Download Skeletal System PPT

The Skeletal System - HBS
Functions
• _________________
▫ Bones are the body’s supporting framework.
▫ Your bones give you shape and structure
▫ Your bones have to support the tissue that you
have on your body.
• Protection
▫ Bones protect our delicate _____________
including the brain, heart, and lungs.
• Movement
▫ Bones need muscles for ________ ___
_____________.
▫ Muscles contract and relax to cause movement of
the body.
• Storage
▫ Bones store ____________________
▫ Calcium is needed for nerve impulses to cause
muscle movement.
The last function…..
• Hematopoiesis
▫ The process of ____________________ within
the bone.
Number of Bones
• We have 350 bones
at birth
▫ Why?
• Adults have 206
Types of Bones
• We have four different types of bones found
throughout the body
 ________
 ________
 ________
 ________
Irregular
Flat
Long
Short
Divisions of the Skeletal System
• Axial Skeleton Vs Appendicular – color your
picture
Bone Is a Living Tissue
• Bones need a blood supply, nutrients, and
__________
• There are also nerves that run through bones as
well.
Microscopic Structures of
Bone
• Bone can be divided into how it is constructed
▫ ________________________
▫ ________________________
• Both types are found throughout the body and
have very specific functions
Spongy Bone
Compact Bone
Spongy Bone
• Contains many spaces
that may be filled with
bone marrow.
• The areas of spongy
bone can be found at
the
________________.
• These areas are where
hematopoiesis occurs.
Compact (dense) Bone
• Does not contain a
network of open
spaces.
• It is used for ________,
structure and support
▫ Yet it is still light so that
we can move our
bodies without extra
weight
Structures of Long Bones
• Long bones include
▫
▫
▫
▫
▫
▫
Humerus
Ulna
Radius
Femur
Tibia
Fibula
Diaphysis
•The ______________ of the bones.
•It is _____________ but made of hard, compact bone.
•It is strong in structure
•Gives bone their “strength”
Epiphyses
•The _________________ of the bones
•Composed of spongy bone and red bone
marrow.
Medullary Cavity
•The ________ ________within the bone
•Contains yellow bone marrow
•Soft and fatty form of bone marrow.
Articular Cartilage
•A thin layer of
cartilage covering
each epiphysis.
•Functions as a
_________________
________________.
Periosteum and Endosteum
• __________________- a
fibrous membrane covering
the long bone except at the
joint surfaces.
• _________________- a
thin membrane that lines
the medullary cavity.
Compact (dense) Bone
• Does not contain a network of open spaces.
• Bone tissue is composed of repeating,
circular units called ___________________.
• These circular systems are called _______
as well.
• Within each Haversian system, there is a
central canal where blood vessels and nerves
can be found.
• The osteon or
Haversian systems
is composed of
layers of a calcified
matrix of circles
called __________.
• The darkly-stained
spots are spaces called
___________.
• The lacunae contain
_____________ which
are bone cells.
• ____________________ connect multiple
lacunae for nutrients to pass.
• Nutrients pass from blood vessel in
________________ canal through the
canaliculi to the osteocytes.
Osteoblasts
• Bone ____________ cells.
• Synthesize and secrete collagen fibers and
other organic components of bone matrix.
• Initiate the process of calcification.
• Found in both the periosteum and the
endosteum
The blue arrows indicate the
osteoblasts. The yellow arrows indicate
the bone matrix they’ve just secreted.
Osteoclasts
•
Cells that _________________________– this process is called
bone resorption and is part of normal bone growth, development,
maintenance, and repair.
Concentrated in the endosteum.
The osteoclast secretes digestive enzymes to digest the bone
matrix.
•
•
•
•
It also pumps out hydrogen ions to create an acid environment that
eats away at the matrix.
Why do we want a cell that eats away at bone? (Hint: bone is a
very dynamic tissue.)
Osteocytes
• Mature Bone Cells.
• Osteoblasts that
have become
trapped by the
secretion of matrix.
• No longer secrete
matrix.
• Responsible for
_________________
________________.
Yellow arrows indicate
osteocytes – notice
how they are
surrounded by the
pinkish bone matrix.
Blue arrow shows an
osteoblast in the
process of becoming an
osteocyte.
On the right, notice how the osteocyte
is “trapped” within the pink matrix
•Here, we see a cartoon showing all 3 cell types. Osteoblasts and osteoclasts are
indicated.
•Note the size of the osteoclast (compare it to the osteoblast).
•What is the name of the third cell type shown here?
•What do you think the tan material represents?