Musculoskeletal system Flashcards
What is the musculoskeletal system composed of?
- bones of the skeleton.
- muscles.
- cartilage.
- tendons.
- ligaments.
- joints
- other connective tissues that support and bind tissues and organs together.
How are bones joined?
- Ligaments hold the ends of bones together at joints.
What are the properties of cartilage?
- firm connective tissue but more flexible than bones.
- insufficient rigidity to withstand gravity.
- does not contain blood vessels or nerves.
What is a ligament?
- Fibrous connective tissue that connects bones to other bones.
What is a tendon?
- A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
What is a mesenchymal cell?
- Multipotent stromal cell which can differentiate into a variety of cell types including osteoblasts (bone cells), chondrocytes (cartilage cells), myocytes (muscle cells) and adipocytes (fat cells).
What are the properties of a fibroblast?
- Cell in connective tissue that produces collagen and other fibres.
- Synthesises the extracellular matrix and plays a role in wound healing.
What are the properties of connective tissue?
- Elastic, compressible, tough packing material.
What are the properties of cartilage?
- Turgidity, tensile strength, tough and resists deformation.
Properties of bone?
Hard, rigid, weight bearing, tensile strength
What are the four main types of biological tissue that support, connect or separate different types of tissues and organs in the body?
- connective.
- epithelial.
- muscle.
- nervous.
Give 2 examples of connective tissues?
- Tendons and ligaments.
Is cartilage slow or fast to repair?
- Slow.
What are the components of cartilage?
- Extracellular matrix: ground substance - GAGs and large proteoglycans complexed with collagen fibres. And fibres - type 2 collagen (hyaline cartilage), type 2 and type 1 collagen (fibrocartilidge) and type 2 collagen and elastic fibres (elastic cartilage).
- cells: chondroblasts (from perichondrium) - secrete matrix and chondrocytes - maintain matrix.
How is cartilage grown and maintained?
- the matrix is permeable to water and so dissolved oxygen and nutrients are delivered this way, as well as waste products removed.
- it’s mainly non-vascular, therefore relies on diffusion via extracellular fluid.
- can grow by interstitial (within the matrix) as well as appositional (on surface) growth.
What are the three types of cartilage?
- Hyaline, fibrocartilidge and elastic cartilage.
How many types of cartilage?
3.
Where is hyaline cartilage?
- Most common: articular surfaces (joints e.g. Knees and ankles), tracheal rings etc.
Where is fibrocartilidge?
- Found in the intervertebral discs and pubic symphysis.
What is the musculoskeletal system?
- Organ system that gives humans the ability to move using their muscular and skeletal systems.
- The musculoskeletal system provides form, support, stability and movement to the body.
Where is elastic cartilage?
- External ear, auditory canal and epiglottis etc.
How is cartilage repaired?
- No blood vessels in cartilage, nutrients to chondrocytes diffusing through the ground substance.
- Lack of blood vessels means that damage heals slowly or not at all.
- Lack of nerve supply means that damaged cartilage is painless although effect on neighbouring structures may cause pain.
What are the components of bone?
- extracellular matrix (ECM): consists of ground substance GAGs (osteocalcin and sialoprotein) and minerals (Ca++ PO4(2)- and hydroxyapatite) and fibres (type 1 collagen).
- bone cells (osteoprogenitor, osteoblasts, osteocytes and osteoclasts).
What are the four types of bone cells?
- osteoprogenitor.
- osteoblasts.
- osteocytes.
- osteoclasts.
What is an osteoprogenitor cell?
- Mesenchymal stem cells that form osteoblasts (stem cells from periosteum).
What is an osteoblast?
- An immature bone cell that secretes organic components of the matrix (produce and maintain matrix).
What is an ostocyte?
- A mature bone cell that is formed from osteoblasts, they maintain the matrix and communicate via cell processes in canaliculi.
What is an osteoclast?
- Multinucleated macrophages acting as scavengers of unwanted material, remove matrix.
How is bone grown and maintained?
- It has a mineralized matrix impermeable to water and small molecules.
- It needs an intimate blood supply (key to structural organisation) and it grows by appositional growth only.
What is appositional growth?
- Process by which old bone that lines the medullary cavity is reabsorbed and new bone tissue is grown beneath the periosteum, increasing bone diameter.