Model of a Nerve Synapse

Nerve Synapse

The model of the nerve synapse consists of several parts that are printed separately in different colours and after printing the individual parts are assembled into one overall model. The model of the synapse is composed of two basic parts. The first part shows the presynaptic part of the synapse consisting of a knob-like extension of the axonal ending. In the presynaptic part, holes are modeled to represent the vesicles into which individually printed neurotransmitters in the shape of small balls need to be glued. In the presynaptic part there are also several models of mitochondria, which are inserted into the modeled holes designed for them. The second part of the model consists of a postsynaptic section showing the location on the cell to which the nerve impulse passes. A total of five receptors are modelled in the cell membrane, to which the binding neurotransmitters need to be glued, because the receptors show the gradual opening of ion channels. The ion models are made up of small spheres printed separately in the same way as the neurotransmitter models, and the ions are then glued into the ion channels as well as into the designated holes for them located in the postsynaptic model. These two basic parts of the model are connected at the back by a bracket. The bracket in the model serves to make visible the synaptic cleft between the presynaptic and postsynaptic membranes, which in reality is located between them. The model is made in such a way that the process of nerve impulse transmission from one nerve cell to another can be seen. The model does not show the ion channels for Ca2+ ion input, nor does it show models of these ions, for the reason that they are not mentioned in the description of nerve synapses in naturaly history textbooks.

Model of Neuron

Neuron

The neuron model consists of several parts that need to be printed separately with different colours in the case of single filament 3D printers, and then assembled. The model is based on the morphology of a multipolar neuron, as this is the model type of neuron shown in all natural history textbooks, which describes the basic structure of a nerve cell. At the same time, the model is made so that you can see what the body of the neuron looks like in section. The basic part of the model is the body of the neuron, on which several differently branched dendrites are modelled. This base also includes the axon, which is expanded as it exits the body to represent the initial segment of the axon. The body of the neuron is cut so that a hemispherical model representing the cytoplasm can be inserted into it. The cytoplasm model contains a blank space for a spherical model of the nucleus. Two small models of mitochondria are also inserted into the cytoplasm. Only these two organelles are shown in the neuron model because they are the most important in terms of function and because they are the only organelles depicted in the context of the neuron in natural history textbooks. Another part of the model is the myelin sheaths, which are made up of cylinders that have a hole inside them so that they can be slid onto the axon. A total of three models of myelin sheaths fit on the axon and show that the myelin sheath of the axon is not continuous, so Ranvier's notches located between the myelin sheaths can be shown on the model of the neuron. The last part of the neuron model is the axonal termination model consisting of individual branches at the end of which there is a knob-like extension participating in the synapse. The axonal ending is connected to the rest of the model by a peg that is modelled at the end of the axon.

Model of Xylem and Phloem

Xylem and Phloem

The model shows the elements of xylem - blood vessels (tracheae), tubular cells with dissolved transverse septa. Dead blood vessel cells do not contain protoplasts, only an aqueous solution of minerals (shown as empty cells).
The model shows elements of the lycae - sieve cells (phloem), living cells connected by perforated cell walls (sieves). Living cells do not contain vacuoles and nuclei, their contents consist of protoplast (cytoplasm shown in white) containing mitochondria (red organelles) and plastids (black and yellow organelles).
The cell size ratio of blood vessels and sieve cells approximately corresponds to reality.