The Skeletal System

Question 1

bone tissue

Answer 1

• made of protein collagen, hardened by calcium phosphate
• two types of tissue:

1. compact (cortical) = hard outer layer, dense/strong/durable
2. spongy (cancellous/trabecular) - internal, lighter, less dense, flexible. consists of network of rod like structures

Question 2

cellular components of bone -> osteoblasts

Answer 2

responsible for making new bone/repairing older

produce protein mixture -> osteoid = mineralized = bone

also manufacture hormones

Question 3

cellular components of bone -> osteocytes

Answer 3

inactive osteoblasts (trapped in bone created)

maintain connections to cytes/blasts

important for communication w/in tissue

Question 4

cellular components of bone -> osteoclasts

Answer 4

large cells, 1+ nucleus = break down bone

release enzymes/acids -> dissolve minerals = resorption

help remodel injured bones

Question 5

bone function - protection

Answer 5

give a supportive structure or framework for the body

Question 6

bone function - movement

Answer 6

attachments for tendons and muscles = movement

muscle contracts -> pull on bone = movement

Question 7

bone function - boundary

Answer 7

boundary to thoracic, pelvic, cranial cavities

protective role for vital organs (hold in place -> efficient functioning)

Question 8

bone function - RBC production

Answer 8

haemopoiesis (RBC production) in red bone marrow (spongy inside)

also produces WBC -> immune response

Question 9

bone function - storage

Answer 9

area for Ca, P, Na, K

calcium = healthy bones/bp regulation
phosphorous = healthy bone/teeth
sodium and potassium = fluid balance, nerve transmits, muscles contract

Question 10

long bones

Answer 10

consist of 2 extremities + shaft

found in limbs as bone is longer than width e.g. femur, tibia

role = strength/structure/mobility

Question 11

structure of long bone

Answer 11

diaphysis = compact bone/central medullary canal/composed of fatty yellow bone marrow

epiphysis = outer cover of compact present, spongy = inside

periosteum = complex vascular 2 layer membrane (outer - fibrous = protection) (inner = osteoblasts + osteoclasts)

Question 12

short bones

Answer 12

no extremities or shaft, different shape/size = roughly cube (same width and length)

e.g. carpals of the wrists

role = stability/some movement

Question 13

irregular bones

Answer 13

no regular shape of characteristics

e.g. vertebra and some skull bones

role = protection of vital organs

Question 14

flat bones

Answer 14

provide flat areas for muscle attachment, usually enclose cavities for organ protection

e.g. some skull bones, sternum and ribs

Question 15

sesamoid bones

Answer 15

small bones developed in tendons around some joints

e.g. patella/knee cap

role = reinforce/decrease stress on tendon

Question 16

axial skeleton

Answer 16

forms long axis of the body, includes bones of skull/spine/ribcage, and the clavicle

Question 17

axial skeleton -> spine bones

Answer 17

cervical (7) C1-C7 (C1 = atlas, sits on C2 = axis)

thoracic (12) T1-T12

lumbar (5) L1-L5

sacral (5 fused) S1-S5

coccygeal (4 fused)

Question 18

appendicular skeleton

Answer 18

bones of the upper and lower limbs and their girdles that join to the axial skeleton

Question 19

fibrous joints

Answer 19

structure -> tough connective tissue

function -> permit no movement + stability

e.g. joints between skull

Question 20

cartilagenous joints

Answer 20

structure -> connected entirely by cartilage

function -> acts as a shock absorber

e.g. rib

Question 21

synovial joints

Answer 21

structure -> space with a capsule between two articulating bones

function -> movement e.g. flexion and extension

e.g. shoulder

Question 22

features of synovial joints (structure + function)

Answer 22

ligament: band of strong fibrous tissue, connect bone to bone (stability)

synovial fluid: slippery fluid contained within joint cavity, reduce friction between articular cartilage and joint (mobility)

articular cartilage: spongy, covers ends of bones in the joint, absorb shock and prevent friction between end of bone and joint (mobility)

joint capsule: tough fibrous tissue (2 layers), strengthen joint and secretes synovial fluid (stability)

Question 23

types of synovial joints -> movements and examples

Answer 23

hinge = flexion/extension e.g. elbow

ball and socket = circumduction, flexion/extension, abduction/adduction e.g. shoulder

pivot = rotation e.g. atlas and axis

plane = gliding/sliding e.g. tarsals

saddle = rotation, circumduction, flexion/extension e.g. thumb

condyloid = flexion/extension, circumduction, abduction/adduction e.g. between radius and carpals

Question 24

connective tissue

Answer 24

made of collagen and elastin fibers

connect muscular and skeletal system

cartilage/ligaments/tendons

Question 25

cartilage - structure and function

Answer 25

specialized connective tissue present in joints/ears/nose/rib cage/bronchial tubes/invertebrate discs

avascular -> very slow healing

shock absorption/joint lubrication/reduce friction

Question 26

types of cartilage

Answer 26

hyaline - smooth/lines articular surfaces of all long bones/found in ribs and trachea/glassy/no nerves or blood vessels

fibrous - tough and strong/lots of collagen

elastic - main protein = elastin (flexible)/found in pinnae (external ear flap)

Question 27

ligaments - structure and function

Answer 27

regular collagen fibers, slightly elastic, strong fibrous band of connective tissue

connect bone to bone, control movement and stability of joints, support organs

Question 28

tendons - structure and function

Answer 28

soft, connective tissue found throughout body, less elastic and arranged in parallel fibers

transfers force between muscle and bone to crease movement

Question 29

osteopenia

Answer 29

condition of lower than normal bone density

Question 30

osteoarthritis (OA)

Answer 30

degenerative, slow onset
affects fingers and weight bearing joints
severe cartilage destruction -> rubbing of bone on bone

Question 31

rheumatoid arthritis (RA)

Answer 31

autoimmune disorder, rapid or gradual onset (week/month)

affects bilateral joint involvement e.g. wrist, hand, elbow, feet

Question 32

accessories of synovial joints

Answer 32

bursa (pl. bursae)​ - fibrous sac lines with synovial fluids, function = prevent friction​

meniscus (pl. menisci)​ - making the joint more stable and reducing wear and tear on joint surfaces.​

pad of fat​ - provides cushioning between the fibrous capsule and a bone or muscle.