On a Beach Walk: #71 (Homeostasis)

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I like walking the beach. It’s good for the mind, body, and soul – and refreshing on my feet.

Recently thinking about balance caused me to wonder toward a related word – a very important biological concept. A word that is often mentioned and defined in biology textbook’s Chapter 1 or 2 as an important term – then seldom resurfacing. Teachers knowing its importance will regularly reinforce the concept throughout the course. Textbooks stressing this important concept are rare, therefore outside the mainstream.

The word – homeostasis – isn’t one that pops into everyday conversation. We don’t hear it on the news broadcasts or read it in news articles. Homeostasis has probably appeared as a Jeopardy answer in the form of a question, but doubtfully as a full category.

Homeostasis is that word that many do not know, but one that people know examples while not associating the examples to the word. Homeostasis has to do with balance, but not in the same sense as the actions when trying to walk a railroad track or balance beam.

Although our body is constantly producing heat, homeostasis is that mechanism keeping our body temperature relatively the same by releasing heat. If the body temperature lowers, a homeostasis mechanism adjusts to keep heat in and possibly produce more heat. After all, have you ever shivered?

Because reptiles don’t have an automatic mechanism to regulate body temperature, they adjust by responding with behaviors –  sunning on a rock to increase body temperature, or seeking  cool shade or a hole in the ground to keep the body from overheating.

In order to maintain a body temperature, the organism must have senses to detect external and internal temperature, plus ways to transmit those information/signals to bring about a response to maintain the balance – that’s homeostasis.

We take in water – most commonly through food and beverages. Our cells also constantly produce water. Our blood, over 50% water, continuously passes through our kidneys, which constantly removes water from the blood so it is released from the body as the key ingredient in urine. That’s homeostasis.

Water moving in and out of our body – yet, a mechanism is in place to keep the water level within us relatively constant. Making us thirsty when necessary – retaining water when needed – eliminating the excess if necessary. That’s homeostasis.

Many cells have water continuously entering, yet they don’t explode from over-swelling because of a mechanism for removing water is in place. That’s homeostasis.

Plants take in water through their roots, but also release water through their leaves – so plants must have a mechanism for regulating the two. Who would have imagined a similarity our kidneys have with plants – That’s homeostasis.

All living things require constant energy to survive, and regardless if caught, prepared, or made themselves, that energy comes from food – That’s homeostasis.

Our cells are constantly using food from the blood to make the energy required to sustain life. After we eat, our digestive system prepares the food so cells can use it. The final products of digestion move into the blood from transport to the cells for their use or to storage cells for later use. Insulin plays an important role in maintaining the sugar level in the blood – that’s homeostasis.

Living things have many examples of homeostasis, and maintaining body temperature and water and food levels are a few examples – but there are many others.

Yes – homeostasis is an important concept in biology and in life because it is important to all living things – birds, fish, reptiles, amphibians, mammals, single cells, insects, worms, sponges, jellyfish, clams, crabs, plants, and more – all living things.

My teacher side came out for this walk – but maybe my thoughts have given you something to think about. After all, I like walking the beach is good for the mind, body, and soul – and refreshing on my feet.

On Containers

 

Why is the astronaut in a space suit?

I always enjoyed asking that question to biology students. Knowing the knew the answer is one thing, but the question and the crafted discussion was a setup of what was to come. After all, I wanted to expand their view of the situation and use the discussion throughout the entire unit (3 chapters).

The space suit serves as a barrier between two environments – one suitable for the human body, and the other quite harsh – therefore, the space suit is a container similar to a can of vegetables on the grocery self.

The body within the space suit is also a container with a barrier separating different environments on each side of the barrier. Within the human body are several cavities – open spaces that are sealed spaces for organs. For instance, the chest cavity is sealed with a protective barrier to play an important role in inhaling and exhaling. Yes, another container within a container that is inside the protective space suit.

Tissues and organs (composed of tissues) are not only within the cavities, but throughout the body. Tissues are composed of two or more different types of cells working together in a common function. Surprise, surprise, surprise – cells are also containers because each cell has a protective barrier (cell membrane) separating two environments. It is through these membranes that essential materials pass through to reach their site of need for processing. Through these same membranes, the waste removal process occurs.

Cells contain individual parts with specialized functions. Are you surprised to know that many of these parts are covered with protective barriers separating two distinct environments?

Substances continually pass in and out of the cell through the membrane. Some of these movements occur naturally without the cell expending energy. On the other hand, some movements require energy to occur.

Cells are the reason we take in oxygen from the atmosphere and return carbon dioxide. Cells are the reason we eat. Cells are the reason the heart pumps blood throughout the body to transport nutrients and carry away wastes. Cells are the reason we go to the bathroom. Cells are the reason all vital activities exist.

Cells have to survive in order to reproduce. Cells require food and eliminate wastes. Cells must interact with their surrounding environment. Cells require amino acids to produce proteins. Cells contain DNA to serve as the code of life not only for itself, but for the organism as a whole. As Bruce Lipton (scientist) states, “In reality, a cell is a biological mini-me compared to the human body. A cell has every biological system that you have.” …. now, that is quite the container.

On a Scope

Yesterday’s post provided a snapshot of the microscopic world in the human body. It’s amazing to think that we transport along a wonderland no matter where we go. So that gave me an idea – another trip journey.

Today’s trip is a bit more advanced because besides regular microscope views, this video offers one of my favorites – electron micrographs. Enjoy the journey. Any favorite stops along the way?

On a Small World

Yesterday journey started at the subatomic level, displayed on Earth in the beautiful city of Venus, and only to drop us off somewhere in deep space. Simply wow – the scale of it all.

I appreciate deep space. After all, most of my headers (including this one) have been images from the Hubble Telescope. (See my Past Headers page).

Although the universe is vast, telescopes as Hubble have brought something very far away seem so person and close. On the other hand, let us not forget the beauty of the microscopic world. Who would have ever thought that cells, bacteria, and viruses within the human body had such intricate beauty.

PS: I have one more tomorrow.