osteology

Question 1

what is the function of bones/skeletal sys

Answer 1

1- support and protect soft tissues
2- to allow movement thru interaction w muscles to form a system of levers.
3- to produce blood cells
4- to store calcium, phosphorus, and other salts

Question 2

explain what compact bone is, where it is located, and its purpose

Answer 2

compact bone is the dense hard outer surface or cortex of bone.
it is found in the shaft of long bones.
helps to protect and uphold weight.

Question 3

explain what cancellous bone is, where it is located, and its purpose

Answer 3

it is the spongy interior of bone containng trabeculae.
it is located on the interior of compact bone.
in the axial skel it contains red and yellow bone marrow, and in the appendicular skel it contains yellow bone marrow.
trabeculae run many ways to ensure strength

Question 4

what is ossification

Answer 4

the formation of bone from CT

Question 5

what is intramembranous ossification? where does it occur?

Answer 5

oss within a fibrous mem in embryo.
occurs in- skull, facial bone, and shafts of clavicles

Question 6

what is endochondral ossification? where does it occur?

Answer 6

oss within hyaline cart in embryo.
occurs in- short, irregular, and long bones in 2 distinct centres called primary and secondary centres of oss

Question 7

how are bones classified

Answer 7

by long, short, flat, irrgeular, and sesamoid bones

Question 8

what is a short bone? give examples

Answer 8

cuboidal bone made mostly of cancellous. they are string and dont move lots
carpal and tarsal bones

Question 9

what is a long bone? give examples

Answer 9

has a body/shaft with 2 expanded ends that provide area for articulation and musc attachment
humerus and femur

Question 10

what is an irregular bone? give examples

Answer 10

bone shapes that dont fit into other categories.
vertebrae and facial bones

Question 11

what are flate bones? give examples

Answer 11

flat compact bone plates w spongy in middle that has red bone marrow.
found where protection is needed like in skull or sternum

Question 12

what are sesamoid bones? give examples

Answer 12

small bones inside tendons near joonts to prevent wear on a tendon and bear weight.
thumb and big toe

Question 13

how many bones are in the skeletal system?

Answer 13

206 separate bones

Question 14

what is cartilage

Answer 14

resilient, semi rigid for of CT that forms parts of skeletal sys where flexibility is needed. it is avascular so cells obtain nutrients and oxygen by diffusion.

Question 15

when does cartilage become bone

Answer 15

when blood flow is gained

Question 16

what is the difference between bone and cartilage

Answer 16

bone is a living struture. bone is vascular CT and it regenerates itself

Question 17

what is the axial skeleton

Answer 17

supports and protects the head and trunk with 80 bones

Question 18

what is the appendicular skeleton

Answer 18

allows body to move in various positions with 126 bones

Question 19

what is a central haversian canal

Answer 19

contains blood, lymph vessels, and nerves

Question 20

what are lamellae

Answer 20

concentric rings around haversian canal

Question 21

what are lacunae

Answer 21

spaces between lamellae that contain osteocytes

Question 22

what are canaliculi

Answer 22

channels carrying nutrient fluid , which connect the lacunae

Question 23

what is the volkmanns canal

Answer 23

transvere channels that join the various canals

Question 24

what is the periosteum? what is its functions?

Answer 24

vascular membrane that surrounds and adheres to bone except at articulating surfaces.
it has an outer layer (collagen) and inner layer (osteocytes)
func- protect, attachment for musc and ligamens, allows blood supply, and forms new bone tissue

Question 25

what is hyaline cartilage

Answer 25

transparent cart found on joint surfaces that covers ends of bones to prevent erosion and rubbing

Question 26

what is red bone marrow

Answer 26

centre for haemopoiesis (productions of blood cells) at ends of long bones, sternum, ribs, and pelvis

Question 27

what is yellow bone marrow

Answer 27

stores fat cells found in medullary cavity of long bones

Question 28

what are membranous gaps called at birth

Answer 28

fontanels

Question 29

what is the primary centre of ossification

Answer 29

aka diaphysis. appears in the middle of the bone and becomes the body.

Question 30

what are osteoblasts and osteoclasts?

Answer 30

1- build bone by laying down fibers, matrix, and calcium 2- destroy bone and form medullary cananls and sinuses. destroys bone to make stringer, lighter, and thinner

Question 31

what are osteocytes

Answer 31

mature bone cells that maintain bone tissue and turns into lacunae

Question 32

what is the secondary ossification centre?

Answer 32

aka epiphysis appears at the ends of long bones after birth.

Question 33

when does ossification stop

Answer 33

when all cart is replaced by bone and 2 centres fuse together, around age 21

Question 34

what is the epiphyseal plates?

Answer 34

cartilage plates found between diaphysis and each epiphysis. during childhood this is where growth occurs at the side of each plate closest to the shaft called the metaphysis