Musculoskeletal System

Question 1

what are the 6 functions of bone?

Answer 1

• support (structural framework)
• protection (internal organs from injury)
• assistance in movement (skeletal muscle attachments)
• mineral homeostasis (stores several materials)
• blood cell production (red bone marrow produces RBC, WBC & platelets)
• triglyceride storage (yellow bone marrow consists of adipose cells that store triglycerides)

Question 2

what are the 4 types of bones?

Answer 2

• long bones
• short bones (most wrist and ankle bones)
• flat bones
• irregular bones

Question 3

what is the typical structure of a long bone?

Answer 3

• diaphysis is the shaft/body
• epiphyses are the distal/proximal ends
• metaphyses are the regions where the diaphysis joins the epiphyses
• articular cartilage is a thin layer covering the regions of the epiphyses where the bone articulates with other bones
• periosteum - sheath of dense irregular connective tissue and blood vessels surrounding the bone outside of the articular cartilage
• medullary cavity - hollow space within diaphysis that contains fatty yellow bone marrow
• endosteum - thin membrane lining medullary cavity

Question 4

what are the four principle situations where ossification occurs?

Answer 4

1. initial formation of bones in an embryo and fetus
2. growth of bones during infancy, childhood and adolescence until their adult sizes are reached
3. remodelling of bone
4. repair of fractures throughout life

Question 5

how do bones grow in length and thickness from fetus to adult in different ways?

Answer 5

• grow in length as chondrocytes at the epiphyseal plate reproduce faster than they are calcified by bone
• as adolescence ends, bone replaces cartilage and the bone is at its final length
• grow in thickness as perichondrium cells become osteoblasts which lay down bone matrix before becoming osteocytes.
• osteocytes create new osteons and thicken the bone.

Question 6

how does bone remodelling occur?

Answer 6

• a continuous process as old bone tissue is replaced with new tissue
• bone resorption is the removal of minerals and collagen by osteoblasts
• bone deposition is the addition of minerals and collagen by osteoblasts
• occurs naturally through life as exercise, diet, and lifestyle require the body to change bone density, thickness and mineral availability

Question 7

how many bones does the average adult human have?

Answer 7

206

Question 8

how many bones are babies born with?

Answer 8

300

Question 9

what occurs during ossification?

Answer 9

• baby’s bones are primarily made up of cartilage
• overtime this cartilage turns into bone through this process

Question 10

what do bone cells contain?

Answer 10

• collagen fibers
• ground substance
• mineral crystals
• carbohydrates and other substances
• protein
• calcium and phosphate

Question 11

what four kinds of joint classifications?

Answer 11

• synostotic
• cartilaginous
• fibrous
• synovial

Question 12

what are the 3 types of joint?

Answer 12

• those that allow free movement (ie diarthrosis)
• those that are fixed (ie synarthrosis)
• those that permit limited movement (amphiarthrosis)

Question 13

what are the 3 different types of synovial joints?

Answer 13

• pivotal joints (ie between the humeral radius and the ulna)
• ball and socket joints (ie hip joint)
• hinge joints (ie interphalangeal joints of fingers)

Question 14

what do body mechanics incorporate?

Answer 14

• maintain balance
• provide posture
• ensure body alignment