Studied by 1 Person
Looks like no one added any tags here yet for you.
Name the parts of the skeletal system
bones, joints, cartilages, ligaments, tendons
What are the 2 divisions of the skeletal system?
axial and appendicular
What are the 5 functions of the skeletal system?
Support
Mineral and Triglyceride Storage
Blood Cell Production
Production
Movement
Matrix always contains _____, _____, ____, _____, ____.
Collagen, ground substance, organic molecules, water, and minerals
T/F: proteoglycans make up a large amount of ground substance
True
Proteoglycans attract _______.
Water
Proteoglycans help tissue _____________.
Withstand compression
Tendons are
Muscle to bone
Ligaments are
Bone to bone
Cartilage is
Pad/cushion areas around bone
Cells embedded with cartilage are called _____.
Chondrocytes
What is an osteoblast?
Formation of bone matrix; repair/remodel of bone tissue; produce collagen and proteoglycans (ossification)
What is an osteocyte?
Mature cells that maintain bone matrix
What is an osteoclast?
Cells that break down matrix; bone cells release minerals through osteolysis
Most minerals are in a form of _________.
Calcium phosphate
T/F: mineral component gives weight-bearing strength and is responsible for 3/4 of the weight of the 206 bones in an adult.
False- it's responsible for 2/3 of the weight
Osteocytes are located in spaces called ______, in the _________.
Lacunae; lamellar matrix
Canaliculi is
Small channels that run through the matrix to transport nutrients and remove waste
Compact bone is made of a repeating functional unit called_____.
Osteon
Osteon is made up of concentric circles of ________.
Lamella w/ embedded lacunae; and surrounds the central canal
What are perforating canals?
They allow for blood vessels in the central canals to linked to other vessels
Spongy bone is located @ the ______ of ______ & at the center of other bones.
Epiphysis; long bones
Spongy bone contains _____ interconnecting rods and spaces that contain ______.
Trabiculae; bone marrow
T/F: spongy bone has no osteons
True
Spongy bone is found in locations w/ ______ arriving from many different directions.
Stresses
______ bone is much lighter than ______ bone and reduces weight of skeleton and makes it easier for muscles to move.
Spongy; compact
What are the 4 general shapes of bones?
Long, short, irregular, flat
What is an example of a long bone?
humerus, femur
What is an example of a short bone?
carpals and tarsals
What is an example of a flat bone?
Sternum, cranial bones
What is an example of an irregular bone?
Vertebrae, hip bones, facial bones
Which bone shape has compact bone on the inside w/ hollow central marrow cavity?
Long bone
The epiphysis are wider portions at each end, made up of _____.
Spongy bone
What is an epiphyseal plate?
Site of growth between diaphysis & epiphysis; solidifies into epiphyseal line when full adult height is reached
What is a medullary cavity?
Center of diaphysis; holds red/yellow marrow
What is periosteum?
Membrane around bone's outer surface; contains blood vessels/nerves; tendons/ligaments attach here
What is endosperm?
Membrane that lines the medullary cavity; contains osteoblasts & osteoclasts; involved in growth & repair
Ossification is _______.
Formation of bone by osteoblasts
Intramembranous ossification is_______.
Bone formation occurs within connective tissue membranes
Endochondral ossification is________.
Bone formation that occurs inside hyaline cartilage
Both intramembranous and endochondral bone formation result in ______ and _____ bone.
Compact, spongy
Intramembranous ossification occurs primarily in the ______ when osteoblasts begin to produce bone within connective tissue, known as mesenchyme.
Skull
In intramembranous ossification, osteoblasts line up ________, & begin depositing bone matrix to form trabiculae, which radiate out from centers of the ossification centers.
On the surface
____ or more _________ exist in each flat skull bone and mature skull bones result from fusion of these centers as they enlarge.
2, ossification centers
Intramembranous ossification generally occurs during the ________ of fetal development, & forms the bones of the skull, mandible, and the clavicle.
First 2 months
Endochondral ossification is initially formed is a ________, which is bone formation in the diaphysis of a long bone.
Primary ossification center
__________ is bone formation in the epiphysis.
Secondary ossification center
What are the steps in endochondral ossification?
Chondroblasts build a cartilage model, then become chondrocytes
Cartilage model hardens (calcifies)
Osteoblasts invade calcified cartilage and a primary ossification center forms the diaphysis
Secondary ossification centers form the epiphysis
Original cartilage model is almost completely ossified; remaining cartilage is known as articular cartilage
During bone growth, when cartilage is broken down, the enclosed cartilage is digested away which opens up a _______.
Medullary cavity
Bone replaces _____ through the action of _____.
Cartilage, osteoblasts
Dying chondrocytes are replaced by ______.
Osteoblasts
Bones grow in width by the periosteum & the existing matrix _______.
Appositional growth
What are the requirements for bone growth?
Mineral supply, vitamin D3, hormones, & vitamins A, B, C, D, K
T/F: timing of epiphyseal closure varies from bone-bone and from person-person
True
Bones are remodeled in response to what 2 factors?
Free calcium levels in the blood
Pull of gravity & muscles on the skeleton
Bone remodeling involves:
-removal of existing bones by osteoclasts
-deposition of new bones by osteoblasts
In young adults ____ of the skeletal mass is replaced each year.
1/5
T/F: spongy bone is replaced more often than compact
True
In adults, osteocytes in lacunae continuously _____ & _____ surrounding calcium salts.
Remove, replace
Remodeling bone (esp. spongy bone) is based on:
Appropriate stress & exercise
T/F: muscle is a major storage site for calcium
False- bone is major storage site
Calcium homeostasis is maintained by _____ & ______.
Parathyroid hormone, calcitonin
Parathyroid hormone (increase or decrease) formation/activation of osteoclasts.
Increase
A closed fracture is
Simple; completely internal and only seen on x-rays
An open fracture is
Compound; project through the skin and are at most risk for infection
What are the steps in bone repair?
Broken bone causes bleeding and a fracture hematoma forms
Cells of periosteum/endosteum divide to form a callus(internal/external)
Cartilage model forms first, then osteoblasts enter the callus and form spongy bone; continues for 4-6 weeks after injury
Cancellous bone is slowly remodeled to form compact & cancellous bone
When placed under stress, tissue becomes stronger through ________ & production of collagen fibers.
Increased decomposition of mineral salts
Without mechanical stress, bone does not remodel normally because ________.
Resorption out-spaces bone formation
When there's an absence of mechanical stress, bone weakens through decreased # of ______ and demineralization (loss of bone minerals).
Collagen fibers
What is osteopenia?
Inadequate ossification that naturally occurs in aging as early as 30-40 years old
Osteoblasts _____.
Slow
Osteoclasts _____.
Remain constant
What is osteoporosis?
Loss of bone mass that impairs normal function and can lead to more fractures
T/F: osteoporosis is more severe that osteopenia
True
Osteoporosis is more common in what gender?
Females
For women, osteoporosis usually accelerates after _____ due to decline in circulating estrogen.
Menopause
Foramen is
A large hole/opening
Fossa is
depression
Process is
Projection
Condyle is
Smooth, round ended
Meatus is
Canal-like passageway
Tubercle is
Lump of bone