Download Chapter 7 - Skeletal System PPT

Bone Formation
Facial Bones
Skeletal System
Skull
Bone Disorders
Osteology – The Science of Bones
Bone is living tissue it grows and changes throughout your life.
You completely replace your entire skeleton
about every ten years.
Bone are composed of: Cells, Fibers and a Matrix ( Ca2+)
The Matrix of the Bone is referred to as an
Hydroxyapatite
The Chemical Composition of the bone matrix is
(Ca2+)10(PO4)6 (OH)2
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Structure of a
Long Bone
Figure 07.01
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Bone Formation
Two Types 1. Intramembranous – Develops in the connective tissue membranes
in the embryo called Mesenchyma – embryonic CT
2. Endochrondral Bone Formation – Bone forms in cartilage
A cartilage model of the skeleton is in place and the cartilage is
removed and bone is laid down.
NOTE : Bone is NOT calcified cartilage
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Formation of bone is called Ossification
-
it starts in the embryo and continues to age 18 in females and 20 in males.
Within the cartilage skeleton model of the embryo are ossification centers.
This is where the cartilage is being destroyed and the bone is being made.
Ossification takes place in the middle of the bone shaft first and then at the
ends. The bone develops moving very slowly toward the ends of the bone.
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Two types of bone are produced :
Spongy Bone – Contains a lot of cavities this structure reduces
weight and increases strength of the bone.
This is the region that is effected by osteoporosis the most.
Hemopoietic tissue (makes blood) fills the cavities of spongy
bone.
Compact Bone - Dense strong bone that makes up the outer
surface of the bone.
Compact bone is composed of millions of subunits called:
Haversian Systems or Osteons
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Figure 07.02
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Diaphysis
Volksman Canal
Epiphyseal Plate
or Growth Plate
Articular
Cartilage
Spongy Bone with
Hemopoietic Tissue
Epiphysis
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Three types of Bone Cells
1. Osteoblasts – Makes new bone
2. Osteocytes – Maintain existing bone if damage occurs. Live
inside calcified bone in lacuna (“little pond” in Latin)
3. Osteoclasts – Remove bone, act like white blood cells. They
are triggered by parathormone from the thyroid to breakdown
bone to increase calcium level in blood.
Their action can lead to osteoporosis – Loss of bone mass
due to lack of calcium. Bones can become weak and brittle.
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Haversian System
Lamella of bone
or Osteon
Canaliculi
Haversian
Canal
Osteocyte
Haversian Canal Systems
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Function of Bones
1. Support
2. Motion – Muscle Attachment
3. Protection – Skull protects Brain
Ribs & Sternum protects Heart & Lungs
4. Calcium Storage – There is a constant exchange between bones
and blood.
5. Bone Marrow – Process called Hemopoisis is the making of Red
and White blood cells.
In the infant red marrow is found in most of the bones.
In the adult it is only found in 1. Sternum and Ribs
2. Hip Bones (iliac Crest)
Take marrow samples here
3. Bodies of Vertebrae
4. Proximal end of Long Bones
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Classification of Bones
1. Long Bones
Upper Extremities - Humerus
Radius & Ulna
Lateral
Medial
Palm - Metacarpals
Fingers - Phalanges
Lower Extremities - Femur
Tibia & Fibula
Medial
Lateral
Foot - Metatarsals and Phalanges
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2. Short Bones
- Wrist - Carpal bones or carpus
Ankle - Tarsals bones or Tarsus
3. Irregular Bones - Vertebrae & Skull
may be movable or immovable
contain many irregular bones
4. Flat Bones - Scapula – Shoulder blade
Clavicle – Collar bone
Skull - Frontal & Parietal bones of skull
5. Sesamoid Bones “seed” – small, nodular found within
tendon ex: patella (knee cap)
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Identifying Characteristics of Bones
1. Fossa – Depression in a bone
ex: TMJ (Temporal Mandibular Joint) forms a fossa
2. Sinus – Cavity in a bone
ex: maxillary sinus – cavity above upper jaw
3. Foramen – Hole in a bone
ex: Foramen Magnum – hole for spinal cord in skull
4. Meatus – Tubular structure in bone
ex: External auditory meatus let sound enter skull
5. Condyles – Large smooth curved surfaces that touches another
bone.
ex: Distal end of femur
6. Trochanter – A large projection on a bone for muscle attachment
Lec 1
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Table 07.02
Axial Skeleton
Figure 07.09
Appendicular
Skeleton
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Skeleton
Axial Skeleton -
Skull
Ossicles (ear bones)
Hyoid
Sternum & Ribs
Vertebral column
Appendicular Skeleton -
Upper Extremities
Pectoral Girdle - clavicle &
scapula (attachment to axial skeleton)
Lower Extremities
Pelvic Girdle – ilium, ischium, pubic bone
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Skull
Two major components –
1. Skull Cap - Calvarium or cranium contains 8 bones
that enclose the brain.
2. Facial Bones – 14 bones that support muscles of the
face.
Bones of the Calvarium –
1. Frontal – forehead – Anterior fossa of base of skull
2. Parietal – 2 – means “walls”- top of skull
1
3. Temporal – 2 – sides of skull
2
4. Occipital – posterior part of skull
6
5. Sphenoid
5
3
6. Ethmoid
4
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Temporal Bone
- Four Parts
1. Squamous – Flat/thin part of skull ( Don’t get hit here)
2. Mastoid Process – “breast” – contain sinus for middle ear.
3. Zygomatic Process – “bar” – posterior portion of cheek bone
4. Petrous portion – “hard” – houses the inner ear
Occipital Bone
– Thick Bone
Contains the Foramen Magnum “Big Hole”
Articulates with first cervical vertebra - Atlas
Greek god Atlas
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Sphenoid – Floor of skull – called the keystone of the skull
keeps the other bones in place.
Holds the Pituitary Gland in the “Turkish Saddle” formed by the
four Clinoid processes.
Sphenoid
Ethmoid
Ethmoid Bone – “sieve” contains holes for olfactory nerves
to pass through. This is called the Cribriform Plate.
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Looking down
into skull
Pituitary
would be here
Clinoid Processes
“Turkish Saddle”
Squamous
Petrous portion
V shape of Occipital
is called a
Lambdoidal Shape
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The immovable joints between the bones of the skull are called
Sutures
Anterior
Posterior
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Infant Skull – Contains areas of connective tissue called
Fontanelles
Allows the skull to move during birth and accommodates rapid growth of brain.
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3
Facial Bones
4
2
5
7
1
There are two of each of the facial bones
1. Maxilla – Upper Jaw called keystone of face all facial bone touch the
maxilla except mandible.
2. Zygomatic Process – Anterior roof of mouth formed by maxilla
3. Nasal Bones – Forms bridge of nose
4. Lacrimal Bones – Inferior medial orbit
5. Zygomatic Bones – Middle of cheek
6. Palatine Bones – Posterior portion of the roof of the mouth
7. Vomer – Bone of lower septum of nasal cavity
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The Cheek is made up of :
Zygomatic Process - Maxilla
Zygomatic Bone
Zygomatic Process - Temporal
The roof of the mouth is called the Hard Palate
It is composed of the:
Maxilla - Anterior
Palatine - Posterior
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Nose –
Lateral Nose - Two inferior Conchae in the Inferior lateral
nasal cavity
Medial Nose - Vomer – medial nasal cavity (called the Septum)
Mandible – Jaw bone only moveable joint of skull
Coronoid
Process
Condyloid Process
Part of TM Joint
Ramus “branch”
Angle
Body
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Figure 07.12
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Teeth—Humans have a heterodont dentition
( Different Teeth)
C1
Figure 07.17
C7
T1
Ribs attach to all the
Thoracic Vertebrae
T12
L1
L5
C1 – Atlas
C2 – Axis
Odontoid Process
“tooth” connects these
two together allows you
to rotate your head
Laminectomy – Cut through
this part of the vertebra to get
to the spinal cord
Longest spinous processes
in Thoracic region
Figure 07.18
Muscle attachment
Spinal cord found here
Rib attachment
Thoracic is area most
common for tumors
Largest bodies in Lumbar
region due to carrying all of
the body’s weight
Vertebral Column –
Posterior
Lateral
Anterior
Cervical
Scoliosis
Thoracic
Lumbar
Sacral
Abnormal Curves –
Coccyx
Kyphosis – Hunchback – Accentuated Thoracic Curve
Lordosis – Swayback – Accentuated Lumbar Curve
Scoliosis – Lateral curve in Thoracic region more common in
females begins during puberty.
Intervertebral Discs –
Rings of Fibrocartilage between the vertebrae
Annulus Fibrosis
Stiff cartilage ring
Nucleus Pulposus –
Soft gelatinous center
Slipped Disc When someone has a slipped disc the disc doesn’t really move. The
Annulus tears and the soft gelatinous center gets squeezed out. Sort of
like putting pressure on a jelly donut the jelly squeezes out.
Best cure is bed rest and to let the ring heal and the center to regenerate.
Figure 07.21
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Deltoid
Tuberosity
Surgical Neck
Humerus – Bone of Arm
Proximal
Figure 07.25
Semilunar notch
Lateral
Distal
Medial
Figure 07.29
Female
Male
Common fracture site
Figure 07.30
For muscle attachment,
you can see how active
person is by looking at this
area of a bone.
Patella in tendon
found here
Femur
Articulates with femur
Articulates with Talus
Figure 07.31
Bumps on side of ankle
Figure 07.33
Dancer’s Fracture
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Bone
Fractures
Box Figure 07.01a
Repair of Bone Fracture
1. Severe Bleeding
2. Blood clot forms in the bone
3. Cells from the Periosteum produce
Osteoblasts that produce new bone.
4. New bone fragment + Blood clot
form a Callus
5. Bone forms between fracture ends
called a Bony Collar
6. Osteoclasts remove excess bone
Box Figure 07.01b
Arthrology – Science of Joints
1. Fibrous Joints – Contain very little connective tissue between the bones.
ex: sutures of the skull
2. Cartilaginous Joints – Fibrocartilage between bones – strong joints
ex: Intervertebral Discs, Pubic Symphysis
3. Synovial Joints – Connections between bones of appendicular skeleton
“ with egg white” ex: Humerous & Glenoid fossa, Femur & Acetabulum
Synovial Fluid is there to reduce friction in the joint and to moisten and
nourish the cartilage. Cartilage doesn’t have blood vessels so the
cartilage celled get nourish by synovial fluid.
A Bursa is a bag of synovial fluid attached to a joint that is there to reduce
friction. Inflammation of the bursa is called Bursitis.
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Figure 07.35
Made of Hyaline
Cartilage
Produces Synovial Fluid
Figure 07.37
Types of
Joints
Movement of a Joint
Flexion - Decrease an angle
Extension - Increase an angle
Adduction - Bring limb toward the midline
Abduction - Move limb away from midline
Circumduction - Circular motion
Dorsiflexion – Lift foot toward shin
Supination / Pronation- rotate hand palm up or palm down
Arthritis
Rheumatoid Arthritis – “discharge” of synovial fluid. Disorder
of the immune system, joints swell with stiffness and pain
due to excess of synovial.
Osteoarthritis – Breakdown of articular cartilage so bone
grind on bone with pain and reduced movement
Bone Loss
Osteoporosis - Loss of bone mass more frequent in women.
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Plate 10
Table 07.01