Lec 5: Musculoskeletal system Flashcards
Basic structures of musculoskeletal system
- Bones
- Joints
- Muscles
- Nerve Supply
The bones along the longitudinal axis of the body that support the head, neck and trunk
Axial skeleton
The bones of the upper and lower limbs
Appendicular skeleton
Mechanical functions of bone
- Providing support for the body against external forces
- Acting as a lever system to transfer forces
- Protection for vital organs
Physiological functions of bone
- Hematopoiesis (forming blood cells)
- Mineral homeostasis (storing calcium)
Bones that act as levers and transmit longitudinal forces
Femur, tibia, radius
Bones that provide strength and transmit longitudinal forces
Carpal bones, tarsal bones (wrist and ankle)
Bones that provide protection and are points of muscle and ligaments attachments
Sternum, ribs, skull, scapula
A bone that improves mechanical leverage of the knee
Patella (sesamoid bone)
Type of bones that make up about 80% of the bones of the human body, their basic structural unit is the haversian system (osteon), mostly form all long bones, stiff and brittle
Compact bones
Type of bones that constitute 20% of the body bones, their functional unit is trabeculaes, have several pores that are filled with nerves and blood vessels, compliant and ductile
Spongy/cancellous bones
Joint function
- Facilitating movement
- Sensing position and movement
- Providing stability
- Shock absorption
- Supporting weight and force transfer
Structures of the joint that help in shock absorption
Cartilage and synovial fluid
List the positions of these bones:
- Femur
- Humerus
- Ulna
- Tibia
- Scapula
- Thigh bone
- Upper arm bone
- One of the forearm bones
- Shinbone
- Shoulder blade
Structural classification of joints
- Fibrous
- Cartilaginous
- Synovial
A joint where the articulating surfaces of the bones are not directly connected, but instead meet each other within a joint cavity that is filled with a lubricating fluid, is the most common joint of the body
Synovial joint
Joints that are present in skull sutures, teeth, ulna and radius connection
Fibrous joint
Joints that are present in pelvis and epiphyseal plate (responsible for growth)
Cartilaginous joint
Functional classification of joints
- Synarthrosis joint
- Amphiarthrosis joint
- Diarthrosis joint
Immobile joints
Synarthrosis (fibrous and cartilaginous)
Slightly movable joints
Amphiarthrosis (fibrous and cartilaginous)
Freely movable joints
Diarthrosis (synovial joints)
Uniaxial joint in the body (flexion/extension)
Elbow
Biaxial joints in the body (flexion/extension & abduction/adduction)
Joints connecting fingers and hand
Triaxial joint in body (flexion/extension & abduction/adduction & medial/lateral rotation)
Shoulder and hip (ball-and-socket joints)
A type of diarthrotic joints that allow movement in one plane usually flexion and extension
Hinge (elbow, ankle, knee)
A diarthrotic joint that is characterized by opposing articular surfaces with a reciprocal concave-convex shape, 2 DOF, present in thumb
Saddle joint
A diarthrotic joint that allows for rotation only
Pivot joint
A diarthrotic joint that contains a convex surface which articulates with a concave elliptical cavity, similar to ball-and-socket but with no rotation (2 DOF), present in wrist
Condyloid/ellipsoid joint (e.g. wrist joint)
Joints that have 1 DOF
- Hinge
- Pivot
- Plane
Joints that have 2 DOF
- Saddle
- Ellipsoid
A thick fluid that provides lubrication between bones of joint, provides nourishment to the articular cartilage which doesn’t contain blood vessels
Synovial fluid
A type of cartilage that covers the entire articulating surface at each bone, also helps in shock absorption, and weight transfer
Hyaline cartilage
A fibrous connective tissue that connects bone to bone, allows for normal movements but limit the range of motion, preventing excessive or abnormal joint movements
Ligaments (الأربطة)
A connective tissue that attaches a muscle to bone and provides and additional joint support
Tendon (الأوتار)
Most common cartilage found in the body
Hyaline cartilage
Strongest cartilage
Fibrocartilage
Least common cartilage
Elastic cartilage
Mature cells found in the extracellular matrix in cartilage and is responsible for maintenance of ECM
Chondrocytes (fibrochondrocytes in fibrocartilage)
Cartilage components that provide a flexible tissue that can resist compressive stresses
ECM, collagen and ground substance
Part of the cartilage which contributes to load transfer
Collagen (has tensile strength)
Cartilage present in joint surfaces, the ribs, nose, larynx, trachea, responsible for weight transfer and reducing friction
Hyaline cartilage
Cartilage present in intervertebral discs, ligaments, fibrous joints, usually a transitional layer between hyaline cartilage and tendon, increase congruence (shape fitting)
Fibrocartilage
Cartilage present in the external ear, epiglottis, and larynx, provides strength and maintains the shape of certain structures
Elastic cartilage
Forces encountered by hyaline cartilage
- Compressive
- Tensile
- Shear
A type of fibrocartilage that minimizes friction between bone and tendon
Stratiform Fibrocartilage
A type of fibrocartilage found in intervertebral discs, increases shock absorption and transmits load
Connecting fibrocartilage
A type of fibrocartilage found in the menisci of the knee, acts as thrust pads and helps prevent instability of the joints
Intra-articular fibrocartilage
A part of the musculoskeletal system which has high resilience and acts like a biological spring
Tendons
A mechanism where energy is initially absorbed by the tendon during a brief and rapid event, followed by a relatively slow flow of energy from the tendon to the muscle
Tendon buffering mechanism
A part of the musculoskeletal system that acts as a joint stabilizer (requires no metabolic energy)
Ligaments
Which is less elastic tendon or ligaments
Tendon is less elastic (more rigid) for force transmission while ligament is more elastic to allow joint flexibility and prevent dislocations
A type of bone that is involved in the dynamic process of formation and breakdown of bone (bone remodeling)
Trabecular bone
Bone cells that play a crucial role in liberating minerals and other molecules stored in the bone matrix
Osteclasts
Bone cells responsible for the formation of new bone tissue by secreting osteoid which is composed of collagen and ground substance
Osteoblasts
