Neural Tissues Flashcards
What is the difference between the central nervous system and the peripheral nervous system?
- CNS - brain and spinal cord - information processing including reflexes and behaviour
- PNS - cranial nerves and spinal nerves - Sensory detection and motor activation
- CNS - … and … cord - information processing including … and …
- PNS - … nerves and … nerves - Sensory detection and … activation
- CNS - brain and spinal cord - information processing including reflexes and behaviour
- PNS - cranial nerves and spinal nerves - Sensory detection and motor activation
Which embryonic layer/tissue is the nervous system derived from?
Ectoderm
What are the main functions of neuroglia?
- Glia differ from neurons
- Glia: have no action potentials, do not form synapses, are able to divide (most common source of tumours of NS) and form myelin sheaths
What is a Node of Ranvier?
- … neuron: transmit sensory information to brain/spinal cord
- … neuron: motor neuron transmitting information from brain to effector organ i.e. muscle
- Afferent neuron: transmit sensory information to brain/spinal cord
- Efferent neuron: motor neuron transmitting information from brain to effector organ i.e. muscle
A ganglion is a group of neuron cell bodies in the … nervous system (outside …)
A ganglion is a group of neuron cell bodies in the peripheral nervous system (outside CNS)
- … ganglia are associated with neurons of the autonomic nervous system e.g. parasympathetic ganglion
- They have … neurons and … nuclei
- Motor ganglia are associated with neurons of the autonomic nervous system e.g. parasympathetic ganglion
- They have smaller neurons and eccentric nuclei
… ganglion have big neurons, central nuclei - example is a … root ganglion
Sensory ganglion have big neurons, central nuclei - example is a dorsal root ganglion
In CNS groups of neurons are called…
nucleus
What is myelin?
Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord
What is a Brodmann area?
- Names regions
- 2 maps - just for our benefit - do not have to learn these regions
- Should be able to understand how to navigate it when given to you
Directions in human prefrontal cortex
Neurons
What is the purpose of myelin?
- Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord
- Purpose - increase conduction velocity (so does increased diameter)
Neuron classification:
- Neurons: multipolar, bipolar and unipolar
- All neurons have just 1 …
- Majority of neurons several … = multipolar
- Neurons: multipolar, bipolar and unipolar
- All neurons have just 1 axon
- Majority of neurons several dendrites = multipolar
Important neurons
- … cells - neocortex
- … cell - cerebellum
- … root ganglion - sensory neuron
- Pyramidal cells - neocortex
- Purkinje cell - cerebellum
- Dorsal root ganglion - sensory neuron
Neuron classification:
- … - one dendrite and one axon - least numerous - sensory neurons e.g retina
- …-… one axon and one dendrite e.g. dorsal root ganglion
- Bipolar - one dendrite and one axon - least numerous - sensory neurons e.g retina
- Pseudo-unipolar - one axon and one dendrite e.g. dorsal root ganglion
Synaptic transmission - chemical
- Chemical Synapse:
- physical … (30nm)
- Neurotransmitter released from presynaptic neuron through to the postsynaptic cell receptor - triggers … signal in this cell
- Signalling is not in … direction - moving backward
- Chemical Synapse:
- physical gap (30nm)
- Neurotransmitter released from presynaptic neuron through to the postsynaptic cell receptor - triggers electric signal in this cell
- Signalling is not in Retrograde direction - moving backward
Post-synaptic cell examples
neuron, myocyte or gland
- … - single neuron sends its output signal to many neurons
- … - multiple inputs influence a single neuron
- Divergent - single neuron sends its output signal to many neurons
- Convergent - multiple inputs influence a single neuron
… occur only in CNS - neither motor nor sensory - process signals
Interneurons occur only in CNS - neither motor nor sensory - process signals
Interneurons (also known as association neurons) are neurons that are found exclusively in the … nervous system.
Interneurons = Interneurons (also known as association neurons) are neurons that are foundexclusively in the central nervous system. That means that they are found in the brain and spinal cord and not in the peripheral segments of the nervous system
Brodmann area
1,2,3
- Glia differ from neurons
- Glia: have no … …, do not form …, are able to … (most common source of tumours of NS) and form myelin …
- Glia differ from neurons
- Glia: have no action potentials, do not form synapses, are able to divide (most common source of tumours of NS) and form myelin sheaths
Directions in human prefrontal cortex
What glial cell type is this?
Oligodendrocytes (CNS)
Many more glial cells than neurons
- Neurons - basic nerve cells, … conducting
- Glial cells - s.. and p..
- Neurons - basic nerve cells, impulse conducting
- Glial cells - supportive and protective
Glial cell types - overview
- … cells - set of epithelial cells lining ventricles - determine fluid make up inside of this system - cilia and large SA to determine what fluid goes in and salt
- Astrocyte - star shape - support and controls blood vessels
- … … - covers overall brain (innermost)
- Oligodendrocyte - CNS - making or forming myelin sheath
- … cells - almost like immune cells - external / unwanted pathogens - keep it clean
- Ependymal cells - set of epithelial cells lining ventricles - determine fluid make up inside of this system - cilia and large SA to determine what fluid goes in and salt
- Astrocyte - star shape - support and controls blood vessels
- Pia mater - covers overall brain (innermost)
- Oligodendrocyte - CNS - making or forming myelin sheath
- Microglial cells - almost like immune cells - external / unwanted pathogens - keep it clean
Oligodendrocytes
- In … only - Not …
- Production/maintenance of myelin …
- … oligodendrocyte myelinates … axons (from different neurons)
- In CNS only - Not PNS
- Production/maintenace of myelin sheath in CNS
- One oligodendrocyte myelinates multiple axons (from different neurons)
Approximately how many neurons are in the brain?
100 billion
Name a place where you would find afferent neurons.
near brain and spinal cord
Name a place where you would find efferent neurons
The cell bodies of efferent neurons are located within the central nervous system.
Astrocytes (CNS)
- Supports neurons:
- Assists neuronal …
- Protects neurons from … substances
- Little feet - affect endothelium and influence blood flow and blood … …
- …-shaped
- Supports neurons:
- Assists neuronal development/growth (Neurotrophic - neuron growth)
- Protects neurons from harmful substances
- Little feet - affect endothelium and influence blood flow and blood brain barrier
- Star-shaped
What glial cell type is this?
astrocyte
Microglia (CNS)
- Immune cells - protect neurons from disease, migrate to … sites, engulf microbes /debris
- MOST … but these have … origin like other immune cells
- Also develop from …
- Immune cells - protect neurons from disease, migrate to injury sites, engulf microbes /debris
- MOST ECTODERM but these have mesodermal origin like other immune cells
- Also develop from monocytes
What glial cell type is this?
Microglia - CNS - protect neurons from disease - mesodermal origin like other immune cells
Ependymal cells (CNS)
- Line brain … and central canal of spinal cord - Responsible for forming and maintaining … in ventricles
- The cilia and microvilli on … membrane allows for increase SA on apical membrane (extend into ventricle) to allow for interaction with … and …
- Line brain ventricles and central canal of spinal cord - Responsible for forming and maintaining CSF in ventricles
- The cilia and microvilli on apical membrane allows for increase SA on apical membrane (extend into ventricle) to allow for interaction with fluid and salts
Ependymal cells (CNS) have what which increase SA?
Cilia and microvilli on apical membrane - Allows for increase SA on apical membrane (extend into ventricle) to allow for interaction with fluid and salts
Schwann cells (PNS)
- Production/maintenance of … …, PNS regeneration
- … axon wrapped per Schwann cell - compare to oligodendrocytes in CNS
- Production/maintenance of myelin sheath, PNS regeneration
- 1 axon wrapped per Schwann cell - compare to oligodendrocytes in CNS
Where are Schwann cells found?
PNS
Satellite cells (PNS)
- … neurons, regulate … of materials between neurons and interstitial flui.
- Perform analogous role in PNS to what … do in CNS
- Support neurons, regulate exchange of materials between neurons and interstitial fluid
- Perform analogous role in PNS to what astrocytes do in CNS
Glial Classifications
- CNS: … (4)
- PNS: … (2)
Meninges
Glial pathology: glioma
- Largest group of primary tumours derived from glial cells
- Usually highly …
- Grow …
- Difficult to remove completely with surgery
- Usually inside …
- largest group of primary tumours derived from glial cells
- Usually highly malignant
- Grow rapidly
- Difficult to remove completely with surgery
- Usually inside cranium
Glial pathology: glioma
- … group of primary tumours derived from glial cells
- Usually highly malignant
- Grow rapidly
- Difficult to remove completely with …
- Usually inside cranium
- largest group of primary tumours derived from glial cells
- Usually highly malignant
- Grow rapidly
- Difficult to remove completely with surgery
- Usually inside cranium
Neuroblastoma
- Tumour (cancer)
- Most common in … and …
- Outside …
- Derived from neural crest cells from … NS
- Increased catecholamine levels (often)
- Survival rates vary: depends on type
- Initial prognosis is typically …
- Survivors often develop neurological problems approx … years later
- Treatment depends on type
- Tumour (cancer)
- Most common in children and infants
- Outside cranium
- Derived from neural crest cells from sympathetic NS
- Increased catecholamine levels (often)
- Survival rates vary: depends on type
- Initial prognosis is typically good
- Survivors often develop neurological problems approx 30 years later
- Treatment depends on type
Neuroblastoma
- … (cancer)
- Most common in children and infants
- Outside cranium
- Derived from … … cells from sympathetic NS
- Increased … levels (often)
- Survival rates vary: depends on type
- Initial prognosis is typically good
- Survivors often develop … problems approx 30 years later
- … depends on type
- Tumour (cancer)
- Most common in children and infants
- Outside cranium
- Derived from neural crest cells from sympathetic NS
- Increased catecholamine levels (often)
- Survival rates vary: depends on type
- Initial prognosis is typically good
- Survivors often develop neurological problems approx 30 years later
- Treatment depends on type
What is a Node of Ranvier?
Nodes of Ranvier are microscopic gaps found within myelinated axons.
Name a cell type or place where you would find a multipolar neuron.
They are located in the central nervous system (brain and spinal cord) and in autonomic ganglia.
Name a cell type or place where you would find a bipolar neuron.
. They are sensory neurons found in olfactory epithelium, the retina of the eye, and ganglia of the vestibulocochlear nerve.
Name a cell type or place where you would find a pseudounipolar neuron.
Pseudounipolar neurons are found in the sensory ganglia of most cranial nerves, dorsal root ganglion
Name 4 ways in which glia (in general) differ from neurons (in general).
Glia have no action potentials, do not form synapses, are able to divide (most common source of tumours of NS) and form myelin sheaths
Name 4 differences between a glioma and a neuroblastoma.
- Glioma usually inside cranium, whereas neuroblastoma outside cranium
- Glioma derived from glial cells wherfeas neuroblastoma from neural crest cells from sympathetic NS
- Neuroblastoma associated with increased catceholamine levels (often), glioma not
- Neuroblastoma most common in children and infants , glioma in adults
Name two locations where you would expect to find ganglia in the peripheral nervous system.
parasympathetic galgnion
dorsal root ganglion
Name two differences between an oligodendrocyte and a Schwann cell.
oligodendrocyte - CNS - one oligodendrocyte myelinates multiple axons
Schwann cell - PNS - 1 axon per schwann cell
What is the function of a Schwann cell?
produce/maintain myelin sheath, PNS regeneration
What is the function of an oligodendrocyte?
production/maintenance of myelin sheath in CNS
What is the function of an ependymal cell?
Forming and maintaining CSF in ventricles
What is the function of a satellite cell in the peripheral nervous system?
support neurons, regulate exchange of materials between neurons and interstitial fluid
What is the function of a microglial cell?
immune cell - protect from disease
What kind of axon fibres have the fastest conduction velocity?
myelinated
What kind of neurons (histologically) would you expect to find in the dorsal root ganglia?
pseudo-unipolar
Which part of the prefrontal cortex is nearest to the primary auditory cortex (on the outer shell of the temporal lobe): ventrolateral, ventromedial, dorsolateral, dorsomedial?
ventrolateral?
Which part of the prefrontal cortex is nearest to the primary auditory cortex (on the outer shell of the temporal lobe): ventrolateral, ventromedial, dorsolateral, dorsomedial?
ventrolateral?
