Bones and Levers for Movement

Questions and Answers

What is the approximate percentage of inorganic material in the bones of a child?

65%

50% (correct)

35%

80%

What happens to the proportion of organic material in bones as a person ages?

It fluctuates drastically.

It increases.

It remains constant.

It decreases. (correct)

What is a potential consequence of bones having a high proportion of inorganic material?

Increased flexibility.

Increased elasticity.

Increased brittleness. (correct)

Increased strength.

Why are bones more prone to fractures in the elderly?

They have a lower proportion of calcium. Signup and view all the answers

What property of bone allows it to bend under stress?

Elasticity Signup and view all the answers

What is the primary function of the lever system formed by the long bones?

To sustain the weight of the trunk Signup and view all the answers

Which of the following types of bones have a length greater than width?

Long bones Signup and view all the answers

What is the name of the bony structure located at each end of a long bone?

Epiphysis Signup and view all the answers

Which of the following bones are examples of short bones?

Carpal bones Signup and view all the answers

What is the term for the tubular shaft of a long bone?

Diaphysis Signup and view all the answers

What type of cartilage is primarily found in 1º (Primary) cartilaginous joints?

Hyaline cartilage Signup and view all the answers

Which joint is classified as an inferior tibiofibular joint?

Joint between the tibia and fibula Signup and view all the answers

How many types of cartilaginous joints are identified?

Two types Signup and view all the answers

Which of the following statements is true regarding 1º (Primary) cartilaginous joints?

They are united by a plate of hyaline cartilage. Signup and view all the answers

Which of the following types of cartilage is NOT typically found in cartilaginous joints?

Bone Signup and view all the answers

What is the main function of the cruciate ligaments in the knee?

To restrict excessive movement Signup and view all the answers

What type of synovial joint allows movement in several axes?

Ball and socket joint Signup and view all the answers

What is the characteristic feature of a ball and socket joint?

A rounded head fits into a concavity Signup and view all the answers

What determines the classification of synovial joints?

The arrangement of articular surfaces and types of movements Signup and view all the answers

What is the term for the rounded head of a bone that fits into a concavity of another bone?

Ball Signup and view all the answers

Which type of joint allows for only rotational movement?

Pivot joint Signup and view all the answers

What characterizes the pivot joint structure?

A round bony process fitting into a bony socket Signup and view all the answers

What type of movement is associated with the acromioclavicular joint?

Gliding movement Signup and view all the answers

Which statement about the pivot joint is true?

It enables rotational movement only. Signup and view all the answers

Which of the following statements is correct regarding motion at the acromioclavicular joint?

It enables gliding and limited rotation. Signup and view all the answers

Study Notes

Bone Composition and Characteristics

Bones consist of 35% organic material and 65% inorganic material, with variations occurring throughout life.
In children, bone composition is roughly equal, around 50% organic and 50% inorganic.
Damage to bones may result in bending due to elasticity or partial fractures.
Aged bones tend to have a higher proportion of inorganic material, making them more brittle, leading to easier fractures.
Common examples of skeletal bones include the clavicle, humerus, femur, metacarpals, metatarsals, and phalanges.

Bone Structure

Long bones have a tubular shaft (diaphysis) with epiphyses at each end, characterized by a length greater than width.
Short bones, such as carpal bones in the hand, have more equal dimensions.
Some bones, like those in the skull, are classified as sutural bones.

Cartilaginous Joints

Two types of cartilaginous joints exist: primary (1º) and secondary (2º).
Primary joints are united by a plate of hyaline cartilage, such as cruciate ligaments, which help stabilize the knee joint.

Synovial Joints

Classified based on articular surface arrangement and movement types.
Ball and Socket Joints: Allow movement in multiple axes, featuring a rounded head fitting into a concavity (e.g., acromioclavicular joint).
Pivot Joints: Facilitate rotational movement; consist of a round bony process fitting into a bony or ligamentous socket.

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Description

This quiz covers the composition of bones, including the ratio of organic to inorganic constituents, and how it changes throughout life. It also touches on how bones react to injury.