Nervous Tissues 1 Flashcards
the CNS consists of the ___ and ___ ___
brain and spinal cord
the PNS consists of the ___ ___ and ___ ___
nerves, ganglia, and sensory receptors.
the ___ nervous system carries info toward the CNS or up the spinal cord to the brain
AFFERENT
the ____ nervous system carries info from the brain and AWAy from the CNS to effector organs and muscles
EFFERENT
the afferent and efferent systems have ___ and ___ components
somatic (relating to skin and skeletal muscles) and visceral/autonomic NS components.
THe autonomic/visceral system is divided into the ____ and ____ division
sympathetic (thoracolumbar) parasympathetic (craniosacral)
2 basic cell types of nervous tissue
1) neurons: functional cells of nervous tissue 2)glial cells: support cells found in the CNS
purpose of neuron
to generate an action potential
a cell body is aka
perikaryon
what gives a neuron’s cell body a nice and dark appearance?
chromatophillic substance called NISSL BODIES.
neurofibrils purpose. What are they made of?
they cushion and support the nucleus and nucleolus in the cell body. made of intermediate filaments.
Where is the neuropil space? What is the neuropil space composed of?What is the arrow pointing to?
The neuropil space is the regions of rounder cells with blue background. It is composed of glial cells that surround neurons. The arrow is pointning to an axon hillock/cell body region of a neuron
Nissl bodies are ____ and are found mainly in the _____
chromatophilic and found mainly in the cell body/perikaryon
what are the black spots in this slide
glial cells
the myelin sheath consists of 3 types of lipids: ___, ____ and ___ as well as proteins
phospholipids, cholesterol and glycolipids.
Myelin is made by ___ cells in the PNS and ____ cells in the CNS
Schwann cells in the PNS and oligodendrocytes in the CNS
How is myelin synthesized?
one layer at a time. You dont eed to know about true myelin synthesis
What stain is good at visualizing nervous tissue? (besides H and E)
Golgi stain
glial cells function is to :
and they are typically associated with cells of ___ ___ ___
glial cells are meant to support (both structurally and metabolically) neurons. They are associated with FIBROUS CONNECTIVE TISSUE.
What is this? What are the arrows pointing to?
This is myelin cross section. The nerve is in the middle, with layers of myelin surrounding it. M= myelin sheath
S= schwann cell nucleus
F= nerve fiber.
What is this?
Node of ranvier: between adjacent schwann cells that appear as an unmyelinated gap. Impulses jump from node to node (saltatory conduction), which INCREASES the speed of conduction.
What would happen if no myelin sheath was present in an axon
slower conduction because saltatory conduction would not be a thing.
two purposes to Schwann cells. What are they also known as?
1) provide structural and metabolic support for axons
2) secrete myelin sheath
aka neurolemmocytes
Neurons can be classified as ___, __, or ___ based on the number of processes
unipolar, bipolar, or multipolar.
T/F: golgi apparatus is really dark in a neuronal stain
false. Golgi appears as pale cytoplasmic region near the nucleus.
A ___ neuron wolud have many short dendrites and a long axon arising from a cell body
MULTIPOLAR
a ____ neuron would have a single dendrite and a single azon emerging from opposite ends of the cell body
BIPOLAR
Unipolar neurons are derived from ___ neurons.
Bipolar neurons
in a unipolar neuron, the dendrite is longer than the axon and is called a ___ ___. It carries the impulse from a ___ __ to the cell vody. the “axon becomes the ___ ___, and carries the impulse from the cell body to a neuron in the CNS. Which types of neurons are unipolar?
in a unipolar neuron, the dendrite is longer than the axon and is called a PERIPHERAL PROCESS It carries the impulse from a SENSORY RECEPTOR to the cell vody. the “axon becomes the CENTRAL PROCESS , and carries the impulse from the cell body to a neuron in the CNS. Most SENSORY NEURONS ARE UNIPOLAR
Based on FUNCTION: neurons are classified as ___, __ or ____.
MOTOR: control muscle fibers and glands
SENSORY: received sensory stimuli from environment and body
INTERNEURONS: form complex functional networks with other neurons.
Which neuron is most likely a sensory neuron? interneuron? motor?
Left: sensory neuron: unipolar
Middle: interneuron
Right: motor neuron
motor neurons and interneurons are often _____ polar
MULTIpolar
Cell bodies lay in ___ ___ in the CNS
Cell bodies lay in ____ in the PNS
Cell bodies are in the GREY MATTER in the CNS, and GANGLIA in the PNS
Myelinated axons/neuron processes lie in ___ ___ in the CNS and in ____ in the PNS
myelinated axons = white matter in CNS, NERVES in PNS.
___ cells are non-neuronal cells in the CNS
- provide mechanical and metabolic support to neurons
Glial cells
Glial cells are located in _____.
NEUROPIL: the interneuronal space of the CNS
4 main types of glial cells
oligodendrocytes, astroctyes, microglia and ependymal cells
Function of microglia. How are they made?
phagocytic glial cell that act as a microphage. derived from monocytes.
Label the image.
N= neuron
G= glial cell
Np= neuropil
What kind of stain was most likely used?
most likely a silver/gold/golgi stain. Given that there is blue, maybe hematoxylin.
____ are HIGHLY branched glial cells and help maintain signalling capacity. What are they connected to? How do these cells support neurons metabolically? How do these cells help with protection of neural tissue?
ASTROCYTES are highly branched
- connected to each other, blood vessels, and neurons
- inactivates neurotransmitters
- metabolic support via glycogen reserves
- protection of neural tissue by helping build the blood-brain barrier: regulate entry of molecules and ions from the blood into the CNS.
astrocytes contained ____ ___ ___ ___, a type of intermediate filament that allows them to be seen under micrscope.
GLIAL FIBRILLARY ACIDIC PROTEIN
Two types of astrocytes
1) protoplasmic: seen in grey matter
2) fibrous: found in white matter and have longer processes, and more GFAP.
What is the glia lamitans? What is it made of?
glia laminatans: ASTROCYTES that are on the surface of the permeability barrier (BBB) between on basal lamina of the PIA MATER.
What type of cells are these?
astrocytes. note their star shaped processes and how they are surrounding a capillary
______ are glial cells responsible for producing myelin in the CNS. Where are they most abundant?
OLIGODENDROCYTES. most abundant in white matter (they created it lol)
_____ cells line the centricles of the brain and central canal of the spinal cord. What shape are they?
EPENDYMAL CELLS line the ventricles, and are cuboidal or columnar in shape.
T/F: ventricles have a basal lamina.
False
what two structural accessories to ependymal cells posess to help them function properly?
1) cilia: circulation of cerebrospinal fluid
2) microvili: absorption and secretion
Ependymal cells join with the pia mater to form the ___ ___, whats the function?
CHOROID PLEXUS. responsible for production of cerebrospinal fluid.
What cell is this? What is the function?
ependymal cells. found lining ventricles of the brain and is joined to pia mater to form the choroid plexus for CSF production.
