Text of Lecture 6: Skeleton, bones, joints, muscle, heart
BASIC ANATOMY FACTS
BASIC ANATOMY FACTS
THE SKELETON What the skeleton does? The skeleton is the basic framework of the body. It has
four major functions
SHAPE AND SUPPORT MOVEMENT PROTECTION BLOOD PRODUCTION
SHAPE AND SUPPORT - the skeleton provides us with our shape, without it our body would have no framework to support itself on. The skeleton also
gives the body its size and in some cases can influence overall bodyweight.
MOVEMENT - some of the bones of the body are held together by freely moveable joints. This means you are able to bend your body and move about.
PROTECTION - The skeleton also protects the vital soft tissue organs of the body. The most important are:
the rib cage - protects the heart and the lungs the pelvic girdle - protects the abdomen the spinal column chord - protects the spinal
chord the skull - protects the brain.
BLOOD PRODUCTION - blood is made in the bone marrow, particularly in the marrow of the long bones of the body. Blood contains both red and white blood cells. The red blood cells carry oxygen to muscles and the white blood cells fight infection in the body.
TYPES OF BONES There are 206 bones in the body and over 100
Bones are divided into four main types : 1) FLAT BONES - the scapula, the sternum,
the pelvis, the ribs, and the scull 2) IRREGULAR BONES - the vertebrae and
the short bones of the hands and feet. 3) LONG BONES - the bones of the arms and
the legs, and the long bones in the hands and feet.
blanks – write the names of all the bones numbered 1 -18
2.State whether the bone is a:
long bone irregular bone flat bone sesamoid bone
JOINTS AND MOVEMENT
Bones and muscles are connected through joints. Ligaments connect bone to bone over the joint; tendons connect bones to muscles.
WE can move arms and legs, tilt head and use fingers because of the joints
JOINT STRUCTURE Most joints are enclosed inside a
capsule filled with a lubricating fluid, called synovial fluid.
This fluid reduces the friction on the joint surfaces as they move against each other. A membrane seals the synovial capsule so that the fluid does not leak out.
LIGAMENTS AND TENDONS Ligaments are very strong elastic
fibres that keep joints intact. Ligaments attach bone to bone.
all the major joints rely on ligaments and tendons for stability.
Tendons attach muscles to bones.
both ligaments and tendons can be strained or torn as a result of violent movement.
LIGAMENTS AND TENDONS
TYPES OF JOINTS The type of joints that are particularly
important for physical activity and sport are: 1) BALL AND SOCKET JOINT - allows a full
range of movement. E.g. the hip and shoulder joints
2) HINGE JOINT - movement in one plane: flexion and extension. E.g. knee
KNEE JOINT - HINGE
3) GLIDING JOINT - these occur in the many small bones of the hand and feet. They allow a slight sliding motion forwards and backwards and from side to side.
4) PIVOT JOINT - allows rotation. E.g. atlas and axis in the neck.
TASK: the picture shows: 1: Shoulder joint -ball
and socket 2: Elbow joint - hinge
can you name another ball and socket and hinge joint?
MUSCLES Every movement of your body depends on
muscles. There are three different types of muscles:
1 ) INVOLUNTARY MUSCLE (SMOOTH) - is found in the body’s internal organs – stomach, intestines. It is control by spinal cord and we can’t control it consciously
2) VOLUNTARY OR SKELETAL MUSCLE (also known as ‘striped’ or ‘striated’ muscle) - mainly found attached to the skeleton, capable of rapid contraction which cause skeletal movement. It is under our conscious control.
3) CARDIAC MUSCLE - is only found in the heart and is also involuntary. It never stops working until we die. It pumps blood from our heart around the body.
We can train cardiac muscle through cardio (dynamic exercise – running, jumping, rowing)
HOW SKELETAL MUSCLES WORK? muscles can only create movement in one
direction - by becoming shorter. This means that you need two muscles at every joint to allow movement in two directions.
Therefore MUSCLES WORK IN PAIRS. For example, when your biceps CONTRACT it makes your elbow flex pulling your forearm up. To allow your elbow to extend, you need your triceps to CONTRACT and pull your arm back down. Meaning the biceps are RELAXING.
INDEPENDENT WORK: USE THE DIAGRAMS IN THE LINK BELOW TO STUDY MUSCLES