Human musculoskeletal system

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Musculoskeletal system
Features of the human activity system from the 1911 Encyclopædia Britannica
Identifiers
MeSHD009141
TA2351
FMA7482
Anatomical terminology

The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body.

It is made up of the

hematopoietic system.[3]

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. Cartilage prevents the bone ends from rubbing directly onto each other. Muscles contract to move the bone attached at the joint.

There are, however, diseases and disorders that may adversely affect the function and overall effectiveness of the system. These diseases can be difficult to

orthopaedic surgeon
.

Subsystems

Skeletal

The skeletal system serves many important functions; it provides the shape and form for the body, support and protection, allows bodily movement, produces

muscles and cartilage. It is a complex structure with two distinct divisions; the axial skeleton, which includes the vertebral column, and the appendicular skeleton.[6]

Function

The skeletal system serves as a framework for

lungs being protected by the rib cage
.

Located in

leukocytes
form in adults. From the red marrow, erythrocytes, platelets, and leukocytes migrate to the blood to do their special tasks.

Another function of bones is the storage of certain minerals.

minerals is high, these minerals are stored in the bone
; when it is low it will be withdrawn from the bone.

Muscular

The body contains three types of muscle tissue: (a) skeletal muscle, (b) smooth muscle, and (c) cardiac muscle.
On the anterior and posterior views of the muscular system above, superficial muscles (those at the surface) are shown on the right side of the body while deep muscles (those underneath the superficial muscles) are shown on the left half of the body. For the legs, superficial muscles are shown in the anterior view while the posterior view shows both superficial and deep muscles.

There are three types of muscles—

joints.[8] Muscles are innervated, whereby nervous signals are communicated[9] by nerves, which conduct electrical currents from the central nervous system and cause the muscles to contract.[10]

Contraction initiation

In

nerve terminal. The space between the nerve terminal and the muscle cell is called the neuromuscular junction. These neurotransmitters diffuse across the synapse and bind to specific receptor sites on the cell membrane of the muscle fiber. When enough receptors are stimulated, an action potential is generated and the permeability of the sarcolemma is altered. This process is known as initiation.[11]

Tendons

A tendon is a tough, flexible band of

fibrous connective tissue that connects muscles to bones.[12] The extra-cellular connective tissue between muscle fibers binds to tendons at the distal and proximal ends, and the tendon binds to the periosteum
of individual bones at the muscle's origin and insertion. As muscles contract, tendons transmit the forces to the relatively rigid bones, pulling on them and causing movement. Tendons can stretch substantially, allowing them to function as springs during locomotion, thereby saving energy.

Joints, ligaments and bursae

Human synovial joint composition

Joints are structures that connect individual bones and may allow bones to move against each other to cause movement. There are three divisions of joints,

articular capsule, binding the joint with its taut tissue.[6]

Ligaments

A

elastic tissue.[6] Ligaments connect the ends of bones together in order to form a joint. Most ligaments limit dislocation, or prevent certain movements that may cause breaks. Since they are only elastic
they increasingly lengthen when under pressure. When this occurs the ligament may be susceptible to break resulting in an unstable joint.

Ligaments may also restrict some actions: movements such as

hyper flexion are restricted by ligaments to an extent. Also ligaments prevent certain directional movement.[13]

Bursae

A bursa is a small fluid-filled sac made of white

fibrous tissue and lined with synovial membrane. Bursa may also be formed by a synovial membrane that extends outside of the joint capsule.[7] It provides a cushion between bones and tendons or muscles around a joint; bursa are filled with synovial fluid
and are found around almost every major joint of the body.

Clinical significance

Disability-adjusted life year for musculoskeletal diseases per 100,000 inhabitants in 2004.[14]
  no data
  less than 400
  400–450
  450–500
  500–550
  550–600
  600–650
  650–700
  700–850
  850–900
  900–925
  925–950
  more than 950

Because many other body systems, including the vascular, nervous, and integumentary systems, are interrelated, disorders of one of these systems may also affect the musculoskeletal system and complicate the diagnosis of the disorder's origin. Diseases of the musculoskeletal system mostly encompass functional disorders or motion discrepancies; the level of impairment depends specifically on the problem and its severity. In a study of hospitalizations in the United States, the most common inpatient OR procedures in 2012 involved the musculoskeletal system: knee arthroplasty, laminectomy, hip replacement, and spinal fusion.[15]

Articular (of or pertaining to the joints)[16] disorders are the most common. However, also among the diagnoses are: primary muscular diseases, neurologic (related to the medical science that deals with the nervous system and disorders affecting it)[17] deficits, toxins, endocrine abnormalities, metabolic disorders, infectious diseases, blood and vascular disorders, and nutritional imbalances.

Disorders of muscles from another body system can bring about irregularities such as: impairment of ocular motion and control, respiratory dysfunction, and bladder malfunction. Complete

toxic origin; however, the primary disorder is usually related to the nervous system, with the muscular system acting as the effector organ, an organ capable of responding to a stimulus, especially a nerve impulse.[3]

One understated disorder that begins during pregnancy is pelvic girdle pain. It is complex, multi-factorial, and likely to be also represented by a series of sub-groups driven by pain varying from peripheral or central nervous system,[18] altered laxity/stiffness of muscles,[19] laxity to injury of tendinous/ligamentous structures[20] to maladaptive body mechanics.[18]

See also

References

  1. ^ Musculoskeletal+System at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
  2. ^ Mooar, Pekka (2007). "Muscles". Merck Manual. Archived from the original on 10 November 2011. Retrieved 12 November 2008.
  3. ^ a b Kahn, Cynthia; Scott Line (2008). Musculoskeletal System Introduction: Introduction. New Jersey, US: Merck & Co., Inc.
  4. ^ a b Applegate, Edith; Kent Van De Graaff. "The Skeletal System". Archived from the original on 3 June 2010. Retrieved 3 January 2009.
  5. ^ Engelbert, Phillis; Carol DeKane Nagel (2009). "The Human Body / How Many Bones Are In The Human Body?". U·X·L Science Fact Finder. eNotes.com, Inc. Retrieved 24 January 2009.
  6. ^ a b c Gary, Farr (25 June 2002). "The Musculoskeletal System". Archived from the original on 29 November 2014. Retrieved 18 November 2008.
  7. ^ a b "Skeletal System". 2001. Archived from the original on 25 February 2011. Retrieved 8 January 2009.
  8. ^ Mooar, Pekka (2007). "Muscles". The Merck Manuals Online Medical Library. Retrieved 16 November 2008.
  9. ^ "innervated". Dictionary.com. 2008. Retrieved 3 January 2009.
  10. ^ Bárány, Michael; Bárány, Kate (2002). "Smooth muscle". Biochemistry of muscle contraction. Archived from the original on 2 December 2008. Retrieved 19 November 2008.
  11. ^ "The Mechanism of Muscle Contraction". Principles of Meat Science (4th Edition). Archived from the original on 17 February 2012. Retrieved 18 November 2008.
  12. ^ Jonathan, Cluett (2008). "Tendons". Retrieved 19 November 2008.
  13. ^ Bridwell, Keith. "Ligaments". Retrieved 16 March 2009.
  14. ^ "WHO Disease and injury country estimates". World Health Organization. 2009. Retrieved 11 November 2009.
  15. ^ Fingar KR, Stocks C, Weiss AJ, Steiner CA (December 2014). "Most Frequent Operating Room Procedures Performed in U.S. Hospitals, 2003–2012". HCUP Statistical Brief #186. Rockville, MD: Agency for Healthcare Research and Quality.
  16. ^ "articular". Random House Unabridged Dictionary. Random House, Inc. 2006. Retrieved 15 November 2008.
  17. ^ "neurologic". The American Heritage Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company. 2006. Retrieved 15 November 2008.
  18. ^
    pelvic girdle pain
    disorders— Part 1: A mechanism based approach within a bio psychosocial framework. Manual Therapy, Volume 12, Issue 2, May 2007, PB. O’Sullivan and DJ Beales.
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