Types of Cell Signaling

in this video, we're going to begin our lesson on types of cell signaling. And so it's important to note is that communication between cells of multi cellular organisms is really, really important for maintaining the organisms Home yo Stasis and recall Home Yo Stasis is basically just the idea of maintaining internal conditions within the cell, and this is really, really important for organisms. So communication between cells eyes going to occur via cell signaling and communication via cell signaling can occur and really two different types of ways it can occur directly. Or it could occur indirectly and so moving forward, we're going to talk about direct cell signaling and indirect cell signaling in their own separate videos. But we're going to start with the direct cell signaling, so I'll see you all in our next video to talk about that

in this video, we're going to introduce direct cell signaling and so direct sells. Signaling, as its name implies, is going to be local signaling between cells that are in direct contact with each other. And so recall from our previous lesson videos that neighboring cells are able to directly communicate via different types of cell junctions. And so notice down below in our image. Over here on the left hand side, we're showing you an example of how cell junctions can be used for direct cell signaling and so recall that gap junctions are junctions that connect the cytoplasm of two animal cells. And so what you'll notice is that these gap junctions, these proteins, here they create a gap between the two cells, where the cells are able to exchange nutrients and exchange signaling molecules with each other to directly communicate and notice that they are in direct physical contact here with these gap junctions. Now, over here, notice that we have plant cells and plant cells, use plasma. Does Mata as their version of gap junctions that connects there cytoplasm. And so here we're showing you plasma does model, which again is gonna connect the cytoplasm of plant cells, allowing them to exchange nutrients, materials and signaling molecules so that they could be in direct contact and signal and communicate with each other. Now, cell to cell recognition is going to be one. Cells make direct contact via membrane proteins, and so these membrane proteins ultimately are going to cause a cellular response. And so if we take a look at our image down below over here, cell to cell recognition, notice that we have two cells that are in direct contact this cell here in this cell over here, and notice that they have membrane proteins. This one has green membrane proteins, and the other one has purple membrane proteins here. And so what you'll notice is that with cell to cell recognition, a cell is able to recognize the proteins on the surface of another cell is able to recognize membrane proteins, and so here on the left hand side, what we have is our signaling cell. And on the right hand side, what we have is the target cell, and the reason this is the target cell is because ultimately this is where the cell response is being generated, and so we could say this cell is signaling a to this cell to respond. And so this year concludes our introduction to direct cell signaling. And in our next lesson video, we'll talk about indirect cell signaling, so I'll see you all in that video.

In this video, we're going to introduce indirect cell signaling and compare and contrast para cran versus endocrine hormones. And so indirect cell signaling, unlike direct cell signaling and, as its name implies, is going to be distant, signaling between cells that are not and direct contact with each other, and indirect cell signaling commonly uses hormones. Now hormones are really just defined as signaling molecules that are released by a seller gland and that can travel and affect distant cells in other areas. And so really, there are two types of hormones that we're going to mention here, and those are the para Quran hormones and the endocrine hormones. Now, peregrine hormones are hormones that travel very, very short distances, and Onley act on nearby cells in the vicinity of its synthesis. Whereas endocrine hormones are going to specifically be released into the bloodstream. And once endocrine hormones are released into the bloodstream, they can travel long distances to their target self and still allow for cell signaling. And so let's take a look at our image down below to get a better understanding of indirect cell signaling, and so notice that in our image we have this top half of the image, and we have this bottom half of the image and the top half of the image here, circled in yellow, is really the para Quran, showing peregrine hormones indirect signaling using Perricone hormones and again, peregrine hormones travel short distances. And so one thing to note is that the signaling cell here is not in direct contact with the target cell. Over here, there is a gap here in between them. And so, with peregrine hormones, the signaling molecules are only going to travel a short distance to get to the target cell and trigger. Ah, cell response now down below in the bottom half of the image. What we're showing you is in direct signaling using endocrine hormones. And so endocrine hormones again are gonna be secreted into the blood stream and ultimately travel long distances to the target self. So notice. Over here. On the left hand side, we have the signaling cells secrete ing endocrine hormones into the bloodstream here, and so once the endocrine hormones have been secreted into the blood stream, they can travel much, much further distances, so notice there's a larger distance here between the two cells as compared to peregrine hormones and these endocrine hormones, they they end up getting received by the target self for a cell response to be initiated. And so, ultimately this year concludes our introduction to indirect cell signaling and the difference between peregrine and endocrine hormones, and we'll be able to get some practice applying these concepts as we move forward in our course, so I'll see you all in our next video.

in this video, we're going to introduce synaptic cell signaling. And so synaptic cell signaling is when specific cells release nure oh transmitters across a synapse activating a target cell. Now, nure oh, transmitters can be defined as chemicals that are released by the end of a neuron or, in other words, a nerve cell in order to transmit a signal or convert the signal into a cell response. Now a synapse is defined as a small junction or region between the end of a nerve cell or the end of a nerve neuron and another cell. So let's take a look at our image down below to get a better understanding of synaptic cell signaling. So notice up above here, this is showing the very end of a neuron and recall the neuron is a nerve cell. And notice that at the very end of this neuron here, there are these little vesicles or um, membrane bubbles that contain nure oh transmitters. And so notice that these little purple circles that you see are the neuron transmitters. And these neurotransmitters can be released into this region here that we have, uh, colored and grain. And this region is the synapse. And so the synapses again the junction or the region between the very end of a neuron and another cell down here. And this is our target cell, which is at the bottom. And so the neuro transmitters are going to help transmit, uh, the signal or convert the signal into a cell response. And so notice that the neuro transmitter will bind to a receptor embedded in the target cells membrane. And that receptor ultimately is going to trigger, uh, signal transaction, a Siris of events that ultimately leads to the cell response. And so, ultimately here, synaptic cell signaling is going to be a form of pair Quran, signaling since it's going to be, uh, the neuro transmitter is going to travel short distances across the synapse. But ultimately, uh, synaptic cell signaling is gonna be a specific type of peregrine signaling between a neuron and some other target cell. And so this year concludes our introduction to synaptic cell signaling, and we'll be able to get some practice as we move forward in our course. So I'll see you all in our next video