Unit 8.2: Physiology of Human Body System
By Leah Pearson
The Musculoskeletal System
Your body's skeleton serves as a framework, giving it the stability and mobility, it
requires. The 206 bones that make up the adult human skeleton are divided into
two groups: the axial skeleton and the appendicular skeleton. The longitudinal axis
of the skeleton, which extends from your head to your feet, is formed by the axial
skeleton. This skeleton category includes the cranium (head), mandible and maxilla
(the upper and lower jaw bones), the vertebral column (cervical, thoracic, and
lumbar) and intervertebral discs that are located between them, the rib cage, and
the sternum (breastbone). The bones that make up your appendages (limbs) and
the limb girdles that connect your limbs to your axial skeleton make up your
appendicular skeleton.
There are various kinds of bones. Each type can carry out a particular task:
- Long bones are cylindrical in shape, made of strong bone, and contain soft,
spongy marrow inside. The bones have more stability at the joint where they
articulate with other bones because the extremities of the bones are wider
than the middle.
- The bones in your wrist and ankles are short bones; they are squat and
share the same structure as long bones. The bones can move in a wider
range of ways as a result without losing strength.
- A layer of spongy tissue is sandwiched between two pieces of hard bone to
form flat bones. Some of them provide protection, such as the skull, which
shields the brain, or, in the case of the scapula, a sizable space for muscular
attachment. The sternum is another flat bone.
- Irregular bones come in a variety of shapes. For instance, the face bones
are irregular, and they also feature air-filled chambers that make them light.
The hip bones are also irregular, another irregular bone is the box-shaped
vertebrae that make up the backbone; these strong, marrow-filled bones also
shield the spinal cord.
- Sesamoid bones are the little bones that are located in tendons at areas
where there is a lot of pressure, such as your kneecaps (patellae).
The functions of the musculoskeletal:
The musculoskeletal system consists of many organs that all work together so that
the system functions effectively. The skeleton’s function is to support, protect,
movement and maintain mineral homeostasis.
- Because the tendons attach the skeletal muscles to the bone and are
relatively inelastic, when muscles contract, a force is applied that pushes on
the bone and causes it to move. Tendons are less elastic than ligaments but
have dense regular connective tissue with collagen coiled strongly.
, - At synovial joints, ligaments bind bone to bone, strengthening the joints and
enabling flexibility. Large tensile strength is provided by dense, regular
connective tissue with collagen bundles, while flexibility is provided by elastin
fibers.
- Muscles that attach to cover the skeleton are composed of skeletal muscle
tissue. In addition to allowing bone to move through their ability to contract
and relax, they also aid in stabilizing the joints. These muscles are also
voluntary muscles since your brain actively directs them. When examined
under a microscope, the strained tissue appears striped. Your ability to move,
breathe, and manipulate items is all down to your skeletal muscles, which
function in antagonistic pairs (one contacts while the other relaxes). In order
to maintain posture, some muscle fibers in the skeleton are constantly
contracted and develop muscular tone. The rate of respiration of muscles
cells rises during movement or shivering, causing the production of ATP for
contraction and the release of energy as heat, which helps to regulate body
temperature.
- The human skeleton provides support to withstand the forces of gravity,
compression, and tension. It also prevents your internal organs from being
crushed by the force of gravity. The skeleton also offers protection for
internal organs such as the lungs, heart, and liver via the rib cage. The skull
then protects the brain, and the vertebral column protects the spinal cord.
The skeleton provides points of attachment, such as the tendons of skeletal
muscles, and the bones articulate at joints to permit movement.
Hematopoietic stem cells, which are found in some bones' red marrow, divide
and develop into several types of blood cells. Calcium ions from the skeleton
are present in the bones and can be used to increase calcium ions levels to
assist maintain the mineral content.
Muscles
Your skeleton is covered by muscles that are made of skeletal muscle tissue. They
can tighten and loosen, allowing bones to move. Your joints are stabilized by them
as well. These muscles are also known as voluntary muscles since your brain
consciously controls their action. Under a microscope, this tissue is known as
striated because it looks striped.
As neither smooth muscle nor cardiac muscle is linked to bones, they are not
included in the musculoskeletal system. There is no voluntary control over any type.
- Walls of the digestive, urinary, reproductive, and respiratory tracts are made
of smooth muscle. Its gradual, continuous contractions are used to contract
and relax some of these tracts as well as transfer chemicals across them. It
can alter the airways' diameter in the respiratory system.
- The heart's walls are made of cardiac muscle. Given that it is striated, it
mimics skeletal muscle.