Title: The Skeletal System
1The Skeletal System
- Lindsey Bily
- Austin High School
- Anatomy Physiology
- Ch. 7, 8 9 in your textbook
2Types of Bone
- Compact Bone Dense or solid in appearance.
- Cancellous (Spongy) Bone has open spaces (looks
like a sponge, wow, I wonder how they came up
with that name?) - The 4 types of bone have different amounts of
compact and cancellous bone.
3Long Bones
- They are long, hence the name.
- Examples Humerus and femur
4Short Bones
- They are cube or box-shaped.
- Examples Carpals in the wrist and tarsals in the
ankle
5Flat Bones
- Broad and thin with a flattened and often curved
surface. - Examples certain skull bones, sternum, scapulae,
ribs
6Irregular Bones
- Usually found in groups and come in various sizes
and shapes. Thats why they are called IRREGULAR. - Examples vertebrae, facial bones.
7Parts of the Long Bone
- 1. Diaphysis (di-AF-i-sis) main portion that is
hollow, cylindrical and is composed of compact
bone. - 2. Epiphyses (e-PIF-i-sis) at both ends of the
long bone, they have a bulbous shape and are
composed of spongy bone. The spongy bone
contains red bone marrow. - 3. Articular Cartilage thin layer of hyaline
cartilage that covers the joint surfaces of the
epiphyses. Cushions jolts and blows. - 4. Periosteum (pair-ee-OS-tee-um) membrane that
covers the bone (contains bone forming and bone
destroying cells and blood vessels). - 5. Medullary (marrow) cavity tubelike, hollow
space in the diaphysis that contains yellow
marrow in adults. - 6. Endosteum (end-OS-tee-um) A thin epithelial
membrane that lines the medullary cavity.
8Parts of the Long Bone
9Bone (Osseous) Tissue
- Bones have an Inorganic and an Organic Matrix.
- Inorganic Matrix
- Bones are calcified (contain calcium phosphate
(Ca3(PO4)2) which is why they are hard and so
strong. - Magnesium, sodium, sulfate, and fluoride are also
found in bone.
10Bone (Osseous) Tissue
- Organic Matrix
- Ground Substance composed of collagenous fibers,
protein, and polysaccharides. - Chondroitin sulfate and glucosamine are required
for repair and maintenance of bone and cartilage.
People take it to treat arthritis pain.
11Compact Bone Microscopic Level
- Remember OSTEONS? Theyre baaaa-aaaack
- Osteons are also called Haversian systems, who
discovered them. - They are cylindrically shaped structural units of
bone. - The structure of the osteons allows for the
delivery of nutrients and the removal of waste
from the bone cells that are imprisoned in bone.
12Osteons
- There are no empty spaces in compact bone, it is
made up of lots of osteons (Haversian System). - Each ring is called a concentric lamella and
resemble rings in an onion. - These surround the Haversian canal, which contain
blood vessels. - Osteocytes are bone cells
- Nutrients pass from the blood vessel in the
Haversian canal through canaliculi, tiny passages
or canals, to osteocytes located in little spaces
called lacunae.
13Osteons
14Cancellous Bone Microscopic Level
- No osteons in cancellous (spongy) bone.
- Consists of needle-like bony spikes called
trabeculae. - Bone cells are found in the trabeculae.
- Spongy bone lies between two layers of compact
bone like an Oreo cookie. - The trabeculae are organized so that they are
able to handle the stress that is put on the bone
so that the bone is stronger.
15Cancellous Bone
16Bone
A Spongy Bone B Compact Bone C Medullary Cavity
17Bone Cells
- Three major types found in bone
- Osteoblasts (bone-forming cells)
- They are small and make osteoid which is in the
ground substance of bone which then can absorb
calcium and phosphate. - Osteoclasts (bone-reabsorbing cells)
- They are giant cells and have multiple nuclei and
they erode the bone minerals. They contain lots
of lysosomes and mitochondria. - Osteocytes (mature bone cells)
- They are nondividing osteoblasts that are
surrounded by bone and lie in the lacunae.
18Osteoblasts
19Osteoclasts
20Osteocytes
- Since osteocytes are surrounded by bone, they
must have a way to get nutrients. They have
projections that extend into the canaliculus in
the bone that allows them to get nutrients.
21Bone Marrow
- This is where blood cells are made and is found
in the medullary cavities of certain long bones
in and the spaces of spongy bone in some areas. - In the infant and child, virtually all marrow is
red marrow. It produces red blood cells. - As we age, the red marrow is replaced by yellow
marrow which contains lots of fat and does not
produce red blood cells. - Bones in the adult that still contain red marrow
are the ribs, vertebrae, ends of the humerus,
pelvis, and femur.
22Bone Marrow
- If we have a low blood supply due to injury,
exposure to radiation or toxic chemicals and
certain diseases the yellow marrow will change to
red marrow. - A bone marrow transplant may be required if the
marrow is severely damaged. - Healthy bone marrow from a compatible donor is
injected into the blood and if the recipients
immune system doesnt reject it, new, healthy
bone marrow can grow.
23Functions of Bone
- Support
- Protection
- Movement
- Mineral Storage
- Bones store calcium, phosphorus, magnesium,
fluoride, etc - Hematopoiesis
- Blood cell formation done in the red marrow in
the epiphyses of long bones, flat bones of the
skull, pelvis, sternum, and ribs.
24Regulation of Calcium Blood Levels
- Bones store 98 of the bodys calcium reserves
- We need a certain level of calcium in our blood
in order for our muscles to contract, heart to
pump, blood to clot and nerves to fire. - Calcium moves in and out of the bone into the
blood to maintain homeostasis. - Osteoblasts take calcium out of blood and into
bone. - Osteoclasts take calcium out of bone and into the
blood.
25Regulation of Blood Calcium Levels
- Parathyroid Hormone (PTH)
- Released by the parathyroid glands which lie on
the thyroid gland in your neck. - When calcium levels are LOW, parathyroid hormone
is released which stimulates the osteoclasts to
break down bone and release calcium into the
blood. - PTH also increases calcium absorption from the
urine and stimulates Vitamin D synthesis which
stimulates the intestines to absorb calcium more
efficiently.
26Regulation of Blood Calcium Levels
- Calcitonin
- Hormone released by the THYROID gland
- When blood calcium levels are too HIGH,
calcitonin is released. - Calcitonin stimulates the osteoblasts and
inhibits the osteoclasts so that calcium is taken
out of the blood and put into the bone. - http//bcs.whfreeman.com/thelifewire/content/chp42
/4202003.html
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28Development of Bone
- When the skeleton begins to form it is made of
cartilage shaped like bones. Over time the bones
calcify. - Osteogenesis (osteo-bone genesis creation)
is when the cartilage undergoes calcification.
29Growing Taller
- As a person is growing, there is a line of
cartilage in between the epiphysis and the
diaphysis in the long bones called the epiphyseal
plate. - You grow taller when the plate grows bigger, then
becomes ossified. - Once a person is no longer growing taller, the
plate totally ossifies.
30Bone Fractures
- Fracture is a break in the bone.
- Open or Compound Fracture the broken bone goes
through the surrounding tissue and skin. Risk of
infection is high. - Closed or Simple Fracture does not produce a
break in the skin. - Complete Fracture break across the entire
section of bone. - Incomplete Fracture partial break in the bone
31Bone Fractures
32Bone Disorders Diseases
- Neoplasms (new growth)
- Osteochondroma tumor that develops early in life
and causes projections (spurs) at the ends of the
long bones. Usually they are benign but
sometimes can become cancer. - Osteosarcoma malignant tumor in the bone tissue
that is the most fatal. Almost 10 of patients
grow tumors in the lungs and other organs. - Chondrosarcoma malignant tumor in the hyaline
cartilage. Slow growing and occurs most often in
middle aged people. Chemotherapy usually doesnt
work, so amputation of the affected area usually
occurs.
33Bone Disorders Diseases
- Osteoporosis Excessive loss of calcified matrix,
minerals, and collagen fibers. Bones become
porous, brittle and fragile. They can fracture
easily. - Pagets disease Have a lot of osteoclast growth
which in turn will cause the body to produce more
osteoblasts. Since there are so many bone cells,
the remodeling process is too rapid and
disorganized. The bones are poorly made and
weakened. Sometimes patients feel pain in their
bones and may have fractures, but most people
dont have symptoms - Osteomylelitis Bacterial, fungal or viral
infection of the bone and bone marrow. Usually
associated with another infection.
34The Skeleton
- Terms used to describe bone markings
- Condyle rounded bump that usually fits into the
fossa on another bone, forming a joint - Foramen round hole in bone that allows vessels
and nerves to go through. - Fossa depression in the bone that often receives
an articular bone. - Meatus tubelike opening or channel
- Process a raised area or projection
- Sinus cavity within a bone
- Trochanter Large bump on bone for muscle
attachment - Tuberosity smaller than a trochanter and a bump
for muscle attachment
35The Skeleton
- The human skeleton is composed of 206 bones and
divided into two sections. - Axial Skeleton
- Appendicular Skeleton
36The Axial Skeleton
- Composed of the bones of the
- Skull
- Hyoid Bone
- Vertebral Column
- Sternum
- Ribs
37The Skull
- Composed of 28 irregular bones
- Divided into two sections
- Cranium
- Face
38Cranial Bones
- Sutures are where 2 cranial bones fuse together.
- Frontal Bone (forehead)
- Contains sinuses which are lined with mucous
membranes and filled with air. - Parietal Bones
- There are two on both upper sides of your head.
Fuse with the frontal bone. - Temporal Bones
- there are two on the lower sides of your head.
They house the middle and inner ear
39Cranial Bones
- Occipital Bone
- There is one at the lower, posterior part of your
skull. - Sphenoid Bone
- Looks like a bat with its wings outstretched.
40The Cribiform Plate
- This is a part of the ethmoid bone that separates
the nasal from the cranial cavities. - It has many small holes in it so that the
olfactory nerve can go from the nose to the
brain. - It is very dangerous though because infections in
the nose and nasal cavities can have a tendency
to reach the brain. - Also, if the cribiform plate is fractured, shards
of bone may enter the brain.
41Facial Bones
- Bones you need to know
- Maxillae
- Mandible (jaw bone)
- Zygomatic bone (the cheekbone)
- Nasal bones
42Hyoid Bone
- A single bone in the neck.
- It is the only bone in the body that does not
articulate (touch) another bone. - U shaped and you can feel it just above the
larynx (voice box) - The tongue muscle and other mouth muscles attach
to it.
43Vertebral Column
- The spinal column
- Flexible and segmented
- Consists of 24 vertebrae and the sacrum and
coccyx - The head is balanced on the top
- The ribs are suspended in the front
- The lower extremities are attached below
- The spinal cord is enclosed within.
44Vertebral Column
- The vertebrae are separated into divisions
- 7 cervical vertebrae
- 12 thoracic vertebrae
- 5 lumbar vertebrae (includes the sacrum and the
coccyx)
45Atlas and Axis
- Atlas first cervical vertebra (C1)
- Has concave ovals that the condyles of the
occipital bone fit on like a rocker-like cradle. - Named Atlas after the titan in Greek mythology
because it supports the head as Atlas supports
the world. - Axis 2nd cervical vertebra (C2)
- Named the axis because the atlas rotates about on
it like a pivot.
46Sternum and Ribs
- Top of the sternum is called the manubrium.
- The first 7 ribs attach to the sternum. Called
True Ribs - The remaining 5 ribs dont attach to the sternum
and are called False Ribs - The last two pairs of False Ribs do not attach
and are called Floating Ribs
47The Appendicular Skeleton
- Upper Extremity
- The shoulder girdle is composed of the clavicle
and scapula - i.e. the collarbone and the shoulder blades
- The Arms are composed of the humerus, radius and
ulna. - Humerus upper arm
- Radius on the thumb side when in anatomical
position. - Ulna on the pinky side when in anatomical
position - The Hand
- Carpals the bones of the wrist
- Metacarpals bones of the hand
- Phalanges fingers
48The Appendicular Skeleton
49The Appendicular Skeleton
- Lower Extremity
- Includes bones of the hip, thigh, lower leg,
ankle and foot. - The pelvis is composed 2 coccal bones which are
connected to the sacrum posteriorly and by the
pubic symphysis anteriorly.
50The Appendicular Skeleton
- Femurs
- Thigh bones connected to the pelvis.
- Longest and heaviest bones in the body.
- Patella (kneecap)
- Lower leg bones
- Tibia the larger, and stronger bone. Is placed
medially and superficially. Holds the bodys
weight. - The proximal end of the tibia articulates with
the femur to form the knee joint. - Fibula the smaller bone. Is placed laterally and
deep.
51The Appendicular Skeleton
- The Foot
- Similar to the hand bones.
- Tarsals (ankle)
- Metatarsals ( foot bones)
- Phalanges (toes)
52Skeletal Differences Between Men and Women
- The male skeleton is larger and heavier.
- The male pelvis is deep and funnel shaped
- The female pelvis is shallow and broad.
- Skull
- Forehead in male is shorter
- The mandible and maxilla in the male are larger
- Facial area is more pronounced
- The processes (projections) are more prominent.
53Male vs. Female Pelvis
54Articulations
- Articulations are joints, which are points of
contact between bones. - Some allow a lot of movement, some are completely
immovable. - Can be named based on their functionality (degree
of movement) or based on their structure (what
type of connective tissue holds the bones
together or if the joint has a fluid filled
capsule)
55Primary Joint Classifications
- Synarthroses are Fibrous Joints that are
immovable. - Ex. Sutures of the skull
- Amphiarthroses are Cartilaginous Joints that are
slightly movable. - Ex. Symphysis Pubis
- Diarthroses are Synovial Joints that have a fluid
filled capsule and are freely movable. - Shoulder joint
56Synarthroses (Fibrous Joints)
- The bones that have synarthroses fit very closely
together. Most of the joints are fixed. - Syndesmoses (SIN-dez-MO-ses) joints where two
ligaments (fibrous bands) connect two bones. - Ex. Distal ends of the radius and ulna are joined
together by the radioulnar interosseous ligament.
- Sutures found only in the skull. Fit together by
teethlike projections that interlock. Sutures
start out fibrous tissue, but then ossify in
adults. - Gomphoses (gom-FO-ses) unique joints that occur
between the root of the tooth and the mandible
and maxilla. The fibrous tissue between the
tooths root and the bone is the periodontal
membrane.
57Synarthroses (Fibrous Joints)
- Syndesmosis between radius and ulna
- Sutures on the skull
- Gomphosis
58Amphiarthroses (Cartilaginous Joints)
- Bones in these joints are joined together by
either hyaline cartilage or fibrocartilage. - These joints have very limited movement.
- Two Types
- Synchondroses have hyaline cartilage between the
bones. - Ex articulation between the ribs and the sternum
and the epiphyseal plate is a temporary
synchondrosis in growing people. - Symphyses have fibrocartilage between the bones
which is a pad or disk. Remember fibrocartilage
is extremely tough so there is only slight
movement. - Ex symphysis pubis and the articulations between
the bodies of the vertebrae.
59Amphiarthroses (Cartilaginous Joints)
60Diarthroses (Synovial Joints)
- Freely movable joints.
- Most mobile, most numerous, and most complex
joints. - Parts of the synovial joint
- 1. joint capsule- the periosteum of both bones
forms a sleeve around them, connecting them to
each other. - 2. synovial membrane- the lining of the joint
capsule and secretes synovial fluid which
lubricates and nourishes the inner joint
surfaces. - 3. articular cartilage- hyaline cartilage that
covers the epiphyses of each bone. - 4. joint cavity- small space between the
articulating bones - 5. menisci (articular disks)- pads of
fibrocartilage between the articulating ends of
bones in some synovial joints. The knee joint
contains two. - 6. ligaments- strong cords of dense, white
fibrous tissue that hold the two bones together
reinforcing the joint. - 7. bursa- closed pillowlike structure that are
filled with synovial fluid and function to
cushion the joint and facilitate the movement of
tendon (connections between muscles and bones).
Bursitis is inflammation of the bursa.
61General Structure of a Synovial Joint
62Types of Synovial Joints
- Synovial joints can be further grouped by their
shape, which controls the movement they allow. - Ball and socket joints, such as the shoulder and
hip joints. These allow a wide range of movement.
- Condyloid joints (or ellipsoid), such as the
thumb. A condyloid joint is where two bones fit
together with an odd shape (e.g. an ellipse), and
one bone is concave, the other convex. Some
classifications make a distinction between
condyloid and ellipsoid joints. - Saddle joints, such as at the thumb (between the
metacarpal and carpal). Saddle joints, which
resemble a saddle, permit the same movements as
the condyloid joints. - Hinge joints, such as the elbow (between the
humerus and the ulna). These joints act like a
door hinge, allowing flexion and extension in
just one plane. - Pivot joints, such as the elbow (between the
radius and the ulna). This is where one bone
rotates about another. - Gliding joints, such as in the carpals of the
wrist. These joints allow a wide variety of
movement, but not much distance.
63Types of Synovial Joints
64Representative Synovial Joints
- Humeroscapular Joint (shoulder joint)
- The joint between the head of the humerus and the
glenoid cavity of the scapula. - Shoulder muscles and tendons from a cufflike
arrangement around the joint called the rotator
cuff - The joint is more mobile than stable. Injuries
to the rotator cuff and dislocations are fairly
common.
65Humeroscapular Joint
66Hip Joint
- The hip joint is first stable, secondly, mobile.
- The ball-like head of the femur fits into the
cup-like shape of the acetabulum (socket) of the
hip.
67Tibiofemoral Joint (Knee)
- Largest and one of the most complex and most
injured joint. - Condyles of the femur articulate with the flat
upper surface of the tibia. - This is an unstable arrangement, however there
are numerous ligaments, tendons, and cartilages
that stabilize it. - 2 menisci (medial and lateral) attach to the flat
top of the tibia and form a socket for the femur
to fit. - There are about 13 bursae that serve as pads
around the joint. The largest is the prepatellar
bursa on the front of the knee. - Compared to the hip joint, the knee isnt well
protected by muscle so generally it is the one
that is injured by blows or sudden stops or
turns. Athletes frequently tear the cartilage in
their knee, the menisci.
68Tibiofemoral Joint (Knee)
69Types and Range of Movement at Synovial Joints
- The types of movements possible at a joint depend
on the shapes of the articulating bones
surfaces, the positions of the ligaments, tendons
and nearby muscles. - The 4 types of movements
- Angular
- Circular
- Gliding
- Special
70Angular Movements
- Flexion decreases the angle between articulating
bones. It bends or folds one part on another - Extension increases the angle between
articulating bones. It returns a part from its
flexed position to its anatomical position.
Straightening or stretching. - Plantar flexion pointing the toe
- Dorsiflexion flexing the foot
- Abduction moves a part away from the median
plane of the body. - Adduction moves a part toward the median plane.
71Angular Movements
72Circular Movements
- Rotation and circumduction
- Rotation Pivoting a bone on its own axis (ex.
Shaking your head no) - Circumduction moves a part so that the distal
end moves in a circle. (ex. Doing arm circles) - Supination and Pronation
- Supination turns the palm side up
- Pronation turns the palm side down
73Gliding Movements
- Simplest of all movements.
- The articulating bones move past each other, but
there is no angular or circular movement. - Ex the carpal and tarsal bones glide past each
other.
74Special Movements
- Often unique or unusual movements that occur only
in a very limited number of joints. - Inversion and eversion inversion turns the foot
inward and eversion turns it outward. - Protraction and retraction protraction moves a
part forward and retraction back. - Elevation and depression elevation moves a part
up and depression lowers a part.
75Noninflammatory Joint Disease
- Osteoarthritis or degenerative joint disease
- wear and tear deterioration of the articular
cartilage and formation of new bone at the joint
surfaces. The cartilage is no longer a shock
absorber, bone spurs grow, and ligaments calcify.
- Occurs most often in the hips, lumbar spine and
knee. weight bearing joints - Can occur in the finger joints and inflammation
can occur causing swelling deformities. - No treatment of osteoarthritis is available but
can control the pain and inflammation with
NSAIDs, nonsteroidal anti-inflammatory drugs
(Ibuprofen, aspirin, Celebrex or Vioxx). May need
partial or full joint replacement.
76Noninflammatory Joint Disease
77Traumatic Injuries
- Dislocation when the articular surfaces of the
bone are no longer in the correct place. Can have
damage to nerves and blood vessels - Athletes tend to get torn menisci. Symptoms are
edema, pain, instability of the knee and limited
motion. - Surgeons use arthroscopic surgical procedures to
see inside joints without having to open the
joint cavity. A narrow tube with lenses and
fiberoptic light is inserted into the joint and
saline solution is injected into the synovial
space that spreads the joint structures and
allows them to see inside. - Sprain injury to the ligament. Blood vessels may
be ruptured, bruising and swelling occur.
78Inflammatory Joint Disease
- Arthritis
- Rheumatoid arthritis chronic and systematic
inflammatory connective tissue disease. - Juvenile rheumatoid arthritis more severe than
the adult form. Destroys growth of cartilage and
growth of long bones slow. More common in girls. - Gouty arthritis metabolic disorder where excess
blood levels of uric acid deposit as crystals
within the synovial fluid of joints and other
tissues. A drug called Allopurinol (Zyloprim)
inhibits the synthesis of uric acid and is used
as treatment.
79Inflammatory Joint Disease
- Top left Gouty arthritis
- Top right rheumatoid arthritis
- Bottom Juvenile rheumatoid arthritis
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