Introduction to Human Anatomy- A Basic Guide to Human Life
Outline of the Human Body: Cells, Tissues, Organs, Organ Frameworks, and Bones
The human body is a complex, profoundly coordinated structure comprised of cells that cooperate to achieve the unique capabilities essential for supporting life.
Anatomical life systems and physiology change astoundingly between fertilization and birth. After birth, the pace of anatomic and physiologic changes eases back, however, youth is as yet a period of momentous development and improvement. A few anatomic changes happen past adulthood, however, the physiologic changes in the body’s cells and organs contribute most to what we experience as we mature.
The Cellular Level
Cells are the fundamental structural blocks of the body. All tissues and organs are made of billions of various cells.
Some types of cells found within the body include:
- Blood cells
- Muscle cells
- Skin cells
- Nerve cells
- Glandular cells
The human body also contains foreign cells such as bacteria and fungi. These microorganisms live on the skin, mouth, and stomach. They also live in the digestive and reproductive organ systems. These microorganisms make up what is known as the microbiome. The bacteria and fungi that make up the microbiome do not cause harm. Instead, they are essential in maintaining total human health.
All cells in an individual’s body are relatives of two cells, a woman’s egg and a man’s sperm. After the egg and sperm combine, the fertilized egg is simply a solitary cell. This cell, the zygote, divides multiple times, creating descendant cells that will eventually develop into the human organ system.
Cellular Structure
Frequently considered the smallest unit of a living organism, a cell is comprised of many smaller parts, each with its own function.
Human cells have a surface layer (called the cell membrane) that acts as the gatekeeper of the cell. The cell membrane controls what substances can enter and leave the cell. The cell membrane contains receptors that respond to substances created in the body and to external drugs that enter the body. Responses that occur at the receptors frequently modify or control a cell’s function. An illustration of this is when insulin binds to receptors on the cell membrane to permit glucose to enter cells and assist with keeping up with suitable glucose levels.
Cell Membrane
The cell membrane is primarily composed of phospholipids, cholesterol, proteins, and carbohydrates. Directly inside the cell membrane is the cytoplasm which is a thick solution that holds molecules responsible for cellular processes. Bound to the cell membrane is the mitochondria. The mitochondria generate most of the energy needed to power the cell’s biochemical reactions.
One of the most important components of the cell is the nucleus. The nucleus acts as the cell’s control center and contains the cell’s genetic material (genes and chromosomes). The primary function of the nucleus is to produce and assemble the cell’s ribosomes.
Tissues
Tissues are a group of related cells that work together to perform a specific function. There are 4 types of tissues, connective tissue, epithelial tissue1, muscle tissue, and nervous tissue. Connective tissue is a tough tissue that binds (or connects) the body structures and other tissues. Epithelial tissue provides a protective layer over all the body surfaces. Muscle tissue is attached to bones and provides movement. Nervous tissue is made up of nerve cells (neurons) and is used to send messages throughout the body system.
Organs
Organs are made up of several types of tissue, meaning they are also made up of several types of cells. The body has several different types of organs, such as the heart, liver, and kidneys. Each with its own specific function, that allows the body to perform daily tasks such as digestion, breathing, blood circulation, filtration and elimination of toxins, and movement. Did you know that the skin is the largest organ in the body?
Bones
There are 206 bones in the human body. Bones are actually living tissue. They’re made up of:
- Compact tissue – the harder outer layer
- Cancellous tissue – the soft spongy inner layer
- Subchondral tissue – the smooth end of the bone which is covered in cartilage – another type of tissue.
The bones provide support and shape for the body. Some bones, such as the ribs, provide protection for vital organs such as the lungs, digestive tract, and heart.
Summary
This is a basic description of what makes up the human body. The body is an incredibly complex vessel. To describe every facet requires many thousand-page novels, and even that barely scratches the surface. To learn more about the integral parts of the human body, explore our site to find more articles written specifically for each part of the body.
Supporting Research
- https://humanhealthco.com/?p=2192 ↩︎
