The Bone Marrow

The bone marrow is a flexible, soft, spongy tissue that lies in the hollow interior of long bones. It forms about 4% of the total body weight, where it is a key component of the lymphatic system, producing the lymphocytes that support the body´s immune system. In it, there are two types of stem cells. The hematopoietic, which can produce approximately 500 billion blood cells per day, and use the bone marrow vasculature as a condiut to the body´s systematic circulation. Also, the stromal which can produce fat, cartilage, and bone. Without bone marrow, our bodies would not be able to produce the white cells we need to fight infection, and the red blood cells we need to carry oxygen to the tissue, and the platelets we need to stop bleeding.

There are two types of bone marrow. One of them is the red marrow. The red marrow consists mainly of the hematopoietic tissue. It is found mainly in the flat bones such as the hip bone, breast bone, skull, ribs, vertebrae and shoulder blades, and in the cancellous material at the proximal ends of the long bones femur and humerus. Red blood cells, platelets, and most white blood cells arise in the red marrow. At birth, all bone marrow is red, but adults have about half of it red. This is because with the aging, more and more of it is converted to yellow.

The other type of bone marrow is the yellow marrow. The color yellow is due to the much higher number of fat cells it is made up of. It is found in the medullary cavity, in the hollow interior of the middle portion of long bones. Some white blood cells develop in the yellow marrow. However, in some cases the body can convert the yellow marrow back to the red marrow in order to increase blood cell production.

Wrapping it up, the bone marrow is the spongy tissue in the cavities of the bones, in which both the red marrrow and the yellow marrow contain numerous blood vessels and capillaries that produces blood cells. Without these blood cells we would be very vulnerable to infections, we would not oxygenize our tissues, and could bleed to death.

Osmosis and Kidneys

What does osmosis have to do with kidneys?

The kidneys help control the levels of certain dissolved minerals called electrolytes. They also help filter out waste products called metabolites, that are created by cells using energy. This helps the body maintain stable amounts of compounds such as sodium, potassium and calcium in the blood. It also helps remove potentially toxic compounds that are filtered out of the blood and then concentrated by the kidneys into urine.

How does this happen? The kidneys have nephrons, the loop of Henle, the renal medulla, and the adrenal cortex that help this process take place.

The nephron is the basic structural and functional unit of the kidney. Its function is to regulate the concentration of water and slouble substances like sodium salts by filtering blood, reabsorbing what is needed and excreting the rest as urine. Usually, humans have 800,000 to 1.5 million nephrons in each kidney.

In the kidney, the loop of Henle is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. The loop of Henle´s main function is to create a concentration gradient in the medulla of the kidney, near the collecting duct, which is the difference in concentration. This process reabsorbs water and creates a concentrated urine for excretion.

The renal medulla is the innermost part of the kidney. It is split up into a number of sections, known as the renal pyramids. The renal pyramids include the renal artery, the renal tubules, and the renal ureter where blood enters and exits the kidney. The renal medulla contains the structures of the nephrons responsible for maintaining the salt and water balance of the blood. It is hypertonic to the filtrate in the nephron and aids the reabsorption of water.

Situated along the perimeter of the adrenal gland, the adrenal cortex mediates the stress response through the production of mineralocorticoids and glucocorticoids, including aldosterone and cortisol respectively. It is also a secondary site of androgen synthesis.

After all this explanation, you may still wonder why is osmosis important in the function of kidneys.Well, Osmosis is a physical and chemical process where any solvent or dissolved chemicals move across a semipermeable membrane seperating two solutions of different concentrations. In other words these solvents or chemicals migrate from an area of high concentration to one of low concentration. For example, if you dissolve something in a liquid, the dissolved compounds which are solutes will spread out until there is an equal concentration of solute everywhere.

Osmosis also provides the primary means by which water is transported into and out of cells. It is also an essential process where nutrients are delivered to the cells. Hence, the movement of water by osmosis is the main reason why it is so important to control the water balance of the body.

To wrap this up, it is osmosis that enables the kidneys to function in the right way. Without osmosis, our kidneys wouldn´t be able to seperate water and other substances from the wastes called urine.

The Breathing System

Breathing is something that comes by nature. You can control your breathing, but you don´t necessarily have to. When your watching a movie, or doing some work, you almost never think about breathing. This is why you are able to breathe unconsciously without a problem.

Breathing is the process of passing air into and out of our lungs to supply the body with oxygen. It is also part of the respiratory system. However, repiration is a little bit different. According to the dictionary, it is the process by which organisms exchange gases, especially oxygen and carbon dioxide with the environment, (inhale and exhale). In air-breathing vertebrates, respiration takes place in the lungs, while in fish and many invertebrates it takes place through the gills, and plants also respire using photosynthesis. Respiration and breathing are both co-dependent.

Have you ever asked yourself why we breathe? Your first thought was probably, “so I won´t die”. Yet, is there something deeper than that? Indeed, breathing brings oxygen to your blood, which then is circulated throughout your body making all your organs, muscles, etc., to function in the way they should. In other words, without oxygen you´re body woudn´t be able to move at all.

So, how does breathing work? The diaphragm has a primarily job on breathing. It is a large dome-shaped muscle under your rib cage that seperates the thoracic cavity from the abdominal cavity. When you breathe in air, your diaphragm contracts, drawing downward, creating a vacuum in the thoracic cavity. Then, this vacuum inflates the lungs by drawing air into the body through the trachea. Once you breathe air out, the diaphragm relaxes allowing the air to flow out as the lunggs deflate.

When you breathe, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened, and enters the back of your throat where the esophagus is located. While the trachea is located at the front of the throat. The air flows down the trachea, or windpipe, passing your vocal cords, to where the lowest ribs meet the center of your chest. This is where the trachea splits into two tubes, or bronchi, which connect to the lungs. These bronchi, then branch out into smaller bronchioles. At the end of these bronchioles, there are millions of sacs called alveoli.

When the air moves through the lungs, oxygen is exchanged for carbon dioxide in the alveoli. Inside the alveoli, oxygen is exchanged for carbon dioxide. After this, your red blood cells will show up at the alveoli, ready to trade the old carbon dioxide for some new oxygen. Then, the new oxygen is transported by these red blood cells in the arteries throughout the body, where tissues use the oxygen for energy.

In the process of using oxygen, your body´s cells create carbon dioxide. This is the waste your body made, and therefore cannot use. This carbon dioxide is moved by the blood inside the veins back to the lungs, where it is exchanged in the alveoli once more. It then will be moved from the lungs, back up your trachea, and out of your nose and mouth with every single exhale.

For our end result, we have air passing our trachea, to our bronchi that connect to our lungs, into smaller bronchioles, towards the alveoli. Then, from the alveoli, into the red blood cells, to our whole body, back to the alveoli, up our trachea, and out of our mouth and nose releasing carbon dioxide.

The Digestion Process

Imagine your favorite food on a plate right in front of you. Imagine the taste of it once you put it in your mouth. You begin chewing it bite by bite and you swallow it so it can go into your stomach. Being able to feel that sensation of satisfaction once it´s in your tummy is like going to the moon and coming back.

Have you ever asked yourself what happens to that food once you´ve swallowed it? You´re probably thinking on the process called poop. Yet, what really happens to it before getting there? Digestion is the process of changing food into a substance that the body can absorb and use as energy. It is a process that is half mechanical, and half chemical.

In the mechanical process, you teeth tear and grind the food in order to swallow it, and the muscular walls of your esophagus, stomach, and intestine continue this process by pushing the food along, and breaking it into smaller particles. While the chemical process occurs at every point in the digestive system. It involves the smelling and seeing of food that set off nerve impulses that trigger the release of enzymes and other substances that will break down food to release the nutrients inside for the body to use.

Now, picture that favorite food of yours again. Imagine taking a bite. When this happens your teeth chew breaking the food into small pieces, your salivary glands release saliva to help the food become softer, and slide down your throat on a flow of saliva. Then, enzymes in the saliva begin to digest the carbohydrates of that food.

After this, the food passes through the esophagus, which leads the food into the stomach. The stong and muscular walls of your stomach contract with force to break down the food into even smaller pieces while the glands in the stomach walls release stomach juices. These juices begin the digestion of proteins and fats into their respective amino and fatty acids. As a result, what began as your favorite food is now a thick, soupy mass called chyme.

Then, the stomach´s wavelike contractions push the chyme into the small intestine where your body begins to pull out the nutrients it needs. Likewise, your small intestine uses its contracting muscles to push the food along. After your small intestine has squashed every last piece of useful material out of the food, the indigestible remainder moves toward your large intestine. This large intestine is called the colon whose job is to absorb the water from the mass you delivered to it and then squeeze the leftovers into a compact bundle of waste known as feces (or poop). Finally, muscular contractions in the rectum push the feces out of your body, and the digestion process is completed.

To wrap up this process, when you eat, the food goes into your stomach, then into your small intestine, and finally into your colon converting food into poop.

Human and Animal Intelligence

What does it mean to say a creature is “intelligent”? What is intelligence anyway? It is the ability to learn or understand things or to deal with new or difficult situations according to the dictionary. Based on this, let´s compare human intelligence with animal intelligence.

Some of the potential criteria for human intelligence involves the use of tools and technology. However, chimpanzees are able to approach human levels of tool use. Studies revealed that they sharpened their sticks to use them as spears; this is also the first systematic use of weapon ever observed outside humans.

Also, self-consciousness is the classical test using mirrors. Here is where an animal´s face is marked while it´s asleep, and then it´s brought to a mirror when it´s awake. If the animal begins to groom the strange new mark, then the creature recognizes the face in the mirror as its own. Ultimatley, it is a sign of self-awareness.

There is also language involved in the human intelligence, but we are not the only ones that can communicate with each other. There are a number of seemingly and complex forms of animal communication. These include whale songs, bee dances, color changes in the animal´s body, etc. Nevertheless, there have been many attempts into teaching primates the basics of human language. Yet, it is still asked if these primates truly understand what they´re saying, or how much of what they´re saying. We have also made research on mimicking birds such as parrots into their language and reasoning capabilities. Even so, our understanding of animal language remains in its minority. Still, we can not say that language is the exclusive province of human beings.

Animals have also shown that math isn´t something just for human´s knowledge, instead elephants have performed simple arithemtic, monkeys can count, ants show a remarkable grasp of quantitative values, and chimps have an exceptional memory for remembering numbers.

Finally, elephants have even been able to paint whatever comes out of their minds without human beings teaching them. Remarkably, they never paint the same picture, but always something different.

As we can see, humans are not the only creatures that have intelligence. There are a many number of animals that can understand various things such as humans. I believe that if we could research on every single animal to its fullness, we´d be astonished.

Poisonous Arthropods and its Venom

Arthropods are invertebrates with jointed legs that make up about 75% of all the animals on Earth. Their major role is to maintain ecosystems as pollinators, recyclers of nutrients, scavengers, pest controlers, and food for other animals and humans. They include animals such as spiders, bees, wasps, ants, centipedes, slaters, scorpions, etc.

There are many different kinds of poisonous arthropods, and their venom can be used in many ways to help cure several sicknesses. Their venom has been used for thousands of years in traditional medicine. The honey of bees has been used to clot wounds, horseshoe crab blood is used to test antibiotics, the venom of scorpions can be used as a medicine that could inhibit harmful enzymes without harming inportant enzymes in the human body. Only 25 species of scorpions possess a venom that is deadly to humans, however scorpion toxins could be used for the treatment of arthritis, inflammatory bowel disease and multiple sclerosis. The sting of bees have several healing effects, they are probably the first natural cure for arthritis. Bee venom can be used to heal parkinson, alzheimer, back pain, cancer (strengthening the immune system by BV), HIV, and skin and eye diseases. It has also been claimed to be the new Botox.

However scientists use their venom to help heal sicknesses, the venom of arthropods has potential medical value.

Chordates and Vertebrates

Chordates are primarily animals with some very distinctive characteristics that possess a notochord that develops into the backbone, a dorsal nerve cord that is the spinal cord, pharyngeal slits that are a series of openings found immediately posterior to the mouth, an endostyle that is an internal groove found in the ventral wall of the pharynx and a post-anal tail for at least some period of their life cycles. These features characterize any animal as a chordate. They do not have spines; they just need to have a spinal cord, and generally it has four appendages that are in the forms of legs, arms, wings or fins. The Phylum Chordata includes more than 60,000 species with over 57,000 vertebrate species, 3,000 tunicate species and few lancelets. Animal groups in the chordate phylum include fish, amphibians, reptiles, birds, and mammals.

Vertebrates are a subgroup of the chordates, this means that all vertebrates are chordates, but not all chordates are vertebrates. They are distinguished from other chordates by having a backbone or spinal columns, a brain case, and an internal skeleton. They have a muscular system that consists of paired masses, and a central nervous system. Vertebrates are the major group of the chordates in terms of the number of species, evolutionary sophistication, and many other aspects as well. The most important feature of the vertebrates is the well-developed brain covered by the bony structure called “skull”.

In conclusion, all the vertebrates are chordates, but not all the chordates are vertebrates. There are more vertebrates than non-vertebrate chordates.  Clear cephalization is much pronounced in vertebrates than in non-vertebrate chordates. The vertebrates’ muscles are arranged in paired masses, but not in all chordates. Also, vertebrates have a spinal cord and a backbone, but not the other chordates.

Soil

Is soil really just dirt? Is it only used to hold up the plant? Or is it more valuable than what we imagine?

It is funny how sometimes we’re never taught about the importance of soil, or how we should care for it. According to the Bible our bodies were made by it.

Genesis 2:7

Then the Lord God formed man of dust from the ground and breathed into his nostrils the breath of life, and the man became a living creature.

So what really is soil? Soil is the mixture of minerals, organic matter, gases, liquids and a myriad of organisms that can support plant life. However, it also performs important functions like being a medium for plant growth, a means for water storage, supply and purification; it modifies the atmosphere, and it is also a habitat for organisms that take part in the decomposition and creation of a habitat for other organisms. It is one of the three major natural resources along with air and water. Actually, without it there would be no life.

It can also act as a filter against pollutants. This means that the water in the soil can transport harmful substances to humans and wildlife; such as nitrate, phosphorus and pesticides to water sources such as rivers, while they are important to soil and plant life. Soil can also filter urban pollutants like oil breaking it down into carbon dioxide and water; and metals can be absorbed into plants, which can be disposed of safely.

There are thousands of different types of soil around the world that in fact the USA has more than 20,000 varieties. Soil differs regionally because of the parent material, the climate and terrain of the region, as well as the type of plant life and vegetation present, and also because of human influence.

Soil is not an inexhaustible resource which needs no caring for. There is a major erosion problem affecting soil all over the world. It is a process that involves the removal and transport of soil by wind and water. It is a natural process, but changes in farming and land management practices can cause it to occur much faster than under natural conditions.

The rapid growth of the world’s population has made an increase in the cultivation of land, putting more pressure on the land, leading the soil to lose its structure and cohesion. It’s amazing how not only changes in farming methods contribute to soil erosion, but also activities such as construction, and hill walking have led to severe erosion. However, soil scientists are now developing new methods of land cultivation and management to control the problem.

Healthy soil is important for human health, because what is in the soil affects the health and quality of the food we eat that derives from it.

In conclusion, soils are a dynamic part of the ecosystem whose study crosses many scientific disciplines. The relationship between plants and soils is subtle and complex, involving the interaction of multiple biotic and abiotic factors. Also, a better understanding of soil is leading to new measures to protect and restore soil, and we must be aware of the importance of soil to protect it too.  

Gymnosperms and Angiosperms

Gymnosperms are a group of seed-producing plants, in which the term “gymnosperm” comes from the Greek word gymnospermos which means “naked seeds”. In contrast to seeds and ovules of flowering plants (angiosperms), they are not enclosed within ovaries. They also have seeds specialized on sporophylls, which often form cones. They are one of the largest subdivisions of the plant kingdom.

There are 4 plant phyla that are gymnosperms; Phylum Cycadophyta (it is the oldest phylum), Phylum Ginkgophyta (only Ginkgo biloba remains), Phylum Gnetophyta (it has a high variation but genetic similarity), and Phylum Coniferophyta (pine redwood, spruce, larch, etc.).

Conifers can have complex life cycles, taking up to a year or more for reproduction from pollination to fertilization.

   

Angiosperms are seed-bearing vascular plants that produce flowers and fruits, and are enclosed within ovaries. Out of all the plant species 90% of them are angiosperms. They have up to 4 types of modified leaves (sporophylls); sepals, petals, stamens, and carpels.

In the formation of the fruit the egg is fertilized after pollination takes place, the ovule develops into a seed, and then the ovary wall thickens, and forms many forms of mature fruits. The structure of the flower often determines the type of the fruit. Forming fruits in these plants is very hard work, but to the plant it is worth it. The only purpose of forming a fruit is to help the seeds become successful plants. Besides, what a great blessing for us and animals.

Angiosperms can also be either monocots or dicots. Monocots have only one cotyledon, and dicots have two. They each have different characteristics, that you would be able to detect them at simple sight. Angiosperms have a rich diversity and many strategies for survival and propagation.

In conclusion, gymnosperms and angiosperms are very different from each other, but both have a special and fundamental job for survival. They also help us in many ways, and we must work hard to protect them.

Photosynthesis and Cellular Respiration

Photosynthesis is a process used by plants and some algae to convert light energy, or energy from the sun, into chemical energy and storing it in the bonds of sugar. This will later be released to fuel the organisms’ activities. Photosynthesis is the most important biological process on Earth. It completes the carbon cycle by absorbing atmospheric CO2 and releasing free oxygen. In other words, it gives us oxygen to breathe.

Cellular respiration is the process by which the chemical energy of “food” molecules or waste products are released, and partially captured in the form of ATP, carbohydrates, fats, and proteins. It can be divided into three metabolic processes which are glycolysis, the Krebs cycle, and oxidative phosphorylation.

Both are used in plants and other organisms, they work together to make oxygen, and survive. What their difference basically is that photosynthesis makes glucose molecules, while cellular respiration breaks them down. Photosynthesis involves the production of carbohydrates by plants, while cellular respiration is the use of carbohydrates by cells of plants and animals. Photosynthesis captures light energy and converts it to chemical energy, while cellular respiration takes that chemical energy and breaks it down, releasing energy. The energy in photosynthesis is solar energy converted to chemical energy. The energy in cellular respiration is the stored chemical energy that originated from photosynthesis, and this chemical energy is converted to other kinds of energy like heat and motion.

In conclusion, plants use carbon dioxide and water to make sugar and release oxygen as a byproduct, while animals use sugar and oxygen to create energy, and release carbon dioxide as waste.