UNIT 8: Musculoskeletal system
The musculoskeletal system
This is a system made up of muscles, ligaments, bones, tendons and soft tissues which
combine together to create a foundation so that your body is able to do all the things it's
supposed to do such as:
● Support- The skeleton supports the
body's standing position and acts as
a foundation for the connection of
tissues and muscles.
● Protection of vital organs- bones
of the skeletal system protect
internal organs such as your brain,
heart, lungs, reproductive organs,
and spinal cord.
● Joints for Movement- the skeletal
and muscular system are connected
by tendons by attaching the muscle
to the bone. As the muscle fibres
contract, the tendon acts on the
bone, pulling them therefore causing
movement.
● Storage of calcium and
phosphorus- Collagen, a protein
that gives bones inside the body
their structure of hardness and
strength, is combined with calcium
phosphate, a mineral. While other
body parts require calcium, bones
discharge a small amount of calcium
they have stored into the blood. The
reason bones are so tough is that
when blood mineral levels are
excessively high, bones ingest part
of the minerals and preserve them as trace minerals. Minerals from bones are
released into the blood when blood levels drop too low, reestablishing equilibrium.
● Production of red and white blood cells-Red blood cells, white blood cells, and
platelets are all created by the body from stem cells, which are produced by the
bone marrow.
,The skeletal system
Our skeleton is divided into two parts 74 of these bones come from the Axial skeleton and
126 of these bones come from the Appendicular skeleton and 6 from the auditory ossicles.
The combination of these is what makes our skeletal system. The skeletal system consists
of bones, cartilage, ligaments, tendons and connective tissues
The appendicular skeleton
● The limbs, shoulder and pelvic girdle are part of the appendicular skeleton
The axial skeleton
● The skull, rib cage and vertebral column are part of the axial skeleton
, Bones
● Bones are living growing tissues that have rigid structures and are made mostly
of collagen with a mineral called calcium phosphate. They provide the structure
for our bodies and produce new blood cells
Bone anatomy
Compact bone tissue- The bone's tougher exterior is what
gives it its ivory-colored, smooth, and sturdy look. It is
perforated with pores and pathways that house blood vessels
and nerves.
Spongy bone tissue- has a porous, spongy look and is
located inside the compact bone. The bone marrow is located
here and is made up of a collection of small bones called
trabeculae. Hematopoiesis occurs there as well.
Endosteum- a membrane that protects the yellow marrow
and resembles the medullary canal
Periosteum- a tough membrane that shields the outskirts of
the bone
Medullary cavity- a cavity in the diaphysis which is filled with
yellow marrow
Yellow and red bone marrow- red bone marrow contains
blood stem cells that can become red or white blood cells or
platelets. Yellow bone marrow stores fat and contains stem
cells that can become cartilage, bone or fat cells
varieties of bones include:
● Long bones- These are tough, thick bones
that administer movement, shape, and durability like the radius, ulna, femur,
humerus, fibula, tibia
● Short bones-mostly cube-like shaped they are found in the metacarpal
bones that enable wrist movement and metatarsal bones that enable foot
movement
● Flat bones- found in the axial skeleton, flat bones often serve to protect vital
organs including the heart, pelvic organs, and brain. They are flat and
sometimes curved in shape and consist of two thin sheets of compact bone
placed between a sheet of spongy tissue.
● Irregular bones- They have an intricate form that aids in protecting the
interior organs, such as the vertebral column's role in safeguarding the spinal
column, bones of the skull help connect and support the bones in your skull
and the irregular bones of the pelvis protect organs in the pelvic girdle
● Sesamoid bones-The tendons of the hands, knees, and feet include these
little spherical bones. They serve to shield tendons from strain and abrasion.
The patella, sometimes referred to as the kneecap, is an illustration of a
sesamoid bone.
