Lab 8 Nervous System Lab

Nerve Histology

 Sensory Peripheral Nerves

Peripheral Nerve

The comparison of the Nervous tissue with that of the muscle tissue is that nervous tissues provide the impulse for the motor functions of the muscle tissue. A neuromuscular junction is a place where the nerves meet the muscle, which cause the muscle to contract and relax.  Connective tissue fills the spaces between organs and tissues, and provides structural and metabolic support for other tissues and organs.

There are two classification for connective tissue.  They are Connective Tissue Proper (ie., loose irregular tissue and dense  irregular tissue) and Specialized Connective Tissue. Examples of Specialized Connective Tissue are as follows:

    

     The other specialized types of connective tissue are covered in other topics.

     Cartilage - (see the topic on bone and cartilage)

     Adipose tissue (see adipose cells)

     Hemopoietin tissue (bone marrow, lymphoid tissue)

     Blood (see the topic on blood)

     Bone (see the topic on bone and cartilage)

You may ask yourself why is the distal part of a peripheral nerve narrower than its proximal part?  The distal part of a peripheral nerve is narrower than its proximal part due to there are fewer fibers. 

The myelin sheath of a nerve accepts biological dye easily because of the abundance of lipids in the membranes wrapping around the axon.  In cross section  the myelin sheaths looks like tiny donuts.  The adipose cells may stand out as they contain preserved fat droplets that stain dark brown-black. 

A deficiency in the lipids of the myelin sheath can diagnose diseases.  One such disease would Multiple Sclerosis.  There are several symptoms: Blurred or double vision, loss of balance, numbness or tingling.

 Senelick, Richard. "Multiple Sclerosis (MS) Center: Symptoms, Treatments, Diagnosis, Stages, and Causes - from WebMD." WebMD. WebMD, 25 Oct. 2014. Web. 25 Oct. 2015.

Motor Peripheral Nerves carry information from the central nervous system to organs, muscles, and glands.

Motor Peripheral

Anatomy of a Neuron 

 Anatomy of a Neuron

Reaction Time Rulers

            The brain processes stimuli from the environment through its five senses: sight, taste, touch, sound, and smell.  At most there is a measurable difference between the rate at which one can process sensory information obtained visually, orally, and tactually.

	Visual Stimulus		Auditory Stimulus		Tactile Stimulus
	Person 1	Person 2	Person 1	Person 2	Person 1	Person 2
Trial 1	15”	20”	30”	28”	33”	35”
Trial 2	25”	30”	20”	15”	27”	33”

 

 

In my experience with this chart the dropper and catcher responded quicker using the visual stimulus than the other two methods.  The conclusion for the outcome was that the two participants were able to see approximately where the meter stick would drop compared to being blind folded.

The slower response came during the tactile stimulus experiment.  Both dropper and catcher did not trust the other.  It was like the game of trust where one person would stand in front of the other and would fall back.  That person was putting trust into the first person to catch him/her.

A message moving along pathways may take a longer time due to nerve impulses relies on positive movement on the ions across the nerve cell membrane.  The impulse must go down the entire axon.  The presynaptic nerve cell relays the message to the postsynaptic nerve by using neurotransmitter which takes time to get to the synapse.

The process of spinal reflex occurs without any involvement of the brain.  It activates pair receptors (like stepping on a tac) from here it causes the action potentials in the sensor neuron to stimulate interneurons whining the spinal cord.  After that the motor neurons.

Somatic Division		Autonomic Division
Function	Serves Skeleton Muscle	Fight or Flight; arouse body to deal with situations involving physical activity, mental alertness	Relaxes body; promotes digestion and other basic functions
Neurotransmitter	Acetylcholine	Norepinephrine	Acetylcholine