Functional Anatomy and Physiology Bones and Joints Athlete Management Term 4
Terminology for the Location of Body Structures
To allow people to describe the location of the body structure, we use an Anatomical Reference System . This reference system has three parts
To give location of the body part, it is assumed that the body is in the Anatomical Position . This is standing erect, facing forward, arms by sides and palms forward.
A body structure may be located in a particular cavity. Each cavity contains particular organs. For example the Thoracic cavity contains the heart and lungs and is separated from the abdominal cavity by the diaphragm.
There are five major cavities
Thoracic Cavity – pleural (lungs)
Body structure and Movement of the Musculoskeletal System.
The musculoskeletal system is a combination of the skeletal, muscular and articular systems of the body and is responsible for the movement and locomotion of the body.
Skeleton – framework
Muscles – force
Joints – movement
The Skeletal System
The human skeleton is an endoskeleton ie it lies within the soft tissue of the body. It differs from the exoskeleton of an insect or crayfish.
It is the major supporting structure of the body
It is a living structure , capable of growth, adaptation and repair.
The human body contains a total of 206 bones.
Bones are approximately 50% solid matter and 50% water
By weight, bone is 65% mineral and 35 % cells, fibres and blood vessels
Bones are living structures containing blood vessels and nerves that grow, adapt and repair
Bones continue to grow in length until girls are 13 – 15 years and boys are 16 – 18 years.
Is 20% of total body weight.
Functions of the Skeletal System
The skeletal system has four main functions:
Body Movement – there are up to 206 bones in the skeleton, all of which provide sites for muscle attachment. When a muscle contracts, it moves the bones to which it is attached and thus creates movement. Any irregularity on a bone surface provides a possible site for muscle attachment.
Support and Protection – the skeleton provides support for the body and helps battle forces of gravity. The strong protective skeletal layer protects vital organs eg the rib cage protects heart, lungs, kidneys from all but the most traumatic injuries.
There are two main types of bone tissue:
Compact bone – found in the shaft (diaphysis of the long bone. It surrounds the cavity of the long bone, giving body rigid framework. Collagen is the central ingredient in providing compact bone rigidity and strength.
Cancellous bone – or spongy bone, provides some of the shock absorption required at end of long bones or at edges of more irregular bones.
Mineral storage sites – bone tissue stores a number of minerals important for health. Calcium, phosphorus, sodium and potassium all contribute to maintenance of bone tissue as well as other roles in the body.
Production of blood cells – essential production of new Red Blood Cells occurs within cavity of the long bones. Production levels are high during growth years, reducing as age increases and need for high rates of RBC decreases. Haemoglobin transports 02 inside RBC and much of adult’s bone activity are filled with yellow bone marrow, a source of long-term energy.
Bones of the Body
Major bones of the Skeleton
The skeleton is divided into two main parts:
Axial skeleton , which provides a central support axis and includes the skull, vertebral column, sternum and ribs
Appendicular skeleton , which includes the bones of the limbs, together with the shoulder girdle and pelvic girdle, which support and attach them to the axial skeleton.
The vertebral column has some special features.
Each vertebra has a hollow centre through which the spinal cord travels which controls most conscious movements within the body.
Vertebras increase in size as they descend from
Helps to support the weight of the body.
Movement between the (2) vertebrae is limited, but movement of the vertebral column as a whole is great allowing bending and twisting.
Provides a central structure for maintenance of good posture. This is dependent on the person maintaining correct levels of strength and flexibility of muscles groups that connect with the vertebral column.
The cervical vertebrae support the head and neck, the thoracic vertebra anchor the ribs and strong weight bearing regions towards the bottom of the vertebral column and provide a stable centre of gravity during movement.
The Articular System
An articulation is the place of union between two or more bones.
There are three different types of articulation (or joints), determined by the degree of movement they permit
Fibrous joint (immovable joint)
Bones are united by short bands of fibrous tissue at their ends eg skull bones, pelvic bones and sternum.
The Articular System
Cartilaginous joint (slightly immovable joint)
Bones are united by a disc of tough fibrous cartilage separating the ends allowing a small amount of movement eg vertebral column, pubic bones, diaphysis and epiphysis, ribs joining the sternum.
The Articular System
Synovial joints (moveable joints)
All synovial joints have a capsule that encloses the joint space
Synovial membrane lines the inner surface of the capsule and secretes synovial fluid into the joint cavity to keep it lubricated.
Shock absorbent articular cartilage is found on the ends of the bones to protect then from wear and tear.
Eg knee, hip, elbow joints
Types of Synovial Joints
Types of Synovial Joints Hinge Joint Pivot Joint Ovoid (ellipsoid) joint Gliding (plane) joint Saddle Joint Ball and Socket joint Hip and shoulder joint; head of femur/humerus fits into pelvis/scapula. Allows side to side, back and forth and rotational movement. Triaxial. Between carpal and metacarpals of thumb Allows back and forth and side to side movements. Biaxial. Between carpals, tarsals, ribs and thoracic vertebrae. Flat bones slide on each other. Side to side and back and forth movement. Biaxial. Between carpals and radius; between metacarpal and phalange. Allows back and forth and side to side movement, Biaxial. Between atlas and axis, between radius and humerus. Allows rotation only. Uniaxial. Knee, knuckle, ankle and elbow Allows back and forth movement, such as bending and straightening. Uniaxial. EXAMPLE DESCRIPTION JOINT TYPE
Structures within the Synovial Joints
Movements of the Synovial Joints
Movements of the Synovial Joints and their definitions Movement of the end of the bones in a circular motion Circumduction Movement of the side of the foot outwards at the ankle Eversion Movement of the sole of the foot inwards at the ankle Inversion Downward movement of the scapula Depression Upward movement of the scapula Elevation A decrease in the angle between the foot and the tibia in the ankle joint Dorsi flexion An increase in the angle between the foot and the tibia in the ankle joint (toes pointed) Plantar flexion Rotation of the palm of the hand upwards or outwards Supination Rotation of the palm of the hand downwards or inwards Pronation Movement of a body part around its longitudinal axis Rotation Movement of a body part back toward the midline of the body Adduction Movement of a body part away from the midline of the body Abduction Extension in the shoulder joint where the arm moves away from the body in a horizontal plane Horizontal extension Flexion in the shoulder joint where the arm moves close to the body in a horizontal plane Horizontal flexion Extension beyond that seen in the anatomical position Hyperextension Flexion sideways Lateral Flexion In increase in the angle of a joint Extension A decrease in the angle of a joint Flexion