-
what gives an animal the ability to respond appropriately to changes in its environment
nervous system
-
what are the components of nervious tissue (2)
- neurons
- neuroglia (support)
-
what part of the nervous system does the brain and spinal cord consist of
central nervous system
-
components of the central nervous system (2)
-
what part of the nervous system does the cranial and spinal nerves consist of
peripheral nervous system
-
components of the peripheral nervous system (2)
- cranial nerves
- spinal nerves
-
what innervates the visceral organs
autonomic nervous system
-
what does the autonomic nervous system innervate
visceral organs
-
what are layers that surround the CNS and the roots of the peripheral nerves
meninges
-
what do the meninges surround (2)
- CNS
- roots of the peripheral nerves
-
what is present in the cavities of the brain and spinal cord aind in the space within the meninges
cerebrospinal fluid
-
where is cerebrospinal fluid present (3)
- cavities of the brain
- cavities of the spinal cord
- spaces within the meninges
-
what is the structural and functional units of teh nervous system
neurons
-
composition of a neuron (2)
- cell body (perikaryon)
- processes (axon and dendrites)
-
what are the classifications of neurons (3)
- multipolar
- bipolar
- unipolar
-
structure of multipolar
1 axon, several dendrites
-
structure of bipolar
1 axon, one dendrite
-
where can bipolar neurons be found
bipolar cells of the retina
-
structure of unipolar
1 process (axon) that bifurcates into central and peripheral branches
-
where are unipolar neurons found
sensory ganglia
-
what is another name for unipolar neurons
pseudopolar neuron
-
staining of the nerve cell body
relatively euchromatic (high protein synthesis)
-
what is another name for nerve cell body
perikaryon
-
what is a perikaryon
a neuron's cell body
-
how does a nucleus present in an neuron
- nucleus centrally located (or eccentrically in autonomic ganglia)
- prominent nucleolus
- sex chromatin (bar body) may be present in cats and rodents
-
what is nissl substances
aggregation of rER and ribosomes in neurons
-
what does the cytoplasm present in neurons that make it chromatophilic (6)
- nissl substances
- neurofilaments
- microtubles
- prominent golgi complex
- mitochondria
- lipofuscin pigments
-
what do dendrites of neurons lack that should normally be there
golgi bodies as it does not need to secrete anything in this area of the cell
-
how are synaptic sites distinguished
by a thick band of electron-dense material associated with plasmalemma
-
what are the types of synaptic sites of a dendrite (2)
- electron dense plate
- dendritic spines (gemmules)
-
what is a gemmule
a membrane sac of a dendrite that projects out to attach to an axon
-
what is a projection of a dendrite that connects to an axon with a membrane sac
gemmule or dendritic spine
-
where does an axon originate
axon hillock
-
what is the distal part of an axon
telodendrites
-
what is a telodendrite
the terminal/distal end of an axon
-
what is a terminal bulb
at the end of the axon where neurotransmitter molecules are packaged and stored within a synaptic vesicle
-
where do neurotransmitter molecules get packed and stored within synaptic vesicles
terminal bulb
-
what can go out of an axon's terminal end (3)
- neurotransmitter
- neuromodulator
- neurohormone
-
what is a neuromodulator
agents that augment neurotransmitter effect
-
what are neurohormones
oxytocin and vasopressin in hypothalamic neurons
-
what are synapses (2)
- sites where contact occurs between 2 neurons or
- between neurons and other effector cells (muslce or glands)
-
what makes up a synapse (3)
- presynaptic terminal (telodendron)
- synaptic cleft (intercellular space)
- post synaptic terminal (gemmules)
-
what are the types of synases (3)
- axo-somatic (axon -> nerve cell body)
- axo-dendritic (axon -> dendrite)
- axo-axonic (axon -> axon)
-
what connects axon to nerve cell body
axo-somatic
-
what connects axon to dendrite
axo-dendritic
-
what connects axon to axon
axo-axonic
-
what are the structural and functional support for neurons
neuroglial cells or gliocytes
-
what types of neuroglial cells are in the CNS (4)
- astrocytes
- oligodendrocytes
- microglial cells
- ependymal cells
-
what do astrocytes, oligodendrocytes, microglial cells and ependymal cells do
neuroglial cells for the CNS
-
what was microglial cells derived from
mesoderm
-
what was astrocytes derived from
ectoderm
-
what was oligodendrocytes derived from
ectoderm
-
what was ependymal cells derived from
ectoderm
-
what neuroglial cell supports the PNS
neurolemmocytes (Schwann cells)
-
what is another name for schwann cells
neurolemmocytes
-
what neurons do schwann cells support
PNS neurons
-
what do neurolemmocytes do
myelinate axons and become a satellite cell in ganglia
-
what are neurolemmocytes derived from
the neural crest
-
what is the largest and most neumerous neuroglial cell
astrocytes
-
staining of astrocytes
silver stain
-
structure of astrocytes
star shaped cell with multiple radiating processes that contain glial filaments
-
function of astrocytes (2)
- provide structural support by binding neurons to capillaries and to the pia mater
- helps maintain the lectrolyte balance in teh CNS
-
in white matter what are astrocytes called
fibrous astrocytes
-
what are fibrous astrocytes
astrocytes in white matter
-
in grey matter what are astrocytes called
protoplasmic astrocytes
-
what are protoplasmic astrocytes
astrocytes in the grey matter
-
what do end feet of astrocytes do
cover the endothelium of blood vessels in the brain and spinal cord to form the blood-brain barrier
-
what has simmilar functions as neurolemmocytes in the CNS
oligodendrocytes
-
what do oligodendrocytes do
in the CNS, they have a few small processes that wroap around the axons producing a myelin sheath to give electrical insulation
-
what has simmliar properties as schwann cells in the CNS
oligodendrocytes
-
what are the spaces in between myelin sheaths called
nodes of Ranvier
-
what is the myelin sheath between nodes called
internode
-
what are phagocytic cells of the nervous system
microglia or microglial cells
-
where are microglia dervied from
bone marrow
-
function of microglial cells
phagocytosis in the CNS
-
fuction of ependymal cells
facilitate the movement of cerebrospinal fluid
-
what facilitates the movement of cerebrospinal fluid
ependymal cells
-
structure of ependymal cells (2)
- ciliated
- cuboidal or columnar in shape
-
location of ependymal cells
lining the ventricles of the brain and central canal of the spinal cord
-
what is the endoneurium
a thin layer of connective tissue fibers surrounding a nerve fiber
-
consistancy of a nerve fiber (3)
- axon
- neurolemmocytes
- endoneurium
-
in order of biggest to smallest what how is a peripheral nerve structured
- epineurium (holds together perineurium)
- perineurium (hold a bunch of endoneurium)
- endoneurium (holds an axon)
- axon (afferent or efferent)
-
what is a aggregations of nerve cell bodies in the PNS
ganglia
-
what is a ganglia
an aggregation of nerve cell bodies in the PNS
-
what are the 2 types of ganglia (2)
- sensory ganglia
- autonomic ganglia
-
what are sensory ganglia (3)
- associated with crainal nerves (cranial ganglia) or with dorsal root of spinal nerve (spinal ganglia)
- neurons are unipolar
- cell bodies are tightly encapsulated by ganglionic gliocytes (satellite cells)
-
what are autonomic ganglia (5)
- accumulations of multipolar nerve cell bodies that run along automomic nerves
- centrally palced or eccentric nuclei
- marginally distributed nissl granules
- loosely encapsulated by ganglionic gliocytes
- found in visceral tissue brain and spinal cord
-
what is the process of nerve repair (3)
- 1. injury: nissl bodies move to site of injury, due to injury of nerve, innervated muscle shows atrophy. nerve fiber distal to injury degenerates
- 2. regen in progress: schwann cells proliferate, axson grows, muscle fiber atrophied
- 3. regen successful: muslce fiber regen, nissl bodies return to cell body
-
what are the types of recptors by location (3)
- exteroreceptors (body surface)
- enteroreceptors (viscera)
- proprioceptors (musculoskeletal structures)
-
what receptor deals with the body surface
exteroreceptors
-
what receptor deals with viscera
enteroreceptors
-
what receptor deals with musculoskeletal structures
proprioceptors
-
what types of receptors by the type of stimulus (3)
- mechanoreceptors
- chemoreceptors
- thermoreceptors
-
what are the types of receptors anatomically (2 sets)
- nonencapsulated receptors:
- -free nerve ending
- -tactile corpuscles
- encapsulated receptors:
- -encapsulated tactile (Meissner's) corpuscles
- -lamellar (Paccinian) corpuscles
- -Bulbous (Krause's) or genital corpuscles
- -neurotendinous and neuromuscular spindles
-
what are the encapsulated receptors (4)
- Encapsulated tactile (Meissner’s) corpuscles,
- Lamellar (Paccinian) corpuscles,
- Bulbous (Krause’s) or genital corpuscles,
- Neurotendinous and neuromuscular spindles.
-
what are the nonencapsulated receptors (2)
- Free nerve ending,
- Tactile corpuscles
-
what consists of presynaptic neuronal end plate overlaying a postsynaptic muslce sole plate
neuromuscular synapse (efferent terminations)
-
how big is the neuromuscular gap
40-50nm
-
what is a motor end plate
formed by very short branches within a circumscribed zone (plate) at the end of one terminal branch of a n efferent neuron.
-
where does a motor end plate rest on
muscle sole plate
-
what does the moter end plate cytoplasm contain (2)
- mitochondria
- synaptic vesicles containing acetylcholine
-
what does acetylcholine do
- gets released at the active sites
- diffuses across the neuromuscular gap
- binds to postsynaptic receptor site
- leads to muscle fiber depolarization
-
what is a neurolemmocyte
support cells (like shwann cells) that holds the axon to the muscle
-
what does the grey matter of the spinal cord contain
nerve cell bodies
-
what does the ventral grey matter contain
efferent neurons
-
what does the dorsal grey matter contain
interneurons
-
what does the lateral grey matter contain
sympathetic neurons
-
what does white matter contain
processes (axons)
-
what are the parts of white matter (2)
- dorsal, ventral and lateral funiculi
- ascending and descending tracts
-
what is the central canal of the CNS lined with
ependymal cells
-
what are the canals in the white matter called (2)
- dorsal median septum
- ventral median fissure
-
histologically, what are the layers of the cerebral cortex (6)
- -most superfical to most deep
- molecular layer
- ext. granular layer
- ext. pyramidal layer
- int. granular layer
- int. pyramidal layer
- fusiform layer
-
where are the 6 layers of the cerebral cortex found
grey matter
-
define the molecular layer in the cerebral cortex
composed of processes of the stellate or pyramidal neurons (neuropil), arranged tangentially
-
what does the ext. granular layer in the cerebral cortex composed of
small pyramidal neurons
-
define the ext. pyramidal layer of the cerebral cortex
small and medium pyramidal neurons
-
define the int. granular layer of the cerebral cortex
small stellate neurons
-
define the int. pyramidal layer
med to large pyramidal neurons that send axons into the white matter
-
define the fusiform layer
many spindle shaped neurons
-
what differentiates the medulla and the spinal cord
they're the same thing structurally, spinal cord is caudal to foramen magnum and the medulla is cranial
-
what are gyri and sulci in the cerebral cortex
gyri = ridges, sulci = grooves
-
what is the white matter composed of in the cerebral cortex
nerve fibers going to and coming from the cortex
-
in relation to their gray and white matter, does the cerebellum and spinal cord have the same orientation
no, in the spinal cord, the gray matter is on the inside and white on the outside, in the cerebellum the white matter is on the inside and the grey matter is on the outside
-
structure of the celrebellum
- outer grey
- inner white
- highly folded (folia)
- 3 layers (outer molecule layer, purkinje cell layer, inner granule layer)
-
what are the layers of the cerebellum (3)
- outer molecular layer: neuropil arranged horizontally
- inner granular layer: densely packed small neurons with intensely stained nuclei
- intermediate purkinje cell layer: single layer of piriform cells, sends their ramified dendrites into molecular layer, axons into white matter.
-
what is the white matter composed of in the cerebellum
the nerve fibers of the cortex
-
what do purkinje cells in the cerebellum send to the white matter and what do they send to the molecular layer (2)
- white matter: axons
- molecular layer: ramified dendrites
-
what is the sequence, from superficial to deep, of the meninges' layers
- dura mater (pachymenix)
- arachnoid
- pia mater
-
together, arachnoid and pia mater make up what
leptomeninges
-
including bone and the spaces, how is the meninges stratified (superfical to deep)
- bone
- epidural space
- arachnoid
- subarachnoid space (arachnoid trabecule)
- pia mater
-
where is the cerebrospinal fluid produced
by the choroid plexuses in ventricles
-
where is cerebrospinal fluid found normally
subarachnoid space
-
what is the function of cerebrospinal fluid
provides physical protection to the brain and spinal cord
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