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Flashcards in musculoskeletal system Deck (42)
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list the function of the skeletal system


storage - minerals, fats, salts

attachment - for bones to muscles

articulation - when 2 bones move around each other


production - of RBCs


explain what the epiphyses is in the structure of a long bone

ends of the bone


explain what the diaphyses is in the structure of a long bone

the main shaft, hollow cylinder of compact bone surrounding a cavity


explain what compact bone is in the structure of a long bone

forms the cortex/hard outer shell of most bones

very dense and rigid

filled with tiny holes that hold blood vessels

protects spongey bone and bone marrow


explain what spongey bone is in the structure of a long bone

bone on the inside

porous and has large spaces filled with marrow

Red bone marrow in flat and long bones, produces RBCs, WBCs and platelets


explain what the medullary cavity is in the structure of a long bone

hollow cavity in the diaphyses, filled with yellow bone marrow for fat storage


explain what articular cartilage is in the structure of a long bone

Covers epiphysis for protection and cushioning


explain what epiphyseal lines are in the structure of a long bone

Bone growth areas


what is an osteoblast

Secrete bone matrix around themselves until nutrients struggles to reach osteoblast when matrix becomes dense and can’t diffuse

When oxygen is low enough, combines with chemical signals, the osteoblasts differentiate into an osteocyte


what is an osteocyte

Bone cell

Maintains bone tissue


what is an osteon

Basic unit of bone cells (whole individual circle in diagrams)


what is the Haversian canal

Centre of osteon, blood vessel run up it to deliver nutrients to osteocyte


what are the lamellae

Concentric layers surrounding central canal

Forms 3 layers


what are the lacunae

Spaces in lamellae where osteocytes live


what are the canaliculi

Small crevices moving nutrients between osteocytes from the central canal

Run across from lamellae

Deliver nutrients from lacunae to lacunae


what is the process of bone formation/growth called



what are the 2 types of ossification processes

endochondral ossification- long bones

intramembranous ossification - flat bones


explain the process of endochondral ossification

Chondrocytes secrete cartilage matrix

Chondrocytes within the cartilage absorb the surrounding cartilage matrix

The matrix calcifies and the chondrocytes die

Stem cells in the pericardium divide to form osteoblasts

The periosteal bud (consisting of capillaries) form the primary ossification centre

Bone development from the osteoblasts extends toward epiphyses

Same process is repeated in epiphyses  second ossification centres formed

Calcified cartilage is replaced with spongey bone

Osteoclasts reabsorb bone in the diaphysis creating a hollow medullary cavity

Remaining cartilage is over epiphyses forming articular cartilage.


explain the process of intramembranous ossification

Mesenchymal cells differentiate into osteoblasts

Osteoblasts lay down osteoid – organic part of bone made of collagen fibres

Some osteoblasts become entrapped in the osteoid and becomes an osteocyte

The osteoid calcifies and forms a type of spongey bone called spicules

These aggregate in small connecting beams called trabeculae

As trabeculae thicken they form compact bone

The blood vessels on the outside of the cells condense to form the periosteum


what is a joint

A site where 2 bones come together


what are the 3 types of joints





explain what a fixed joint is

no movement, held by fibrous connective tissue e.g. sutures in skull


explain what a cartilaginous joint is

slight movement, held in place by cartilage e.g. symphysis pubis, between vertebrae


explain what a synovial joint is

amount of movement only limited by ligaments, tendons and adjoining bones e.g. shoulder, wrist, knee,


list the different types of synovial joints

ball and socket







explain what a ball and socket joint is

Form when the spherical head of one bone fits into a cup-like cavity of another

E.g. head of humorous into scapula, head of femur fit with pelvis


explain what a hinge joint is

Allow movement in one plane only

Form when the convex surface of 1 bone fits into the concave surface of another

E.g. elbow, knee, ankle


explain what a pivot joint is

Formed when the rounded, pointed or conical end of 1 bone articulates with a ring, formed partly by a bone and partly by a ligament

E.g. joint between the first vertebrae and skull, between radius and ulna


explain what a gliding joint is

Allow movement in any direction in a side-to-side or back-and-forth motion

Restricted only by ligaments of bony processes

E.g. between carpals, between tarsals, between sternum and clavicle


explain what a saddle joint is

2 bones forming the joint are both saddle shaped

They fit together in a way that allowed side-to-side movement and back and forth movement

E.g. where the thumb joins the palm of the hand