DAT Bootcamp - Skeletal System
the _____ provides structure, support, rigidity, and protection to organs
the skeletal system serves as a reservoir of _____ and _____ substances
_____ skeletons belong to organisms without bones, especially backbones
insects tend to have _____, which are skeletons on the outside of the organism
_____ skeletons belong to organisms that have a backbone
vertebrates have _____, which are skeletons on the inside of the organism
what are the 2 parts of human endoskeletons?
axial; appendicular skeletons
what are the types of bones?
long; short; flat; sesamoid; irregular
long bones are _____ than they are _____
what are some examples of long bones?
femur; radius; ulna
what are some of the predominant structural features of long bones?
epiphyses; diaphysis; a medullary cavity; metaphyses; epiphyseal growth plates
_____ are the bumpy parts at the ends of long bones
_____ covers epiphyseal compact bone in synovial joints
articular cartilage covers epiphyseal compact bone in _____ joints
what type of joint is formed between long bones?
at birth and early adolescence, all bone marrow is _____ bone marrow, which gradually gets replaced with _____ bone marrow at certain bone locations
(yellow bone marrow mainly replaces the red bone marrow in long bone medullary cavities)
_____ bone marrow is located in spongy trabecular bone of adults
_____ is the process where stem cells create new blood cells
hematopoiesis occurs in the _____ bone marrow of _____ bone
red; spongy trabecular
the _____ of a long bone is the shaft between the ends
the _____ is the "hollow" part of the diaphysis, which contains _____ bone marrow in adulthood
medullary cavity; yellow
the _____ bone marrow stores energy as fat
(hematopoiesis does not occur at yellow bone marrow)
_____ are found between the medullary cavity and epiphyseal plates of a long bone
metaphyses have a similar structure to the _____ of a long bone
(structure is spongy trabecular bone)
epiphyseal plates are _____ cartilage during adolescence, and they _____ to an epiphyseal line during puberty
epiphyseal plates grow before ossification to promote _____
epiphyseal plates grow toward the _____ to lengthen the _____ of a long bone
epiphyseal lines are found between long bone _____ and _____ in adults
(same holds true for epiphyseal plates in adolescents)
cartilage is _____, which makes it difficult to heal
breaking a bone at the epiphyseal plate can stunt growth because epiphyseal plates are made of _____, which is avascular and difficult to heal
_____ bones are cuboidal and provide support with little movement
short bones are primarily _____ bone covered by a thin layer of _____ bone
cancellous (spongy trabecular); cortical (dense)
what are some examples of short bones?
carpals of the wrist or tarsals of the ankle
_____ bones are thin, with outer layers of cortical bone surrounding spongy, cancellous interiors
what are some examples of flat bones?
sternum and the bones forming the skull
sesamoid bones are found in _____, and they act to increase muscle power - what is an example of a sesamoid bone?
irregular bones have _____ layers surrounding _____ interiors; however, their shapes do not fit any other bone class
dense, cortical; spongy, cancellous
what are some examples of irregular bones?
vertebrae; sacrum; pelvis
_____ bone is the outer layer of bones
what allows bones to support weight?
cortical bone density
what are the microstructures in cortical bone?
osteons; Haversian canals; lamella; lacunae; canaliculi; Volkmann's canals
_____ are the functional unit of cortical bone, and they appear as multi-layer cylinders
what direction do osteons travel within cortical bone?
parallel to the bone's long axis
the layers that make-up an osteon are called _____
_____ contain cortical bone and collagen fibers
_____ are the central canals of an osteon
Haversian canals contain blood vessels to supply nutrients to the _____ of an osteon
(Haversian canals connect to osteocytes through canaliculi)
_____ are small spaces between lamellae that house osteocytes
canaliculi connect _____ and _____ of a single osteon
lacunae (housing osteocytes); Haversian canals
_____ canals connect adjacent osteons, and they also connect peripheral osteons to the periosteum
_____ bone is soft and flexible, and it is made of _____ that soak up bone marrow like a sponge
(trabecular/cancellous bone = spongy bone)
_____ are precursors to osteoblasts
osteoblasts contain _____ nucleus
what is the main function of osteoblasts?
to build bone (secrete collagen + proteins that make osteoid)
_____ are mature bone cells that develop from osteoblasts
how do osteoblasts become osteocytes?
osteoblasts get trapped in the osteoid they secrete
osteoclasts contain _____ nuclei, and they are found in _____
multiple; Howship's lacunae
what cell type gives rise to osteoclasts?
what is the main function of osteoclasts?
to resorb ("chew") bone
pits created by osteocytes
what is bone remodeling?
the back and forth between resorption (osteoclasts) and ossification (osteoblasts)
what are the primary factors that affect bone remodeling?
parathyroid hormone, vitamin D, calcitonin
parathyroid hormone (PTH) is secreted from the parathyroid gland, and it _____ blood Ca2+
PTH stimulates _____ (bone cell) and depresses _____ (bone cell)
vitamin D is activated by _____ to _____ blood Ca2+
activated vitamin D provides _____ to PTH
vitamin D stimulates Ca2+ _____ in the intestines, and increases the # of _____ for resorption
calcitonin is secreted by the _____ gland, and it opposes PTH to _____ blood Ca2+
calcitonin decreases the activity of _____, so _____ have less competition
_____ is made of proteins and type 1 collagen fibers, to provide bones with tensile strength
_____ provides bone density, and it is made of inorganic crystals of Ca2+, phosphate, & H2O
what are the 2 types of embryonic ossification?
intramembranous and endochondral
what is the most common type of embryonic ossification?
_____ ossification occurs when bone is created directly within a fibrous membrane
what types of bones are usually made by intramembranous ossification?
_____ ossification occurs when bones are created indirectly, from a cartilage model
what bones are made through endochondral ossification?
what are the 3 main types of connective tissue?
fibrous; cartilage; joints
fibrous connective tissue includes what 3 things?
tendons; ligaments; periosteum/endosteum
_____ connect bones to muscle
_____ connect bones to other bones
the _____ is a protective fibrous membrane that covers cortical bone
what are the 2 sublayers of the periosteum?
outer fibrous layer; inner/cambium layer
(cellular layer = inner/cambium layer)
the outer fibrous layer of the periosteum is _____
the _____ layer of the periosteum contains collagen and osteoprogenitor cells
the _____ is a single layer membrane between cortical and cancellous bone
cartilage is _____ and not _____
how do cells living in cartilage get nutrition/immune support?
from the surrounding fluid
(cartilage does not contain blood vessels and it is not innervated)
cartilage building cells are called _____
(analogous to osteoblasts)
chondrocytes are mature _____
(analogous to osteoblasts --> osteocytes)
how do chondroblasts give rise to chondrocytes?
chondroblasts get trapped by the matrix they secrete
(analogous to osteoblasts --> osteocytes)
what is the primary function of chondrocytes?
(similar to osteocytes, which maintain bone)
where are chondrocytes found?
(similar to osteocytes inhabiting lacunae of an osteon)
chondroblasts secrete a cartilaginous matrix containing:
collagen and elastin
how can you change the type of cartilage?
change the amounts of collagen and elastin
what is the most common protein in mammals?
what are the 3 types of cartilage?
hyaline; fibrous; elastic
_____ cartilage has a glassy appearance, and it absorbs shock by supporting the ends of long bones at synovial joints
(the articular cartilage found at synovial joints is hyaline cartilage)
what does hyaline cartilage matrix contain?
chondroitin sulfate, collagen, and elastin
_____ cartilage has many collagen proteins to provide rigidity and resist tension
what are some examples of places that have fibrous cartilage?
intervertebral discs and knee meniscus
elastic cartilage is similar to hyaline cartilage; however, it contains more _____
elastic cartilage is _____, and it is found in tissues like the _____&_____
flexible; ears & epiglottis
unlike cartilage, joints are _____ and _____
what are the 3 main types of joints?
synarthroses; amphiarthroses; diarthroses
_____ are dense, fibrous joints between bones that do not move
_____ are cartilaginous joints between bones that partially move
_____ are synovial joints between bones that are fully movable
what are the 6 types of synovial joint?
pivot; hinge; saddle; plane; condylar; ball and socket
which type of joint is prone to the most injuries?
ball and socket
what are the main components of a synovial joint?
bones; articular cartilage; ligaments; fibrous joint capsule; synovial fluid