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Learn about the structure and function of the human body, from the skeletal system to the reproductive system, with detailed diagrams and names. Explore the anatomy of the head, neck, upper and lower limbs, and more.
In general, the human body can be divided into 3 main anatomical areas: head, torso, and limbs. In addition to the physical external parts, the human body can also be divided by organ system and the parts that compose those systems.
- Alexander Bolano
- 2018
- Overview
- Chemical composition of the body
- Organization of the body
Chemically, the human body consists mainly of water and organic compounds—i.e., lipids, proteins, carbohydrates, and nucleic acids. The human body is about 60 percent water by weight.
What are the four main types of tissue in the human body?
The four main types of tissue in the human body are epithelial, muscle, nerve, and connective.
What are the nine major organ systems in the human body?
The nine major organ systems in the human body are the integumentary system, the musculoskeletal system, the respiratory system, the circulatory system, the digestive system, the excretory system, the nervous system, the endocrine system, and the reproductive system.
human body, the physical substance of the human organism, composed of living cells and extracellular materials and organized into tissues, organs, and systems.
Chemically, the human body consists mainly of water and of organic compounds—i.e., lipids, proteins, carbohydrates, and nucleic acids. Water is found in the extracellular fluids of the body (the blood plasma, the lymph, and the interstitial fluid) and within the cells themselves. It serves as a solvent without which the chemistry of life could not take place. The human body is about 60 percent water by weight.
Lipids—chiefly fats, phospholipids, and steroids—are major structural components of the human body. Fats provide an energy reserve for the body, and fat pads also serve as insulation and shock absorbers. Phospholipids and the steroid compound cholesterol are major components of the membrane that surrounds each cell.
Proteins also serve as a major structural component of the body. Like lipids, proteins are an important constituent of the cell membrane. In addition, such extracellular materials as hair and nails are composed of protein. So also is collagen, the fibrous, elastic material that makes up much of the body’s skin, bones, tendons, and ligaments. Proteins also perform numerous functional roles in the body. Particularly important are cellular proteins called enzymes, which catalyze the chemical reactions necessary for life.
Carbohydrates are present in the human body largely as fuels, either as simple sugars circulating through the bloodstream or as glycogen, a storage compound found in the liver and the muscles. Small amounts of carbohydrates also occur in cell membranes, but, in contrast to plants and many invertebrate animals, humans have little structural carbohydrate in their bodies.
Nucleic acids make up the genetic materials of the body. Deoxyribonucleic acid (DNA) carries the body’s hereditary master code, the instructions according to which each cell operates. It is DNA, passed from parents to offspring, that dictates the inherited characteristics of each individual human. Ribonucleic acid (RNA), of which there are several types, helps carry out the instructions encoded in the DNA.
Along with water and organic compounds, the body’s constituents include various inorganic minerals. Chief among these are calcium, phosphorus, sodium, magnesium, and iron. Calcium and phosphorus, combined as calcium-phosphate crystals, form a large part of the body’s bones. Calcium is also present as ions in the blood and interstitial fluid, as is sodium. Ions of phosphorus, potassium, and magnesium, on the other hand, are abundant within the intercellular fluid. All of these ions play vital roles in the body’s metabolic processes. Iron is present mainly as part of hemoglobin, the oxygen-carrying pigment of the red blood cells. Other mineral constituents of the body, found in minute but necessary concentrations, include cobalt, copper, iodine, manganese, and zinc.
The cell is the basic living unit of the human body—indeed, of all organisms. The human body consists of trillions of cells, each capable of growth, metabolism, response to stimuli, and, with some exceptions, reproduction. Although there are some 200 different types of cells in the body, these can be grouped into four basic classes. These four basic cell types, together with their extracellular materials, form the fundamental tissues of the human body:
1.epithelial tissues, which cover the body’s surface and line the internal organs, body cavities, and passageways
2.muscle tissues, which are capable of contraction and form the body’s musculature
3.nerve tissues, which conduct electrical impulses and make up the nervous system
4.connective tissues, which are composed of widely spaced cells and large amounts of intercellular matrix and which bind together various body structures
Bone and blood are considered specialized connective tissues, in which the intercellular matrix is, respectively, hard and liquid.
- The Editors of Encyclopaedia Britannica
Body Parts Name: 50 Body Parts in English with Pictures. Learning Vocabulary, Skills. The names of body parts play a significant role in our lives, and knowing them contributes to health awareness and effective communication for adults and children alike.
Learn about the skeletal, muscular, cardiovascular, digestive, endocrine, nervous, respiratory, immune/lymphatic, urinary, female reproductive, male reproductive, and integumentary systems of the human body. Select a system to get started and explore its anatomy, functions, and diseases.
Nov 3, 2023 · There are two parts of the skeleton; axial and appendicular. The axial skeleton consists of the bones of the head and trunk. The appendicular skeleton consists of the bones within the limbs, as well as supporting pectoral and pelvic girdles. There are 206 bones in an adult human body.
Composition. The human body is composed of elements including hydrogen, oxygen, carbon, calcium and phosphorus. These elements reside in trillions of cells and non-cellular components of the body. The adult male body is about 60% water for a total water content of some 42 litres (9.2 imp gal; 11 US gal).
