Nervous Tissue (L2, C9 & C11) Flashcards
Anatomically the nervous system is divided into _________ and ______
Central nervous system (CNS)
Peripheral nervous system (PNS)
The nervous tissue is made of 2 types of cells: _________ and __________
Neurons
Neuroglia
Which of the following cell types contributes to maintenance of the blood-brain barrier?
A/ astrocytes
B/ oligodendrocytes
C/ microglia
D/ ependymal cells
Astrocytes
Anterograde Axonal transport is performed by which protein?
Kinesin
Retrograde Axonal Transport is performed by which protein?
Dynein
Axonal transport is of 2 types: either __________ or __________
Anterograde or retrograde
What is the direction of anterograde transport?
Transport from the soma to the nerve terminals
What is the direction of retrograde transport?
From the nerve terminals to the soma
Give examples of materials transported by anterograde transport
Organelles and vesicles
Give examples of materials transported by retrograde transport
Protein subunits
Enzymes
Endocytosis (viruses and toxins)
Give examples of viruses that spread by retrograde transport
Herpes simplex and rabies
Give examples of toxins that spread by retrograde transport
Tetanus
Unmyelinated axons in the PNS are covered by
Neurolemmal sheath
Unmyelinated axons in the CNS are covered by
Nothing
Myelinated axons in the PNS are covered by an outer ____________ and an inner ____________ interrupted by ____________
Myelinated axons in the PNS are covered by an Outer neurolemmal sheath and an inner myelin sheath interrupted by nodes of ranvier
Neurolemmal sheath in the PNS is formed of which type of cells?
Schwann
Myelin sheath in the PNS is formed of which type of cells?
Schwann
Myelin sheath in the CNS is formed by which type of cells?
Oligodendrocytes
Neurolemmal sheath in the CNS is formed by which type of cells?
Neurons in the CNS don’t have Neurolemmal sheath
Identify the cell:
Flattened nucleus
Small amount of cytoplasm
Found in the PNS around axons
Schwann cells
What is the endoneurium?
- Thin layer of CT
- Surrounding single nerve fiber
- Reticular fibres secreted by Schwann cells
- Contains fibroblasts, perivascular mast cells, macrophages and capillaries
What is the perineurium?
- Surrounding a fascicle/bundle of nerve fibers
- Inner layer of epitheloid cells joined by zonula occludens
- Surrounded by basal lamina to isolate environment
What is the epineurium?
- Surrounding entire nerve
- Dense irregular collagenous CT with thick elastic fibres
- Continuous with dura mater
- Prevents overstretch of nerve
A collection of neuronal cell bodies surrounded by CT outside the CNS is called?
Ganglia
What are the 2 main types of ganglia?
Sensory
Autonomic/Motor
What are the 2 types of Sensory ganglia?
Cranial Spinal (dorsal root)
What are the 2 types of autonomic ganglia?
Sympathetic
Parasympathetic
Nerve cells in sensory ganglia are:
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Pseudounipolar
Nerve cells in autonomic ganglia are:
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Multipolar
Which of the following types of ganglia is covered by a complete capsule of satellite cells?
A/ Sensory
B/ Autonomic
Sensory
Which of the following types of ganglia have myelinated nerve fibers?
A/ Sensory
B/ Autonomic
Sensory
Which of the following types of ganglia has more nerve cells?
A/ Sensory
B/ Autonomic
Sensory
Which of the following types of ganglia have nerve fibres that lie close together?
A/ Sensory
B/ Autonomic
Autonomic
Which of the following types of ganglia have neurones with eccentric nuclei?
A/ Sensory
B/ Autonomic
Autonomic
Which of the following types of ganglia is covered by an incomplete capsule of satellite cells?
A/ Sensory
B/ Autonomic
Autonomic
Which of the following types of ganglia have synapses between the preganglionic fibres and postganglionic dendrites?
A/ Sensory
B/ Autonomic
Autonomic
Which of the following types of ganglia don’t have synpases?
A/ Sensory
B/ Autonomic
Sensory
Which of the following types of ganglia have neurones with large, central nuclei?
A/ Sensory
B/ Autonomic
Sensory
All glial cells originate from the neural plate except :
Microglia
In nervous tissue, which of the following is more abundant: neurons or neuroglia?
Neuroglia
All CNS neuroglia cells, except the microglia, originate from the:
Neural tube
All PNS neuroglia cells originate from:
Neural crests
The fibrous intercellular network of fine cellular processes emerging from neurons and glial cells is called
Neuropil
What is the most common type of neuroglia?
Astrocytes
A 45 year old man presents at the clinic suffering from pneumocytis pneumonia. This disease may affect cells that stain with anti glial fibrillary acid protein. Name these cells.
Astrocytes
A 45 year old man presents at the clinic suffering from pneumocytis pneumonia. This disease may affect cells that stain with anti glial fibrillary acid protein. These cells function in
A/ Forming synapses B/ Presenting antigens C/ Phagocytosis D/ Forming glial scars E/ Forming myelin sheathes in CNS
Forming glial scars
A 45 year old man presents at the clinic suffering from pneumocytis pneumonia. This disease may affect cells that stain with anti glial fibrillary acid protein. These cells function in
A/ Forming synapses B/ Presenting antigens C/ Phagocytosis D/ Forming myelin sheathes in CNS E/ Forming the blood brain barrier
Forming the blood brain barrier
Identify the cell
Has glial fibrillary acid protein
Present in gray matter
Has short branched processes
Proteoplasmic astrocytes
Identify the cell
Has glial fibrillary acid protein
Present in white matter
Has long unbranch processes
Fibrous astrocytes
The blood brain barrier is formed of
- Tight junctions between Endothelial cells
- Their basement membrane
- Astrocyte processes
Gliosis is one of the functions of which nueroglial cell in the CNS?
Astrocytes
Aggregates of carbohydrates and proteins that accumulate with age in the CNS are called
Corpora amylacea
Aggregates of carbohydrates and proteins that accumulate with age in the CNS are formed by
Astrocytes
Which neuroglial cells cover the synapses of neurons in the CNS?
Astrocytes
What is a glioma?
Tumor of glial cells
What is the most common type of glioma?
Astrocytoma
A 35 year old man comes to the outpatient clinic complaining of severe headaches and blurred vision. Imaging to the brain reveal an abnormal mass in the parietal lobe of the cerebrum. The doctor suspects that this mass is a
Astrocytoma
The blood brain barrier selectively controls the substances that pass from the blood to brain. Name the 4 areas of the brain not protected by the blood brain barrier.
- Postrema
- Posterior pituitary
- Median eminence of hypothalamus
- Pineal gland
Oligodendrocytes are predominant in ________ matter
White
Which of the following are the main electrical insulators of CNS?
A/ Microglia
B/ Oligodendrocytes
C/ Satellite cells
D/ Ependymal cells
Oligodendrocytes
Which of the following are the main electrical insulators of PNS?
A/ Schwann cells
B/ Satellite cells
C/ Microglia
D/ Astrocytes
Schwann cells
What is the origin of Microglia cells?
Monocytes
What is the function of Microglia?
Phagocytosis
Identify the cell:
- Present in both white and gray matter
- Elongated, small, dense nucleus
Microglia
Which of the following are the antigen presenting cells of the nervous system ?
A/ Schwann cells
B/ Satellite cells
C/ Microglia
D/ Astrocytes
Microglia
Identify the cells:
- Columnar cells with apical cilia and microvilli
- Lining the brain ventricles and central canal of spinal cord
- Lack a basal lamina
- Bases extend processes into underlying neuropils
Ependymal cells
Which of the following are the responsible for the secretion of cerebrospinal fluid?
A/ Schwann cells
B/ Satellite cells
C/ Microglia
D/ Ependymal cells
Ependymal cells
A 3 year old child is brought to the outpatient clinic after suffering a seizure. Her medical history reveals she has long lasting weakness in the legs that make it difficult for her to walk normally. MRI images reveal a mass in the fourth ventricle of her brain. The doctor suspects that this is a
Ependymoma
A 30 year old woman comes to the outpatient clinic complaining of nausea, vomiting, headaches and numbness in the right lower extremity. She claims these symptoms have been troubling her for months. An MRI scan is ordered. The images reveal a tumour in the central canal of the spinal cord. The doctor suspects that this is an
Ependymoma
Identify the cells:
- Small
- Surround somas in ganglia
- Insulate, nourish and regulate neurone soma
Satellite cells
Processes that conduct nerve impulses towards the soma are called
Dendrites
Processes that conduct nerve impulses away from the soma are called
Axons
Name the largest neurones
Anterior motor neurons of the spinal cord
Name the smallest neurons
Granule cells in cerebral cortex
Identify the structure:
- Basophilic irregular masses
- Scattered in neuron soma
- Flat rER cisternae with free ribosomes
Nissl body
Which of the following are the most common type of neurons?
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Multipolar
Which of the following are neurons that have one short process that bifurcated into 2 processes; an axon and a dendrite?
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Pseudounipolar
Which of the following neurons are present in sensory systems (visual, auditory and olfactory)?
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Pseudounipolar
Which of the following neurons have 2 processes ?
A/ Unipolar
B/ Pseudounipolar
C/ Bipolar
D/ Multipolar
Bipolar
What is the tropic centre of a neuron?
Its soma
The nucleus of a neuron soma is active. That means it’s
A/ Euchromatic with peripheral heterochromatin
B/ Heterochromatic with peripheral euchromatin
Euchromatic with peripheral heterochromatin
Identify the cell:
- Spherical or ovoid active nucleus
- Scattered Nissl bodies
- Long processes
- One or more prominent nucleoli
- Golgi body with vesicles near the nucleus
- Lipofuscin accumulation
- Abundant Mitochondria
- sER
- Lipid droplets
- Peroxisomes
- Melanin granules
Neurone
What’s the function of the nucleolus?
Synthesis of rRNA
What is the function of Nissl bodies?
Manufacturing protein for intracellular use and export
What is the function of Golgi body in neurons?
- Packaging and concentration of secretory products
- Post translation modification of proteins and macromolecules
- Production of lysosomes
- Accumulation of lipofuscin with age
What are the 3 components of neuronal cytoskeleton?
Microtubules
Neurofilaments
Actin filaments
Which of the following components of cytoskeleton function in neuronal transport?
A/ Neurofilaments
B/ Microtubules
C/ Actin filaments
Microtubules
Which of the following components of cytoskeleton have high affinity for heavy metals?
A/ Neurofilaments
B/ Microtubules
C/ Actin filaments
Neurofilaments
Which of the following components of cytoskeleton function in Axonal growth and regeneration?
A/ Neurofilaments
B/ Microtubules
C/ Actin filaments
Both Neurofilaments and Microtubules
Functionally, what are the 2 types of synapses?
Excitatory
Inhibitory
Which of the following changes is triggered by an excitatory neurotransmitter?
A/ depolarisation
B/ repolarisation
C/ hyperpolarisation
Depolarisation
Which of the following changes is triggered by an inhibitory neurotransmitter?
A/ depolarisation
B/ repolarisation
C/ hyperpolarisation
Hyperpolarisation
The most common type of synapse is
Axodendritic synapse
The least common type of synapses is
Axoaxonic
Oxytocin and vasopressin (ADH) are classified as
A/ neurotransmitters
B/ neurosecretory products
C/ enzymes
Neurosecretory products
Structurally, synapses are classified into
Axodendritic
Axoaxonic
Axosomatic
Give an example of an amino acid neurotransmitter
Glutamate
Acetylcholine, endorphin, epinephrine, norepinephrine and neuropeptides are examples of _____________ neurotransmitters
Catecholamine
Name the 3 major components of a synapse
Presynaptic membrane
Synaptic cleft
Postsynaptic membrane
Abundant secretory vesicles containing neurotransmitters are observed in the ___________ membrane
Presynaptic
What happens when the action potential reaches the presynaptic membrane?
Secretory vesicles containing neurotransmitters are released into the synaptic cleft
What is the effect of neurotransmitters on the postsynaptic membrane?
Neurotransmitters change the conductance of the postsynaptic membrane
Pre- and postsynaptic membrane specializations contain electron-dense material that extends into underlying cytoplasm and is usually thicker in
Postsynaptic membrane
Which of the following drugs mimics the action of endorphin binding to its μ1-receptors?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Morphine
Which of the following drugs are antidepressants?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
B/ Monoamino oxidase inhibitors (MAO)
D/ Sélective serotonin reuptake inhibitor (SSRI)
Which of the following drugs inhibit the mitochondrial enzyme responsible for breaking down serotonin?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Monoamino oxidase inhibitors
Which of the following drugs increase the amount of serotonin in the synaptic cleft?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Selective serotonin reuptake inhibitors
Which of the following drugs inhibits glutamate (NMDA) receptors?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Alcohol
Which of the following drugs increases the inhibitory effect of γ-aminobutyric acid (GABA)?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Alcohol
Which of the following drugs causes hyperpolarisation of the post-synaptic membrane?
A/ Alcohol
B/ Monoamino oxidase inhibitors (MAO)
C/ Morphine
D/ Sélective serotonin reuptake inhibitors (SSRI)
Alcohol
Nerve regeneration occurs by a process called
Axon reaction
Axon reaction is formed of 3 types of changes. Name them
Local
Anterograde
Retrograde
Anterograde changes during regeneration occur ___________ to the site of injury.
Distal
Retrograde changes during regeneration occur ___________ to the site of injury.
Proximal
Nerve regeneration in the PNS is impossible if the 2 stumps are ________ from each other at the site of injury
Far away
In the local reaction, what happens to prevent loss of axoplasm?
Fusion of axon membrane on each side of the cut
Which cells are responsible for secreting cytokines and growth factors during nerve regeneration?
Macrophages and fibroblasts
Which cells are responsible for phagocytosis of debris during nerve regeneration?
Macrophages and Schwann cells
Which cells are responsible for up-regulating the receptors for cytokines and growth factors during nerve regeneration?
Macrophages and fibroblasts
During anterograde reaction, what happens to the the axon terminals?
Phagocytosed by Schwann cells
What happens during Wallerian/Orthograde degeneration?
1/ Axon is phagocytosed by macrophages and Schwann cells
2/ Schwann cells dedifferentiate
3/ Myelin production stops
4/ Schwann cells proliferate forming Schwann tube
What are the events that occur during chromatolysis of neuron soma?
1/ Nucleus is displaces
2/ Nissl bodies disperse
3/ Perikaryon hypertrophy
During nerve regeneration, the injured axon disintegrates as far as
Proximal collateral axon
What is the function of the Schwann tube?
Guide the axon stumps towards the effector
What are the 4 things necessary for the nerve regeneration?
Macrophages
Fibroblasts
Schwann cells
Basal lamina of endoneurium
During nerve regeneration, a new synapse is formed by
The first axon stump to reach the target
The final step of nerve regeneration is
Proliferation of Schwann cells to form neurolemmal and myelin sheathes
Each nerve cell has _________ influence of other surrounding effectors and neurons
Trophic
Can nerve regeneration occur if the Soma is injured
No
Nerve regeneration doesn’t occur in the CNS. How does the CNS get rid of these cells
Phagocytosis by Microglia
Injured cells in the CNS are replaced by
Glial (astrocyte) cells
Neural stem cells are
A/ Unipotent
B/ Oligopotent
C/ Multipotent
D/ Totipotent
Multipotent
If a neuron is damaged, its effector may continue to receive innervation from
Collateral innervation/ Neuronal circuits from other neurons
What are neutrophins?
Neuronal Growth factors
Which cells secrete neutrophins?
1/ Schwann cells
2/ Other glial cells
3/ Neuron
4/ Some target cells