Musculoskeletal System

Question 1

functions of the musculoskeletal system

Answer 1

to provide mechanical support and permit movement

Question 2

composition of the musculoskeletal system

Answer 2

skeletal muscle
bones
joints
tendons
ligaments

Question 3

characteristics and functions of skeletal muscles

Answer 3

responsible for voluntary movement
contractile levers connected to bone by tendons
orderly alignment
anchored to other tissues by fibrocollagenous support tissues
rich blood supply
controlled by motor neurons
striated, peripheral nuclei

Question 4

characteristics and functions of bones

Answer 4

provide mechanical support, allow locomotion, provide protection, metabolic reservoir for mineral salts (calcium)
support cells: osteoblasts and osteocytes
collagen and glycosaminoglycan matrix: osteoid
inorganic mineral salts
remodeling cells: osteoclasts

Question 5

characteristics and functions of joints

Answer 5

rigid bones attached by ligaments to form muscular contractile levers
innervated to sense position and allow voluntary movement

Question 6

characteristics and functions of tendons

Answer 6

attach some muscles to bone
made of dense collagenous tissue
low oxygen, limited blood supply
very slow to heal

Question 7

characteristics and functions of ligaments

Answer 7

join one bone to another

made of tightly packed collagen fibers

Question 8

embryological development of muscle fibers

Answer 8

skeletal muscle develops from the mesenchymal cells of the mesoderm

Question 9

bone remodeling

Answer 9

bone is constantly formed and destroyed by osteoblasts and osteoclasts
turnover is low in adults but high in children for growth as well as fracture healing

Question 10

woven bone

Answer 10

haphazard collagen fibers, mechanically weak

produced during growth or healing when osteoblasts produce osteoid rapidly

Question 11

lamellar bone

Answer 11

parallel alignment of collagen into lamellar sheets, mechanically strong
woven bone is remodeled into lamellar bone after a fracture
the majority of adult bone is lamellar

Question 12

4 main types of bone cells

Answer 12

osteoprogenitors: mesenchymaly derived bone stem cells that can differentiate into osteoblasts and osteocytes
osteoblasts: synthesize osteoid bone matrix
osteocytes: inactive osteoblasts trapped in lacunae within mineralized bone
osteoclasts: erode and remodel mineralized bone

Question 13

structure of compact bone

Answer 13

cortical
rigid outer shell that resists deformation
unit is the osteon surrounding a haversian canal, concentric osteocytes, and filament-like canaliculi

Question 14

structure of spongy bone

Answer 14

trabecular
softer, weaker and more flexible
lamellar in appearance with osteocytes but no haversian canals

Question 15

characteristics and location of hyaline cartilage

Answer 15

nose, respiratory tract, ends of ribs, articular surfaces of bones

Question 16

characteristics and location of elastic cartilage

Answer 16

external ear, epiglottis, larynx

Question 17

characteristics and location of fibrocartilage

Answer 17

intervertebral discs, knee joint, tendons attach to bone

Question 18

characteristics and location of hyaline cartilage

Answer 18

nose, respiratory tract, ends of ribs, articular surfaces of bones
chondrocytes in lacunae in isogenous groups
outer surface is covered in dense connective tissue called perichondrium

Question 19

characteristics and location of elastic cartilage

Answer 19

external ear, epiglottis, larynx
less defined isogenous groups of lacunae
perichondrium and elastic fibers

Question 20

characteristics and location of fibrocartilage

Answer 20

intervertebral discs, knee joint, tendons attach to bone
difficult to see the chondrocytes in lacunae
no perichondrium