Chapter #7
Skeletal System
Chapter 7.1 Introduction
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Bones the organs of the skeletal system
Provide points of attachment for muscles
Protect soft tissue/organs
Support soft tissue
House blood-producing cells
Store inorganic salts
Provide passageways for blood vessels
and nerves
 There are 206 bones in the adult human
body
Chapter 7.2 Bone Structure
• Epiphysis (epifisis)
end of the bone
• Articular cartilage
covers end of bones
• Diaphysis (diafisis)
the shaft of the bone
• Periosteum is a
tough vascular
covering of
fibrous tissue.
Bleeds when
you fracture
your bones.
Compact bone
Spongy bone
• Compact bone is a type of bone with a
continuous matrix with no gaps. (Diaphysis)
• Spongy bone is a type of bone with numerous
branching bony plates. (Epiphysis)
Medullary cavity the hollow
chamber/tube in long bones.
Endosteum lines the medullary
cavity. Lies under the
periosteum.
Marrow is a specialized type of
soft connective tissue that fills
the medullary cavity.
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Osteocytes bone cells.
Lacunae very small, bony chambers.
Haversian canals (Central canals)
Osteon cylinder-shaped unit.
Volkmann’s canal perforating canals
Chapter 7.3 Bone Development
and Growth
• Intramembranous
bones originate
between sheetlike
layers of
connective tissue.
• Osteoblasts
bone-forming
cells.
• Endochondral bones-Long Bones they
develop from masses of cartilage shaped
like future boney structures.
• Epiphyseal plate is the
portion of bone where
growth happens. Bones
continue to grow until the
plate closes.
• If an Epiphyseal plate is
damaged before it
ossifies, elongation of the
long bone may cease
prematurely, or growth
maybe uneven.
Chapter 7.4 Bone Function
• Hemopoiesis the process of blood cell formation.
Begins in the yolk sac, which lies outside the
human embryo.
• Marrow is a soft, netlike mass of connective tissue.
• Red Marrow- makes red blood cells, white blood
cells, and platelets. It is red because it contains
hemoglobin. It occupies the cavities of most bones
in an infant. In an adult, RM is found in the spongy
bone of the skull, ribs, sternum, clavicles,
vertebrae, and pelvis.
• Yellow marrow- stores fat and is inactive in blood
cell production.
• Bone tissue is rich in calcium phosphate.
• When blood is low in Ca, the body makes
osteoclasts (breakdown bone) and release
calcium into the blood for the body to use
for metabolic processes.
• Osteoporosis- lose of bone volume and
mineral content. Factors that increase
osteoporosis are low calcium intake, lack
of physical exercise, decrease in blood
estrogen.
Chapter 7.5 Skeletal Organization
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Axial Skeleton
Skull, Ribs, Vertebral column
Appendicular skeleton
Arms, legs, and bones that anchor the
limbs to the axial skeleton.
Chapter 7.6 Skull
• Fontanels (Soft Spots)- membranous
areas. Found in infants skulls they will
close as they develop.
Infant skull
Chapter 7.7 Vertebral Column
• Atlas- 1st cervical
vertebrae
• Axis- 2nd cervical
vertebrae
Chapter 7.8 Thoracic Cage
• Thoracic cage
includes ribs,
thoracic vertebrae
and sternum.
Chapter 7.9 Pectoral Girdle
• Pectoral girdle
(Shoulder girdle)
includes the clavicles
and scapulae.
Chapter 7.10 Upper Limb
• Know the bone
identification
sheet
7.11 Pelvic Girdle
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Includes two hipbones (coxae)
Ilium (hip bones)
Ischium (butt bones)
Pubis (where the 2 hip bones meet)
Male
Female
Chapter 7.12 Lower Limb
• Know bone identification
sheet
Chapter 7.13 Joints
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Joints are functional junctions between bones.
Fibrous joints
Cartilaginous joints
Synovial joint
Ball-and-socket Joints
Condyloid
Gliding
Hinge
Pivot
Saddle
• Fibrous joints These joints are also called
"fixed" or "immoveable" joints, because
they do not move. These joints have no
joint cavity and are connected via fibrous
connective tissue. The skull bones are
connected by fibrous joints.
• Cartilaginous joints
These joints also have
no joint cavity and the
bones are connected
tightly to each other
with cartilage. These
joints only allow a small
amount of movement,
so are also called
"partly" or "slightly
moveable" joints. The
vertebrae are
examples of
cartilaginous joints.
• Most of the joints in the body are
synovial joints. These joints are "freely
moveable" and are characterised by
being surrounded by an articular
capsule which contains the synovial
fluid. Synovial fluid lubricates the
joints, supplies nutrients to the
cartilage and it contains cells that
remove microbes and debris within
the joint cavity. Because of the larger
range of movements of these joints,
there is an increased risk of injury
example dislocations. Synovial joints
are located predominantly in limbs.
• Many synovial joints also have
ligaments either inside or outside the
capsule.
Synovial Joints
1. Ball and socket - allows movement around 3 axes flexion / extension, abduction / adduction and rotation, ex.
shoulder, hip.
2. Condyloid – permits a variety of movements. Examples
joint between the metacarpals and phalanges.
3. Gliding - Flat bone surfaces allow side to side and
backwards and forwards movements ex. between
carpals, tarsals, between the sternum and the clavicle
(sterno-clavicular) and the scapula and the clavicle.
4. Hinge - movement occurs primarily in a single plane ex.
elbow, knee , ankle, interphalangeal joints.
5. Pivot - a ring of bone and ligament surrounds the surface
of the other bone - movement in one plane, primarily
rotation ex. between the atlas and axis (ie the cervical
vertebrae numbers 1 and 2) and the radius and ulna.
6. Saddle joints - example thumb.
Work Cited
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“Femur”. March 6, 2007. http://webschoolsolutions.com/patts/systems/bone-growth.gif
“Aged femur” and “Long bone”. March 6, 2007.
http://images.google.com/imgres?imgurl=http://www.curehandpain.com/images/bone/spongy_bone.gif&imgrefurl=http://w
ww.curehandpain.com/pages/bone/bone.php&h=226&w=347&sz=23&hl=en&start=40&tbnid=ZzjWovrGxZeNyM:&tbnh=7
8&tbnw=120&prev=/images%3Fq%3Dcompact%2Bbone%26start%3D20%26gbv%3D2%26ndsp%3D20%26svnum%3D
10%26hl%3Den%26sa%3DN
“Intramembranous bones”. March 6, 2007.
http://academic.wsc.edu/faculty/jatodd1/351/intramembranous_bone_growth.jpe
“Bone development”. March 6, 2007.
http://classes.aces.uiuc.edu/AnSci312/Bone/Gil%209%2014%20Endochondral%20ossification.jpg
“X-ray”. March 6, 2007. http://www.shoppingtrolley.net/images/epiphyseal-plate.gif
“Plate injury”. March 6, 2007. http://cal.vet.upenn.edu/saortho/chapter_34/34F4.jpg
“Pelvis, lower limb and upper limb”. March 7, 2007. http://www.gpc.edu/~jaliff/spinchar.gif
“Vertebral Column”. March 7, 2007. http://www.shockfamily.net/skeleton/SPINE.JPG
“Rib Cage”. March 7, 2007. http://www.netterimages.com/images/vpv/000/000/007/7191-0550x0350.jpg
“Skull”. March 7, 2007. http://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Gray_188__Side_view_of_the_skull.png/180px-Gray_188_-_Side_view_of_the_skull.png
“Infant Skull”. March 7, 2007.
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files
/Bio%20102/Bio%20102%20lectures/Motor%20Systems/inf
ant_skull.jpg
• “Skull joints”. March 9, 2007.
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Motor%20Systems/im
movable_joint.jpg
• “Vertebrae joint and synovial joint”. March 9, 2007.
http://www.shoppingtrolley.net/images/anatomy/cartilaginous-joint.jpg