Download The Skeletal System

• Support- framework that supports body and
cradles its soft organs
• Protection- for delicate organs, heart, lungs,
brain
• Movement- bones act as a passive movement
while muscle as an active movement
• Mineral storage- calcium & phosphate
• Blood cell formation- hematopoiesis
•
When you were born you had over 300 bones! As you grow
up bones fuse (grow) together into 206 bones.
How Bones Grow
• When a baby is born, its body contains
300 bones. Baby bones are made of a
special material called cartilage. It is
soft and flexible. Your earlobes and
nose are made of cartilage.
• During puberty some bones start to
grow together to produce the 206 adult
skeleton.
• Until people reach between 17 and 21
years of age, the cartilage has
completely hardened into bone. Once
completed, there can be no more
growth.
Human skeleton
• Long Bones- metacarples, metatarsals,
phelangies, humerus, ulna, radius, tibia,
fibula
• Short Bones- carpals, tarsals
• Flat Bones- rib, scapula, skull, sternum
• Irregular Bones- vertebrae, some facial
bones
• Sesamoid- patella
spongy bone
Proximal
compact bone
epiphysis
Endosteum
diaphysis
epiphyseal line
yellow marrow
Sharpey’s fibers
Distal
epiphysis
hyaline cartilage
periosteum
The Vertebral Column
Cervical Vertebrae
(7)
Thoracic Vertebrae
(12)
Lumbar Vertberae (5)
Sacrum
Coccyx
Cervical Vertebrae
The Thoracic Cage
Sternum
True Ribs (7)
False Ribs (3)
Floating Ribs (2)
Sacrum & Coccyx
Bones of the Pectoral Girdle
Humerus
Ulna
Radius
8 Carpals
5 Metacarpals
14 Phalanges
Pelvis
Pelvis (lateral view)
Ilium
Acetabulum
Obturator
foramen
Ischium
Pubis
Ischium
Male Pelvic Girdle
Female Pelvic Girdle
The Lower Limb
(Legs)
Femur
Patella
Tibia
Fibula
7 Tarsals
5 Metatarsals
14 Phalanges
phelangies
metatarsals
tarsals
tarsals
metatarsals
phelangies
The Joints
• The place where two bones meet is called
a joint.
• There are two types of joints in every
person's body: fixed joints and moving
joints.
Immovable Joints
(synarthrosis)
suture
pubis symphisis
Slightly Movable Joint
(ampharthrosis)
Types of Joints in the Human Body
MOVING JOINTS
Moving joints are enable you to twist, bend, and
move many different parts of your body.
 Types:
1. Hinge joints, like in your knee and elbow,
enable movement similar to the opening and
closing of a hinged door.
2. Ball and socket joint (shoulders and hips).
It allow for lots of movement in every direction.
3. Ellipsoidal joints, such as the joint at the base
of your index finger, allow bending and
extending, rocking from side to side, but rotation
is limited.

Moving joints
4. Gliding joints occur between the surfaces of
two flat bones that are held together by
ligaments. Some of the bones in your wrists
and ankles move by gliding against each other.
5. Pivot joint in your neck allows you to turn your
head from side to side.
6. The only Saddle joints in your body are in your
thumbs. The bones in a saddle joint can rock
back and forth and from side to side.
hematoma
callus
bony callus
bone
remodeling
Diseases of the Skeletal System:
Osteoporosis- bone reabsorption
outpaces bone deposit; bones
become lighter and fracture easier
Factors:
• age, gender (more in women)
• estrogen and testosterone decrease
• insufficient exercise (or too much)
• diet poor in Ca++ and protein
• abnormal vitamin D receptors
• smoking
Osteoporosis
29
40
84
92
Diseases of the Skeletal System:
Rickets- vitamin D deficiency
Osteomalacia- soft bones, inadequate
mineralization in bones, lack of vitamin D
Pagets Disease- spotty weakening in the
bones, excessive and abnormal bone
remodeling
Rheumatoid arthritis- autoimmune
reaction
MUSCLES
• A type of elastic tissue (sort of like the
material in a rubber band). Thousands, or
even tens of thousands, of small fibers
make up each muscle.
• Types
MUSCLES
Characteristi Skeletal
cs
muscle
Shape
Long,
cylindrical
cell
Smooth
muscle
long, narrow
"spindle"
shaped cells
Cardiac
muscle
Long,
cylindrical,
branch
shaped cell
Many nuclei
Number of
nucleus
Many nuclei
Work
Voluntary
One in the
middle of the
cell
Involuntary
Involuntary
Movement
Fast,
Slow,
Organize and
unorganized organize, not not easily
and tired
easily tired
tired
easily