Skeletal System Flashcards Preview

MCAT Biology > Skeletal System > Flashcards

Flashcards in Skeletal System Deck (33)
Loading flashcards...
1
Q

two types of skeletons:

A

exoskeletons

endoskeletons

2
Q

exoskeletons

A

usually found in arthropods (insects)
encase whole organisms
must be shed and refrain to accommodate growth

3
Q

endoskeletons

A

found in vertebrates (humans)

are internal but are not able to protect the soft tissue structures as well as exoskeletons

4
Q

axial skeleton

A

skull, vertebral column, ribcage, and hyoid bone

provide central framework for the body

5
Q

appendicular skeleton

A

bones of limbs, pectoral girdle and pelvis

6
Q

the skeleton is created from two major components:

A

bone and cartilage

7
Q

bone strength come from

A

compact bone - both dense and strong

8
Q

spongy or cancellous bone

A

latice structure is visible under the microscope

consists of bony spicules (points) known as trabeculae

9
Q

bone marrow

A

found in the cavities between trabeculae

may be red or yellow

10
Q

Red marrow

A

filled with hematopoietic stem cells which are responsible for generation of all the cells in our blood

11
Q

Yellow marrow

A

composed primarily of fat and is relatively inactive

12
Q

long bones contain shafts called

A

diaphyses that flare to form metaphases and that terminate in epiphyses. The epiphysis contains an epiphyseal (growth) plate that causes linear growth of the bone

13
Q

bone is surrounded by a layer of connective tissue called

A

periosteum (site for muscle attachment)

14
Q

bones are attached to

A

muscles by tendons and each other by ligaments

15
Q

bone matrix

A

has both organic components like collagen, glycoprotein and other peptides and inorganic components like hydroxyapatite

16
Q

bone is organized into concentric rings called

A

lamellae around a central Haversian or Volkmann’s canal

this structural unit is called an osteon or Haversian system

17
Q

between lamellar rings are

A

lacunae

where osteocytes reside which are connected with canaliculi to allow for nutrient and waste transfer

18
Q

bone remodeling is carried out by

A

osteoblasts and osteoclasts

19
Q

osteoblasts

A

build bone

20
Q

osteoclasts

A

resorb bone

21
Q

parathyroid hormone

A

increases resorption of bone, increasing calcium and phosphate concentrations in the blood

22
Q

vitamin D

A

increases resorption of bone, leading to increased turnover and the production of stronger bone

23
Q

Calcitonin

A

increases bone formation, decreasing calcium concentrations in the blood

24
Q

cartilage is a firm elastic material secreted by

A

chondrocytes

its matrix is called chondrin

25
Q

Cartilage

A

found in areas that require more flexibility or cushioning

is avascular and is not innervated

26
Q

in fetal life, bone forms cartilage through

A

endochondral ossification

some bones form directly from undifferentiated tissue (mesenchyme) in intramembranous ossification

27
Q

joints may be classified as

A

immovable or movable

28
Q

immovable joints

A

are fused together to form sutures or similar fibrous joints

29
Q

movable joints

A

are usually strengthened by ligaments and contain a synovial capsule

30
Q

synovial fluid

A

secreted by the synovium

aids motion buy lubricating the joint

31
Q

each bone is coated with

A

articular cartilage to aid in movement and provide cushioning

32
Q

muscles that serve opposite functions come in

A

antagonistic pairs; when one muscle contracts, the other lengthens

33
Q

muscles that serve same functions :

A

synergistic