Search results
Results from the WOW.Com Content Network
This system describes how bones are connected to other bones and muscle fibers via connective tissue such as tendons and ligaments. The bones provide stability to the body. Muscles keep bones in place and also play a role in the movement of bones. To allow motion, different bones are connected by joints.
The muscular system is an organ system consisting of skeletal, smooth, and cardiac muscle. It permits movement of the body, maintains posture, and circulates blood throughout the body. [ 1 ] The muscular systems in vertebrates are controlled through the nervous system although some muscles (such as the cardiac muscle ) can be completely autonomous.
Muscles, bones, and joints provide the principal mechanics for movement, all coordinated by the nervous system. It is believed that the reduction of human bone density in prehistoric times reduced the agility and dexterity of human movement. Shifting from hunting to agriculture has caused human bone density to reduce significantly. [5] [6] [7]
The human body consists of biological systems, that consist of organs, that consist of tissues, that consist of cells and connective tissue. The history of anatomy has been characterized, over a long period of time, by a continually developing understanding of the functions of organs and structures in the body.
[14] [15] There are between 600 and 840 muscles within the typical human body, depending on how they are counted. [ 16 ] [ 17 ] [ 18 ] In the present table, using statistical counts of the instances of each muscle, and ignoring gender-specific muscles, there are 753 skeletal muscles.
There are more than 600 skeletal muscles in the human body, making up around 40% of body weight in healthy young adults. [18] [19] [20] In Western populations, men have on average around 61% more skeletal muscle than women. [21] Most muscles occur in bilaterally-placed pairs to serve both sides of the body.
Nerves connect the spinal cord and brain to the rest of the body. All major bones, muscles, and nerves in the body are named, with the exception of anatomical variations such as sesamoid bones and accessory muscles. Blood vessels carry blood throughout the body, which moves because of the beating of the heart.
In the human body at birth, approximately 300 bones are present. Many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones. [3] [4] The largest bone in the body is the femur or thigh-bone, and the smallest is the stapes in the middle ear.