Exam Lecture Number 2

What bones are part of the Axial Skeleton?

It consists of bones of the skull, thorax, and vertebral column.

What bones are part of the Appendicular Skeleton?

It consist of bones of the limbs and gridles that attach them to the axial skeleton

What are the functions of the skeletal system?

* It provides support
* Keeps us upright
* It stores minerals and lipids
* Minerals
* Large amount of calcium
* Lipids
* Fats
* Bones have a hollow center and in that center it has marrow. The marrow is made out of fat cells/ adipose tissue.
* Our bones store energy molecules
* It produces blood cells
* Protection
* Protects our organs
* Leverage
* Allow movement

What inorganic componnent make up the bone composition?

Calcium

* Main source of bones/ stores in bones

What are the 2 most highly concentrated inorganic molecules found in our bones?

* Calcium
* Phosphate

What organic compound is combined with calcium?

* collagen
* protein

What are the 3 activties that maintain calcium levels?

* Intestine (Digestive System)
* Absorbs calcium and phosphate under hormonal control
* Bones
* Osteoclasts erode the matrix and release calcium
* Osteoblasts use calcium to deposit new matrix/create more bones
* Kidneys
* Reabsorbs calcium depending on the levels of the body from the urine under hormonal control
* Varying levels of calcium and phosphate loss in urine under hormonal control

What are flat bones?

Thin, roughly parallel surfaces

* Flat plate

What are examples of flat bones?

Cranial bones, sternum, ribs, scapulae

What does the flat bone provide?

* Protect underlying soft tissues (ex. Brain)
* Provide a surface area for skeletal muscle attachment
* Can’t move without the use of muscles provide locations for the muscle to attach

What are sutural bones?

Irregular bones formed between cranial bone

* only found on the cranial bone

What are long bones?

They are long and slender

What are examples of long bones

* Femur and Humerus


* Various bones of the limbs

What are irregular bones?

They are complex shapes with short, flat, notched, or ridged surfaces

What are examples of irregular bones?

* Vertebrae


* Pelvis bones
* Facial Bones

What are sesamoid bones?

Small flat, shaped like a sesame seed

What are examples of sesamoid bones?

* Patella
* Developed inside tendons of the knee, hands, and feet

What are short bones?

Small and boxy

What are examples of short bones?

* Carpals
* Tarsals

Name for #1

Epiphysis

What type of marrow is found in the epiphysis?

Red bone marrow

What type of bone is the epiphysis consist of?

Spongy bone/ trabecular bone

Name strucuture for #1

Articular cartilage

Epiphysis

* It consists largely of spongy bone/ trabecular bone
* Red bone marrow is found
* The articular cartilage covers the portions of the epiphysis that form articulations
* Articular means one bone meets another bone

Where is red bone marrow usually found?

Epiphysis

Where is yellow bone marrow usually found?

Diaphysis / Medullary cavity

What covers the surface of the epiphysis when it meets other bones? #1

Articular cartilage

What is the purpose of the metaphysis? #2

It is the entry site where the metaphyseal artery and metaphyseal vein enter

What do the metaphyseal artery and metaphyseal vein do?

-They carry blood to/from the metaphysis
-They also conncet to the epiphyseal arteries and veins

Name the strucuture for #8

Nutrient artery and vein

Name the opening/ hole for #7

Nutrient foramen

Where is the nutrient artey and nutrient vein located on the long bone?

Diaphysis

Name #3

Periosteum

Name #4

Compact bone

Name #5

Medullary cavity

Name #6

Metaphysis

Name #9

Epiphyseal artery and vein

Name #2

Metaphyseal artery and vein

Metaphyseal artery and vein

* Carry blood to/from metaphyseal
* Connect to epiphyseal arteries/veins

Periosteum

* Thin-layer
* Outer-layer
* Incasement
* Around the bone (outside)
* Made of dense regular tissue

What does the diaphysis contain?

* Medullary cavity
* Red bone marrow
* Involved in red blood cell production
* Yellow bone marrow
* Adipose tissue
* Important as energy reserve

What type of marrow is found in the diaphysis?

Yellow bone marrow

What is the name of the cavity for #6?

What type of marrow is found here?

* Medullary cavity
* Yellow bone marrow

Name #4

Spongy bone/ trabecular bone

Name #5

Compact bone

Name #3

Diaphysis / shaft

Name #2

Metaphysis

What does red bone marrow do?

It involves red blood cell production

What does yellow bone marrow do?
What does it contain?

* It reserves energy
* It contains adipose tissue

What does the nutrient foramen contain?

Nutrient artey and vein

Osteogenic cells (osteoprogenitor cells)

* Stem cells that produce more cells that will differentiate (change into) osteoblasts (mature cells) or osteoclasts
* They are important for fracture repair
* Locations
* Inner lining of periosteum
* Lining endosteum in medullar cavity
* Lining passageways containing blood vessels
* Ex. Central canal

What is the name of this cell #1?

Osteogenic cells

What are osteogenic important for?

* In fracture repair

Osteoblasts

* They produce new bony matrix
* First matrix is called Osteoid
* Its an unmineralized matrix
* Its a immature bone that hasn’t fully developed into bone
* It hasn’t been solidified
* It’s just collagen (type of protein) in the matrix
* Second matrix is called bone
* Calcium salts is added to solidify bone
* The matrix becomes bone
* Mature bone

Osteoblasts (Continuation)

* Osteoblast become osteocytes once they surrounded/ trapped themselves by the bone matrix
* They get stuck in a lacuna

Osteogenesis / Ossification

Is the name of the processes that makes osteoid

What is the name of this type of cell #1?

Osteoblasts

Osteocytes

* They are mature bone cells that cannot divide
* They occupy lacuna/e
* They are seperated by layers of matrix called lamellae
* They are interconnected by canaliculi
* Small little canals
* They maintain protein and mineral content of surrounding matrix

What do osteocytes maintain?

Protein and mineral content of the surrounding matrix

What is the name of this cell? #1

Osteocytes

What is the name of this cell?

Osteoclasts

Osteoclasts

* They remove and remodel bone matrix
* It releases acids and proteolytic enzymes to dissolve matrix and release stored minerals / calcium
* This processes is called osteolysis
* Digest

What do osteoclasts do?

They remove and remodel bone matrix by releasing acids and proteolytic enzymes

Name the structure for #2

Lacuna

Name the structure for #3

Canaliculi

Name the structure for #4

Lamellae

What is the functional unit for compact bone?

Osteon

Osteon

* It is organized in concentric lamellae around a central cannal
* Osteocytes lie between lamellae
* Central canal contains small blood vessels

Periosteum

Outermost layer of the long bone

Compact bone

* Outer bone tissue layer
* Consists of
* Circumferential lamellae
* Outer and inner surfaces
* Interstitial lamellae
* Fill spaces between osteons
* Osteons
* Connected by performing canals (perpendicular to surface)

Spongy bone/ trabecular bone

* Inner most later
* Found in the medullary cavity
* Lamellae form struts and plates (trabeculae) creating an open network
* Theres no blood vessels in matrix
* Nutrients reach osteons through canaliculi open to trabeculae surfaces

What type of movement is synarthrosis?

No movement In

* Extremely strong

What type of movement is amphiarthrosis?

Little movement

* Much stronger than diarthrosis
* Articulating bones connected by collagen fibers or cartilage
* Collagen fibers - fibrocytes
* Cartilage - chondrocytes

What type of movement is diarthrosis?

Free movement Info

* Freely moveable

What structural category is this?

What functional category is this?

1. Suture
2. Synarthrosis

What structural category is this?

What functional category is this?

1. Gomphosis
2. Synarthrosis

What structural category is this?

What functional category is this?

1. Synchondrosis
2. Synarthrosis

What structural category is this?

What functional category is this?

1. Syndesmosis
2. Amphiarthrosis

What structural category is this?

What functional category is this?

1. Symphysis
2. Amphiarthrosis

What structural category is this?

What functional category is this?

1. Synovial
2. Diathrosis

Joints or articulation

* Means locations where two or more bones meet
* Only points at which movements of bones can occur
* Joints allow mobility while perserving bone strength
* Amount of movement allowed is determined by anatomical structure
* Categorized
* Functionally by amount of motion allowed, or range of motion (ROM)
* Structurally by anatomical organization

Suture

* Synarthrotic joint connected by dense fibrous connective tissue
* Location between bones of the skull

Gomphosis

* Synarthrotic joint binding teeth to bony sockets in maxillae and mandible

Syndesmosis

* Amphiarthrotic joint with bones connected by a ligament
* Ex
* Distal joint between tibia and fibula

Symphysis

* Amphiarthrotic joint where articulating bones separated by a pad of fibrocartilage
* Ex
* Joint between the two pubic bones

Synchondrosis

* Synarthrotic joint formed by a rigid, cartilaginous bridge between two articulating bones
* Ex
* Between ends of the first pair of ribs and the sternum

Synovial

* Diarthrotic joints
* Permit wider range of motion than any other joint type
* Located at the ends of long bones

Components of a synovial joint

* Articular cartilage
* Joint capsule or articular capsule
* Synovial membrane
* Synovial fluid

Articular cartilage

* ==Covers bones at joint to prevent degradation==
* Structure resembles hyaline cartilage but with no perichondrium\\
* Matrix contains more water than other cartilages

Joint capsule or Articular Capsule

* ==Sac enclosing the articular ends of the bones in a joint ; like an encasement between the bones==
* Reinforced with accessory structure (tendons, ligaments)
* Continuous with the periosteum of each bone
* ==Adds strength and mobility to the joint==

Synovial membrane

* Lines the interior of the joint capsule
* Secretes synovial fluid into the joint cavity
* Fluid lubricates, cushions, prevents abrasion, and supports chondrocytes

Synovial fluid

* Clear, strawed-colored, viscous fluid
* Consistency of raw egg white
* %%Viscosity due to high concentration%%

Functions of Synovial Fluid

* %%Lubrication%%
* Under compression, fluid squeezes out of the cartilage and into the space between bones
* Layer of fluid reduces friction
* %%Nutrient distribution%%
* Circulates continuously, providing nutrients and carrying away wastes
* Compression and expansion of articular cartilage assist in circulation
* %%Shock absorption%%
* Viscosity increases with increasing pressure

What are the 3 functions of the synovial fluid?

* Lubrication
* Nutrient distribution
* Shock absorption

Accessory Structures Supporting the Knee

* It provides support and additional stability
* ^^Tendon of the quadriceps muscle^^
* ^^It is not part of the knee joint itself^^
* ^^It limits the range of motion and provides mechanical support^^
* Bursa
* Fat pads
* Meniscus
* Patellar ligament
* Cruciate ligaments

Bursa

* Small, thin fluid-filled pocket filled with synovial fluid and lined by synovial membrane
* Mini sacs / bags
* Forms in connective tissue outside a joint capsule
* Reduces friction
* Acts as shock absorber

Fat pads

* Localized masses of adipose tissue covered by a layer of synovial membrane
* Usually superficial to joint capsule
* Protect articular cartilage
* Fill in spaces created as joint moves and joint cavity changes shape
* Storage of nutrient molecules
* Absorbs more shock/compression shock

Meniscus

* Pad of fibrocartilage between opposing bones in a synovial joint
* May subdivide a synovial cavity
* May channel synovial fluid flow
* Allows variations in the shapes of the articular surfaces
* Made of chondrocytes; its cartilage

2 Type of Accessory Ligaments

* %%Extrinsic liagments%%
* Separate from the joint capsule
* Extracapsular ligaments (pass outside the joint capsule)
* Ex. Patellar ligament
* %%Intracapsular ligaments%%
* passes inside the joint capsule
* Ex. cruciate ligaments