Sponge: Set up Cornell
Notes on pg. 57
Topic: 7.1 Functions of bone
Essential Question:
1. Distinguish between
the functions of red
marrow and yellow
marrow.
Bone Function
2.1 Atoms,7.1
Ions,
and Molecules
1. Distinguish between the
functions of red marrow
and yellow marrow.
Skeletal System
• Bones may appear to be
non-living, but bone
contains very active, living
tissues
–
–
–
–
–
Bone tissue
Cartilage
Dense connective tissue
Blood
Nervous tissue
On p. 57 Tree Map of functions of bone
Skeletal System:
Functions of Bone
Support
Protection
Movement
Blood cell
formation
Inorganic
Salt Storage
Support/Framework
• Give shape to head, face, thorax
(chest), and limbs
• Bones of lower limbs, pelvis, and
vertebral column support the body’s
weight
Protection
• Skull protects eyes, ears, and brain
• Ribs cage protects heart and lungs
• Pelvic girdle protects reproductive organs
Movement
• Provide points of attachment for muscles
Blood cell formation
Hematopoiesis (he-mă-tō-poi-ē-sis): process of blood cell
formation that occurs in the bone marrow
• Red marrow: forms RBC, WBC, and platelets
• Yellow marrow: stores fat and is inactive in blood cell
production
– In cases of severe blood loss, the body can convert yellow
marrow back to red marrow to increase blood cell production.
Inorganic Salt Storage
– The salts account for 70% of the extracellular matrix
of bone tissue by weight
– Body requires calcium for blood clot formation
– Osteoporosis- loss of bone mass and mineral content
•
•
•
•
•
Bones develop spaces and canals
Enlarge and fill with fatty tissue
No longer able to support body weight
Easily fracture
Associated with aging
Clinical Application 7.1
Classwork/Homework
•Read Clinical App 7.1
on fractures
•Answer and
HIGHLIGHT the
answers in your reading
as a way to cite your
evidence
9
Body Story: Breaking Down
1m28-24m45s
Sponge: Set up Cornell
Notes on pg. 59
Topic: 7.1 Bone
Classification
7.1Ions,
Bone Classification
2.1 Atoms,
and Molecules
What is the major difference between osteoblasts and
osteoclasts?
Essential Question: What is
the major difference between
osteoblasts and osteoclasts?
GET OUT CLINICAL APP.
HW FROM YESTERDAY
Bone Classification Sheet
• Send someone up for
your bone classification
sheet
• Make sure you include
a description of the
parts
– Include examples of
bones
Bone Structure:
Bone Classification
Bones are classified according to their shapes:
A. Long bones have long longitudinal
axes and expanded ends.
Ex: the femur
B. Short bones are cube-like,
lengths and widths roughly
equal
Ex: wrist and ankle bones
C. Flat bones are plate-like structures
with broad surfaces.
Ex: the ribs, scapulae, and
some bones of the skull
D. Irregular bones have a variety of
shapes.
Ex: the vertebrae and many facial
bones
E. Round (sesamoid) bones These
bones are small and nodular and
imbedded within tendons adjacent
to joints.
Ex: The patella
Structure v. Function
A bone’s shape makes its functions
possible:
• Bony projections called
processes, provide sites for
attachments of ligaments and
tendons
• Grooves and openings are
passageways for blood vessels
and nerves
• A depression in one bone might
articulate with the process of
another.
Parts of a Long Bone
(Back of handout)
• Make sure you label
AND give a description
of the parts and/or
function
Please add
Label your
long bone
18
Bone Structure:
Parts of a long bone
Epiphysis (ĕ-pif-ĭ-sees)- an
expanded portion of bone found
at the end of a long bone
• Forms a joint with another
bone
• Red bone marrow found here
Diaphysis (dī-af’-ĭ-sis)- the shaft of
the bone
• Yellow bone marrow found
here
Periosteum (per-ē-os-te-um)- a tough, vascular covering
of fibrous tissue
• Firmly attached to bone
• Help form and repair bone tissue
Spongy bone• Filled with spaces
• reduces the weight of bone
• Spaces contain red marrow
• Found in the epiphyses
• Strong and resistant to bending
• Cells NOT collected near a central canal
Trabeculae (trah-bek-ū-le) the many branching bony
plates within the spongy bone
Canaliculi (can-ă-lic-ū-lī) Small channels where
nutritional substances diffuse to the bone cells
• lead to the surface of the trabeculae
Spongy bone (w/ marrow)- microscopic
Spongy bone
Red Marrow
Bone Structure
Compact bone• Tightly packed bone tissue with no gaps
• Found in the wall of the diaphysis and in
thin layers above spongy bone
• Strong and resistant to bending
• Compact bone is made of osteons
cemented together by bone
matrix
• Osteons-Cylinder-shaped unit
containing osteocytes that
surround a central canal
• Osteocytes- bone cells
Central Canal- contains blood vessels and nerve fibers
• Ensures that every bone is close to a nutrient supply
Medullary cavity- hollow
chamber in a semi-rigid
tube within compact bone
• Continuous with the
spaces of the spongy
bone
• Endosteum thin layer of
tissue that lines the
Medullary cavity which
contain bone-forming
cells
• Marrow- filled with
yellow marrow
Compact bone- microscope
Bone Formation
Osteoblasts: “Bone formers” cells
• Will eventually become
osteocytes
Osteoclasts: “Bone destroyers”
• Resorb bone material
P. 59
Bone Remodeling
Bone remodeling: Osteoclasts destroy bone tissue, while
osteoblasts replace tissue
• Important so that total mass of bone remains constant
• Completely new skeleton about every 10 years!
• Slows as we age
•
i.e. osteoporosis
Fun Fact!!!
• Astronauts experience a one percent loss of bone
mass per month in space
– Under microgravity conditions:
•
•
•
•
Osteoclast activity increases
Osteoblast activity decreases
Greater loss of spongy bone than compact bone
Astronauts could have 50% bone loss occurrence on a
several-year long space flight
Bone Growth and Development
The skeleton starts forming during the first two weeks of
prenatal development, and bones continue to grow into
adulthood.
Bone Growth and Development
• Bones form by replacing connective tissue in one of two
ways:
1. Intramembranous bones originate within sheetlike layers of connective tissues.
Ex: Skull bones, clavicle, and mandible are
intramembranous bones
Bone Growth and Development
2. Endochondral bones begin as masses of cartilage
that are later replaced by bone tissue. Most of your
bones are endochondral
• Ossification- formation of cartilage into bone
Skeletal Function and Classification
30s-3m
P. 58
Clinical Application 7.2
Classwork/Homework
•Read Clinical App 7.2
on Osteoporosis
• Answer and
HIGHLIGHT the
answers in your
reading as a way to
cite your evidence
•Read/highlight article on
back
37