Nervous System

neurons and synapses , that is nerve cells and their connections

A Dendrite

I am going to assume you are talking about decapod crustaceans, which is the kind most people eat. You can imagine a lobster as I describe the parts, but the description applies generally to all decapods, even crabs. The animal is covered by a chitinous exoskeleton. The shell that makes up the head is called a carapace, and it covers both the animal's head and thorax (similar to your torso). The head and thorax in a lobster have been fused together to form a cephalothorax. The part most people call a tail is actually the abdomen of the animal. Now I'll describe the main appendages on the animal going from front to back. In front, there are 10 walking legs (5 on each side), called pereiopods (pereio = thorax, pod = leg or foot). Usually, at least the first pair are modified at the tips to form chelae(claws). These are always attached to the cephalothorax. There are also appendages attached to the bottom of the abdomen, called pleopods (pleo = abdomen, pod = leg or foot). At the very end of the tail, there are additional flattened appendages which make up the tail fan. The flattened portion are called uropods (uro = tail). The center piece, flat in lobsters, a sharpened tip in shrimp, is called the telson. Crabs are constructed more or less the same way except the abdomen is greatly reduced and folded under the cephalothorax (check it out next time you are eating a crab!).

Yes. All animals in the world have muscles, otherwise they wouldn't be able to move.

nah, the sympathetic part of the autonomic nervous system actually inhibits bladder contraction. the sympathetic response of the autonomic nervous system is in charge of a fright response. It seems contradictory that you pee yourself when scared, I'm looking this up myself

it is located in the brain and goes from the retina (back of the eye) to center of the brain.

for more details research OPTIC NERVE or CN 2 (for short)

ANS reflex arcs are stimulated by input from sensory or visceral receptors. The signals are processed in the hypothalamus (or regions of the spinal cord) and target effector control is then regulated via myelinated preganglionic neurons

theres chemicals that are released by the brain to make you think and be more cautious. because you dont know what will happen. you dont have memories about what the implications will be, what the result of your actions will be

I believe the answer is skeletal muscles.

Chemical

bogo

i believe nervous because it's not as deep in the skin as the others

Axon Terminals

in many cases yes

hghhgj

Tactile Anesthesia

The nervous system receives information and by the sensory nerves it transports to the brain what you learnt.

The Motor Area registers information and controls movement of the body.

tinnitus

layering

Chronic pain
The Cones are responsible for sharp focus and color perception. (particularly in bright light)

yes third nerve palsies (Bells palsy) will typically resolve on their own. The llength of symptoms varies

The endocrine system.

The Ascending pathways of the central nervous system is made of "White Matter." (Vast amount of Axons coated with a sheath of Myelin)

They may not have been designed to do so, but they do stimulate the central nervous system.