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Nervous System/Tissu
Nervous Tissue
Question | Answer |
---|---|
What derives from the neural tube? Neural crest? | Neural Tube: CNS. Neural Crest: PNS |
What is the CNS divided into? PNS? | CNS: Divided into Brain and Spinal Cord. PNS: Divided into ganglia and peripheral nerves |
What does neurons refer to? What are the parts? | Neurons are the cell and all of its parts. The receiving end is called the dendrites and a transmission end is called the axon. |
Can axons be long and short? | YES |
Where can long axons exist? | In both the CNS and PNS |
Where can short axons exist? | Only in the CNS |
What defines the boundary of the CNS and PNS? | Axon myelin |
What system is the Schwann cell located? Oligodendrocyte? | PNS: Schwann cell. CNS: Oligodendrocyte. |
Name some things the PNS is composed of | Spinal nerves, cranial nerves,satellite cells |
Do motor axons leave or enter the CNS? | Motor axons leave the CNS and sensory axons enter the CNS |
What are satellite cells homologous to in the CNS? | To glial cells (astrocytes) |
What does the somatic system deal with? | Voluntary muscles and skin |
What does the autonomic system deal with? | Smooth muscle, organs and glands |
What does the enteric nervous system? | Enormous amount of neurons associated with the gut |
What is meant by robotic neurons? | They are not the basis for intellect or plasticity |
How do neurons communicate? | Majority is chemical then there are electrical (gap junctions) electrically coupled |
What do glial cells provide? | Specialized metabolic support |
What are ependyma cells? | Line the ventricles of the brain. Ventricles are fluid filled cavities |
What is the vasculature involved in the brain? | Oxygen, glucose and blood brain barrier |
Name some features of neurons | Signaling and information processing, most neurons do not divide in adults (no repair) |
What is in the cell body of neurons? | Nucleus, nucleolus, cytoskeleton, Endoplasmic reticulum |
What are NISSL bodies? | Unique to neuronal cells |
How is melanin related to Parkinson's disease? | Melanin is found in a nucleus of the brain called the substanta nigra associated with Parkinson's disease |
Where do axons tend to synaspe? | On dendrites and transmit information to other neurons and targets |
What color does the cell body(soma) stain? | Euchromatic nucleus, stains lightly, uncoiled DNA |
Are neurons multipolar? | Yes, each dendritic branch coming off is considered to be a pole and the axon is considered to be another pole |
What are Golgi Type 1 axons? Golgi Type 2? | Type 1 is long axons and Type 2 is short axons |
What type of axons do white matter have? | Myelinated axons |
What does gray matter have to contain? | Neurons |
In the brain are the axons deep to the gray matter? | Yes, the gray matter is on the outer part |
In the spinal cord are the axons deep to the gray matter? | No, Gray matter are deep to the axons. The outer part is white matter |
What is antergrade transport in neurons? | From the cell body to dendrites along axon (Kinesin) |
Waht is the retrograde transport in neurons? | From the axon to cell body (Dynein) |
What factors are involved in retrograde transport? | Mitochondria, vesicles and trophic factors |
What are trophic factors? | Other proteins that may be release from post-synapic cells that are picked up by endocytosis by pre-synaptic cells and transported back to nucleus |
What can be described as fast? | Membrane associated proteins, vesicles, mitochondria, neuorfilaments and kinesin |
What can be described as slow? | Cytoskeletal, axoplasmic proteins and kinesins too |
Where is the axon hillock? What does it do? Do organelles stay very long? | It is between the soma and the axon, where action potentials are generated, no organelles stay very long |
Describe an Electrical synapse | Gap junctions; connexins involved driven by calcium to open and close |
Describe exitatory and inhibitory neurotransmitters | Excitatory facilitates the generation of an action potential post-synaptically. Inhibitory depresses it |
Do both presynaptic terminal and postsynaptic terminal contain vesicles? | Presynaptic does and postsynaptic does not |
What leads to fusion of vesicles with the presynaptic membrane? | Calcium influx |
When do vesicles release neurotransmitters? Where is it released to? | After fusing they release it into the synapic cleft |
Name examples of excitatory transmitters? Inhibitory | Excitatory: Acetylcholine and Glutamate. Inhibitory: GABA, dopamine, norepinephrine and serotonin |
What is the clathrin protein involved in? | Vesicle recycling |
Can neuronal cells be isolated without axons? | No |
Describe upper motor neurons | Located in the cerebral cortex, they synaspe on top of lower motor neurons through interneurons activating the lower motor |
What happens if you damage an upper motor neuron? | Weakness |
Describe lower motor neurons | Located in the brain and spinal cord. Leave and synaspe on striated muscle |
What happens if you damage lower motro neurons? | Paralysis |
Why are sensory neurons referred to as being pseudounipolor? | They start out bipolar and become unipolar |
Describe interneurons | The are multipolar, interposed between upper motor and lower motor neurons |
Where do the dorsal and ventral roots merge? | In the spinal nerve |
What are purkinje cells exclusive to? | Exclusive to the cerebellum |
Where are amacrine exclusive to? | Exclusive to retina and contain no axon |
Where are mitral cells found? | In the olfactory system |
Where are golgi cells found? | In the cerebellum |
What are granule cells unique to? | Cerebellum (Predominate in Cerebellum) |
Is the cerebellum the largest structure in the brain? | No it's 2nd to cerebral cortex |
What is on the outer molecular layer of the cerebellum? | Purkinje cell dendrites and unmyelinated granule cells |
What do granule cells synapse on? | The dendrites of purkinje cells |
Where is protein synthesis occuring? | In the Nissl material |
What is meant by axotomy? | Axons are crushed |
Where are the largest neurons located? | In the ventral horn and are lower motor neurons |
With Weigert stain (silver stain) what color do myelinated axons stain? Gray matter? | Myelinated axons: stain black. Gray matter are unstained |
Describe interoreceptors | Sensory information from the internal organs or from visceral structures |
Describe exterorecptors | Deal with the exterior with the body such as taste, pressure, toch, pain, temp.... |
Describe proprioreceptors | Allow for transmission of information for the location of your limbs and joints in space |
Name skin receptors associated with touch | Merkel disc and Meissner |
Name skin receptors associated with pressure | Ruffini and Pacinian |
Describe the role of astrocytes and types in white and gray matter | Fibrous: White matter. Protoplasmic: Gray matter. Astrocytes are involved in blood brain barrier. Suck up glutamate and separates damaged tissue from healthy tissue |
Describe microglia | Do not have a nuclear origin. They phagocytize dead neuronal material |
Describe a difference between oligodendrocyte and schwann cell | Oligo: 1 cell myelinates a portion of many axons. Schwann: 1 cell myelinates a portion of 1 axon |
True or False: Short axons are myelinated | False |
True or False: Osmium stains myelin black | True |
True or False: All PNS axons are myelinated | False. Some are loosely ensheathed by Schwann cells |
The region between 2 myelin | Internodal |
Describe Node of Ranvier | Between each myelinated segment where axon potential is regenerated |
Describe glial limitans | The end feet form a glial to surround entire CNS |
What are some of the astrocytes betwen blood vessels and neuronal cells responsible for? | For passing nutrients between the vasculature and neuronal cells |
Name deadly brain tumors derived from glial cells | Glioblastoma, Astrocytoma |
True or False: Ventricular canals are found in adults | False, only found in fetus |
True or False: Ependyma+pia+vessels=choroid plexus | True |
Describe tubes of Schwann cells | When there is cell damage, facilitate peripheral axonal regeneration called Bands of Bunder or Fiber bands |
Describe the outer most layer of CNS | Dura matter, thick, inelastic |
Describe the Arachnoid Membrane | Only on surface of the brain, attached to dura and trabecula. connect to pia. Has arachnoid processes |
True or False: Pia can be peeled off the brain | False. Pia follows the contour of the brain |
What happens when an axon is cut? | Dispersion of Nissl material, then it starts to regenerate |