Download The Skeletal System

The Skeletal System
By: Alaa Alshaibani and Alexis Samuelson
System Structures
and location
link to video: http://www.youtube.com/watch?v=gp4SBFiP4-Y
The Skull
• Made up of the cranium and the facial bones
• It is located at the top of the body, the head of
the body
• Made up of roughly 22 bones:
Cranial Bones:
• Frontal bones
• Parietal bones
• Occipital bone
• Temporal bone
• Sphenoid bone
• Ethmoid bone
Facial bones:
• Mandible
• Maxillae
• Palatine bones
• Zygomatic bones
• Lacrimal bones
• Nasal bones
• Vomer bone
• Inferior nasal conchae
Vertebral Column
• Begins at the base of the skull and ends at the
pelvis.
• Composed of vertebrae that are separated by
intervebral discs
• The column is divided into three parts
• The final five is what creates the lumbar vertebrae
• The sacrum forms the bottom of the lumbar
vertebrae, the tip being the coccyx
Vertebral Column
Cervical Vertebrae
• The first seven vertebrae
• The first two are the
atlas and axis and they
help to rotate the head
• The vertebrae are special
in that they have
transverse foramina and
their spinous processes
are bifid.
Thoracic Vertebrae
• The next 12 bones of
the vertebral column
• Long pointed spinous
process, the bodies
increase in size as you
go down
• Connects to the ribs
Lumbar Vertebrae
• The final five vertebrae
• The sacrum forms the
bottom of the lumbar
vertebrae, the tip being
the coccyx
Thoracic Cage
• Made up of:
• The ribs
• Thoracic
vertebrae
• Sternum
• Costal
cartilages
• 24 ribs total which attach to each of the
thoracic vertebrae
• The sternum is made up of the manubrium,
body, and xiphone together are the breast
bone
Pectoral Girdle
• Located at the
shoulder
• Made up of the
clavicles
(collarbones) and
scapulae (shoulder
blades)
Upper Limb
Upper Limb
• Bones form framework for arm, forearm, and
hand
• Provide attachments for muscles, function in
levers
• Bones include: humerus, radius, ulna, carpals,
metacarpals, and phalanges
Upper Limb - Humerus
• Extends from the scapula to the elbow
• Greater and lesser tubercles provide attachments for
muscles
• Deltoid tuberosity provides attachment for deltoid muscle
that raises the upper limb horizontally to the side
• Coronoid fossa receives a process of the ulna when the
elbow bends
• Olecranon fossa receives ulnar process when upper limb
straightens at elbow
• The capitulum helps the humerus articulate with the radius
Upper Limb - Humerus
Upper Limb - Radius
• Located on thumb side of forearm; extends
from elbow to wrist and crosses over ulna
when palm faces backward
• Head at upper end of radius articulates with
humerus and a notch of the ulna
• Allows radius to rotate freely
Upper Limb - Ulna
• Longer than radius; overlaps the end of the
humerus posteriorly
• Trochlear notch articulates with the humerus
• Olecranon process and coronoid process
provide attachments for muscles
• Head articulates laterally with a notch of the
radius
Upper Limb – Radius and
Ulna
Upper Limb - Hand
• Made up of the wrist, palm, and fingers
• Eight small carpal bones that are bound in two
rows of four bones
• Five metacarpal bones form framework of the
palm
• Each finger has three phalanges (proximal,
middle, and distal phalanx), except for thumb
Upper Limb - Hand
Pelvic Girdle
• Consists of two coxae which articulate with each
other anteriorly and with the sacrum posteriorly
• Sacrum, coccyx, and pelvic girdle form pelvis
• Girdle supports trunk of the body, provides
attachments for lower limbs, protects the urinary
bladder and reproductive organs
• Each coxa develops from an ilium, an ischium, and
a pubis
Pelvic Girdle
Pelvic Girdle
Lower Limb
Lower Limb
• Bones form frameworks of the thigh, leg, and
foot
• Includes femur, tibia, fibula, tarsals,
metatarsals, and phalanges
Lower Limb - Femur
• Extends from hip to knee
• Large, rounded head projects medially into
acetabulum of the coxa
• Patella (kneecap) articulates with femur
• Lateral and medial condyles articulate with
tibia
Lower Limb - Femur
Lower Limb - Tibia
• Larger of the two leg bones, located on medial
side
• Medial and lateral condyles articulate with
condyles of the femur
• Tibial tuberosity provides an attachment for
patellar ligament
• Inferior surface of tibia’s distal end articulates
with the talus of the ankle
Lower Limb - Fibula
• Long, slender bone on lateral side of the tibia
• Head articulates with tibia just below the
lateral condyle, but does not enter into the
knee joint
Lower Limb – Tibia and
Fibula
Lower Limb - Foot
• Made up of the ankle, the instep, and the toes
• Ankle is composed of seven tarsal bones
(largest is calcaneus)
• Instep is made up of five elongated metatarsal
bones that articulate with the tarsus
• Phalanges align and articulate with the
metatarsals; each toe has three phalanges
except for the great toe (no middle phalanx)
Lower Limb - Foot
Skeletal System
Information
Function of Skeleton
• The skeleton serves to:
•
•
•
•
Protect vital organs
Support the body
Create blood cells
Help to stabilize and shape the body
Bones, Tendons, Ligaments
• Bones: the organs of the skeletal system made
up of cartilage, bone tissue, dense connective
tissue, and nervous tissue
• Tendons: white fibrous connective tissue that
attaches muscle to bone
• Ligaments: connective tissue that ties together
two or more bones at a joint
Structures of a long bone
• Epiphysial plates,
articular cartilage,
compact bone,
medullary cavity,
yellow marrow,
periosteum,
proximal
epiphyses,
diaphysis, distal
epiphysis,
endosteum
Bone growth
• Endochondral bones begin as a cartilaginous model. As it
grows the diaphysis in the middle, with the help of
osteoblasts replace the cartilage with spongy bone—the
primary ossification center, and form a thin layer of
compact bone around it.
• Secondary ossification centers form in the epiphyses, an
epiphyseal plate separates the two ossification centers,
which expands, causing the bone to lengthen.
• The extracellular matrix calcifies, osteoclasts break it
down, osteoblasts release new bone tissue to replace it.
• The bone continues to lengthen, only stopping once the
diaphysis and epiphysis ossification centers meet.
Joints
Joints
• Bind parts of skeletal system, allow bones to
grow, permit the skeleton to change shape
during childbirth, and let the body respond to
skeletal muscle contractions
• Can be immovable, slightly movable, or freely
movable
• Vary in structure and function
Classification of
Joints by Tissue
Classification - Fibrous
• Lie between bones that closely contact one
another
• Formed by thin layer of dense connective
tissue
• Doesn’t allow much movement
• Examples:
• Sutures between pairs of flat bones of the skull
• Articulations of teeth in jaw bones (gomphosis)
Classification Cartilaginous
• Hyaline cartilage (fibrocartilage), makes for
slight flexibility
• Helps to absorb shock and equalize pressure
• Examples:
• Intervertebral discs are composed of a band of
fibrocartilage surrounding gelatinous core
• Symphysis pubis
Classification - Synovial
• Allow free movement, make up a majority of
joints within skeletal system
• Articular ends of bones in synovial joints are
covered with hyaline cartilage and a
surrounding capsule of dense connective
tissue
• This + an outer layer of ligaments + inner lining
of synovial membrane = joint capsule
Classification - Synovial
• Menisci – flattened, shock-absorbing pads of
fibrocartilage between articulating surfaces of
bones
• Bursae – fluid-filled sacs lined with synovial
membrane
• Commonly located between tendons and bony
prominences (patella, elbow, etc.)
6 Types of Synovial
Joints
Ball-and-Socket Joint
• Consists of a bone with a ball-shaped head
that articulates with the cup-shaped cavity of
another bone
• Allows widest range of motion and
movements in all planes, in addition to
rotational movement
• Example:
• Shoulder and hip joints
Condyloid Joint
• Oval-shaped condyle of one bone fits into
elliptical cavity of another
• Permits a variety of movement in different
planes, but not rotational movement
• Example:
• Joints between metacarpals and phalanges
Gliding Joints
• Articulating surfaces are nearly flat or slightly
curved
• Allow sliding and twisting movements
• Examples:
• Most joints within the wrist and ankles
• Sacroiliac joints and joints formed between ribs
2-7 that connect with the sternum
Hinge Joint
• Convex surface of one bone fits into concave
surface of another
• Resembles the hinge of a door
• Permits movement in one plane only
• Examples:
• Elbow
• Joints of phalanges
Pivot Joint
• Cylindrical surface of one bone rotates within a
ring formed of bone and ligament
• Movement limited to rotation around central
axis
• Example:
• Joint between proximal ends of the radius and
the ulna
Saddle Joint
• Forms between bones whose articulating surfaces
have both concave and convex regions
• Surface of one bone fits the complementary
surface of the other
• Permits variety of movements
• Example:
• Joint between carpal (trapezium) and metacarpal
bones of thumb
Types of Joint
Movement
Joint Movements
• One end of muscle is attached to a relatively
immovable part on one side of joint, other end
fastened to movable part
• When muscle contracts, the fibers pull the
insertion (movable end) towards the origin
(fixed end)
Joint Movements
• Flexion: Bending parts at a joint so the parts
come closer together (angle between
decreases)
• Extension: Straightening parts so that they
move further apart (angle between widens)
• Dorsiflexion: Bending the foot at the ankle
upwards
• Plantar flexion: Bending the foot downwards
Joint Movements
• Hyperextension: Excess extension of the parts
at a joint beyond anatomical position
• Abduction: Moving a part away from the
midline
• Adduction: Moving a part towards the midline
• Rotation: Moving a part around an axis
• Circumduction: Moving a part in a circular
motion
Joint Movements
• Pronation: Turning the hand so that the palm is
facing downwards
• Supination: Turning the hand so the palm is
facing upward
• Eversion: Turning the foot so that the sole
faces laterally
• Inversion: Turning the foot so that the sole
faces medially
Joint Movements
• Retraction: Moving a part backward
• Protraction: Moving a part forward
• Elevation: Raising a part
• Depression: Lowering a part
Distinguish
Between the
Appendicular and
Axial Skeletons
Axial Skeleton
• Consists of the bony and cartilaginous parts
that support and protect the organs of the
head, neck, and trunk
1. Skull – Composed of the cranium and facial
bones
2. Hyoid bone – Located between lower jaw and
larynx; supports the tongue and is an
attachment for muscles that move the
tongue
Axial Skeleton
3. Vertebral column – Consists of many
vertebrae separated by cartilaginous
intervertebral discs, the sacrum, and the
coccyx
4. Thoracic cage – Protects the organs of the
thoracic cavity and upper abdominal cavity;
composed of 12 pairs of ribs, and the sternum
Appendicular Skeleton
• Consists of the bones of the upper and lower
limbs and the bones that anchor the limbs to the
axial skeleton
1. Pectoral girdle – Scapula and clavicle form the
pectoral girdle on both sides of body; connects
bones of upper limbs and aids in movement
2. Upper limbs – Each consists of a humerus, radius,
and ulna, which articulate with each other at the
elbow joint. At the distal end are carpals,
metacarpals, and phalanges.
Appendicular Skeleton
3. Pelvic girdle – Two coxae connect the bones
of the lower limbs to the axial skeleton; form
the pelvis with the sacrum and coccyx
4. Lower limbs – Each consists of femur, tibia,
fibula, and a foot. The patella covers the
anterior surface of the knee joint. The foot
consists of tarsals, metatarsals, and
phalanges.
Diseases/Disorders
Osteogenisis Imperfecta
• Literally translated to mean: “bone that is imperfectly
made from the beginning of life.”
• A genetic bone disorder, caused by a mutation that
prevents the creation of collagen, resulting in extremely
brittle bones, bones break easily
Hemarthrosis
• When there is bleeding in a joint, due to joint
pain/ swelling
Rickets
• Caused by a lack of either Vitamin D, Phosphate, or calcium
• Bones become weakened and curve
Osteochondritis
Dissecans
• Occurs when a fragment of bone in a joint
separates from the rest of the bone because its
blood supply was not sufficient
• The joint will become inflamed and painful, and
can catch or lock during movements
• Most common in the knee, but can also occur in
other joints, such as the hip or ankle
• Can be caused by repeated stress on the joint,
inherited faulty genes, or ischemia, which restricts
a bone’s blood supply
Osteochondritis
Dissecans
Osteoid Osteoma
• A benign bone tumor that has a center of
growing cells surrounded by a shell of
thickened bone
• Most common in long bones, but can occur in
any bone of the body
• Occurs primarily in males of 4-25 years of age
• Can sometimes disappear on its own, or be
treated surgically
Osteoid Osteoma
Epiphysiolysis
• The loosening or separation of the epiphysis
from the shaft of the bone
• Some treatments include physical therapy or
prosthetic implants
• Occurs often in hip and leg bones
Epiphysiolysis