Chapter 11: Nervous Tissue Cells Flashcards
neuron cell body
(also known as soma) performs the typical functions of any cell
Nissle bodies
extensive rough endoplasmic reticulum within the neuons
dendrites
the extensions of the neuron cell body that receive information from other neurons.
dendritic spines
where axons of other neurons form connections with dendrites
what are the parts of the axon?
axon hillock (cone-shaped area)
initial segment (beginning of the axon)
trigger zone (where action potentials are generated)
axoplasm (the cytoplasm of the axon)
axolemma (the plasma membrane of the axon)
sensory neurons
conduct action potentials toward the CNS
motor neurons
conduct action potentials away from the CNS toward muscles or glands
interneurons
conduct action potentials within the CNS from one neuron to another
multipolar neurons
account for most of the neurons in the body. They have many dendrites but a single acon.
bipolar neurons
have two processes: one dendrite and one acon. The dendrite is specialized to receive the stimulus (retina of the eye)
pseudo-unipolar neurons
start as bipolar, but the two processes that extend from the cell body fuse into a single process.
What are the four types of glial cells in the central nervous system?
astocytes
ependymal cells
microglia
oligodendrocytes
astrocytes
star shaped
regulates what substances reaches the CNS from the blood
produces chemicals that tighten the blood-brain barrier
regualates extracellular brain fluid composition
ependymal cells
they line ventricles and spinal cord central canal.
chyroid plexuses
specialized ependymal cells that secrete cerebrospinal fluid
microglia
macrophages that have been slightly altered for the nervous system to respond to inflammation
oligodendrocytes
form myelin sheaths if surrounding an axon.
what are the two types of glial cells in the peripheral nervous system?
schwann cells
satellite cells
schwann cells (neurolemmocyte)
wrap around one portion of axon to form a myelin sheath.
satellite cell
surround neuron cell bodies and provides nutrients and support.
myelinated axons
Schwann cells in the PNS or oligodendrocyte extensions in the CNS repeatedly wrap around a segment of an axon to form a series of tightly wrapped membranes rich in phospholipids.
non continuous covering
helps axons conduct electrical signals faster
nodes of Ranvier
gaps in the myelin sheaths
unmyelinated axons
these axons rest in invaginations of the Schwann cells or oligodendrocytes. Gray matter.
Axons transmit electrical signals slower.
