ch 11.6- skeletal system

Question 1

what has an exoskeleton

Answer 1

arthropods and many invertebrates

Question 2

what makes up the endoskeleton

Answer 2

axial skeleton- central bones, skull, spinal column, and ribcage

appendicular skeleton- appendages

Question 3

long bones

Answer 3

cylindrical bones in the appendicular
skeleton that are longer than wide, are important for
support, movement, and hematopoiesis.

Question 4

what are long bones made up of

Answer 4

cortical bone (compact) and pockets of
cancellous bone (spongy).

Question 5

what are the features of long bones

Answer 5

epiphysis
diaphysis
medullary cavity
metaphysis
epiphyseal plate

Question 6

epiphysis

Answer 6

End of a long bone that forms joints
with other bones and contains red bone marrow
for hematopoiesis (blood cell synthesis).

Question 7

diaphysis

Answer 7

Long hollow shaft in center of bone.

Question 8

medullary cavity

Answer 8

Located within the diaphysis
and contains red and yellow bone marrow (area
of fat storage).

Question 9

metaphysis

Answer 9

Similar to epiphyses and found
between the medullary cavity and epiphyseal
plates.

Question 10

epiphyseal plate

Answer 10

“Growth plate” located between
epiphysis and metaphysis. Made out of cartilage
and works to lengthen the diaphysis through
growth and ossification.

Question 11

cancellous bone

Answer 11

is the spongy inner layer of bone
that soaks up red bone marrow via a web of
trabeculae (connective tissue that supports
cancellous bone).

Question 12

cortical bone

Answer 12

is the dense outer layer of bone that
supports the weight of our bodies. It is composed of
many microstructures:

osteons
haversian canals
lamellae
volkmanns canals

Question 13

osteons

Answer 13

Cortical bone functional unit,
composed of tiny multi-layered cylinders. Also
known as haversian systems because they
contain a haversian canal in their center.

Question 14

haversian canals

Answer 14

Tubes that contain blood
vessels for nutrient supply.

Question 15

lamellae

Answer 15

layers of osteon

Question 16

volkmann canals

Answer 16

Connect Haversian systems
to the periosteum.

Question 17

bone remodeling

Answer 17

is the process alternating between
ossification (bone formation) and resorption (bone
loss).

Question 18

osteoblasts

Answer 18

Build bone by secreting proteins
and utilizing blood calcium. They mature into
osteocytes after getting trapped inside the bone
matrix they create.

Question 19

osteocytes

Answer 19

Live in osteons to maintain bone.

Question 20

osteoclasts

Answer 20

Eat and resorb bone, releasing
calcium and phosphate back into the blood.
Derived from monocytes.

Question 21

PTH

Answer 21

○ Stimulates osteoclasts to increase bone
resorption, which releases calcium into the
bloodstream.
○ Increases reabsorption of calcium in the
kidneys, leading to decreased excretion in the
urine.

Question 22

calcitonin

Answer 22

○ Inhibits osteoclast activity, reducing bone
resorption and leading to decreased blood
calcium levels.
○ Decreases reabsorption of calcium in the
kidneys, leading to increased excretion in the
urine

Question 23

osteoid

Answer 23

is the organic component of bone containing
many proteins such as collagen (gives bone tensile
strength).

Question 24

hydroxyapatite

Answer 24

is the inorganic mineral component
of bone that gives the bone density and strength.

Question 25

what are the types of embryonic ossification

Answer 25

intraembranous ossification

endochondral ossificaiton

Question 26

Intramembranous ossification:

Answer 26

Bone forms
directly in sheets of embryonic connective tissue.
Osteoblasts deposit osteoid, which calcifies and
forms cortical bone. Occurs primarily for flat
bones (e.g., skull, ribs).

Question 27

Endochondral ossification:

Answer 27

An indirect process
of bone formation. A cartilage model is initially
formed. Cartilage is gradually replaced by bone
as osteoid is deposited and calcifies. Occurs for
most bones in the body, including long bones
(e.g., femur).

Question 28

fibrous connective tissue

Answer 28

● Connective tissue containing a high degree of
collagenous fibers is called fibrous connective
tissue. It is secreted and maintained by cells
called fibroblasts, with several important
functions in the body.

tendons
ligaments
periosteum
endosteum

Question 29

tendons

Answer 29

atttach muscles to bone

Question 30

ligaments

Answer 30

attach bones to other bones

Question 31

periosteum

Answer 31

Layer that surrounds cortical
(dense) bone. Provides nutrients and nervous
innervation to bone.

Question 32

endosteum

Answer 32

Layer between cortical and
spongy bone.

Question 33

cartilage

Answer 33

is a type of fibrous connective tissue
that is avascular and is not innervated by nerves.
This is distinguished from bone, which is heavily
innervated by nerves and vasculature.

Question 34

joints

Answer 34

are the meeting points between two or
more bones. Muscles run across joints and pull
the bones on either side, producing body
movement. Joints are vascularized, innervated by
nerves, and contain connective tissues.