An Overview Of A Human Cell
What is Cell?
A cell is the smallest fundamental unit of life, and it is responsible for the survival of the living being. Cells are known as the building blocks of human life.
Cell Discovery
Robert Hooke was the first biologist who discovered the cell in 1665. When he observed a piece of bottle cork under a microscope, he noticed minuscule structures, and he named those structures cells. Cells differ, but they share some common organelles, including the nucleus, mitochondria, cytoplasm, lysosome, plasma membrane, Golgi apparatus, vesicle, smooth endoplasmic reticulum, rough endoplasmic reticulum, and ribosomes cytoskeleton.
Types Of Cells Based On Their Structure
Prokaryotic cells:
Prokaryotic cells are without a nucleus and have a nucleoid region where the genetic material is freely suspended. This cell ranges from 0.1 to 0.5 µm in size. Reproduction in these cells is asexual and generally by the process of binary fission.
Eukaryotic cells:
Eukaryotic cells have a nucleus and range between 10-100 µm in diameter. The plasma membrane works as a security guard, maintains nutrients’ transport, and is responsible for cell-to-cell communication. Reproduction is done sexually as well as asexually. Some common examples are plants, fungi, protozoans, and animals. Plant cell contains chloroplast and other plastids in them.
11 Types Of Cells
Stem cells:
Stem cells are found in the embryo and adult tissues such as bone marrow. These cells originate as unspecialised cells. They can develop themselves as specialised cells while others can play the role of building blocks of specific organs and tissues. Stem cells can divide and replicate many times to repair the tissues.
Endothelial cells:
These cells form a single cell layer lining all blood vessels. Signals from endothelial cells organise the growth and development of connective tissue cells. They regulate exchanges between the bloodstream and the surrounding tissues.
Bone cells:
In general, there are three types of bone cells:
- Osteoclast that dissolves bone—Osteoclasts do the work of decomposing for resorption and assimilation while healing
- Osteoblast that forms new bone—They regulate mineralisation and produce organic substance osteoid
- Osteocytes are surrounded by bone and communicate with other bone cells, they are also helpful in the formation of bone and maintaining calcium balance
Blood cells:
Blood cells originate from the bone marrow. There are three types of blood cells:
- Red blood cells: Red blood cells determine the blood type and transport the oxygen to the heart
- White blood cells: White blood cells are the immunity builder cells that destroy pathogens
- Platelets: Platelets help clot the blood and prevent excessive blood loss when the blood vessels are damaged due to external or internal reasons
Muscle cells:
There are three types of muscle cells:
- Skeletal muscles attach to bones and help involuntary movements. These are covered by protective connective tissues that support muscle fibre bundles.
- Cardiac muscle cells, found in the heart, form involuntary muscle. These do not require conscious efforts to operate. They also help in heartbeat synchronisation and heart contraction.
- Smooth muscle, not striated like cardiac and skeletal muscle, is the muscle that lines body cavities. It forms the protective walls of many body organs such as the kidney, intestine, etc.
Fat cells:
Fat cells are also known as adipocytes, and they are the main constituent in the adipose tissue. Fat cells are a storehouse of the stored fat known as triglycerides used for energy. These cells are round and swollen when fat is stored, shrinking when fat is utilised for energy. They also have hormones that help in regulating blood pressure, blood clotting, and cell signalling.
Skin cells:
Skin cells or epithelial tissues are the building block of skin. A layer of connective tissues supports them called the dermis and an underlying subcutaneous layer. These cells help protect the internal structure of the body from damage. Moreover, they guard the body against germs, prevent dehydration, store fat and produce vitamins and hormones.
Nerve cells:
The fundamental unit of the nervous system is a neuron. Neurons are known as nerve cells. They act as a messenger among the brain, spinal cord, and other body organs through nerve impulses. A neuron consists of a cell body, and nerve processes are finger-like structures (axons and dendrites) that transmit signals.
Pancreatic cells:
Pancreatic glands function as exocrine and endocrine organs. It releases hormones through ducts as well as directly into other organs. The main functions of pancreatic cells are regulating blood glucose levels digestion of proteins, carbohydrates, and fats. These cells are found in small clusters known as islets of Langerhans. Insulin, glucagon, and gastrin are the common hormones these cells produce.
Cancer cells:
Cancer cells are opposite to other cells and function to destroy the body. These cells originate from mutation stemming from radiation and ultraviolet light. These cells develop decreased sensitivity to anti-growth signals.
Reproductive or sex cells:
Reproductive cells bring new life into existence. Male reproductive cells called gametes or sperms have a tail called flagella. Female reproductive cells or ova are large in comparison to male reproductive cells. Generally, body cells are replicated by mitosis, but gametes are reproduced by mitosis.
Human Body Difference
The appearance of the human body is determined by the size of the skeleton, muscle shape, and thickness of the fat layer, which varies with age and gender. In general, males possess tall bodies, broad shoulders, body hair, and uneven fat deposits compared to females.
Brain Function
The body's vital control system is made up of the brain and spinal cord. Brain is the driver of the train called body. Thoughts come and go like a crowded train. In order to live your life to the fullest and improve it, it's necessary to track your thoughts. A single unsupervised thought may land the person in trouble. Visualize an over crowded train coming on the station. Passengers who departed from earlier stations are removed, and new passengers start boarding the train for their journey to the next stations.
Thoughts And Waves Similarity
Thoughts have a similar consistency to waves in the ocean. Waves are generated in the ocean and continue to come to the shores. No evidence of the wave's origin has been found by lay people. Brain waves pattern is measured by EEG (Electro Encephalograph), It's essentially an instrument that measures and displays brainwave patterns. The EEG test itself, also called an electro encephalogram, uses electrodes attached to the scalp to detect these electrical signals. Brain cells generate these signals, which are then represented by wavy lines on a recording.
Importance Of Food Quality
Food is the fuel that keeps us alive. Eating good and light food can provide energy to help overcome life's challenges. While the heavy or junk food degenerates energy and creates physical and mental lethargy. Another vital organ of the body is heart that pumps blood. Fresh blood is sent to the other organs and old blood is returned to the heart for purification and freshness.
Heart Function
Heart waves are measured by ECG (Electro cardio graph) it records the electrical signals in the heart. Test results can help diagnose heart attacks and irregular heartbeats, called arrhythmias. ECG machines can be found in medical offices, hospitals, operating rooms and ambulances.
Thoughts keep on coming and going in human mind and more the green flag is used to shed the useless thoughts, lighter becomes the mind and happier the daily life.
Experts say, CELL is the basis building block of human body. The building of basic body is formed by a cell, a tissue, muscle, nerve, skin, blood, bone morrow and bones. Billions of cells make a human body. Cell’s outer layer is called cell membrane and contains cytoplasm. This cytoplasm contains many organelles- the most important of which is nucleus.
The nucleus is the seat of DNA. DNA is a key genetic information that scientists use to determine a child's parentage.
Brain Principle
The brain is also the commander of activities done by the parts of the body. Brain – left or right – has neurons as constituent. Neurons play the role of communicator to carry messages from brain to the entire body.
Neurons are also referred to motor neurons. Motor neurons are of three types – Multi- polar, bipolar and uni-polar neurons. Neurons are characterized by their shoots, which are dendrites. Chemical signals from other neurons are transmitted to dendrites, which results in electrical impulses in the human body.
Central Nervous System (CNS)
The body’s chief controlling and coordinating center depends heavily upon billions of neurons grouped as nerves that transmit impulses between the CNS and other organs of the body. Motor and electrical impulses are two types of impulses that can be categorized. Motor impulses direct different parts of the body to act as warranted by external environment and situations and electrical impulses are always at work within the body and ready to react to the environment and situation. The brain is required to act appropriately when faced with a situation, and it decides whether to fight or flight.
Muscle tightening and motor action are observed during fight or flight mode. The foundation of the mind's response is formed by anxiety, anger, and worry. Motor impulses and electrical impulses both function to decide the reaction to situation. Positive or negative actions ensue. The outcome of winning or losing is determined by the situation and its handling. The nucleus of the cell is responsible for activating motor and/or electrical impulses. Cell- the basic building block- envelopes the nucleus. The nucleus initiates cell activation by getting nourishment from food. Food is the fuel that builds better cells.
Note: The writer is not a doctor. The views expressed in this blog are solely that of the author for general awareness of the reader and the journal shoulders no responsibility.