Written Assignment Unit 2: Bones & the Skeletal System
University of the People
HS 2211 Human Anatomy & Physiology
Branko Jablanovic, Instructor
September 14, 2022
Introduction
Bones are a hard, dense connective tissue that forms most of the adult skeleton, in order to
facilitate movement, protect internal organs, support the structure of the body, produce red
blood cells and store minerals and fats. In the areas of the skeleton where bones move,
cartilage, a semi-rigid form of connective tissue, can be found as it provides flexibility and
smooth surfaces for movement. Essentially, bones act as levers and joints serves as fulcrums
(OpenStax, 2018).
In other words, a bone will not move unless a muscle connected to a joint is stimulated and
causes it to contract.
The joint known as the Synovial joint is the most common with the presence of fluid-filled
space known as the joint cavity which is the site at which the joining surface of the bones
contact each other despite not directly connected like fibrous connective tissue or cartilage
which allows increase joint mobility (OpenStax, 2018).
The synovial joint can be found in the neck, elbow, knee, phalanges, and hip. The Synovial
joints are divided into the pivot, hinge, condyloid, saddle, plane, and ball-and-socket joint.
In this paper I will further discuss the ball-and-socker joint.
The ball and socket joint are a type of synovial joint and their special construction allows
them to move with the greatest range of motion in the body. The ball and socket joints can be
found within 2 parts of the body known as the shoulder and hip. The ball and socket joint
consists of two bones: one with a cup-shaped socket and the other with a spherical head.
The one in the hip is where the round head of the femur rests in the cup like acetabulum of
the pelvis and another in the glenohumeral joint of the shoulder, where the rounded head of
the humerus rests in the cup like glenoid fossa of the shoulder blade.
This joint is lined and sealed into a joint capsule by a tissue known as the synovial
membrane. The joints' components can move against one another smoothly and freely
because of the synovial fluid that exists inside the capsule. The joint is held together by
tendons and ligaments.
According to Britannica (2021), "the ball and socket joint moves within a depression on
another bone, allowing greater freedom of movement than any other kind of joint. It also
provides swing for the arms and legs in various directions and also spin of those limbs upon
the more stationary bones". The ball and socket joint can also be considered as a multiaxial
joint, as this allows movements in multiple directions, i.e., up, down, forward, backward, and
rotation.
The shoulder is made up of a ball and socket joint called the glenohumeral joint where the
humeral head (ball) and the glenoid (socket) meet.
The hip joint is also a ball and socket joint that is made by