The Musculoskeletal System Flashcards
What makes up the skeletal system?
Entirety of the bones and their cartilage
Bone is an organ compared of what different tissues?
Bone (osseous) tissue
Epithelium
Adipose tissue
Nervous tissue
Dense connective tissue
Functions of the Skeletal System
Support by providing a structural framework for the body
Protection of many internal organs from injury
Assistance in movement by providing skeletal muscle attachments
Mineral homeostasis, bone tissue stores several minerals, especially calcium and phosphorus
Blood cell production within certain bones and connective tissues called red bone marrow produces red blood cells, white blood cells, and platelets
Triglyceride storage yellow bone marrow consists mainly of adipose cells, which store triglycerides
Types of Bones
Long, short, flat, irregular
Long bones
greater length than width and consist of a shaft and a variable number of ends
Femur, Tibia and Fibula, Humorous
Short Bones
somewhat cube-shaped and nearly equal in length and width
Most wrist and ankle bones, Trapezoid
Flat Bones
generally thin, afford considerable protection, and provide extensive surfaces for muscle attachment
Sternum, Scapulae
Irregular Bone
complex shapes and cannot be grouped into any of the previous categories
Vertebrae, some facial bones
Structure of Bone
Diaphysis: bone’s shaft or body
Epiphysis: distal and proximal ends of the bone
Metaphysis: regions where the diaphysis joins the epiphyses
Articular Cartilage: thin layer of hyaline cartilage covering the regions of the epiphyses where the bone articulates with other bones
Periosteum: sheath of dense irregular connective tissue and blood vessels that surround the parts of the bone outside of the articular cartilage
Medullary cavity: hollow space within the diaphysis that contain fatty yellow bone marrow
Endosteum: thin membrane that lines the medullary cavity
What is Bone tissue made up of
abundant extracellular matrix (25% water, 25% collagen fibres, and 50% crystallised mineral salts)
4 types of cells:
Osteoprogenitor cells: stem cells that develop into osteoblasts
Osteoblasts: synthesise and secrete the extracellular matrix that calcifies into “bone”
Osteocytes: most numerous cells in bone tissue and they maintain bone tissues
Osteoclasts: break down extracellular matrix to release nutrients, help bones grow, and heal
What is another word for Bone formation
Ossification
Ossification occurs in what 4 principal situations?
- Initial formation of bones in an embryo and fetus
2.Growth of bones during infancy, childhood, and adolescence until their adult sizes are reached
- The remodelling of bone (replacement of old bone tissue by new bone tissue throughout life)
- The repair of fractures (breaks in bones) throughout life
What is Bone remodelling?
a continuous process as old bone tissue is replaced with new tissue
What is bone resorption and bone deposition?
Bone resorption is the removal of minerals and collagen by osteoclasts
Bone deposition is the addition of minerals and collagen by osteoblasts
What is the definition on fracture?
A fracture is any break in a bone
What are the 4 different types of fractures?
Partial: an incomplete break across the bone, such as a crack
Complete: a complete break across the bone; that is, the bone is broken into two or more pieces
Closed (simple): the fractured bone does not break through the skin
Open (compound): the broken ends of the bone protrude through the skin
Repair of a fracture involves several steps:
- Phagocytes begin to remove any dead bone tissue
- Chondroblasts form fibrocartilage at the fracture site that bridges the broken ends of the bone
- fibrocartilage is converted to spongy bone tissue by osteoblasts
- Bone remodelling occurs, in which dead portions of bone are absorbed by osteoclasts and spongy bone is converted to compact bone
Bone growth, repair and remodelling all require multiple factors to be successful
Adequate minerals for bone matrix (calcium, phosphorus and magnesium)
Vitamins A, C, and D
Hormones such as hGH and insulin like growth factors (IGF)
Weight-bearing exercise that places stress on bones
The adult human skeleton consists of how many bones, and which are grouped in what two principal divisions?
206 bones
Axial skeleton: Consists of the 80 bones that lie around the midline of the human body: the bones of the skull, auditory ossicles (ear bones), hyoid bone, ribs, sternum and vertebrae
Appendicular skeleton: contains 126 bones of the upper and lower limbs or appendages plus the bone groups called girdles that connect the limbs to the axial skeleton
What is a joint?
A joint (articulation) is a point of contact between cartilage, or between teeth and bone
Structural classification of joints is based on 2 criteria:
Presence or absence of a synovial cavity, a space between the articulating bones
Type of connective tissue that holds the bones together
Functional classification of joints relates to the degree of movement they permit
Synarthrosis- immovable joint
Amphiarthrosis- slightly movable joint
Diarthrosis- freely moveable joint
What are the 3 types of joints?
Fibrous
Cartilaginous
Synovial
Fibrous Joints (Functional classification & 3 types of fibrous joints)
Permit little or no movement.
3 types of fibrous joints:
Syndesmosis- joint permits limited movement
Suture- fibrous joint that may be a slightly moveable or immovable
Interosseous Membranes- permits slight movement
Cartilaginous Joints (Functional classification & 3 types of fibrous joints)
Allows little or no movement.
3 types of cartilaginous joints are:
Synchondrosis- immovable joint
Symphysis- slightly movable joint
Epiphyseal Cartilages- growth centre during endochondral bone formation
Synovial Joints (Functional classification)
Unique characteristic of a synovial joint is the presence of a space called a synovial (joint) cavity between the articulating bones
Allows a joint to be freely moveable
What are the 6 types of synovial joints?
Plane, Condyloid, Hinge, Saddle, ball-and-socket, Pivot
3 types of muscle tissue? (what is it? straited or not? voluntary or involuntary)
Skeletal muscle tissue: mostly attached to bones. Striated and voluntary.
Cardiac muscle tissue: forms most of the wall of the heart. Striated and involuntary.
Smooth muscle tissue: located in viscera. Nonstriated and involuntary.
Muscular tissue has 5 key functions:
Producing body movement
Stabilising body positions
Regulating organ volume
Moving substances within the body
Producing heat
