It sends a signal to your blood stem cells that you need more red blood cells. This signal is received on the cell's surface. The stem cell transmits or transduces that message to the nucleus, so the cell knows your body needs more red blood cells.
While scientists know the human body contains trillions of cells, exactly how many cell types make up the body is still an active field of study. The most recent estimate notes that there are at least unique cell types in the human body , at least based on appearance.
Some scientists think that estimate is low, though, and new cell types are still being discovered regularly. The bottom line? You're looking at hundreds of different cell specialization pathways that your stem cells can take. All of the or more types of cells that make up the human body are found in one of those four tissue types — a lot more manageable to learn than memorizing hundreds of cell types, right? Now, let's check in one some of the special cell types you're likely to come across in your biology classes — the ones you'll need to know a little more in-depth.
Your circulatory system is one of the ones you're most likely to cover in biology class — so now's the time to get to know it! Your circulatory system is made up of a series of blood vessels — arteries, veins and capillaries — as well as a few specialized blood cell types:. Your body constantly churns out fresh blood cells to replace older or damaged ones. And all your blood cells are "born" within your bone marrow, from a population of stem cells that specialize in creating blood cells. You'll also likely come across the cells of the nervous system in your body.
But don't worry — while the brain might seem complicated, learning about your nerves is likely easier than you think. Neurons are nerves — the cells you're probably picturing when you think of your nervous system. They transmit information to control all the "thinking" in your brain, and also control muscle movement and other basic body functions. Also, nerves throughout your body send signals back to your spinal cord and brain.
Pain-sensing nerves, for instance, tell your brain when you're hurt, so you can avoid whatever caused the pain. Glia are the supporting cells that help your nerves function properly. There are a few major types of glia , and all play a role in helping your brain, spinal cord and other nerves communicate efficiently.
Some glial cells produce myelin, a waxy substance that "insulates" your neurons for better communication. Others act as the immune cells of the brain, helping fight off infections that would otherwise harm your nerves. And still others help keep your neurons supplied with nutrients so that your nervous system has the energy to work properly. The third major cell types you're likely to study are your muscle cells. And, thankfully, the three muscle cell types are easy to learn.
First, you've got skeletal muscle cells — the cells that make up virtually all of the muscles in your body. Skeletal muscle is the kind of muscle that — surprise — is anchored to your skeleton. It contracts to move your bones. So, say, when you contract your bicep, you'll bend your elbow. Skeletal muscle cells are, in part, voluntarily controlled by your brain. The cells in similar tissues and organs in other animals are similar to those in human beings but differ somewhat from cells found in plants.
Various organs and tissues function to serve the needs of cells for food, air, and waste removal. Benchmark 5C The Living Environment: Cells Grades , page Within cells, many of the basic functions of organisms--such as extracting energy from food and getting rid of waste--are carried out. The way in which cells function is similar in all living organisms. Benchmark 5C The Living Environment: Cells Grades , page Within the cell are specialized parts for the transport of materials, energy capture and release, protein building, waste disposal, information feedback, and even movement.
These are called biological drawings and their purpose is to highlight and label important parts of the specimen definition: the cell you are looking at under the microscope you are viewing and record its data. Scientists have set up specific rules when creating these to ensure that all have a similar look and contain the same features. Now, try your own hand at creating biological drawings of specialized cells viewed through the microscope.
Task 1 : Compare red blood cells and skeletal muscle cells, which you have learned about in previous activities. Record these similarities and differences. Task 2 : View the cheek cells slide and complete its biological drawing. Refer to the Microscope Lab to complete this assignment by looking at the following slides of specialized cells under the microscope:. Use the following organizer to compare these cell types. You will have to research the function of each cell and structure using the internet.
You may complete your table in point form. When you have finished your research organizer and biological drawing, look it over to make sure your work is complete and that it addresses the Learning Goals.
Now that you have learned about some specialized cells, it is time to design your own Super Cell. Your Super Cell will be specialized for the human body to help with either the digestive, respiratory or circulatory systems. You will need to research some specialized cells in these systems to help give you ideas for your Super Cell.
To start, you may want to think about some of the issues that these systems could experience, such as indigestion heartburn , carbon monoxide poisoning or heart disease.
The Resources List below is a useful starting point for your internet search. Your Super Cell might be based on a real cell in our systems, or it could have superpowers that human cells do not have. Be sure to think both about the structure and function of the cell.
What will it look like? What will it do? Introduction to Specialized Cells. Your browser does not support the audio element. Organelles To understand specialized cells, we need to recall how cells are built and the function of each organelle.
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