Flashcards in nerves June 7 Deck (558)
What do Platelets do?
Platelets are stem cell fragments made in your bone marrow. These cells bind together to help repair damaged blood vessels and stop bleeding. If you have a cut or a scrape, for example, platelets will stick together causing the blood to clot and stop the bleeding.
Is ACH always excitatory? Is this the same as stimulatory?
The neurotransmitter acetylcholine is excitatory at the neuromuscular junction in skeletal muscle, causing the muscle to contract. In contrast, it is inhibitory in the heart, where it slows heart rate.
My notes say parasympathetic is always stimulatory. Even though it is "stimulatory", that stimulation may mean calming down. Does this mean ACH always stiumulates? or ? only in the Parasympathetic, and why? is it about the receptors?
Cells of cajal - where do they come from? and where do they live?
Interstitial cells of Cajal (ICC) are mesenchymal cells located within the muscle layers of the alimentary tract that mediate communication between the autonomic nervous system and smooth muscle and may underlie dysrhythmias, gastroparesis, and slow intestinal transit comprising diabetic gastroenteropathy
How does arachnoid villi work?
The arachnoid granulations act as one-way valves. Normally the pressure of the CSF is higher than that of the venous system, so CSF flows through the villi and granulations into the blood. If the pressure is reversed for some reason, fluid will not pass back into the subarachnoid space.
Are ependymal cells special?
Ependymal cells are a specialized type of epithelial cells that line the ventricular system of the brain and play a key role in the production of cerebrospinal fluid.
They line the internal cavities of the CNS - part of the blood-brain barrier and they can absorb and secrete cerebrospinal fluid.
What is the purpose of the nodes of ranvier?
The myelin sheath is regularly interrupted along the length of the axon by specialized regions called the nodes of Ranvier, which are necessary for the propagation of an action potential along the axon. The nodes of Ranvier are essential in the speed and timing of delivery of impulses from one neuron to another,
Slow vs fast anterograde flow down axons?
Neurofilaments and other cytoskeletal polymers are transported down the axon at a rate of 0.2–8 mm day−1, in a process known as 'slow' axonal transport. This transport is orders of magnitude slower than the transport of vesicular cargos in 'fast' axonal transport
What is the speed of retrograde flow re axons and what is the danger?
Speed is about 200 (half between fast and slow antero - and danger is toxins - tetanus, herpes, rabies - toxins and viruses.
DYNEin powers retrograde flow
What are the two types of synapses?
Chemical and electrical. neurotransmitters vs. gap junctions, CAN BE EXCITATORY OR Iinhibitory
How many synapses can occur in one nuero
10 or a zillion. Purkinje in cerebellum 100,000
What are NSF and how does it relate to vesicles?
NSF is on the membrane of synaptic vesicles and is required for formation, targeting and fusion w/ membrane
synapses are morpholically classified how?
type 1 - asymmetrical, type ROUNDED / excitatory suggestion 2, symectrical FLATTENED - suggested to be INHIBITORY
Does release of nerotrasnmitter create excitation or inhibition?
Both - depending upon... Parasympathetic only excitation.
M1, M2, M3 (muscarinic - G protein linked) - NICOtinic is Gated ION channel
What are catecholamines?
Norepinephrise, epinephrine, dopanmine - all G protein linked - NE and E bind with alpha 1,2 and beta 1,2,3
Dopamine binds w/ D1,2
NE - roles in anxiety, panic attacks, depression, mania
E - secreted by chromaffin cells in adrenal medulla
DOPA - role in parkinsons
What is required to restore the vesicle fro the membrane edge back into the bulb?
Clathrin, dynamine and syapsin are used to effect this, protein kinase is also involved -
four types of neuerglia?
astrocytes (BBB, etc), oligodendrocytes (made and wrap myelin), ependyma (line w/ cuboidal, / link w/ desmosomes - and CSF) and microglia - police (mesodremal v. neuroectodermal)
CNS has no CT - it's mushy - so these help support. Pathologically, create 40% of tumors.
What protein do astorcytes have?
GFAP - glial fibrillary acidic protein. = these are prominent bundes of intermediate filament
What do astrocyte feet line?
external limiting membrane (pia) and internal limiting membrane (epedympa - lining ventricles)
they COVER the vare areas of nodes of ranvier in myelinated fibers - they lie on cell body or axolemma
They form gap junctions w/ each other -
have adrenergic receptors, GABA and peptide receptors
Can astrocytes remove excess neurotransmitters at synapses?
yes. They can also form scar tissue called gliosis. Huge roll in BBB
What are Tanycytes?
specialized Ependymal glial-like cells that line the third ventricle, are emerging as components of the hypothalamic networks that control body weight and energy balance. They contact the cerebrospinal fluid (CSF) and send processes that come into close contact with neurons in the arcuate and ventromedial hypothalamic nuclei.
Where do microglia come from?
What disease injures Schwann cells?
A rare disorder in which your body's immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body
What disease injures oligodendrocytes?
What causes Wallerian degeneration?
Any lesion of the axons that leads to an interruption and any lesion of the nerve cell bodies that leads to the cell death is followed by Wallerian degeneration. In the CNS common causes are infarction, hemorrhage, tumors, and head injury with shearing of nerve fibers.
four parts of cerebrum
parietal (movement, (TOP) perception of stiumli)
Occiptal (behind - visual)
temporral ( memory speech, auditory stimuli - on the SIDE)
Cerebellum is called the ?
Little brain - associated with regulation and coordination of movement, posture and balance, fine motor skills (ice skating
basic vital life functions - breathing, heartbeat BP
Midbrain (vision, hearing, eye and body movement);
Pons (motor control) consciouness, sleep
Medulla oblongata - breathing, heart rate
forebrain - motor coord
midbrain - lose control of emotion and chance of blackout
brainstem - heart rate, body empt, appetite, consciousness