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5 days ago · human skeleton, the internal skeleton that serves as a framework for the body. This framework consists of many individual bones and cartilages. There also are bands of fibrous connective tissue —the ligaments and the tendons —in intimate relationship with the parts of the skeleton. This article is concerned primarily with the gross ...
- The Spinal Cord
Human skeleton - Spinal Cord, Bones, Joints: For the spinal...
- Hands and Feet
Human skeleton - Hands, Feet, Joints: The skeleton of the...
- Skull
skull, skeletal framework of the head of vertebrates,...
- The Lower Jaw
Human skeleton - Mandible, Muscles, Joints: The left and...
- Interior of The Cranium
Human skeleton - Skull, Bones, Joints: The interior of the...
- Rib Cage
Ask the Chatbot a Question Ask the Chatbot a Question rib...
- Appendicular
Other articles where appendicular skeleton is discussed:...
- Axial
Axial skeleton, the part of the bony structure of the body...
- The Spinal Cord
- 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
Oct 25, 2023 · You already know that a large number of bones exists but how many bones are in the human body exactly? Generally speaking, there are 206 in an adult but the definite number is more nuanced and can vary from person to person. These bones are mainly divided into two parts, called axial and appendicular skeletons.
The internal human body includes organs, teeth, bones, muscle, tendons, ligaments, blood vessels and blood, lymphatic vessels and lymph. The study of the human body includes anatomy, physiology, histology and embryology. The body varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions.
The human skeleton is the internal framework of the human body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together. [1] The bone mass in the skeleton makes up about 14% of the total body weight (ca. 10–11 kg for an average person) and reaches maximum mass ...
Sep 27, 2024 · Function. Conditions. Diagnosis. Skeletal system photos and labeled diagrams can help you to understand the parts of the skeleton, how it's organized, the conditions that can affect it, and tests used to diagnose skeletal health. The skeletal system comprises 206 bones and has two main parts: the axial skeleton and the appendicular skeleton.
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3 days ago · The Skeletal System. Explore the skeletal system with our interactive 3D anatomy models. Learn about the bones, joints, and skeletal anatomy of the human body. The skeletal system includes all of the bones and joints in the body. Each bone is a complex living organ that is made up of many cells, protein fibers, and minerals.
