles and vesicles in the retrograde direction. Retrograde flow can carry ____ and toxins along the axon into the CNS
Dynein
viruses
Dendrite cytoplasm lacks _____
golgi
______ spines are specialized for synaptic contact
dendritic
NT binding a receptor on the post synaptic membrane causes this ion channel to open:
Na
The left-over NT can be enzymatically degraded in the clef or taken up via ______ _____ ______ and degraded
receptor mediated endocytosis
the synaptic _____ is a narrow space between pre and post synaptic membranes
cleft
______ are the largest of neuroglia and have vascular feet that attach to capillary walls
astrocytes
astrocytes are localized benath the ____ of the brain and spinal cord
pia
______ astrocytes have many short and thick branches and are found in CNS gray matter
protoplasmic
_____ astrocytes have long, slender, and infrequently branch processes and are found in CNS white matter
fibrous
_____ are phagocytic cells derived from bone marrow monocytes
microglia
_____ cells line the neural tube and ventricles of brain and often contain motile cilia
ependymal
Ependymal cells and associated capillary loops that are modified to produce CSF =
choroid plexus
_____ contribute to the blood-brain barrier. They are also recruited to areas of damaged CNS tissue where they form scar tissue
astrocytes
Myelin sheath is made of a _____ complex
lipoprotein
dark regular lines of myelin that represent the line of fusion of cytoplasmic surfaces of schwann cells =
major dense lines
Less regular lines that are sites of close contact of extracellular surfaces of schwann cell membranes=
interperiod lines
Nerve fibers are divided into 3 classes based on conduction velocites:
____ are thin, non-myelinated with slow velocity
____are large, myelinated and make up motor neurons
___ are smaller, with medium connection velocity
Type C
Type A
Type B
Small clefts or fissures in the myelin are called ____ clefts. These result from discontinutities in myelin lamellae packaging
schmidt-lantermann
Waviness is the hallmark of _____ nerve fibers
non-myelinated
Nerves are surrounded by a dense connective tissue layer called _____
epineurium
Nerve fiber bundles are surrounded by ____
perineurium
Schwann cell sheathed axons within the fiber bundle are surrounded by a connective tissue ______
endoneurium
_____ fibers have a spoke wheel appearance in microscopy
myelinated
Ganglion are aggregations of nerve cell bodies ______ the CNS
outside
Gray matter consists of a broad anterior horn and a narrow posterior horn joined by a central _____
commisure
The anterior horn contains large _____ neurons
motor
____ corpuscles respond to vibration, pressure, and tension in the subcutaneous tissue
pacini’s
_____ corpuscles are touch receptors common in finger pads. They are involved in _ point discrimination
meissner’s
2
____ cells act as a pressure and texture sensor and are also involved in 2-point discrimination
Merkel
Substances bigger than ____ daltons generally cannot cross the blood-brain barrier
500
____ neurons are motor neurons while _____ are sensory
Efferent, afferent
Axons contain abundant ______ and microtubules, while dendrites contain microtubules but very few ________
neurofilaments
neurofilaments
Another name for schwann cell sheath is _____
neurolemma
________ plexus is made up of parasympathetic ganglion in the walls of lower GI tract
auerbach’s
_____ soluble drugs can pass the blood brain barrier
lipid
