Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
Neuron or Nerve cells
|
-Is the functional unit of the nervous system
-There are 10 billion neurons The central process is the axon and the peripheral process is the dentrite. They do not replicate. |
|
Cell Body
|
Is called the soma/perikaryon
-Has a euchromatic nucleus and Nissl bodies -Has numerous mitochondria and large gogli apparatus. Golgi stains - or silver stains |
|
Nissl Bodies
|
Are stacks of rough ER in the cytoplasm
With free ribosomes extend into dendrites but into the axon. Helps to distinguish between axon and dendrites. Basophilic |
|
Dendrites
|
Carry information towards the cell body and have a greater diameter than axons.
UNMYELINATED Aborizations - called dentritic trees increase receptor surface |
|
Axon
|
Carry information away from cell body, 1 axon for each neuron.
Axon hillock - where axon Axolemma - plasma membrane Axoplasm - cytoplasma - contents Also have terminal aborizations - branching out that connect to other neuron |
|
Axoplasm
|
Contain microtubles and neurofilaments.
Or neurokeratin - which is the cytoskeleton of the axoplasm -black rings are myelin - lipid - perserved with osmium |
|
Gogli Type 1 neurons
|
alpha-motor neurons of CNS
Axons are more than 1 long - muscle |
|
Golgi Type II
|
Golgi cells in cerebellum
-short axons - and interneurons |
|
Sensory Neurons
|
Carry sensations from body to receptor in CNS
-most bipolar neurons, that have one axon and one dendrite. |
|
Motor Neurons
|
Are multipolar and end on affector organs like muscle, glands. Or end on connecting neuron called interneurons.
-multipolar have one axon and numerous dendrites |
|
Interneurons (intercalated)
|
99.9% of neurons, connect most neurons to effector organs
|
|
Unipolar
|
One pole with one process that divides close to cell body into two process. Seen in ganglia
|
|
Kinesin
|
Involved in anterograde transport, from cell body to axon. Facilitates the transport of vesicles.
|
|
Dynein
|
Facilitates reterograde transport of vesicles from axon terminal and dendrites to cell body.
|
|
Terminal Bouton
|
Swollen bulbs at end of axon which synapse with another neuron.
Axosomatic, Axodendritic and Axonaxomic |
|
Myasthemia Gravis
|
Occurs when there are antibodies against your own neurotransmitters which attack acetylcholine receptors. Affect function
|
|
Schwann cells
|
Come from neural crest and responsible for myelination in PNS. One cell myelinates one cell.
Wraps around the cell. Outside is called neurolemma and inside sheaths are myelin sheath. |
|
Formation of Myelin Sheath
|
Sheath contain small amounts of cytoplasm - called Schmidt-Latermann cleft - islands of cytoplasm
-Perinodal cytoplasma is at node of ranvier |
|
Unmyelinated Nerves (PNS)
|
Are enveloped by schwann cell cytoplasm but are not wrapped. Are embedded and axon rests rest in cleft with a single mesoaxon.
|
|
What nerves are myelinated and what aren't?
|
The thick the diameter of axon and the more myeliantion the faster the conduction.
Motor - need quick response - thick axon myelin Sensory - need quick - also thick Smooth muscle (autonomic) - involuntary - unmyelinated |
|
Satellite Cells
|
Are peripheral neuroglia which surround ganglionic neuronal cells.
Are cuboidal cells which line the nerve. are analgous to schwann and arise from neural crest |
|
Central Neuroglia Cells (CNS)
|
1) Oligodendrocytes
2) Astrocytes 3) Microglia 4) Ependymal cells |
|
Oligodendrocytes
|
Large cell with numbers processes which can myelinate many axons (3-50) of CNS.
|
|
Astrocytes
|
Star like cell, largest of glial cells. Have one end connected to capillaries and the other end nerve cell bodies. Transport nourishment from BV to axon (perivascular feet and perineural feet) . Cells evelope capillary around - blood brain barrier
Protoplasmic - astrocytes found in gray matter Fibrous - astrocytes found in white matter -proliferate after CNS damage |
|
Glial Gibrillary Acid Protein (GFAP)
|
Neurokeratin is found in cytoplasm and this protein is specifically present in astrocytes. Can be marked with antibodies. Valuable marker. Important because of brain tumors.
|
|
Microglia
|
Small with several process - come from stem cells.
-Involved with phagocytotic system. Proliferate during injury/disease. Secrete cytokines |
|
Ependymal Cells
|
Simple cuboidal cells with microvilli in Choroid process. Tuft of capillaries lined by ependymal cells, they filter the blood to form the CSF.
Can also be columnar cells - (spinal chord) - have cilia as well. Have aquaporins, create channels. |