Skeletal System

Question 1

Number of named bones in adults

Answer 1

206

Question 2

All bones divided into what categories?

Answer 2

Axial & appendicular

Question 3

Axial skeleton

Answer 3

Skull, hyoid bone, ribs, sternum, vertebrae, sacrum, coccyx

Question 4

Appendicular skeleton

Answer 4

Upper extremity - clavicle, scapula, humerus, radius, ulna, carpals, metacarpals, phalanges
Lower extremity - pelvis (ilium, ischium, pubis), femur, patella, tibia, fibula, tarsals (calcaneus), metatarsals, phalanges

Question 5

What is bone?

Answer 5

Millions of bone cells surrounded by mineral matrix (mostly made of calcium phosphate)

Question 6

Osteoclasts

Answer 6

Carving; remodels bones & releases minerals

Question 7

Osteoblasts

Answer 7

Building; builds bones & stores minerals

Question 8

Osteocytes

Answer 8

Old cells buried in the middle; gives strength

Question 9

Bone types

Answer 9

Flat, short, long, sesamoid, & irregular

Question 10

Flat bones

Answer 10

Not always completely flat, have broad side, grow out (skull, ribs)

Question 11

Short bones

Answer 11

Short as they are long (only in wrists and ankles)

Question 12

Long bones

Answer 12

Longer than they are wide (femur, humerus, etc.)

Question 13

Sesamoid bones

Answer 13

Bone embedded in tendon, grows responding to stress/strain (patella is only named sesamoid, others @ base of thumb & big toe)

Question 14

Irregular bones

Answer 14

Oddly shaped, form in places that fuse later (vertebrae, pelvis)

Question 15

Epiphysis

Answer 15

End part of a long bone

Question 16

Growth plate

Answer 16

Cartilage layer near ends of long bones

Question 17

Synarthrosis joint

Answer 17

Where 2 bones meet but don’t move (skull plates/sutures)

Question 18

Amphiarthrosis joints

Answer 18

Joints that can move but don’t/move minimally (pubis bones in pelvis, ribs)

Question 19

Diarthrosis/synovial joints

Answer 19

Fully movable joints, have a synovial fluid capsule/layer around them that reduces friction & absorbs heat
4 types are ball & socket, pivot, hinge, and gliding

Question 20

Ball & socket

Answer 20

Round end and concave surface, most movable and unstable (shoulder joint, hip joint)

Question 21

Pivot joint

Answer 21

Rotation only (atlas/axis joint, radius/ulna joint)

Question 22

Hinge joint

Answer 22

Single movement; flexion and extension (elbow joint, knee joint, ankle joint)

Question 23

Gliding joint

Answer 23

Bones that glide across each other on one plane (side) (carpals and tarsals)

Question 24

Anatomy of a (long) bone

Answer 24

Epiphyses - rounded ends of bone
Growth plate/epiphyseal plate - between epiphysis & diaphysis
Diaphysis - middle portion of long bone between growth plates
Medullary cavity - hollow space inside diaphysis
Periosteum- outer layer of bone
Endosteum - layer of connective tissue that lines medullary cavity
Compact bone - underneath periosteum
Spongy bone - mostly at epiphysis heads
Yellow marrow - inside medullary cavity

Question 25

Skeletal system functions

Answer 25

Movement, supports, protection, mineral development, & hemopoiesis

Question 26

Hemopoiesis

Answer 26

Red and white blood cells and platelets made red marrow of spongy bone
Some white blood cells made in yellow marrow

Question 27

Mineral storage

Answer 27

Bones store minerals (calcium most importantly)
When other cells of body need calcium osteoclasts break down bone and release it into bloodstream
Osteoblasts store calcium when infested

Question 28

Development

Answer 28

Bones start out as cartilage when baby is in womb, turns into bone by “ossification” when bone cells replace cartilage throughout fetal development
Fontanels - soft spots on baby’s heads; gaps where bone plates haven’t fused to form sutures