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This illustration shows food entering a cell and being broken down into smaller particles of different colors. This is catabolism, which releases energy. In anabolism, the different colored particles are combined with each other to form larger, multi-colored structures. Anabolism requires an energy input.
Anabolic reactions are building reactions, and they consume energy. Catabolic reactions break materials down and release energy. Metabolism includes both anabolic and catabolic reactions.

Every cell in your body makes use of a chemical compound, adenosine triphosphate (ATP) , to store and release energy. The cell stores energy in the synthesis (anabolism) of ATP, then moves the ATP molecules to the location where energy is needed to fuel cellular activities. Then the ATP is broken down (catabolism) and a controlled amount of energy is released, which is used by the cell to perform a particular job.

View this animation to learn more about metabolic processes. What kind of catabolism occurs in the heart?


Responsiveness is the ability of an organism to adjust to changes in its internal and external environments. An example of responsiveness to external stimuli could include moving toward sources of food and water and away from perceived dangers. Changes in an organism’s internal environment, such as increased body temperature, can cause the responses of sweating and the dilation of blood vessels in the skin in order to decrease body temperature, as shown by the runners in [link] .


Human movement includes not only actions at the joints of the body, but also the motion of individual organs and even individual cells. As you read these words, red and white blood cells are moving throughout your body, muscle cells are contracting and relaxing to maintain your posture and to focus your vision, and glands are secreting chemicals to regulate body functions. Your body is coordinating the action of entire muscle groups to enable you to move air into and out of your lungs, to push blood throughout your body, and to propel the food you have eaten through your digestive tract. Consciously, of course, you contract your skeletal muscles to move the bones of your skeleton to get from one place to another (as the runners are doing in [link] ), and to carry out all of the activities of your daily life.

Marathon runners

This photo shows three young men running in a competitive marathon.
Runners demonstrate two characteristics of living humans—responsiveness and movement. Anatomic structures and physiological processes allow runners to coordinate the action of muscle groups and sweat in response to rising internal body temperature. (credit: Phil Roeder/flickr)

Development, growth and reproduction

Development is all of the changes the body goes through in life. Development includes the process of differentiation    , in which unspecialized cells become specialized in structure and function to perform certain tasks in the body. Development also includes the processes of growth and repair, both of which involve cell differentiation.

Growth is the increase in body size. Humans, like all multicellular organisms, grow by increasing the number of existing cells, increasing the amount of non-cellular material around cells (such as mineral deposits in bone), and, within very narrow limits, increasing the size of existing cells.

Reproduction is the formation of a new organism from parent organisms. In humans, reproduction is carried out by the male and female reproductive systems. Because death will come to all complex organisms, without reproduction, the line of organisms would end.

Chapter review

Most processes that occur in the human body are not consciously controlled. They occur continuously to build, maintain, and sustain life. These processes include: organization, in terms of the maintenance of essential body boundaries; metabolism, including energy transfer via anabolic and catabolic reactions; responsiveness; movement; and growth, differentiation, reproduction, and renewal.

View this animation to learn more about metabolic processes. What kind of catabolism occurs in the heart?

Fatty acid catabolism.

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Questions & Answers

) Which of the following best describes the human body's defense mechanism against environmental bacteria?
what is an inflammation
Lodrick Reply
it's a reaction from a body tissue
is the body own mechanism of fighting against disease especially infections or injuries.
which cells are responsible for bone formation?
Richard Reply
which muscles are innervated by the lateral plantar nerve?
Tinyiko Reply
what book should i read for my Msc exam (physiology)
zeleke Reply
let ask u aquiz where bones live in a body
Lowyer Reply
306 bones in a human body
Netope Reply
206 bones in a human body
there are 206 bones in human body and a baby's body has about 300 bones at birth
what is anatomy?
Nuwagaba Reply
anatomy is the study of the internal structure of a living organism
can be define as the Scientific Study Of internal structure of the body Some of this Structures are Very tiny they can only be seen by The assistance of a microscope, While other structures can be seen manipulated and Weighted
Anatomy is the scientific study of the body and the physical relationship between systems
gross anatomy is the study of the internal structure of a living organism at a visible or macroscopic level
Favour Reply
homeostasis is the steady maintenance of the internal system
study of the structure of cells,tissue using a microscope
is the study of how the human body works and relates
i cannot understand this please explain how to calculate
Sania Reply
I don't get it either
How to calculate what exactly?...
be clair
where are bones lived
name of all the bones and eg
Shantal Reply
treatment for hereditary diseases
With gene therapy, the treatment or elimination of inherited diseases or physical conditions due to these mutations could become a reality. Gene therapy involves the manipulation of genes to fight or prevent diseases. Put simply, it introduces a "good" gene into a person who has a disease caused by
Why do cardiac muscle demonstrate autorhythmicity
Olemogile Reply
cardiac muscle tissue has autorhythmicity, the unique ability to initiate a cardiac action potential at a fixed rate. spreading the impulse rapidly from cell to cell to trigger the contraction of the entire heart.
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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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