Neurons come in a few basic shapes. The most common neuron in the CNS is the multipolar neuron. It consists of many dendrites and a single axon. Bipolar neurons are not very common. They are found in the eye, in the nose, and in the ear and consist of a singular dendrite and an axon. Pseudo unipolar neurons make up the sensory nerves of the body. They consist of a cluster of dendrites at one end, a long axon leading to the nerve cell body, and another axon leaving the nerve cell body at the same area.

Neurons connect to each other by synapses. The neuron first carrying the information is called the presynaptic neuron. This neuron has synaptic vesicles that release neurotransmitters. The synaptic cleft is the space between the neurons and the postsynaptic neuron is the receiving neuron. Label the various neurons and their parts as well as the synapse between the neurons.

Neuron Parts

Answer Key: a. Dendrites, b. Nerve cell body, c. Axon, d. Multipolar neuron, e. Bipolar neuron, f. Pseudounipolar neuron, g. Presynaptic neuron, h. Postsynaptic neuron, i. Synaptic vesicles, j. Synaptic cleft, k. Neurotransmitter

Postsynaptic Neuron

The nervous system develops early as a neural groove. This groove folds in on itself to become a neural tube as early as four weeks after conception. At about six weeks of age the beginning cerebral hemispheres can be seen as lateral enclosures from the neural tube along with the developing eye just posterior to the hemispheres. This embryonic brain is divided into three regions, the prosencephalon or forebrain, the mesencephalon or midbrain, and the rhombencephalon or hindbrain. Label the parts of the embryonic brain and the adult derivatives of that brain and color in the regions.

Frontal Section Week Embryo

Frontal section 4-week embryo

Frontal section 6-week embryo

Frontal section 4-week embryo

Frontal section 6-week embryo

Spinal Cord Frontal Veiw

Lateral view 4-week embryo

Lateral view 6-week embryo

Answer Key: a. Prosencephalon, b. Mesencephalon, c. Rhombencephalon, d. Spinal cord, e. Cerebral hemisphere, f. Developing eye, g. Forebrain, h. Midbrain, i. Hindbrain

Forebrain Midbrain And Hindbrain

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  • maximilian
    Where are pseudounipolar, multipolar and bipolar nerves found in the human body?
    8 years ago

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