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 a Beach Walk: #66 (Communities)

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

Community is an interesting word – a word with multiple meanings – a word used differently by biologists, sociologists, and the general population.

I’m confident the initial thought for most people fits into the sociological word. In the biological world, a community is a group of different populations of organisms living and interacting together. All the small mouth bass in a specific lake form a population – not a community.

The lake community made up of different fish, turtles, insects, frogs, algae, single-celled organisms, plants, and more – all living and interacting together in various food chains interwoven into a more complex food web.

There is a biological community on this beach that I walk, although I don’t know enough about the organisms here. Another community exists within the shallow water that refresh my feet. Different communities exist with changing depths and distance from shore.

Whereas in terms of biology, we humans are one population of the same species – Homo sapiens – yet we relate to sociological communities – a group of people identifying themselves in a common spirit.

I think of the main (but different) communities in my current life – my neighborhood, my dance friends, my church, the golf club where I work, my golf league – all are groups of different people with common interests. Work and hobbies also unite people into communities.

I grew up in a small town that would be more of a community than a small city – yet the town had neighborhood communities: Sugar Run, Mulberry Heights, Lincoln Heights, Naylor’s Run, and more.

I think about the community of my nearby neighbors in my small town. We kids within a few streets who played together – and the parents who knew each other. Parents who would watch over all of us while we played – or even provide a snack to the group. It seems those days are not only gone, but I question if they will ever return.

A college campus is a distinct community within a municipal community. The two interact in a variety of ways, yet are quite distinct.

I think about the wave of immigrants who left their homeland to find a new life in America and other countries throughout the world. Many live in the same neighborhood, some of which live on today as areas known as Little Italy, Germantown, Chinatown, Greektown, and others.

I think about other types of communities today where people gather for support around a common interest – LGBT, a variety of personal support groups, like hobbyists as knitting, modern trains, Civil War reenactments, wine and many more. Let us not forget the political communities – groups of like-minded people around an ideology.

Technology has created electronic communities. Facebook connects a social network as a way to keep in touch with people you know. Blogs have fostered new connections of people who didn’t know each other and may never meet – yet join together to form a community of common interests, support, and genuine respect – so yes, technology and travel have brought the world community closer.

As I walk the beach on this day, I can’t forget the snowbird communities found here and throughout the southern US. Snowbirds – mainly retired people from northern locations who migrate to the south for warmer temperatures during winter. Snowbirds know that no matter how cold it gets here, it is warmer than home.

Being a snowbird is good because walking the beach is good for the mind, body, and soul – and refreshing on my feet.

On a Beach Walk: #62 (Food)

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

Looking across the water is a reminder that life lives below surface. A large variety of fish, shrimp, clams, oysters, scallops, and more. Of course the listed ones are commonly available food for us to eat. So I wonder, “What’s for dinner?”

Is an ongoing question for you? We ask it, but also laugh about this seemingly eternal question. Although our time at the beach is away from the normal routine of home, “What’s for dinner?” ever looms in our midst. So, why not, I’ll think about food today.

All of us have a variety of likes and dislikes. Some of us are risk takers when it comes to trying different foods, others have a limited menu of preferences. So food: What is it? Why do we need it? When it comes to food, what do living things have in common with each other?

Food – that basic need for all life forms. All the organisms of the sea and the beach need food for the same reasons as people – for nourishment – for the nutrients that either provide energy, act as a building block, or assists in a process. Yes – that’s what carbohydrates, fats, proteins, vitamins, and minerals are all about.

Food – think of all the cookbooks available – let alone online resources of recipes – all forming a collective of bountiful offerings of culinary delights. Yet, most people limit themselves to a rotation of less than 20 recipes.

Food – Think of the times of our settlers when most ingredients were grown in their own gardens or by other locals. The farmer’s markets of today carry on the tradition of locally grown products, which also seems to carry a greater importance outside North America.

I think of today’s large grocery stores – endless aisles of canned and packaged products that are complete with preservatives, fat, sodium , sugar, and more. Therefore, much of today’s cooking is an act of combining various boxes and cans into a final product.

On the other hand, the food industry today provides fresh fruits and vegetables from throughout the world – a luxury less available during my youth – oranges from South Africa – grapes from Chile – after all, bananas are not grown everywhere.

I think of a time when families ate an evening meal together – and even a more grand meal on Sunday afternoon – whereas today our lives are more on-the-run causing us to yield our food preferences to frozen and packaged products or a wide variety of fast-food establishments.

Today’s life offers many restaurants of a variety of styles and prices without a messy kitchen – well, at least not ours. I find it interesting how cuisines differ not only from country to country, but also from region to region within a country. The fried plate of everything and anything is more common in the US South and the US North. The dishes of northern Italy are different from those of the south.

I think of the abundance of natural food in nature – the corn with its husk but without a label because corn is corn. Let us not forget that corn is a plant – a living thing that also needs food just like we do and for the same reasons. Green plants make their own food by photosynthesis because they can’t catch it or kill it. Animals hunt for food because (and unlike the green plants) they can’t make their own. Whether an organism catches food or makes its own, food’s end result is the same.

Light from the sun is the initial energy source driving photosynthesis, but there are also organisms living in the darkness of the deep sea that can make their own food without the presence of light – but they use the sulfur gases venting into the water from Earth’s core as the energy driving their food production process. Nature’s design is so grand.

It seems food is more complex than many realize, but thinking about food makes me hungry. Besides, it’s lunchtime.  But for now , I continue moving toward the condo because 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 Beach Walk: No. 7

I like walking the beach as it is good for the body, mind, and soul – and refreshing on my feet.

The sands display a myriad of shells. Different shapes, sizes, colors, and patterns. Although they now lay idle on the sand, each was once a home for something alive – a clam, oyster, scallop, whelk, conch, or other Molluscan relative. Home for a comparatively simple life – a life born to eat so it grows and survives so it can reproduce then die. A life aiming at perpetuating the species so that species can fulfill its niche in nature.

A life with a collection point of nerves serving as its neurological center – but not a center of with emotions, intellect, problem solving, and complex communication. But a simple brain – one geared for operating body functions, movements, sensing, and responding. Sensing the presence of food or predators, the current’s direction, the water’s temperature, and more – to sense to react.

The numerous shells I see tell only a fraction of the story of what life in the water must be. All those shells contained a life – a life starting as a simple cell floating free in the water. A life that developed into a free-swimming larva or served as food for something else. A life that continued to develop into a young shelled organism or food for other organisms. Finally developing into an adult that can reproduce, yet also be a food source for other life.

No wonder adults release so many eggs as not all will get fertilized. Not all will survive the free-floating stage or as free-swimming larvae. Not all will develop into reproductive adults. No all will live a full adult life.

That’s the life of a mollusk – a clam, oyster, scallop, whelk, conchs, and others. Compared to ours, a life that is simple, but one that is ecologically important. Each fulfilling a niche in the intricate web of life on our planet.

This is what I ponder as I see the shells on the beaches that I walk. After all, walking is good for the mind, body, and soul – and refreshing on my feet.