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What does the skeletal system contain?
The skeletal system contains bones, as well as cartilage, membranes, and it is considered an organ.
What is the skeletal systems function?
The functions of the skeletal system are support, protection, mineral storage, movement, blood cell production, and storage of lipids.
What are the minerals that bone store?
The minerals bone store are calcium and phosphorus in the form of calcium phosphate also called hydroxyapatite.
What does compact bone and spongy bone contain?
Compact bone and spongy bone contain lamellae, osteocytes, lacunae, canaliculi and trabeculae: BUT only compact bone contains osteons.
How does intramembranous and endochondral ossification differ?
Endochondral ossification involves the replacing of hyaline cartilage, while intramembranous involves replacing fibrous membranes.
How do most bones develop?
Most bones develop via endochondral ossification (involving hyaine cartiage).
What are the major steps of endochondral ossification?
The major steps to endochondral ossification are: 1. Hyaline cartilage breaks down. 2. A periosteal bud invades the cavity and osteoblasts produce spongy bone tissue. 3. a...
What are OSTEOBLASTS?
OSTEOBLASTS are bone FORMING cells.
What are OSTEOCLASTS?
OSTEOCLASTS BREAK DOWN and RESORB bone.
What are OSTEOCYTES?
OSTEOCYTES are mature bone cells, surrounded by bone matrix and can turn into osteoblasts if needed.
What are the types of bone by size and shape?
The types of bone by size and shape are long, short, flat, irregular, and sesamoid.
What's an example of a long bone?
Long bone: Femur and humerus
What's an example of a short bone?
Short bone:Tarsal; Wrists and ankles
What's an example of a flat bone?
Flat bone: Parietal skull and scapula
What's an example of an irregular bone?
Irregular bone: Facial and vertebra
What's an example of a sesamoid bone?
Sesamoid bone: patella
Where is the epiphyses located?
The epiphyses are located at the end of each long bone and ARTICULATES with another bone.
What is the substance that reduces friction at the ends of the bone?
The substance that reduces friction at the ends of the bone is the articular cartilage and it is made from hyaline cartilage.
What is the diaphysis?
The diaphysis is the shaft of the long bone.
What is the periosteum?
The periosteum is a covering of fibrous tissue that completely covers the bone except the articular cartilage at the epiphyses.
What is the fibrous periosteum?
The fibrous periosteum is the outer layer of the periosteum and contains blood vessels, nerves, and lymphatics.
What is the osteogenic layer?
The osteogenic layer is the inner layer of the periosteum and contains osteoprogenitor cells.
What are 'processes'?
'processes' are bony projections that provide sites for attachment of ligaments and tendons.
What is the endosteum?
The endosteum lines the medullary cavity and also contains osteoprogenitor cells.
What is spongy bone also referred to as?
Spongy bone is also referred to as cancellous bone.
What is compact bone also referred to as?
Compact bone is also referred to as cortical bone.
What does the microscopic structure of the matrix consist of?
The microscopic structure of the matrix consists of collagen and inorganic salts.
What is the purpose of collagen with in the matrix?
The purpose of collagen with in the matrix is to provide strength and resiliency.
What is the prupose of organic salts with in the matrix?
The purpose of organic salts is to make it hard and resistant to crushing.
What do osteoblasts do in the bone matrix?
Osteoblasts synthesize and release the proteins and organic components of the bone matrix and are involved in depositing calcium salts in the bone matrix.
What happens to an osteoblast when it is completely surrounded by bone matrix?
When an osteoblast is completely surrounded by bone matrix it differentiates into an osteocyte, but can return to an osteoblast if needed.
Where are osteocytes located?
Osteocytes are mature bone cells and are located in the bony chambers called lacunae, which form concentric circles around haversian canals.
What are the two main functions of osteocytes?
The two main functions of osteocytes are maintain and monitor portein and mineral content and participate in the repair of damaged bone.
How are osteoclasts originated?
Osteocalsts are originated by the fusion of single nucleated white blood cells called monocytes.
What do osteoclasts do?
Osteoclasts are large and breakdown (matrix) by acid and lysosomal enzymes.
What is an osteon?
An osteon (Haversian system) is the basic functional unit of mature compact bone.
What do osteons form?
Many osteon units are cemented together to form compact bone.
What do osteocytes in the outer lamellae do?
Osteocytes in the outer lamellae transport nutrients and wastes to and from nearby cells by canaliculi.
Where is spongy bone located?
Spongy bone is located where bones are not heavily stressed and is typically found in the epiphyses of long bones.
What types of bone are involved in intramembranous formation?
The types of bones involved in intramembranous formation are FLAT: Skull, ribs, clavicle.
What is the epiphyseal plate?
The epiphyseal plate is a band of cartilage that remains between the primary and secondary ossification centers.
What are the layers/zones of the epiphyseal plate?
The layers/zones of the epiphyseal plate are resting zone, proliferative zone,hypertrophic zone, and calcified zone.
What does the resting zone do?
The resting zone contains hyaline cartilage and anchors the plate to the bony tissue of the epiphysis.
What is the proliferative zone?
The proliferative zone is the second layer and has many cells undergoing mitosis.
WHAT DO OSTEOCLASTS DO?
OSTEOCLASTS BREAK DOWN THE MATRIX (BONE), SECRETE ACID, PHAGOCYTIZE AND ARE ALSO USED IN REPAIR.
When are most bones ossified?
Most bones are ossified at age 25.
What do hormones play a role in?
Hormones play a role in development, growth, and repair.
What does growth hormone (GH) do?
Growth hormone (GH) is secreted from the pituitary gland and stimulates osteoblast activity and the synthesis of bone matrix.
What does thyroid hormone (TH) do?
Thyroid hormone (TH) halts bone growth by causing premature ossification.
With GH, TH can?
With GH, TH can stimulate osteoblastic activity.
What does parathyroid hormone (PTH) do?
Parathyroid (PTH) simulates an increase in the number and activity of osteoclasts
What does PTH regulate?
PTH regulates calcium in blood; it increases the conecentration of calcium in the blood.
What do sex hormones stimulate in the epiphyseal plate?
Sex hormones stimulate ossification of epiphyseal plates.
What causes a growth spurt?
Sex hormones stimulate osteoblast (bone forming activity) and during puberty, these hormones are abdundant and cause a growth spurt.
Why do epiphyseal plates ossificate early?
Sex hormones stimulate the 'explosion' of bone growth is the reason the plates ossificate early in life. Certain levels of sex hormones are good, but to much (during the growth spurt),...
What does physical stress and/or exercise do?
Physical stress and/or exercise stimulates the bone to thicken and strengthen.
What does lack of exercise cause?
Lack of exercise or small body frame can cause bone tissue to atrophy (become thin and weak).
How do muscles attach to bone?
Muscles attach to bones by tendons.
What is blood cell formation called?
Blood cell formation is called hematopoiesis, and its another important function of the bones.
What are the two types of marrow in the bone?
The two types of marrow in the bones are red marrow and yellow marrow.
What is red marrows function?
Red marrow functions in the formation of red blood cells, white blood cells, and platelets.
What is yellow marrows function?
Yellow marrow stores fat.
What happens to red marrow in the medullary cavity as we become adults?
In the medullary cavity, the red marrow is replaced by yellow marrow as we become adults; most of the red marrow is in our spongy bone.
What happens if the blood cell supply is low?
If the blood cell supply is low, yellow marrow can change back into red marrow to produce blood cells.
What does the axial skeleton consist of?
The axial skeleton consists of the parts that support the head, neck, and trunk.
What does the appendicular skeleton consist of?
The appendicular skeleton consists of the bones of the upper and lower limbs that anchor the limbs to the axial skeleton.
Amphriarthrotic: slightly movable.
Diarthrotic: free movement.
What joints LACK a joint cavity?
Fibrous joints and cartilaginous joints LACK a joint cavity.
What joints possess a joint cavity?
Synovial joints possess a joint cavity.
What are the three types of fibrous joints?
The three types of fibrous joints are syndemosis, suture, and gomphosis.
What are syndemosis joints bound by?
Syndemosis joints are bound by an interosseous ligament.
What are suture joints seperated by?
Suture joints are seperated by a sutural ligament and are synarthrotic.
How are gomphosis joints formed?
Gomphosis joints are formed by a cone shaped bony process in a bony socket (peg and socket).
What is the symphysis pubis?
The symphysis pubis is a type of cartilaginous joint, which allows maternal pelvic bones to shift as the infant passes through the birth canal.
What is the most common type of joint?
Synovial joints are the most common type of joint.
What holds the structure of the synovial joint together?
The joint capsule of a synovial joint is what holds the structure together.
What are the two layers of the joint capsule?
There are two layers of the joint capsule, the outer and the inner; inner is the synovial membrane.
What does the synovial membrane contain?
What synovial membranes contain: it surrounds the synovial cavity, secretes synovial fluid, and stores adipose tissue.
What happens if the joint cavity is injured or infected?
If the joint cavity is injured or infected, the membrane may reabsorb the fluid.
What produces synovial fluid?
Synovial fluid is produced by the synovial membrane and supplies the articular cartilage with nutrients.
What are the two compartments that some synovial joints are divided into?
Some synovial joints are divided into two compartments by fibrocartilage called menisci.
What are the fluid filled sacs that are found between skin and the underlying prominences called?
Fluid filled sacs that are found between the skin and underlying prominences are called bursae.
Name the types of synovial joints.
The types of synovial joints are ball and soket, condyloid, gliding, hinge, pivot, and saddle.
What joint produces the widest range of motion?
The widest range of motion is produced by ball and socket joints.
What movement is possible with ball and socket joints?
Rotational movement is possible by ball and socket joints.
What movement is NOT permitted with condyloid joints?
Rotational movement is NOT permitted with condyloid joints.
What motion does gliding joints allow?
Gliding joints allow for sliding and twisting motion.
What are some examples of hinge joints?
Elbows and phalanges are examples of hinge joints.
How many planes can hinge joints move in?
Hinge joints move in ONE plane only; an example is the elbow which allows for flexion and extension.
What is the movement of pivot joints centered around?
Movement of pivot joints is around a central access.
What kind of movement is permitted by a saddle joint?
A saddle joint permits a variety of movements, but the only example is between the carpal bone and the metacarpal of each thumb.
How does movement occur?
When a muscle contracts, its fibers pull its movable end (Insertion point) toward its fixed end (origin) and a movement occurs.
What are cartilaginous joints bound by?
Cartilaginous joints are bound by both hyaline cartilage and fibrocartilage.