Week 6

Question 1

function of bones

Answer 1

• support
• protection
• movement
• mineral and growth factor storage
• blood cell formation(hematopoietic tissue)
• chemical energy/triglycerides (Fat)storage
• hormone production

Question 2

5 major bone cells

Answer 2

Osteogenic cells- stem cells
osteoblasts- bone forming
osteocytes- bone maintenance
osteoclasts- bone reabsorption
bone lining cells

Question 3

Chemical composition of bone- organic component

Answer 3

• Bone cells (osteogenic cells, osteoblasts, osteoclasts, osteocytes, bone lining cells)
• Osteoid(bone matrix and collagen):secreted by osteoblasts
• contributes to the bone’s structure and its flexibility and strength

Question 4

Chemical composition of bone- inorganic component

Answer 4

• mineral salts(calcium phosphate): contributes to bone’s hardness
• combination of organic and inorganic components makes bone extremely strong, durable and flexible without being brittle

Question 5

Fibrous joints

Answer 5

• bones are held together by fibrous connective tissue
• no joint cavity
• immovable joint
• eg sutures in skull

Question 6

Cartilaginous joint

Answer 6

• bones are held together by catilage
• no joint cavity
• no or limited movement
• eg.epiphyseal line, pubic symphysis, intervertebral discs

Question 7

Synovial joints

Answer 7

• ends of bones covered with articular cartilage for smooth joint movement
• joint cavity filled with synovial fluid
• free moving fjoints
• eg joints in limbs

Question 8

articular cartilage

Answer 8

• covers ends of bones

- provides smooth movement and absorbs compression

Question 9

joint cavity

Answer 9

• space filled with synovial fluid

Question 10

synovial fluid

Answer 10

• lubricates the joint for reducing friction during movement

Question 11

articular capsule

Answer 11

• dense connective tissue that strengthens the joint so bones do not pull apart

Question 12

synovial membrane

Answer 12

• inner lining of articular capsule; secretes synovial fluid

Question 13

bone development- newborns

Answer 13

• skull bones are incomplete and are connected by fontanelles
• spine is C-shaped
• secondary curvatures develop with reshaping of the invertebral discs
• cervical curvature becomes prominent at 3mths as baby can hold head up independently
• lumbar curvature develops when babies walk

Question 14

bone development- children and adolescents

Answer 14

• bone formation (osteoblast activ.) is greater than bone reabsorption(osteoclast)
• bone growth occurs in epiphyseal plates until young adulthood
• epiphyseal plates site of long bone growth.
• by mid 20s epiphyseal plate ceases activity and fuses forming the epiphyseal line

Question 15

bone development- young adults

Answer 15

• bone formation and bone reabsorption are balanced

Question 16

bone development- older adults

Answer 16

• bone formation decreases while reabsorption continues > bone mass decreases
• impacts bone density (osteoporosis)
• age related bone mass loss is greater in females
• bone mass loss also influenced by hormonal changes particularly in females after menopause

Question 17

developmental aspects- puberty

Answer 17

• female pelvis widens for childbearing
• male skeleton on average is larger than female skeleton
• male skeleton becomes stronger
• regular supply of calcium (& vit D) important for healthy bone strength and development

Question 18

developmental aspects- older adulthood

Answer 18

• osteoporosis causes reduced bone density and contributes to deterioration of skeleton
• discs become thinner and less flexible > increasing risk of back injuries
• rib cage becomes rigid and inflexible > shallow breathing
• fractures heal slower

Question 19

developmental aspects of joints - week 8 embryo

Answer 19

• developed synovial joints resemble adult joints and secrete synovial fluid

Question 20

developmental aspects of joints childhood/teenagers

Answer 20

• strength and flexibility of joints depends on use

Question 21

developmental aspects of joints- late middle age

Answer 21

• begin to display changes that lead to injuries
• ligaments and tendons become shorter and weaker
• intervertebral discs begin to deteriorate and become thinner resulting in back injuries and problems with posture
• arthritis due to deterioration of synovial joint components

Question 22

effect of pregnancy on joints

Answer 22

Relaxin - hormone released by placenta

• softens ligaments and joints in the pelvic region for easier childbirth
• increased flexibility of the pelvic region may contribute to the waddling gait often seen
• however often other joints in the body become less stable and more pront to injury
• increased size of the abdominal region changes the centre of gravity. many women experience an exaggerated lumbar curvature

Question 23

how to maintain a healthy musculoskeletal system

Answer 23

• diet rich in calcium and protein (bones being hard and strong)
• regular exposure to sunlight for production of vitamin D by the body (inc calcium absorption deposited in bones)
• regular exercise (keep muscles strong and flexible which keep joints stable

Question 24

skeletal muscles

Answer 24

• attach to the skeleton
• voluntary control
• body movement and posture; production of body heat; stabilises joints

Question 25

smooth muscles

Answer 25

- layers in the wall of the digestive tract, urinary bladder, respiratory tract, uterus and arteries - involuntary control - contractions serve to move or expel content

Question 26

cardiac muscles

Answer 26

- walls of heart - involuntary control - contractions force blood to circulate through heart and body