1.1 Musculoskeletal system Flashcards
Identifying bones (Cranium, vertebrae, scapula, humorous, ribs, sternum, radius, ulna, pelvis, femur, tibia, fibula, patella and talus.)
The cranium is the anatomical term for the skull found within the head.
The vertebrae are a collection of bones that make up the spine.
The scapula is the anatomical term for the shoulder blade.
The humerus is the large bone in the upper arm between the shoulder and elbow joint.
The ribs are in the upper chest and form a cage structure.
The sternum is the anatomical term for the breast bone in the front of the chest.
The radius and the ulna are both in the lower arm below the elbow and above the wrist. The radius is depicted on the outer side in diagrams and is on the side of the thumb. The ulna is depicted on the inner side in diagrams and is on the side of the little finger.
The pelvis is the anatomical term for the hip bone.
The femur is a very large bone in the upper leg between the hip and the knee joints.
The tibia and the fibula are both in the lower leg below the knee and above the ankle. The tibia is the shin bone at the front of the leg and the fibula is the smaller bone at the back of the leg.
The patella sits in front of the knee joint.
The talus is in the ankle of the foot, just below the tibia and fibula.
Structure of the skeleton
One of the main roles of the skeleton is to help to provide a framework for movement.
A joint is a connection between two or more bones that allows movement.
The structure and position of bones of the skeletal system allows the movement to take place.
The skeleton provides a point of attachment for tendons and muscles. When muscles contract they pull on the bones to create movement.
There are different types of joints that allow different types of movement.
Long bones
The humerus and femur are examples of long bones.
Long bones are found in limbs (arms or legs). They are used for movement, shape, blood cell production and mineral storage.
Short bones
The carpals and tarsals are examples of short bones.
Short bones are found in the hands and the feet. They are used for shape and small movements.
Flat bones
The scapula, sternum and cranium are examples of flat bones.
Flat bones are found near vital organs. They are mainly needed for protection.
Irregular bones
The vertebrae are examples of irregular bones.
They are used for small movements and protection.
Function of the skeleton
Support - the bones are solid and rigid. They keep us upright and hold the rest of the body - the muscles and organs - in place.
Protection - certain parts of the skeleton enclose and protect the body’s organs from external forces, e.g. the brain is inside the cranium, the ribs protect the heart and lungs.
Movement - the skeleton helps the body move by providing anchor points for the muscles to pull against. The long bones in the arms and legs work as levers to allow certain movements.
Structural shape and points for attachment - the skeleton gives us our general shape such as height and build. Tall people have long leg bones and larger vertebrae. People with a heavy build have larger clavicles and scapula as well as bigger pelvises. The skeleton also provides anchorage points for the muscles to attach, so when they contract we move.
Mineral storage - bone stores several minerals, including calcium and phosphorus, which can be released into the blood when needed.
Blood cell production - the inner marrow of the long bones and ribs produces red and white blood cells. Red blood cells are important in activities because they carry oxygen to the working muscles. White blood cells are important to fight off infections in order to keep healthy.
Identifying muscles (latissimus dorsi, deltoid, rotator cuffs, pectorals, bicep, tricep, abdominals, hip flexor, gluteals, hamstring group, quadriceps group, gastrocnemius and tibialis anterior)
Latissimus dorsi - Positioned in the back and is connected to the humerus bone in the arm.
Deltoid - Positioned over the top of the shoulder.
Rotator cuffs - Group of muscles that connect to the upper arm at the shoulder.
Pectorals - Group of muscles in the front of the chest that connect to the shoulder.
Bicep - Large muscle in the front of the upper arm.
Tricep - Large muscle in the back of the upper arm
Abdominals - Group of muscles located in the lower front of the body between the ribs and the pelvis bones.
Hip flexor - Group of muscles that connect around the pelvic bone.
Gluteals - The muscles of the buttocks.
Hamstring group - Group of three muscles in the back of the thigh in the upper leg.
Quadriceps group - Group of muscles in the front of the thigh in the upper leg.
Gastrocnemius - The muscle found in the calf at the back of the lower leg.
Tibialis anterior - Muscle found in the shin at the front of the lower leg.
Synovial joint
Synovial joints are the most common type of joint in the human body.
They are characterised by a joint cavity filled with a lubricating synovial fluid which reduces friction.
The fluid is produced by the synovial membrane, which surrounds the joint.
The joint capsule surrounds the membrane, sealing the joint space and providing stability to the joint. It is made from tough fibrous tissue.
Synovial joints are capable of a variety of different movements which depends on the structure within the joint including the joint type and the ligaments.
Hinge joint
Hinge joints are an important type of freely movable joint. Hinge joints have a limited range of movement, involving flexion (bending) and extension (straightening).
Ball and socket joint
Ball and socket joints are an important type of freely movable joint. A ball and socket joint looks exactly like a ball fitting into a cup. It can move freely in all directions. This type of joint is located in the shoulder and the hip.
Bursae
Synovial joints are also protected by bursae. Bursae are small bags of synovial fluid (oily substance) that help to reduce friction in a joint.
Bursae act like an airbag in a car. They cushion the joint from any external impacts, stopping the bones from coming together.
Joint capsule
The joint is surrounded by a joint capsule that is very tough and fibrous.
The joint capsule is lined with a synovial membrane. This produces an oily substance called synovial fluid.
Synovial fluid keeps joints well lubricated (greased to prevent friction) to stop them wearing down and rubbing together.
Cartilage
Smooth cartilage (tissue) is a protective layer that covers the end of each bone to stop them from rubbing together.
Tendons
Lengths of strong connective tissue called tendons connect muscle to bone. they are tough and inelastic meaning they can’t stretch when a muscle is contracting and pulling the bone.
Ligaments
A ligament is a tough band of connective tissue that connects bones to other bones. ligaments are made up of collagen fibres, which are strong and flexible. ligaments help to stabilise joints and to prevent dislocation.
Flexion and extension
Flexion - This is a movement where the angle of the joint decreases.
Extension - This is a movement where the angle of the joint increases.
Plantar and dorsiflexion
Plantar flexion is the term used for the movement that describes the pointing of the foot towards the ground, as in standing on tiptoes.
Dorsiflexion is the opposite movement, and involves the movement of the foot away from the ground, as in pulling the toes up and walking on one’s heels.
Adduction and abduction
Abduction - movement where limbs are moved away from the body.
Adduction - movement where limbs are moved back towards the body.
Rotation and circumduction
Rotation - turning a limb along its axis.
Circumduction - the movement of the limb, hand, or fingers in a circular pattern, using the sequential combination of flexion, adduction, extension, and abduction motions.
Antagonistic muscle movement
For all movements, the prime mover (or agonist) is the main muscle that causes movement. The antagonist then acts to produce the opposite action to the agonist. they work in antagonistic pairs.
Bicep and tricep. Hamstring and quadriceps. Gluteals and hip flexor. Gastrocnemius and tibialis anterior. Pectorals and latissimus dorsi.
Isotonic contractions
When a muscle contracts and changes length. There are 2 types of isotonic contraction:
Eccentric → when a muscle extends.
Concentric → when a muscle shortens.
Isometric contractions
When a muscle contracts, but stays the same length.
During isometric contractions, we are always stationary.
