HBS 2.2.1

Sensory Neuron

nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.

Axons

A long nerve cell process that usually conducts impulses away from the cell body.

Neurotransmitters

A substance (as norepinephrine or acetylcholine) that transmits nerve impulses across a synapse.

Dendtrites

Any of the usually branching protoplasmic processes that conduct impulses toward the body of a neuron.

Reread the first paragraph of the Introduction. Describe the types of stimuli your body is reacting to as well as the decisions you have to make. Do you think about each of your responses or do they just seem to happen?

During the moments of the accident your body is sensing a great deal of stimuli. In time of panic your body will produce large amounts of adrenaline which will heighten the bodies reception to stimuli while also increasing the heart rate. At these moments a person will feel a fight or flight sensation in which they would either run away from the accident or toward the accident in a panic to help someone.

How do you think a person would be affected if myelin on his/her neurons was damaged or destroyed? Explain.

If the myelin sheath is damaged then the speed of impulses transmission would be slowed causing decreased function of the affected area.

Myelin Sheath

In a neuron, an insulating coat of cell membrane from Schwann cells that is interrupted by nodes of Ranvier.

Describe one way in which neurons are similar to other cells in the body and one way in which they are different.

Neurons are similar to other cells because neurons have a cell membrane, a nucleus, cytoplasm, mitochondria, organelles, and carry out processes such as energy production.

In this activity, you read that there are billions of neurons in the human body that vary in size and somewhat in structure. Suggest and then support a reason why the body needs so many neurons.

The more complex the function the more neurons it takes to carry it out, for example, the brain stem and spinal cord have a large mass of neurons compared to nerves in your arms and legs everything flows back to the spinal column to the brain where it processes the data.

Describe the path of an electrical impulse as it moves through a neuron. You must use the words axon, axon terminal, dendrites, myelin sheath, nodes of Ranvier, synapse and neurotransmitters in your description.

The nerve impulses start in the dendrites then moves down the axon starting in the axon. Nerve impulses speed up the myelin sheath. Then through the nodes of ranvier speeding up action potential then at the axon terminal the electrical impulse goes through the synapse through electrical then chemical with neurotransmitters and electrical again back to a dendrite.

Synapses

The place at which a nervous impulse passes from one neuron to another.

Axon Terminals

The somewhat enlarged, often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells.

Association (interneuron) Neuron

a broad class of neurons found in the human body.

Nucleus

a discrete mass of gray matter in the central nervous system.

Nodes of Ranvier

a gap in the myelin sheath of a nerve, between adjacent Schwann cells.

Motor Neuron

a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.

How does the structure of each type of neuron relate to its function in the nervous system?

helps it process signals and know how to carry out functions from all the senses interneurons structure allow them to communicate between dendrites and axons which is their job

Cell Body

the nucleus-containing central part of a neuron exclusive of its axons and dendrites that is the major structural element of the gray matter of the brain and spinal cord, the ganglia, and the retina

Cell Membrane

the semipermeable membrane surrounding the cytoplasm of a cell.