ANAPHY LEC: CHAPTER 6 SKELETAL SYSTEM
The outer layer of periosteum contains
Blood vessels and nerves
What does the organic material of the bone matrix primarily composed of?
Collagen and proteoglycans
Lends flexible strength to the bone
Collagen fibers
What does foramen mean?
Hole; ex: foramen magnum
Facial bone; medial surfaces of eye orbits
Lacrimal bones
Osteocytes are located in spaces called?
Lacunae between the lamellar rings
Concentric rings of bone matrix which surround the central canal
Lamellae
Lamellar bone is organized into thin concentric sheets or layers called
Lamellae
Mature bone
Lamellar bone
Stimulates the deposition of mineral salts and collagen fibers
Mechanical stress during exercise
Facial bone; forms the bridge of the nose
Nasal
Anatomical name: knee cap`
Patella
What are the two zones where the limbs are attached to the body?
Pectoral and pelvic girdle
This is where the lower limbs attach to the body
Pelvic girdle
What does the pelvis include?
Pelvic girdle and coccyx
Type of bone shape; Approximately as wide as they are long
Short bones
Type of bone shape; Bones of the wrist and ankles
Short bones
Anatomical term: forearm
Ulna and radius
Facial bone; also form floor and lateral wall of each eye orbit
Zygomatic bones
What does the matrix always contain?
collagen, ground substance, and other organic molecules, as well as water and minerals.
Increases formation and activation of osteoclasts, the principal bone-reabsorbing cells
parathyroid hormone
what maintains calcium homeostasis?
parathyroid hormone and calcitonin
How does bone growth occur?
the deposition of new bone lamellae onto existing bone or other connective tissue.
How are bones classified? According to what amount?
Amount of bone matrix relative to amount of space within the bone
Part of the vertebral column; 1st vertebra that holds the head
Atlas
How many percent of bone mass per year occurs after 40 years old?
0.3-0.5%
Functions of skeletal system
1. Body support 2. Organ protect 3. Body movement 4. Mineral storage 5. Blood cell production
Steps in bone repair
1. Broken bone causes bleeding and a hematoma forms. 2. A callus forms which is a bone cartilage network between and around the bone fragments. 3. Woven, spongy bone replaces the callus. 4. Compact bone replaces the spongy bone.
What are the steps in endochondral ossification?
1. Chondroblasts build a cartilage model, the chondroblasts become chondrocytes. 2. Cartilage model calcifies (hardens). 3. Osteoblasts invade calcified cartilage and a primary ossification center forms in the diaphysis. 4. Secondary ossification centers form epiphysis. 5. Original cartilage model is almost completely ossified and remaining cartilage is articular cartilage.
How many times is the loss in bone mass for women after menopause?
10 fold
How many pair of ribs does the thoracic cage have?
12 pair of ribs
How many bones does an average adult have?
206 bones
How many bones does the skull have?
22 bones 8 cranial 14 facial bones
The vertebral column consists of how many individual bones and how many regions?
26 individual bones grouped into 5 regions
Percent composition of organic and inorganic material by weight
35% organic and 65% inorganic by weight
How many major curvatures does an adult vertebral column have?
4; cervical, thoracic, lumbar and sacrococcygreal
Recite the bones of the vertebral column
7 cervical vertebra 12 thoracic 5 lumbar 1 sacrum 1 coccyx atlas and axis
Types of movement: Movement away from midline
Abduction
Part of pelvic girdle, hip socket joint of hip bone
Acetabulum
How does path indirectly increase calcium uptake from the small intestine?
Activation of calcitriol
Types of movement: Movement toward midline
Adduction
Functional classification of joints: between vertebrae
Amphiarthrosis
Functional classification of joints: slightly movable joint
Amphiarthrosis
Increase in bone width or diameter due to deposit of new bone matrix on the surface of bone between periosteum and existing bone matrix
Appositional growth
What age is bone mass highest?
Around 30 years old
Within joints, the end of a long bone is covered with hyaline cartilage called
Articular cartilage
Are where two bones come together
Articulations (joints)
How are bones segregated?
Axial and appendicular skeleton
Part of the vertebral column; 2nd vertebra that rotates the head
Axis
This process produces bone on the diaphyseal side of the Epiphyseal plate
Bone growth in length
Between the trabeculae are spaces which are filled with?
Bone marrow and blood vessels
Bone repair and remodeling by removing existing bone (process)
Bone reabsorption
Inhibits osteoclast activity and stimulates calcium uptake by bones
Calcitonin
Rapidly lowers blood Ca2+ levels by inhibiting osteoclast activity
Calcitonin
Secreted from C cells in the thyroid gland when blood Ca2+ levels are too high
Calcitonin
Stimulates absorption of calcium and phosphate from digestive tract
Calcitrol
Cell extension of osteocytes are housed in narrow, long spaces called
Canaliculi
Small tunnels that radiate between lacunae across the Lamellae
Canaliculi
connect osteocytes to one another, transport nutrients and remove waste.
Canaliculi
Structural classification of joints : subclasses are synchondroses and symphysis
Cartilaginous
Structural classification of joints : united by means of cartilage
Cartilaginous
Lined with endosperm and contain blood vessels, nerves, and loose connective tissue
Central canal
Vertebral column; curves anteriorly
Cervical and lumbar region
Type of fracture: skin remains intact
Closed or simple
a fibrous protein that provides Flexibility but resists pulling or compression.
Collagen
What does the extra cellular matrix of tendons and ligaments contain in large amounts that makes them very tough, like ropes or cables
Collagen fibers
Type of fracture: several breaks results in many small pieces between two large segments
Communited
Has more bone matrix and less space
Compact bone
Solid, outer layer surrounding each bone
Compact bone
What does the types of ossification result in to?
Compact or spongy one
What determines the characteristics of the components of the skeletal system?
Composition of extra cellular matrix
What type of tissue are bones, cartilage, tendons, and ligaments?
Connective tissue
Four principal sutures
Coronal sagittal lambdoid squamous
Effects of aging on the skeletal system and joints
Decreased Collagen Production Loss of Bone Density Degenerative Changes
Explain the logic of fracture vulnerability due to decreased collagen production
Decreased collagen production means less collagen but more mineral, it makes the bone matrix more brittle
What does fossa mean?
Depression; for example: Glenoid fossa
Center portion of the bone
Diaphysis
Functional classification of joints: freely movable joint
Diarthrosis
Functional classification of joints: knee, elbow, and wrist articulations
Diarthrosises
How does bone growth in length occur? What type of ossification?
Endochondral ossification
Type of ossification that starts with a cartilage model
Endochondral ossification
a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones.
Endosteum
Located between epiphysis and the diaphysis
Epiphyseal plate
Where does growth in bone length occur?
Epiphyseal plate
Ends of long bone
Epiphyses
Includes nasal conchae, anterior portion of cranium, including medial surface of eye orbit and roof of nasal cavity
Ethmoid bone
Types of movement: Straightening
Extension
: Anatomical name: thigh
Femur
Layer of joint capsule; It consists of dense irregular connective tissue and is continuous with the fibrous layer of the periosteum that covers the bones united at the joint.
Fibrous capsule
Structural classification of joints : subclasses are sutures, syndesmosis and gomphoses
Fibrous joint
Structural classification of joints : united by fibrous connective tissue
Fibrous joint
How are joints classified?
Fibrous, cartilaginous, synovial or according to the major connective tissues type that binds bones together or Whether a fluid filled join capsule is present
Anatomical name: smaller bone of lower leg
Fibula
In adults, most red bone marrow is located in?
Flat bones
Type of bone shape; Bones of the skull and sternum
Flat bones
Type of bone shape; Have a relatively thin, flattened shape
Flat bones
Types of movement: bending
Flexion
Type of ribs where it is not attached to sternum
Floating ribs
Anterior part of cranium
Frontal
What are the paranasal sinuses
Frontal ethmoid sphenoid maxillary
List down the cranial bones
Frontal parietal occipital temporal sphenoid ethmoid
Refers to the two zones where the limbs are attached to the body
Girdle
Type of fracture: a partial fracture in which only one side of the bone is broken
Greenstick
Increases length of long bones, enhances mineralization, and improves bone density
Growth hormone
What does meatus or canal mean?
Has a canal-like passageway; external auditory meatus
What does the inorganic material of the bone matrix primarily composed of?
Hydroxyapatite, a calcium phosphate crystal
an unpaired, U-shaped bone that is not part of the skull and has no direct bony attachment to the skull or any other bones.
Hyoid bone
has the unique distinction of being the only bone in the body that does not articulate with another bone.
Hyoid bone
Most superior region of hip bone
Ilium
Type of fracture: one fragment is driven into the other, usually as a result of compression
Impacted
Facial bone: attached to the lateral walls of nasal cavity
Inferior nasal conchae
Type of ossification that occurs primarily in the bones of the skull
Intramembranous ossification
Type of ossification that occurs when osteoblasts begin to produce bone within connective tissue
Intramembranous ossification
Type of ossification that starts within embryonic connective tissue membranes
Intramembranous ossification
Two processes of bone formation in the fetus
Intramembranous ossification and endochondral ossification
Type of bone shape; Vertebrae and facial bones
Irregular bones
Type of bone shape; shapes that do not find readily into the other three categories
Irregular bones
Inferior and posterior region of hip bone
Ischium
Capsule that helps hold the bones together while still allowing for movement
Joint capsule
Type of bone shape; Upper and lower limb bones
Long bones
Type of bone shape; longer than they are wide
Long bones
In adults, where are yellow marrow found?
Long bones of femur and humerus
Facial bone: lower jawbone
Maxillae
Facial bone; forms upper jaw, anterior portion of hard palate, part of lateral walls of nasal cavity, floors of eye orbits
Maxillae
Four bone shape classifications
Long, short, flat, irregular
What does tubercle or tuberosity mean?
Lump of bone; greater tubercle
Structural component of bone
Magnesium and fluoride
Part of the facial bones that forms a freely movable joint with the rest of the skull
Mandible
Cavities in spongy bone and the medullary cavity in the diaphysis are filled with soft tissue called
Marrow
A hollow center of the diaphysis
Medullary cavity
Anatomical term: hands
Metacarpals
Anatomical name: foot
Metatarsals
Gives bone compression (weight-bearing) strength
Mineral component
Why is bone breakdown important?
Mobilizes crucial calcium ions
Why is vitamin D as a nutrient needed for bone health?
Needed for calcium absorption
Why is calcium as a nutrient needed for bone health?
Needed to make calcium phosphate and calcium carbonate which will form hydroxyapatite crystals that give bone its hardness
Type of fracture: occurs at an angle that is not 90 degrees
Oblique
Posterior portion and floor of cranium
Occipital
Reduces inflammation that may interfere with osteoblast function
Omega 3 fatty acids
Type of fracture: at least one end of the broken bone tears through the skin, high risk of infection
Open or compound
Formation of new bone by osteoblasts is called
Ossification
Where does the process of Intramembranous ossification begin?
Ossification centers (usually two or more)
Sides and roof of cranium
Parietal
Produce collagen and proteoglycans
Osteoblasts
Responsible for the formation of bone and the repair and remodeling of bone
Osteoblasts
Secrete high concentrations of calcium and phosphate ions, forming crystals called hydroxyapatite
Osteoblasts
The surfaces of trabeculae are covered with a single layer of cells consisting of
Osteoblasts with a few osteoclasts
What are the steps in intramembranous ossification?
Osteoblasts within the center of ossification produce bone matrix around collagen fibers of the connective tissue membrane. Once the osteoblasts are embedded in bone matrix, the osteoblasts become osteocytes. Many tiny trabeculae of woven bone develop. 2. Additional osteoblasts gather on the surfaces of the trabeculae and produce more bone. Trabeculae become larger and longer. Spongy bone forms as the trabeculae join together. 3. Cells within the spaces of the spongy bone specialize to form red bone marrow, and cells surrounding the developing bone specialize to form the periosteum. Osteoblasts from the periosteum lay down Bone matrix to form an outer surface of compact bone.
Bone destroying cells
Osteoclasts
Type of bone cell that accounts for 90-95% of bone cells and are very long lived
Osteocyes
cells that maintain bone matrix and form from osteoblast after bone matrix has surrounded it.
Osteocytes
Functional unit of compact bone
Osteon
Diminished bone density
Osteoporosis
Two layers of joint capsule
Outer fibrous capsule inner synovial membrane
Facial bone; form posterior portion of hard palate, lateral wall of nasal
Palatine bones
Several of the bones associated with the nasal Cavity have large cavities within them, called (which also open into the nasal cavity)
Paranasal sinuses
Stimulates osteoclasts proliferation and resorption of bone by osteoclasts, promotes reabsorption of calcium and phosphate from digestive tract
Parathyroid hormone
Stimulates reabsorption of Ca2+ from urine in the kidney, reducing the amount of Ca2+ excreted in the urine.
Parathyroid hormone
The outer surface of a bone is covered by a connective tissue membrane called
Periosteum
Anatomical name: toes and fingers
Phalanges
Anatomical term: fingers
Phalanges
What is initially formed in endochondral ossification which forms bone in the diaphysis of a long bone
Primary ossification center
What does process mean?
Projection; mastoid process
Types of movement: rotation of the forearm with palms down
Pronation
Water trapping proteins that help cartilage to be smooth and resilient
Proteoglycans
What does the matrix ground substance contain?
Proteoglycans
Types of movement: Movement of a structure about the long axis
Rotation
Vertebral column; curves together posteriorly
Sacral and coccygeal
In endochondral ossification, it forms bone in the epiphysis
Secondary ossification center
Promotes osteoblasts activity and production of bone matrix, responsible for adolescent growth spurt, promotes conversion of Epiphyseal plate to Epiphyseal line
Sex hormones
What does the inner layer of the periosteum contain?
Single later of bone cells, including osteoblasts and osteoclasts
What are the bones found in the axial skeleton?
Skull, auditory ossicles, hyoid bone, vertebral column, thoracic cage
What does condole mean?
Smooth, rounded end; occipital condyle
Where are osteocyte cell bodies housed within bone matrix?
Spaces called lacunae
Includes sella Turkic a, forms part of cranium floor, lateral posterior portions of eye orbits, lateral portions of cranium anterior to temporal bones
Sphenoid
Type of fracture: bone segments are pulled apart as a result of a twisting motion
Spiral
Has less bone matrix and more space
Spongy bone
The cranial bones are connected by immmovable joints called
Sutures
Types of movement: rotation of the forearm with palms up
Supination
Functional classification of joints: skull bone articulations
Synarthroses
Categories of joints according to their degree of motion
Synarthroses, amphiartroses, diarthroses
Functional classification of joints: non movable joint
Synarthrosis
Structural classification of joints : joined by fluid cavity
Synovial
Structural classification of joints : most joints of appendicular skeleton
Synovial
Surrounded by fluid filled joint cavity created by the joint capsule
Synovial joints
Layer of joint capsule; lines the joint cavity, produces synovial fluid, a viscous lubricating liquid.
Synovial membrane
Anatomical name: ankle
Tarsals
Inferior to parietal bones on each side of the cranium
Temporal
When bone stops growing in length, the epiphyseal plate becomes ossified and is
The Epiphyseal line
Vertebral column; curves posteriorly
Thoracic region
How many auditory ossicles do we have in each middle ear?
Three (six in total)
Stimutates bone growth and promotes synthesis of bone matrix
Thyroxine
Anatomical name: larger bone of lower leg
Tibia
In intramembranous ossification, they are constantly remodels and may enlarge or be replaced by compact bone
Trabeculae
Spongy bone consists of interconnecting rods or plates of bone called
Trabeculae
Type of fracture: occurs straight across the long axis of bone
Transverse
Differentiate true ribs from false ribs
True ribs attach directly to sternum by catrtilage false ribs attach indirectly to sternum by cartilage
What are the bones found in the appendicular skeleton?
Two girders, lower and upper limbs
is the central axis of the skeleton, extending from the base of the skull to slightly past the end of the pelvis.
Vertebral column
nutrient that supports mineralization, may have a synergistic effect with vitamin D
Vitamin K
Facial bone: in midline of nasal cavity, forms nasal septum with the ethmoid bone
Vomer
When does calcium move out of bone?
When osteoclasts break down bone
Components of the skeletal system
bones, cartilage, tendons, ligaments
What does the endosteum contain?
osteoblasts and osteoclasts
When does calcium move into bone?
when osteoblasts build new bone