Human Body Systems Pdf

  1. Introduction To Human Body Systems Pdf
  2. Printable Human Body Organ Systems
  3. The 11 Human Body Systems Pdf Amoeba Sisters
Human body

Main content: Human body systems Other contents: Circulation, Digestion, Respiration, Excretion Add to my workbooks (121) Download file pdf Embed in my website or blog Add to Google Classroom Add to Microsoft Teams Share through Whatsapp.

  • (i) Human beings share basic characteristics of living things. (ii) Human anatomy is the study of body structures and the physical relationship among body parts of human beings. (iii) Human physiology is the study of the functions of the human body. (iv) Anatomy and physiology are closely integrated both theoretically and practically.
  • The Organ Systems of the Human Body and Their Functions ORGAN SYSTEM MAJOR ORGANS/PARTS FUNCTIONS 1. Integumentary System Skin, hair, sweat glands, and nails Helps maintain body temperature Covers and protects the body Eliminates wastes through perspiration 2. Skeletal System 206 bones, cartilage, tendons, and ligaments; teeth included.
Please select which sections you would like to print:
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.

Our editors will review what you’ve submitted and determine whether to revise the article.

Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work!
Articles from Britannica Encyclopedias for elementary and high school students.
The Editors of Encyclopaedia Britannica
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....

Human body, the physical substance of the human organism, composed of living cells and extracellular materials and organized into tissues, organs, and systems.

The Human Body: Fact or Fiction?
Can people choose to be left or right-handed? From nerves and genes to muscles and organs, see how ambidextrous you are by choosing between right --and wrong-- in this quiz.

Human anatomy and physiology are treated in many different articles. For detailed discussions of specific tissues, organs, and systems, seehuman blood; cardiovascular system; digestive system, human; endocrine system, human; renal system; skin; human muscle system; nervous system; reproductive system, human; respiration, human; sensory reception, human; skeletal system, human. For a description of how the body develops, from conception through old age, seeaging; growth; prenatal development; human development.

Human body systems worksheet pdf

For detailed coverage of the body’s biochemical constituents, seeprotein; carbohydrate; lipid; nucleic acid; vitamin; and hormone. For information on the structure and function of the cells that constitute the body, seecell.

Many entries describe the body’s major structures. For example, seeabdominal cavity; adrenal gland; aorta; bone; brain; ear; eye; heart; kidney; large intestine; lung; nose; ovary; pancreas; pituitary gland; small intestine; spinal cord; spleen; stomach; testis; thymus; thyroid gland; tooth; uterus; vertebral column.

Get a Britannica Premium subscription and gain access to exclusive content. Subscribe Now

Humans are, of course, animals—more particularly, members of the order Primates in the subphylum Vertebrata of the phylum Chordata. Like all chordates, the human animal has a bilaterally symmetrical body that is characterized at some point during its development by a dorsal supporting rod (the notochord), gill slits in the region of the pharynx, and a hollow dorsal nerve cord. Of these features, the first two are present only during the embryonic stage in the human; the notochord is replaced by the vertebral column, and the pharyngeal gill slits are lost completely. The dorsal nerve cord is the spinal cord in humans; it remains throughout life.

Pdf

Characteristic of the vertebrate form, the human body has an internal skeleton that includes a backbone of vertebrae. Typical of mammalian structure, the human body shows such characteristics as hair, mammary glands, and highly developed sense organs.

Beyond these similarities, however, lie some profound differences. Among the mammals, only humans have a predominantly two-legged (bipedal) posture, a fact that has greatly modified the general mammalian body plan. (Even the kangaroo, which hops on two legs when moving rapidly, walks on four legs and uses its tail as a “third leg” when standing.) Moreover, the human brain, particularly the neocortex, is far and away the most highly developed in the animal kingdom. As intelligent as are many other mammals—such as chimpanzees and dolphins—none have achieved the intellectual status of the human species.

Chemical composition of the body

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 compoundcholesterol 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.

Organization of the body

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; and (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 next level of organization in the body is that of the organ. An organ is a group of tissues that constitutes a distinct structural and functional unit. Thus, the heart is an organ composed of all four tissues, whose function is to pump blood throughout the body. Of course, the heart does not function in isolation; it is part of a system composed of blood and blood vessels as well. The highest level of body organization, then, is that of the organ system.

The body includes nine major organ systems, each composed of various organs and tissues that work together as a functional unit. The chief constituents and prime functions of each system are summarized below. (1) The integumentary system, composed of the skin and associated structures, protects the body from invasion by harmful microorganisms and chemicals; it also prevents water loss from the body. (2) The musculoskeletal system (also referred to separately as the muscle system and the skeletal system), composed of the skeletal muscles and bones (with about 206 of the latter in adults), moves the body and protectively houses its internal organs. (3) The respiratory system, composed of the breathing passages, lungs, and muscles of respiration, obtains from the air the oxygen necessary for cellular metabolism; it also returns to the air the carbon dioxide that forms as a waste product of such metabolism. (4) The circulatory system, composed of the heart, blood, and blood vessels, circulates a transport fluid throughout the body, providing the cells with a steady supply of oxygen and nutrients and carrying away waste products such as carbon dioxide and toxic nitrogen compounds. (5) The digestive system, composed of the mouth, esophagus, stomach, and intestines, breaks down food into usable substances (nutrients), which are then absorbed from the blood or lymph; this system also eliminates the unusable or excess portion of the food as fecal matter. (6) The excretory system, composed of the kidneys, ureters, urinary bladder, and urethra, removes toxic nitrogen compounds and other wastes from the blood. (7) The nervous system, composed of the sensory organs, brain, spinal cord, and nerves, transmits, integrates, and analyzes sensory information and carries impulses to effect the appropriate muscular or glandular responses. (8) The endocrine system, composed of the hormone-secreting glands and tissues, provides a chemical communications network for coordinating various body processes. (9) The reproductive system, composed of the male or female sex organs, enables reproduction and thereby ensures the continuation of the species.

key people
related topics
did you know?
  • The human femur can support a weight thirty times that of the human body, making it even stronger than steel.
  • The evolution of the human eyebrows is believed to have prevented the influx of sweat into the eyes.
  • Chronic stress produces high levels of cortisol, which may cause damage to the hippocampus in the brain, leading to memory loss.
  • An increase in the volume of background noise has been correlated with the perception of food as less sweet or less salty.
  • The human nervous system can relay electrochemical messages at a rate of 249 mph (400 km/hr).

If you’ve been asking this question for too long or for some time, you’re about to get the much needed answer to it , not only can you download human body systems pdf free download PDF in PDF on this PDF book site, you can also download human body systems pdf free download PDF book on this same book site. All you need in one place with easy access and no cost attached. What more could you ask for?

Introduction To Human Body Systems Pdf

ABOUT human body systems pdf free download

Printable Human Body Organ Systems

Human Body Systems: Structure, Function, and Environment is an informative primer that focuses on the organ systems within the human body, and their part in health and disease. The ideal supplement to any Human Biology, A & P, or Microbiology course, it covers: -Nutrition -Digestion -Circulation and Blood -Immunity -Respiration -Senses -Urinary System -Nervous System – Skeletal and Muscular Systems – Endocrine and Reproductive Systems It closes with a brief discussion of ecology and environmental issues that affect the way humans live and interact with the world around them.

The 11 Human Body Systems Pdf Amoeba Sisters

Contents