The Skeletal System

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The Skeletal System
Chapter 36Section 1
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Skeletal System Functions

• Makes up body framework and gives body shape
• Supports the body
• Protects vital internal organs

3
Functions Continued

• Provides for movement
• Stores mineral reserves
• Produces red blood cells

4
Bone Composition

• Bone is living tissue.

• It is a solid network of cells and protein fibers
  surrounded by deposits of minerals.
• Components
• 32 Organic materials(collagen bone cells)
• 43 Minerals(calcium and phosphorous)
• 25 Water

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Bone Cells

• There are four main types of bone cells in bone
  tissue.

• Osteogenic cells respond to traumas, such as
  fractures, by giving rise to osteoblasts and
  osteoclasts.
• Osteoblasts (bone-forming cells) synthesize and
  secrete unmineralized ground substance
• Osteocytes are mature bone cells made from
  osteoblasts
• Osteoclasts are large cells that break down bone
  tissue. They are very important to bone growth,
  healing, and remodeling.

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Skeletal Tissue

• 4 main types
• Compact bone
• Spongy bone
• Cartilage
• Fibroblasts

spongy
compact
cartilage
fibroblasts
Ligament
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Anatomy of a Typical Long Bone
Structure of Bone
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Structure of bone
Periosteum covers bone, is a place for tendon
and ligament attachment, and brings blood, lymph
vessels and nerves into the bone.
Spongy bone is the inside layer of compactbone
that is actually quitestrong but lacy in
appearance and contains red marrow which produces
blood cells.
Compact boneis a dense layer of bone tissue
composed of cylinders or tubes of mineral
crystals and protein fibers, that give bone its
strength.

• Taking a closer look A cross-section of the
  long bone.

Bone marrow (primarily yellow marrow) stores fat
that serves as an energy reserve and contains
blood vessels and nerve cells.
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Structure of Bone
Haversiancanal

• Here is another diagram
• Just to help give you that visual to rememberall
  of this!

Haversiancanal are interconnectednetworks
oftiny tubes that blood vessels and nerves run
through.
Blood vesselscarry nourishment to the
livingbone tissueas well as removing wastes
Osteocytes are responsible for bone growth and
changes in the shape of bone and can either
deposit or absorb calcium salts
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Structure of Bone

• NoticeHyalin cartilage covers the ends of bones
  where they articulate (join) with other bones.
• As adulthood is reached, the epiphyseal
  plate(growth plate) is replaced by bone and
  fuses, thus completing growth.

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Structure of Bone

• What parts do you remember? Lets Quiz
  Ourselves!

• Blood vessels
• Bone marrow
• Compact bone
• Haversiancanal
• Osteocyte
• Periosteum
• Spongy bone

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3
1
7
4
6
2
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Structure of Bone
Bones of the skeleton contain a combination of

spongy and
compact bone.

Do you recognize

the bone at the left?

What classification

(type) of bone is it?

What type of bone

marrow is found
within
the spaces of
the
spongy bone?
Skull Bone
A flat bone
Red Marrow
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Bone Formation

• Called Ossification- Process of producing bone
  from cartilage
• ________ is replaced by _________ which secrete
  ________deposits and then mature into
  __________(bone cells).
• ___________ break down bone and
  remove_________bone tissue when a bone is
  broken.

Cartilage
osteoblasts
mineral
osteocytes
Osteoclasts
damaged
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Bone Formation
Growth in Length

• The _______plate (epiphyseal disc) is an area of
  _______ in the _____of long bones where bone
  _________ occurs.

growth
cartilage
ends
lengthening
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Bone Formation (Ossification)

• Bone growth begins long before birth.

• The basic shape of a long bone, such as an arm
  bone, is first formed as cartilage

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Bone Formation
12 week fetus
Ossification begins to take place up to seven
months before birth
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Bone Formation

• Babies are born with 350 bones, many are composed
  almost entirely of cartilage.
• Later the cartilage cells will be replaced by
  cells that form the bones. (ossification)

The SOFT SPOT of a babies skull
will fuse around age
2, but growth of the
skull continues until
adulthood.
Long bones develop and grow through out childhood
at the centers of ossification (growth plates)
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Bone Formation
Stages of Ossification

• Between the ages of 16 and 25 years, all of the
  cartilage of the epiphyseal disc is replaced by
  bone. This is called closure of the epiphyseal
  disc, and the bone lengthening process stops. 

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Bone Formation

• G
• R
• O
• W
• T
• H
• I
• N
• W
• I
• D
• T
• H

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Bones of the Skeleton

• The adult skeleton contains _____ bones

206
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Name That Bone
Do you recognize these 22 bones?

• carpals
• clavicle
• coccyx
• femur
• fibula
• humerus
• mandible
• metacarpals
• metatarsals
• patella
• phalanges

• pelvis
• radius
• ribs
• sacrum
• scapula
• skull
• sternum
• tarsals
• tibia
• ulna
• vertebrae

6
9
19
16
4
8
7
12
14
17
18
1
3
2
21
10
22
15
20
13
5
11
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Divisions of Skeleton
Axial and AppenicularSkeletons
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Axial Skeleton

• THE AXIAL SKELETON - CONSIST OF
• Skull
• Vertebral column
• Rib cage (ribs sternum)

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Skull Bones

• The Skull consists of 8 CRANIAL BONES
• 13 FACIAL BONES
• The Ears consists of
• 6 BONES and
• Floating in the throat is 1 HYOID BONE

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Rib Cage

• Also called the Thoracic Cage
• 12 pairs of RIBS
• 7 true ribs
• 5 false ribs
• 2 floating ribs
• 1 STERNUM
• (breastbone)

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Vertebral Column

• The Vertebral Column (Spinal Column or Backbone)
• 7 CERVICAL (NECK) VERTEBRAE,
• 12 THORACIC
• 5 LUMBAR,
• 5 FUSED VERTEBRAE INTO 1 SACRUM,
• 4 SMALL FUSED VERTEBRAE INTO 1 COCCYX (YOUR TAIL
  BONE)

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Appendicular Skeleton

• THE APPENDICULAR SKELETON consists of bones of
  the
• ARMS (upper limbs)
• LEGS (lower limbs)
• SHOULDER GIRDLE (pectoral girdle)
• HIP GIRDLE(pelvic girdle)

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Shoulder Girdles and Arms

• The Shoulder girdle is also called the pectoral
  girdle
• Consists of 4 bones
• Upper limbs consist of 60 bones (the hands and
  wrist contain 54 separate bones).

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Hip Girdles and Legs

• The hip girdle is also called the pelvic girdle
• Consists of 2 bones
• Lower limbs consist of 60 bones (the anklesand
  feet contain 52 separate bones)

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Comparison of Skletons

• The Human Skeleton is homologous to skeletons of
  other animals. Once you learn the bones in a
  human, you can identify the bones in other
  animals.

rat
cat
horse
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Bone Classification by Shape

• 5 Types
• Long
• Short
• Flat
• Irregular
• sesamoid

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Shapes of Bones

• Long bones are longer than they are wide and work
  as levers. The bones of the upper and lower
  extremities (ex. humerus, tibia, femur, ulna,
  metacarpals, etc.) are of this
  type.
• Short bones are short,
  cube- shaped, and found in the
  wrists and
  ankles.
• Flat bones
  have broad
  surfaces for protection
  of organs and
  attachment of muscles (ex.
  cranial bones, ribs, and bones
  of hip and shoulder girdles).
• Irregular bones are all others that
  do not fall into the previous
  categories. They have
  varied shapes, sizes, and surface
  features and include
  the bones of the vertebrae and a
  few in the skull.

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Types of Bones

• 1.  The humerus and femur are examples
  of _______ bone.
• 2.  Tarsal and carpal bones are
  examples of _______ bone.
• 3.  Sternum and many skull bones are
  examples of ________bone.
• 4.  Vertebrae and the patella are
  examples of _______ bone.

long
short
flat
irregular
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Joints

• JOINTS WHERE TWO or MORE BONES MEET
• Joints are responsible forkeeping bones far
  enoughapart so they do not rub against each
  other as theymove, preventing damage.
• At the same time, joints hold the bones in
  place.
• Different joints permitdifferent amounts of
  movement.

• Joints are classified by the amount and type of
  movement they permit.

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Classification of Joints

• Three Main Types
• Immovable- A fixed joint, one that allows no
  movement
• bones of skull, pelvis, and sacrum
• Slightly movable- joint that permits a small
  amount of restricted movement
• between vertebrae, two bones of lower leg
• Freely movable- Permit movement in one or more
  directions

•  

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Classification of Joints

• Immovable
• bones of skull,
• pelvis, and sacrum
• Slightly movable
• between vertebrae,
• two bones of lower leg

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Freely Movable Joints

• TYPES OF FREELY MOVABLE JOINTS
• A. BALL AND SOCKET JOINT Permits circular
  movement - the widest range of movement.
• SHOULDER Joint- which enables you to move your
  arm up, down, forward and backward, as well as to
  rotate it in a complete circle.
• HIP Joint- same range of motion.

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Types of Freely Movable Joints Continued

• B. HINGED JOINT - Permits a back- and-forth
  motion.
• The Knee- enables your leg to flex and extend.
• The Elbow -allows you to move your forearm
  forward and backward.
• The Phalanges

• C. PIVOT JOINT - Permits rotation of one
  bone around another.
• The elbow enables your hand to turn over.
  (radiusrotates around ulna)
• It also allows you to turn yourhead from side
  to side. (atlas rotates around axis)

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Types of Freely Movable Joints Continued

• D. GLIDING JOINT - Permits a sliding motion of
  one bone over another.
• Found at ends of the collarbones,
• between wrist bones,
• and between anklebones.

Click Here

• E. SADDLE JOINT- Permits movement in two planes.
  
• This type of joint is found at the base of the
  thumb

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Anatomy of a Joint
Structures of a freely movable joint

• 2 or more bones
• Cartilage
• Joint capsule
• Synovial membrane
• Synovial fluid
• Fat
• Bursa
• Meniscus
• Ligaments
• Tendons

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Anatomy of a Joint
2 or more bones articulate or meet with each
other

• Cartilage - at the joint, the ends of bones are
  covered with cartilage, which is wear-resistant
  and helps reduce the friction of movement.
• Joint capsule- is a thick, tough layer that
  envelops the joint cavity forming a membrane or
  sac that adheres firmly to the periosteum of the
  articulating bones

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Anatomy of a Joint

• Synovial membrane - a tissue that lines the joint
  and seals it into a joint capsule. The synovial
  membrane secretes synovial fluid.
• Synovial fluid - a clear, sticky fluid secreted
  by the synovial membrane to lubricate the joint.

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Anatomy of a Joint

• Fat- Helps pad and cushion the joint.
• Bursa- fluid-filled sac between adjacent
  structures such as ligaments or bones which help
  reduce friction in a joint, cushion it, and
  absorb shock
• Meniscus- wedge shaped cartilage, curved like the
  letter "C" at the inside and outside of each
  knee. A strong stabilizing tissue, helps the knee
  joint carry weight, and glide and turn in many
  directions. It also keeps your femur and tibia
  from grinding against each other.

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Anatomy of a Joint

• ligaments - tough, elastic bands of connective
  tissue
• surround the joint to give support and limit the
  joint's movement.
• Attach bone to bone
• tendons another type of tough connective tissue
• on each side of a joint attached to muscles that
  control movement of the joint.
• Attach muscle to bone

Knee Joint
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Skeletal Disorders
Fractures

• A broken bone is known as a fracture. This can
  simply be a crack or buckle in the structure of
  the bone, or a complete break, producing two or
  more fragments.

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Skeletal Disorders
Bone Fracture Repair
The repair of bone fractures is similar to
embryonic bone formation.
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Skeletal Disorders
Arthritis

• Arthritis- inflammation of the joints

• Consists of more than 100 different conditions
  
• The common denominator for all these
  conditions is joint pain
• Osteoarthritis- nick-named wear and tear
  arthritis
• Rheumatoid arthritis is one of the most
  crippling forms of arthritis. It is characterized
  by chronic inflammation of the lining of joints.

48
Skeletal Disorders
Osteoporosis

• Osteoporosis- literally means "porous bones
• Occurs when a body's blood calcium level is low
  and calcium from bones is dissolved into the
  blood to maintain a proper balance.
• Over time, bone mass and bone strength decrease.
  As a result, bones become dotted with pits and
  pores, weak and fragile, and break easily.
• Other factors besides age can lead to
  osteoporosis, such as a diet low in calcium and
  protein, a lack of vitamin D, smoking, excessive
  alcohol drinking, and insufficient weight-bearing
  exercises to stress the bones.

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Skeletal Disorders
Rickets

• Childhood disorder involving softening and
  weakening of the bones.
• It is primarily caused by lack of vitamin D,
  calcium, or phosphate

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Skeletal Disorders
Scoliosis

• Condition involving complex lateral and
  rotational curvature and deformity of the spine.
• Typically classified as
• Idiopathic (unknown cause)
• Congenital (caused by vertebral abnormality
  present at birth) possibly inherited
• Secondary symptom of another condition, such as
  cerebral palsy ormuscular dystrophy

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Skeletal Disorders
Kyphosis

• Kyphosis can be thought of as an arching of the
  spine in which the top of the arch is seen in the
  back
• This conditionis sometimesreferred to as
  humpback or hunchback
• Caused by inflammation of vertebrae, poor
  posture, or congenital abnormality

52
Skeletal Disorders
Lordosis

• Lordosis is the increase of the spinal posterior
  concavity.
• In most cases the cause is unknown and the
  disorder appears from the onset of skeletal
  growth.

• This condition is also referred to as
  swayback.

53
Skeletal Disorders
Osteomyelitis

• Infection of bone or bone marrow, usually caused
  by bacteria.
• The infective process encompasses all of the
  bone components, including the bone marrow
• Pus is produced within the bone, which may
  result in an abscess which then deprives the
  bone of its blood supply.

• Because of the particulars of their blood supply,
  the tibia, femur, humerus, and vertebral bodies
  are especially prone

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Skeletal Disorders
Osteosarcoma

• The most common type of malignant bone cancer,
  accounting for 35 of primary bone malignancies.
• Usually occurs in the area where the body of
  cartilage (that separates the epiphyses and the
  diaphysis) of tubular long bones is located.
• 50 of cases occur around the knee.

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This is the end of the show.Hope you enjoyed it!
56

• Math problemYou have 1 less ankle bone on each
  leg (7) compared to the number of wrist
  bones(8).The number of feet and hand bones is
  the same (19) each.
• So you have 54 total hand wrist bonesand 52
  total foot and ankle bonesSo why is the total
  number of bones in the lower limbs (60) the same
  as the total number in the upper limbs
  (60)?answer- add the 2 knee caps
• link this to slide 29