Show Menu

Skeletal System Cheat Sheet by

Bone, Joints, and Bone growth

7 Functions of Bones

Bones provide Framework that supports the body and cradles its soft organs
Fused bones of the skull protect the brain
Skeletal muscles which attach to bones by tendons use bones as levers to move
Mineral Storage
Bone stores calcium and phosphate
Blood cell formation
Hemato­poiesis occurs in the red marrow of certain bones
Fat storage
A source of energy for the body. Is stored as yellow marrow in cavities of long bone
Hormone production (osteo­calcin)
Hormone that helps to regulate insulin secretion, glucose homeos­tasis and energy expend­iture

Types of bone cells and their derivation

Osteop­rog­enitor Cells
Stem cells.
Matrix synthe­sizing cell. Respon­sible for bone growth
mature bone cell. Monitors and maintains the minera­lized bone matrix
Bone-r­eso­rbing cell

Types of Bone Fractures

Bone fragments into three or more pieces
Bone is crushed
Ragged break occurs when excessive twisting force are applied
separates from the diaphysis along the spiphyseal plate
Broken bone portion is pressed inward
Bone break is incomp­lete, much in the way a green twig breaks

Classi­fic­ation of Joints

Adjoining bones united by collagen fibers. Suture (short fibers)- immobile Syndes­omosis (long fibers) slightly movable and immobile
Adjoining bone nited by cartilage: Syncon­drosis (hyaline) immobile Symphysis (fibro­car­tilage) Slightly movable
Adjoingin bone covered with articular cartilage. Areas: Plane, hinge, Pivot, condylar, saddle, ball and socket

Axial Skeleton Vs. Append­icular Skeleton

Append­icular Skeleton
Long axis of the body and includes the bones of the skull, vertebral column, and rib cage
Bones of the upper and lower limbs and the girdles

Compact and Spongy Bone

compact Bone
External layer of the bone, is dense and looks smooth and solid to the naked eye
Spongy bone
Honeycomb like structure inside of compact bone that is called trabeculae and its filled with red and yellow marrow

Part of Long bone Explin­ation

Epiphe­lysis is another name for the bone end of the long bone. When someone is growing, their Epiphyseal plate works to extend the bone. (this mostly happens in adolescent years). When someone gets to the age where this stops, the epiphyseal line forms which is basically the remnant of the epiphyseal plate

Chemical Compos­ition of Bone

Organic Components
Inorganic components
Bone cells and osteoid- allow it to resist tension (stretch)
Mineral salts- allow to resist compre­ssion

Postnatal Bone Growth

1) Resting Zone 2) Prolif­eration Zone: cartilage cells undergo mitosis 3) Hypert­rophic Zone: Older cartilage cells enlarge 4) Calcif­ication Zone: Matrix becomes calcified; cartilage cells die; matrix begins deteri­orating 5) Ossifi­cation Zone: New bone is forming

Fibrous Joints

Joint held together with very short, interc­onn­ecting fivers
joint held together by a ligament. Fibrous tissue can vary in length but is longer than in suture
peg in socket fibrous joint

range of motions allowed by Synovial joint

Nonaxial movement: Gliding uniaxial movement ( movement in one lace) Biaxial movement (movement in two lanes. multir­acial (movement in or around all three places space and axes

Long Bone

Structure of long bone
Shaft, bone ends, membranes
Shaft: forms the long axis of the bone that surrounds the medullary cavity, which contains no bone tissue, but yellow bone marrow
The bone ends: outer shell of compact bone that forms the epiphysis exterior and the interior contains spongy bone. Thin layer of hyaline cartilage covers the joint surface which cushions opposite ends of the bones
Perios­teum. covers the external surface of the bone and contains lots of nerve vessels which why it makes breaking a bone so painful
covers the internal bone surface. it covers the trabeculae of spongy bone and lines the canals that pass through the compact bone
Nutrient Foramen
Nutrient artery runs inward to supply the bone marrow and the spongy bone

Bone Growth

Endoch­ondral ossifi­cation
Intram­emb­ranous ossifi­cation
bone develops by replacing hyaline cartilage which leads to endoch­ondral bone
a bone develops from a fibrous membrane and theh bone is called a membranous bone

How the bone Grows Fetus to adoles­cence

1) Bone collar forms around the diaphysis of the hyaline cartilage model 2) Cartilage calcifies in the Center of the diaphysis and then develops cavities 3) the periosteal bud invades the internal cavities and spongy bone forms 4) The diaphysis elongates and a medullary cavity forms. Secondary ossifi­cation centers appears in the epiphyses 5) The epiphyses ossify when ossifi­cation is complete, hyaline cartilage remains only in teh epiphyses plates and articular cartilage

Synovial Joint

articular cartilage
glassy smooth hyaline cartilage covers the opposing bone surface
Joint cavity
contains a small amount of synovial fluid
Articular capsule
enclosed by a two layered joint capsule. A tough external fibrous slayer composed of dense irregular connective tissue that is continuous with the periostea of the articu­lating bone
reinfo­rcing ligaments
reinforced and strengthen by a number of sandlike ligaments.


No comments yet. Add yours below!

Add a Comment

Your Comment

Please enter your name.

    Please enter your email address

      Please enter your Comment.

          Related Cheat Sheets

          Cell Structure and Function Cheat Sheet
          Anatomy & Physiology Unit 1: Intro to Anatomy Cheat Sheet

          More Cheat Sheets by ally_rose

          Muscular System Cheat Sheet