Exam 2 Flashcards
what is the total number of bones in the human body?
206
which part of the body has the highest number of bones?
the hands and feet (28 in both hands and 28 in both feet)
how many axial bones are there?
80
how many appendicular bones are there?
126
what are the functions of bones?
support, protection, movement, storage (minerals, fats), hematopoiesis
what is hematopoiesis?
the formation of blood cellular components
what are the 4 bone shape classifications?
long, irregular, flat and short
describe long bones and give examples
- not necessarily long, just longer than they are wide
- ex: femur, all metacarpal and phalange bones
describe short bones and give examples
- look like little cubes, about as wide as they are long
- ex: tarsals (ankle bones) and carpals (wrist bones)
what are the two types of bone tissue?
- compact bone
- spongy bone
describe irregular bones and give examples
- irregular in shape
- vetebral bones, facial bones
describe flat bones and give examples
- bones that are flat
- ex: sternum, bones of the cranium
short and irregular bone structures are comparable to the structure of the ______ bone
long
what does compact bone look like when magnified?
like a bullseye
what does spongy bone look like when magnified?
honeycomb
a flat bone can be described as a “______ sandwich”
spongy bone
what is the trabeculae of spongy bone?
the delicate beams that give spongy bone its honeycomb-like appearance
what are the types of bone cells?
- osteogenic cells
- osteoblast
- osteocyte
- osteoclast
describe an osteogenic cell
- stem cell
- will divide to produce another stem cell and to create an osteoblast
describe an osteoblast
immature bone cell that builds bone matrix, contributing collagen to matrix
describe an osteocyte
mature bone cell (osteoblasts differentiate into osteocytes), job is to maintain the bone matrix
describe an osteoclast
multinucleate cell that degrades bone matrix, motile
______ fibers are responsible for bone’s strength and flexibility
collagen
the shaft of the bone is known as the _______
diaphysis
the epiphysis is made up of more ______ bone, whereas the diaphysis is made up of more ______ bone
spongy, compact
ends of bones are called _______
epiphyses
bone stem cells come from the ______ layer and an inner layer that’s called the ______
peritoneum, endosteum
what is the periosteum?
protective connective tissue covering around the entire outside of the bone except for the very ends
describe the epiphyseal line
the part of the long bone where growth occurs
______ cartilage is on the ends of bones and is specifically known as _____
hyaline, articular cartilage
what are the two sources of bone cells?
periosteum and endosteum
describe the medullary cavity (where is it, what is it lined by)
- lined by: endosteum
- filled with yellow bone marrow, where fat storage takes place (in adults)
in adults, spongy bone is full of ______
red bone marrow
describe the structure of the epiphysis of an adult long bone
articular cartilage > compact bone > spongy bone (red bone marrow) > endosteum lining inner portion
describe the structure of the diaphysis of an adult long bone
very thick compact bone > medullary cavity (yellow bone marrow) > spongy bone marrow on inside (lined with endosteum) > periosteum on outside, bone is highly vascularized
_______ fibers are responsible for adhering the periosteum to the bone
perforating
each ring of the compact bone is called a _______
lamella/lamellae
the _______ is the structural unit of the compact bone and is responsible for the bullseye look of the bone
osteon
describe the central canal of the compact bone
- innervated
- vascularized
_________ house the osteocytes
lacunae
___________ are tiny, hair-like canals into which the osteocyte processes move and allow for each lacuna to be connected and to connect to the central canal
canaliculi
what is ossification?
the process by which the body makes bone
describe endochondral ossification
occurs during embryogenesis, bones are first made in a hyaline cartilage model
most of the bones in the body are made by ______ ossification
endochondral
what is an articulation?
the place of contact between two bones, bone and cartilage, and bone and teeth
immovable joints are known as
synarthroses
what is the range of motion of a joint?
none to extensive (some joints allow for no movement)
bones articulate at a _____
joint
joint _____ is inversely proportional to joint stability
mobility
the more mobile a joint, the _____ stable it is
less
slightly movable joints are known as
amphiarthroses
what is the least stable joint?
the shoulder joint
what is the most mobile/movable joint?
the shoulder joint
freely movable joints are known as
diarthroses
T / F : most joints are diarthroses
true!
describe fibrous joints
- no joint cavity
- joint material consists of dense regular connective tissue that joins tissue to bones
- immovable to slightly movable
describe suture joints
- found in skull
- dense regular connective tissue
- interlocking fibers
- immovable
describe gomphosis joints
- roots of teeth in sockets of mandible, maxillae
- fibrous periodontal ligaments
- immovable
describe cartilaginous joints
- no joint cavity
- joint material: cartilage joining bones
- immovable to slightly movable
Gomphoses and suture joints are examples of
fibrous joints
describe synovial joints
- joint cavity between bones
- freely movable!
pubic symphysis and intervertebral discs are examples of
cartilaginous joints, specifically fibrocartilaginous joints
T / F : most joints of the body are synovial
true!
in order to have a significant amount of movement between bones, there must be ___________ present
a joint cavity
there are ____ different kinds of synovial joints
6
the knee joint is primarily what two bones?
femur and tibia
in synovial joints, the bones are joined and enclosed by _________
a joint capsule/joint cavity that is fluid filled
describe the articular capsule
- the “sock” of the synovial joint
- continuous with the periosteum, encloses articulating bone ends
- has inner and outer portions
the more warmed up you are, the _____ the synovial fluid is
thinner
what is the inner portion of the articular capsule? describe it
- the synovial membrane
- produces synovial fluid (has lots of capillaries)
- made out of loose areolar tissue
what is the outer portion of the articular capsule? describe it/its function
strengthens, made out of the same stuff as the periosteum
what is the synovial fluid? why is it important?
- liquid within joint cavity
- lubricates the joint, shock absorbs, nourishes
_________ is the thin hyaline cartilage responsible for reducing friction between bones
articular cartilage
what is the functions of ligaments at/in a joint?
to reinforce joint capsule