Topics in BiologyTypes of Desert and their Characteristics Characteristics of Tropical Rainforest Swamp Forest: What are Swamp Forests? Characteristics of Swamp Forests Savanna: Savanna and Grassland explained Savanna - Types of Savanna Tropical Savanna and Temperate Savanna with their Characteristics Introduction to Biomes: What is a Biome? Importance of Swamp Forests Swamp Forests - Types of Swamp Forests Ecology - Ecological Concepts explained Biology: What is Biology? Are Viruses Living Organisms? Differences Between Bone and Cartilage Skeleton: Functions of the Human Skeleton Bone: Type and Classification of Bones based on Shape Skeletal Material: Cartilage and its Functions Cartilage: Types of Cartilage Components of the Ecosystem What is Ecology? Branches of Ecology Ecosystem: What is an Ecosystem?
Academic Questions in Biology
Which of the following is a category of long bones?
The end product of photosynthesis is _____.
The above diagram illustrates a _____.
The living cells that makes up cartilages are called _____.
Which of the following statement is incorrect with regards to chitin?
Which of the following is NOT a function of the human skeleton?
Organisms that manufacture their own food through the help of sunlight or chemicals are best referred to as _____.
Organisms that begins a food chain and also manufacture their food through photosynthesis are best referred to as _____.
Have you ever wondered why on a sunny day you drink a lot of water and tend to produce lesser urine? On the contrary, think about how likely you will produce more urine on a cold day and drink less water too. This is so because some processes are constantly ongoing inside your body and they are necessary for your survival.
Now, let's imagine that someone has a fever. His or Her temperature will be abnormally high as a result of the fever. The person may sweat abnormally or even urinate abnormally. On your part, you will suspect that some processes are not working right inside the person.
Medically speaking, for a person to be physiologically healthy, the conditions and processes in his or her body must be carefully and properly controlled. This internal control is what homeostasis entails.
Homeostasis can be defined as the regulation and maintenance of a constant (or nearly constant) internal environment.
Recall that your environment is everything that surrounds you; for instance air, water, phone, shoes and anything around you right now. This concept of environment is your external environment.
In physiology, we have another concept of environment called the internal environment; and it is this environment that the bodily homeostatic organs constantly regulate to it's best optimum conditions.
Now let's think of it this way; if for instance; the external environment is very dirty and unhealthy (from lack of regulation, cleanliness and healthy living), children will suffer from illnesses and diseases like cholera, typhoid and dysentery. This is true because the respective causative organisms (of such diseases) will find their way into the child's body systems and invariably, the environment inside their body (internal environment).
As living organisms, human beings are composed of trillions of cells. These cells aren't just stacked upon one another (like a pack of cards); instead, they are separated by a fluid filled space.
Image Credit: Quora
The above diagram illustrates the various fluids seen within and around the cell
The fluid filled space present outside all the cells of any multi-cellular organism is termed as the Extracellular fluid or ECF.
Note: The Blood Plasma (found inside the blood vessels; that is "arteries, veins and capillaries") is a component of the ECF because they are present outside the body cells. The same is true for the interstitial fluid which is also another component of the ECF.
The ECF accounts for about 35% (one-third) of the Total Body Water (TBW) in healthy adults.
Similarly, inside each of the cells is another kind of fluid called the Intracellular Fluid or ICF.
The ICF comprises of the cytoplasm of each cell's organelle which contains water, proteins and electrolytes.
About 65% (two-third) of the Total Body Water is ICF. For this reason, the volume of ICF is greater than that of ECF with regards to the Total Body Water (TBW).
The Total Body Water (TBW) accounts for about 65% of the body weight of an average man. (This value will vary with age, for instance children will have a higher percentage value while that of the aged will be lesser).
The above fact on TBW affirms that: "humans are composed more of water (liquid) than solids".
The two compartment accounting for the Total Body Water are the ICF and ECF; and these presents the internal environment.
It is this internal environment that is regulated via homeostasis.
Note: The concentration of substances within the internal environment must be at a very narrow range, else, the organism becomes sick and may eventually die. Most of the medical drugs function by restoring the internal environment to it's normal composition.
In humans, homeostasis is achieved through two systems; these are:
Nervous System: It comprises of the brain and spinal cord.
Please read on the Uniqueness of Man (The Brain).
Endocrine System: It has every thing to do with hormones. The pituitary gland is often referred to as the master endocrine gland; that is, it regulates the homeostatic functions of other endocrine glands.
For now, think of endocrine glands as the producers of hormones.
These two systems coordinates all homeostatic processes by regulating the respective homeostatic organs in the body.
Below are some homeostatic organs alongside a summary of their homeostatic functions:
Hypothalamus: Regulates body temperature, sleep, appetite and thirst.
Kidney: Regulates water, salts and electrolyte via urine formation.
Skin: Regulates water, salts and electrolyte via sweat formation.
Liver: Regulates the storage of glucose, storage of blood, production of bile, breakdown of proteins, cleansing of the body and much more.
Pancreas: Regulates blood glucose and glycogen.
Lungs: Regulates oxygen and carbon(IV)oxide intake through breathing.
The diagram below shows the various homeostatic organs and their locations.
Image Credit: Phagcse Science
Note: The nervous and endocrine systems regulate the above homeostatic organs through a mechanism called the negative feedback mechanism.
To explain what a negative feedback mechanism is, take a moment to imagine yourself walking down the road on a sunny day. You are most likely to sweat.
For the above scenerio, your act of sweating is good for you because this is how the homeostatic process regulates (attempts to cool) your body from the sun's hot rays.
Image Credit: Scientist Cindy
Again, sweating helps lower your body temperature and this is a good thing. This is true because when an increased bodily temperature isn't checked, controlled or regulated, it becomes dangerous to the health.
Still using the above instance, you will notice that the amounts of urine produced by your kidneys will be lesser on this sunny day. This is happening because you are already losing water and salt (through sweating), thus less urine is produced in an attempt to make up for your water loss (that is; an attempt to conserve water).
Again, you are likely to drink a lot of water on this sunny day due to a higher tendency of being thirsty. This thirstiness is brought about by the hypothalamus (through stimulations from the pituitary gland, also called the master endocrine gland). The goal of being thirsty is to enable you drink more water, thus compensating for the water loss which resulted from sweating.
All of these homeostatic processes in the above paragraphs will continue on and on. If not checked, it might become detrimental to the your health.
From our above instance (walking down the road on a sunny day), you can't continue to sweat forever because that will not be good for you.
Now, what seems to be a solution at the beginning of our example (sweating) can now potentially cause excessive water loss; and this is where the negative feedback mechanism comes into play. To this end, the kidneys produces less urine while the hypothalamus stimulates thirst to compensate for water loss through sweating.
Note: When you leave the sunny environment into a cold environment, your homeostatic organs will begin to revert their initial actions. As an instance, the following processes will occur on a cold day:
The above homeostatic organs are able to revert their actions from a process termed negative feedback. Negative Feedback is a result of coordinations from the nervous and endocrine systems.
Negative feedback mechanism therefore allows the increasing product of a process or pathway to be controlled, decreased or put into check.
It generally causes a decrease in the function of a process.
We will discuss more on each of the homeostatic organs in a further article.
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Alfred Ajibola is a Medical Biochemist, a passionate Academician with over 7 years of experience, a Versatile Writer, a Web Developer, a Cisco Certified Network Associate and a Cisco CyberOps Associate.
Amazing facts in Biology
Male Seahorses actually give birth to their young ones, NOT the female
All babies are born with blue eyes
Research made at the University of Vienna suggested that yawning may play an essential role in cooling the brains
All voluntary and concious activity of right handed people are controlled from the left part or hemisphere of the brain
A snail can actually sleep for 3 years 😁
An adult human being is composed of about 60% water. In fact, a newly born baby is composed of about 80% of water. This will drop to 65% after a year and finally to about 60% as the child ages
Without saliva, food can never be enjoyed. Food becomes tasteless since saliva is needed to dissolve the chemicals present in food onto the tongue’s taste buds.
Saliva also contains an enzyme called salivary amylase or "ptyalin" which helps to digest cooked starch to maltose. Maltose is a double sugar or disaccharide. Please read on sugars here
NOTABLE POINTS IN Biology
During strenuous exercises like sprinting or 🏃 running, your body may actually work in the shortage of oxygen. During this time, your body owes oxygen (called oxygen debt) and it must be replenished or repayed after the exercise is stopped. This is why you breathe excess of oxygen after you stopped the exercise.
This is the concept of anaerobic respiration
A food Chain is a diagram that shows the relationship between plants and animals within a habitat on the basis of how they rely on each other for food.
Note: Habitat is a place where an organism live. It is of three types:
The term Biology originated from two Greek words. They are:
Biology can therefore be defined is the study of life
Anything that has life is generally considered as a living organism (or organism) 🌱🐐🐓. All living organisms must be able to carry the following activities:
The above listed points are often regarded as the basic characteristics of life. You can memorize them using the acronym (MR. NIGER DAC).
The gas used in the manufacture of food by plants is Carbon dioxide or Carbon(IV)oxide or CO2.
Plants manufacture food through a process called photosynthesis. Please read on photosynthesis here
Note: Plants are the only orgnisms that take away CO2 from the atmosphere
In the Biological organization of life, it is said that cells form tissues, tissues form organs and organs form systems. There are 12 systems in the human body; these are: