Lecture 15: Nervous tissue Flashcards
Telodendrites
Contain synaptic vessicles
Form presynaptic membrane
Multipolar neuron
Most common
One axon, multiple dendrites
Bipolar neuron
Have two processes, one at each end
Associated with special senses - olfactory/visual
Pseudounipolar
Have single process from body that bifurcates
Found in dorsal root ganglia
Golgi I neuron
Long axons which leave the gray matter
Golgi II
Short axons which ramify through gray matter
Epineurium
Covers entire nerve
Supplied by blood and lymphatics
Type I collagen and fibroblasts
Perineurium
Dense CT
Covers fascicles
Epithelial-like fibroblasts with tight junctions
Blood nerve barrier
Endoneurium
Thin layer of reticular CT
Surrounds individual fibers/schwann cells
Type III collagen
Presynaptic membrane contains
Dense bodies
SCa transport used by
SCb transport used by
Preassembled microtubules, neurofilaments
Enzymes, actin, clathrin
Intermediate transport used by
Mitochondria, other membrane bound organelles
Fast transport used by
Synaptic vessicles
Neurotransmitters
Glial cells derived from
Embryonic neural crest tissue
-except microglia
Astrocytes location/structure
Only in CNS
Numerous processes w/ expanded feet (pedicles) that terminate on capillaries or pia mater
Fibrous astrocytes
White matter
Long processes w/few branches
Protoplasmic astrocytes
Gray matter
Short processes w/many short branches
Astrocyte function
Regulate composition of intracellular environment
BBB- end feet form glia limitans
Development of cerebral cortex
Oligodendrocytes location/function
CNS only
Closely associated with neuron cell bodies, function as satellite cells
Surrounds axons in gray matter
Myelinate axons in CNS-each one myelinates several
Schwann cells
Myelinate single portion of axon in PNS
Microglial cells derived from/function
Derived from macrophage precursors
Phagocytic in CNS
Recruit leukocytes across BBB
Module immune response w/astrocytes
Ependymal cells
Ciliated cuboidal
Function in transport
May secrete cerebrospinal fluid in choroid plexus
Satellite cells
Form moons around cell bodies in ganglia
Insulators
Internal and external mesaxon
Outer and innermost points of fusion between the outer leaflets
Intraperiod line
Electron dense line created by extracellular space between outer leaflets
Major protein zero
PNS-intraperiod lines- binds OUTER leaflets
Mutations are related to Charcot-Marie-Tooth diseases
In CNS this protein is replaced by proteolipid protein-mutations in it cause Pelizaeus-Merzbacher disease
Major dense line
Line created by cytoplasmic space between inner leaflets
Myelin basic protein
PNS-inner leaflets
Stabilized lipids
Schmidt-Lanterman clefts
Residual areas of cytoplasm within major dense lines
Astrocyte endfoot contacts the _______ in the _____
Node of ranvier in the CNS
PNS- node of ranvier covered by
Schwann cell processes
Connexin 32 expressed in ____ mutation causes ____
Schwann cells
Mutation causes Charlot-Marie-Tooth-disease
SNAPs
Bind vesicles to presynaptic membrane
Synapsins
Filaments in presynaptic membrane
Meninges and spaces listed superficial-deep
Epidural space
Dura mater
Subdural space
Leptomeninx
Dura mater “tough mother”
Thick sheet of dense fibrous CT
Found in cranial cavity and spinal cord
Receive blood from CSF
Subarachnoid space
Between arachnoid and pia mater- filled by CSF
Arachnoid villi
Allow CSF to flow from subarachnoid space into dural sinuses
Pia mater is continuous with
Perivascular CT of cerebral/spinal cord blood vessels
Pia mater tightly attached to
Nervous tissue of brain
Perivascular space is covered by
Pia mater
Choroid plexus cell type/cell linked by
Simple cuboidal cells
Tight junctions
Choroid plexus capillaries formed by
Endothelial cells lacking tight junctions
Choroid plexus and CSF
Na, K, ATPase pumps in apical membrane of choroid plexus pump fluid into lumen leading to CSF in ventricles
Ependyma lines
Ventricular walls-simple cuboidal
Ependymal cells linked by and in contact with
Zonula adherens
Contact astrocytic feet
Dorsal root ganglia neurons are
Pseudopolar
Dorsal root postganglionic axons are
Myelinated
Satellite cells in dorsal root ganglia
Form layer around cell body of neuron
Autonomic neuron type-recieve info from
Multipolar-recieve input from myelinated preganglionic neurons
Autonomic postganglionic axons are
Not myelinated