9

The enzyme responsible for the breakdown of acetylcholine (Ach), i.e., acetylcholinesterase, rapidly degrades, and inactivates Ach in the synaptic cleft after release. This process is particularly fast, as the synapse has to be cleared of neurotransmitter for a next action potential to occur (Čolović et al., 2013). So no, Ach does not leak away under ...


5

Read "supply" as "carry action potentials to." When the action potential reaches the junction with the muscle (i.e., the neuromuscular junction), neurotransmitters are released into synapse. A similar membrane depolarization occurs on the muscle cell, ultimately leading to contraction. Nerves visible to the naked eye are actually bundles of individual axons ...


4

From this closeup image, you can see there is more than one nerve on each side that is parallel to the spine. Source: imgur.com First, they are the right and left sympathetic trunk that run from the base of the skull to the coccyx. Image source: Earthslab.com Additionally, they could be the right and left long thoracic nerve, which innervate the serratus ...


3

I am not entirely sure what you are after, but I (as have others that commented on this question) interpret your question as "The linked chapter contains too much technical information". Quite frankly, after scanning the book chapter, I have to agree with you. Therefore I have sought for a quick overview image of all the cranial nerves including their ...


3

The following image of a cadaver shows the hypoglossal highlighted: Source: StudyBlue You can see the flap of skin/muscle that has been removed to get an understanding of the thickness of tissues separating the nerve from outside the body. Additionally, here is an image showing a person receiving an operation. You can see the relative depth of the nerve ...


2

You are looking for the Trigeminal nerve, the largest nerve in the face. Here it is with its branches. It is both afferent and efferent. Afferent and efferent components of the facial nerve in the bullfrog (Rana catesbeiana) Cranial Nerves Illustrated: Figure V-4 General sensory component of the trigeminal nerve, ophthalmic (V1) division. General sensory ...


2

One pathology affecting the vagus nerve is autonomic neuropathy which can be secondary to several causes-one of the most commonly acquired cause is diabetes mellitus. It can manifest with various symptoms such as resting tachycardia (heart beating fast without exercise), exercise intolerance, orthostatic hypotension, constipation, gastroparesis (delayed ...


2

I can't find a great answer to this either, but there is a known concept of a CNS-PNS transition zone, specifically as it pertains to myelination of cranial nerves. With the exception of CN 1 & 2 (which are effectively wholely CNS) the other cranial nerves are anatomically similar to spinal nerves, i.e. they're myelinated by Schwann cells and have an ...


1

I'll attempt an answer, but please know you don't have a clear nor defining question to address. This is more suited for conversation or open discussion, and I recommend starting a chat on the topic. Please be wary the question may be put on hold. I'll give it a go and respond from the top down. I absolutely don't think this is going to be fruitful for other ...


1

Nerves (including cranial nerves) are constituted of neurons, and other supporting cells and structures (e.g. myelin sheath and extracellular protein matrix). Neurons are highly specialized cells that have a particular cellular anatomy: As you can see, the cell body (or soma) contains the nucleus, and projects it's axon towards other structures in the ...


1

Classically, only the CN.IV "decussates" (at the superior medullary velum) but some cranial nerve nuclei are on the contralateral side, so a lesion to the upper moto neurone or to cranial nerve nucleus of some cranial nerves will cause a contralateral deficits. This is seen in cranial nerves VII & XII Lesions at the lower motor neuron of cranial nerves ...


1

I just wanted to add, regarding CN VII. CN VII receives stimulation via the facial nucleus from both the ipsilateral and the contralateral corticobulbar tracts. The upper muscles of facial expression (particularly around the eyes) receive stimulation from both the ipsilateral and the contralateral corticobulbar tracts. The lower portion of the face is ...


1

As you mentioned, the resulting impairment depends on the level of the injury: nuclear, fascicular, central / peripheral. So, you should differentiate lesions inside the brain tissue (which can be at nucleus, at any location of a tract, before crossing or after, and outside. From this, the first thing we should explain is the normal anatomy. From normal ...


1

We can somewhat rule out reason 1 because fingertips are also highly sensitive to sensory stimulus. Moreover innervation is not solely about sensory inputs but also motor functions, visceral control etc. All the nerves required for the motor function and a significant portion of visceral control nerves connect to spinal cord. Therefore in my opinion reason ...


1

I know the vagus nerve is linked to ulcerative colitis, which could have serious effects on the brain due to body-wide inflammation. You could probably search "vagus nerve" "colitis" and "neuroinflammation" and get some good papers on pubmed.


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