Anatomy Unit 4 Skeletal System

Functions of skeletal system

support weight

protect organs

provide bone movement

store minerals to release into blood

hematopoiesis

hematopoiesis

produce red/white blood cells in red bone marrow

Bones are _____ matrix of _____/____ surrounded by _____ deposits

solid

living cells/fibers

calcium

Bone shapes:

Flat (scapula), Long (femur), Irregular (vertebrae), Short (wrist) 

Bone anatomy: diaphysis

shaft, long part

Bone anatomy: epiphyseal plate

thin layer of cartilage

Bone anatomy: Epiphysis

end of bone

Bone anatomy: Articular cartilage

covers epiphyses to provide smooth joint movement

Bone anatomy: Medullary Cavity

filled w/ red bone marrow (young) → yellow (old)

Outer layer of bone

Periosteum, Tough connective tissue

Middle layer of bone

Thick layer of compact bone—arranged in osteons cylinders

Osteons are arranged in ________________

lamellae circles

Haversian canals contain _______ and ______, surrounded by ________

blood vessels

nerves

lamellae

Vokmann’s canals run _________ to ___________

perpendicular

haversian canals

Inner layer of bone

Spongy bone layer made of lattice of trabeculae (resists compression)

Osteocytes

mature bone cells that make up majority of bone structure

Osteoclasts

break bones down

Osteoblasts

produce new bones

Canniculi

connects all bone cells to receive nutrients/remove waste

BONE FORMATION

Embryo made of _________

Osteoblasts secrete ___________ replacing cartilage

_________ → Osteocytes

Ossification incorporates _______ & _______ into cartilage

Chondrocytes divide in _______ plate → ______ calcifies

Osteoclasts secrete _______ to make medullary cavity bigger

cartilage

mineral deposits

Osteoblasts

minerals & calciums

Epiphyseal/ matrix

acid

Bones are ___% Osteoid and ____% Mineral salts

35

65

Calcitonin

deposits calcium from blood → bones

Parathyroid Hormone

adds calcium into blood, stimulates osteoclasts to break bone down

1st step of bone repair process

Hematoma forms - blood enters wound/phagocytes ingest dead cells

2nd step of bone repair process

Callus forms - cartilage forms to hold bones tgt

3rd step of bone repair process

Callus ossifies - spongy bone forms/replace cartilage

4th step of bone repair process

Compact bone forms - osteoclasts form medullary cavity

spongy bone → compact bone

Axial skeleton 

central axis of body w/ 80 bones

Appendicular skeleton

Pectoral/pelvic girdles w/ 126 bones

Vertebral column structure runs from ___ to _____

skull

pelvis

At birth vertebral column has ____ vertebrae, and adolsecence ____ sacral vertebrae and ____ coccyx vertebrae fuse

33

5

4

Invertebral discs

provide cushioning/provide shock

Spine is curved ____ at ____

convexly

birth

Spine’s ______ and ____ vertebrae develop ____ curves later on

cervical

lumbar

concave

Fibrous joints

immovable/slightly

held by fibrous connective tissue

Cartilaginous

immovable/slightly

held by cartilage

Synovial

highly movable

contains synovial fluid for no friction

Ligaments connect ___ to ____

Tendons connect ____ to ____

bone to bone

muscle to bone

Skull sutures aren’t completely _____ under _____

closed/fused

35

Closed/simple fracture 

stays inside skin

open/compound fracture

breaks through the skin surface

 Displaced fracture

bone break ends don't line up

Non-displaced fracture

bones still line up straight.