2.1: Intro to the Skeletal System

Question 1

chemical level

Answer 1

atom and molecular level

Question 2

cellular level

Answer 2

smallest living unit of the body

Question 3

tissue level

Answer 3

group of cells and the materials surrounding them that work together on one task

Question 4

organ level

Answer 4

grouping of two or more tissue types into a recognizable structure with a specific function

Question 5

organ system level

Answer 5

collection of related with a common function (sometimes an organ is part of more than one system)

Question 6

organismal level

Answer 6

a living individual

Question 7

skeletal system includes

Answer 7

bones, cartilage, and ligaments

Question 8

skeletal system major functions

Answer 8

support, protection, movement, storage mineral (calcium bank), blood cell production (makes all sorts of blood cells), fat storage (bones are full of fat, yellow marrow=fat)

Question 9

each bone is an organ

Answer 9

contains bone connective tissue, blood vessels nerves, lymph vessels, cartilage, connective tissue covering

Question 10

skeletal system - cartilage

Answer 10

• precursor to bone, protect while more flexible than bone
• hyaline: ex-articular, costal, respiratory, nasal
  –> cushion for bones, so not bone on bone
• elastic: ex-external ear and epiglottis
  –> always flexibility
  -fibrocartilage: ex-meniscus, between vertebrae
  –>found where you need a lot of cushioning

Question 11

axial skeleton

Answer 11

• creates the longitudinal (long) axis of the body
• houses vital organs
• 80 bones:
  skull (22), vertebral column (26), hyoid (1), thoracic cage (25), and auditory ossicles (6)

Question 12

appendicular skeleton

Answer 12

• appendages (arms & legs) + girdles (shoulders & hips)
• connects to axial
• much greater mobility
• 126 bones:
  pectoral girdle (4), pelvic girdle (2), upper limbs (60), and lower limbs (60)

Question 13

long

Answer 13

longer than wide
ex: humerus, femur, toes

Question 14

short

Answer 14

roughly cube shaped
ex: most wrist and ankle bones

Question 15

flat

Answer 15

thin, flattened, curved
ex: ribs, sternum, cranial bones

Question 16

irregular

Answer 16

complex shapes
ex: vertebrae, hyoid

Question 17

Sesamoid

Answer 17

shape like a sesame seed
form at points of high friction
ex: patella, hands, feet

Question 18

Sutural

Answer 18

formed between cranial bones vary between individuals

Question 19

compact bone

Answer 19

AKA dense bone
forms outer layer of most bones
-provides most structures/support, heavier

Question 20

spongy bone

Answer 20

AKA trabecular bone
surrounds inner cavity (medullary cavity)
-lighter still provides support and resisting mechanical stress

Question 21

short, irregular, and flat bone

Answer 21

• sandwich of compact bone –> spongy bone –> compact bone
• diploe: layer of spongy bone in cranial bones

Question 22

gross anatomy - long bones

Answer 22

• epiphysis: end
• diaphysis: middle
• metaphysis: connects epiphyses to diaphysis epiphyseal line/plate

Question 23

gross anatomy - long bones layers from superficial to deep

Answer 23

• periosteum: not bone, connective tissue wrapping, nervous/blood vessels come/leave
• compact bone
• spongy bone
• endosteum: inside
• medullary cavity: marrow-found in the hole

Question 24

connective tissue - periosteum

Answer 24

• covers outer surface of living bone
• functions: *isolates and protects bone
  *support blood vessels and nerves
  *connects to other tissues: fibrous layer- interwoven collagen fibers with either deep fascia or bone (perforating fibers)
  *growth and repair: osteogenic layer - contains osteogenic cells (bone stem cells)

Question 25

connective tissue - endosteum

Answer 25

• reticular connective tissue
• lines medullary cavity and covers spongy bone surface
• contains osteogenic (osteoprogenitor) cells
  (important for bone growth and remodeling)

Question 26

skeletal blood supply

Answer 26

very vascular tissue
- extensive network of blood vessels:
*run through periosteum and enter diaphysis via nutrient foramina
*nutrient artery and vein -medullary cavity
*metaphyseal vessels
*epiphyseal vessels
*periosteal vessels

Question 27

skeletal innervation

Answer 27

• sensory neurons throughout periosteum
• enter cortex through nutrient foramen to innervate: endosteum, medullary cavity, epiphyses