There are 206 bones in the body. They range in size and function depending on what they are used for in the body. E.g The skull is used for protection of the brain so therefore it is hard and made in a way that it protects soft tissue.
Some bones are to protect vital organs and others are used to transfer a load through a joint.
When discussing the body and it’s skeletal and muscular system health workers talk in Anatomical language. When a person is standing up straight and facing forward and they have their palms facing down; this is called anatomical position.
The AXIAL - This part of the skeleton provides a central support axis. It includes ( the skull, vertebral column, sternum, and ribs ) name each organ each axial skeleton protects?
The APPENDICULAR SKELTON- These skeletons transfer loads through joints ( bones of the arms, and legs, shoulder girdle, pelvic girdle ) The last two join all appendicular bones to the axial skeleton system.
The thorax combines certain skeletal bones to support and protect the heart lungs.
It is made up of the sternum and the ribs . The sternum attaches to the ribs and the ribs are our main shark cage that protects the lungs. If the lungs were not protected then they would be open to puncturing.
There are 12 pairs of ribs that join to the sternum. There are 2 pairs of ribs that are floating.
This section consists of the arm, wrist and hand. So what bones would be included in this list, (Humerus, rad…., ul….,car…..,metac……,phal…..) These bones are meant for manipulation. E.g. throwing, writing.
This consists of three large bones that are fused together.
They are illium, ischium and pubis .
The illium looks like two big elephants ears. This is what you put your hands on when you lean on your hips.
The ischium is at the bottom of the pelvis and has a hole in the middle of it on both sides.
The pubis is V shaped and the bladder rests upon it.
The pelvis allows for the large amount of weight that the upper body brings. It also allows attachment for the lower limbs and muscles of the leg. It also houses some of the reproductive organs for both females and males.
The pelvic girdle doesn’t allow for much movement due to the ligaments shortened length and their strength. The hip joint is quite deep and therefore adds to the stability of the joint.
A joint is a junction of two or more bones (door handle) commonly known as an articulation.
Joints allow for the ranges of movement that allow us to do some of the impressive things humans can do, (flexibility) Each joint has it’s own reason for the way it works and all joints are specific to the type of movement needed by it’s adjoining bones and muscles.
It is the bodies lubricant keeping a joint well oiled (like a motor, motor oil) Synovial fluid allows joints to fit together and acts like a cushion. It is also how the joint eats, it provides nutrition for cartilage and carries away waste products from the joint ( swelling after an injury)
The reason for joint stiffness is a lack of synovial fluid. E.g. in the morning there is a lack of synovial fluid so movement is harder. However in the afternoon is actually worse for the joints to exercise due to the synovial fluid be compressed.
This is a smooth shiny cartilage that allows bones to move freely over one another. (it would be very painful without this = bone on bone. It is fed by synovial fluid and needs to be thicker in areas of greater weight bearing. E.g. legs, knees.
When the body moves muscles can perform one of three roles.
AGONIST: This is the prime mover muscle that allows the joint to work. In the arm what muscle do you think the agonist is?? There are agonist muscles in all moving joints.
ANTAGONIST: This is the relaxing muscle in joint action. It must relax so the agonist can contract. (both can’t contract at the same time) The two roles change every time you change the movement. For example a bicep curl requires the bicep to be the agonist and the tricep to be the antagonist. However the uncurling of the same bicep curl requires the triceps to be the agonist and the biceps to be the antagonist.
STABILISER: This muscle works to stabilize the joint and give an anchor point to the agonist and antagonist. An example of this in action is throwing a ball, some shoulders will propel the ball by contracting and therefore creating force and some shoulder muscles will stablize the joint so the humorous does not just pop out.
Concentric is the most common type of contraction, It shortens the muscle and when a resistance is added that contraction causes muscle tears. (more later) and therefore size can change. E.g. weightlifting
Eccentric contraction occurs when the muscles lengthens while under tension. (e.g lowering yourself slowly in a chin up) Gravity helps with this movement.
Isometric is when no lengthening or shortening occurs, instead the muscle fibers are activated and develop force. (movement does not occur) an action for isometric is rock climbing where the movement does not occur but you still require a force to hang up there.