Structure and Function of the Musculoskeletal System Flashcards
the musculoskeletal system is composed of two systems that allow for mobility, what are those systems
- skeleton: bones and joints
- soft tissues: muscles, ligaments, tendons
movement is accomplished by the _____ of the skeletal muscles and _____ at the joints
contraction; rotation
name three functions of the skeletal system
- movement, supporting tissues, protection of vital organs
- site of blood cell formation (bone marrow)
- central to mineral homeostasis (bones store minerals)
name five components of bone tissue
- osteoblasts
- osteocytes
- osteoclasts
- collagen fibers
- crystallized minerals
______ are bone forming
osteoblasts
(bone is shaped according to its function)
osteoblasts become ____ that are imbedded in bone
osteocytes
____ are responsible for bone maintenance
osteocytes
osteocytes help maintain bone by doing what
signaling osteoblasts and osteoclasts to form and resorb bone
(respond to parathyroid hormone)
_____ are responsible for bone resorption/breakdown elements for transport by bloodstream
osteoclasts
osteoclasts are large, multinucleated cells containing what
lysosomes filled with hydrolytic enzymes
(lysosomes break stuff down)
_______ gives bone its tensile strength to hold itself together
collagen fibers
(developed from osteoblasts and are essential for bone strength)
collagen fibers anchor _____ to the underlying bone
articular cartilage
______ provide rigidity once mineralization occurs
crystallized minerals
___ bone is 85% of skeleton; solid and extremely strong
compact bone
compact bone is built upon the _____ system
haversian system
what does the haversian system consist of
haversian canal, lamellae, lacunae, osteocyte, canaliculi
________ bone is filled with red bone marrow (15% of skeleton)
spongy bone
spongy bone lacks the haversian system but have ______
trabeculae (plates or bars)
trabeculae maintain what
structure and function
_______: double-layered connective tissue covering all bones
periosteum
the _______ in the outer layer of the periosteum allows blood vessels to penetrate to inner bone
volkmann canals
(feeds bone tissue)
(blood supply to the bones isn’t a lot)
the _____ layer of the periosteum contains blood vessels and nerves
outer
the inner layer of the periosteum uses _____ to hold tendons and ligaments to bones
collagenous fibers
name the four types of bones in the skeletal system
long, flat, short, irregular
______: medullary cavity that contains fat (yellow marrow) in long bones
diaphysis
____________= medullary cavity that contains fat (red marrow)
metaphysis
____: known as “growth plate” allowing for growing bone length
epiphyseal plate (before puberty)
______: epiphyseal plate calcifies and merges diaphysis and metaphysis (no more growth)
epiphyseal line (after puberty)
_____ lines the medullary cavities of long bones
endosteum
flat, short, and irregular bones consist of what type of bone
spongy bone that is surrounded by compact bone
________: repair of microscopic injuries and maintenance of bone integrity
remodeling
what are the three phases of remodeling
- inflammatory phase (activation of the remodeling phase; 3-4 days)
- repair phase (lasts a few days)
- resorption/remodeling (4-6 months; bone returns to original size, shape, strength)
in the inflammatory phase of remodeling, what forms
hematoma (provides nutrients)
in the repair phase of remodeling what is formed
callus (begins phases of repairing injury)
_____: sites where two or more bones meet allowing stability and movement
joints
classification of bones is based on _______
movement
________ is an immovable joint that is often fibrous
synarthrosis
(ex. skull)
________ is a slightly movable joint that is usually cartilaginous
amphiarthrosis
(ex. symphysis pubis; moves with childbirth)
____ is a freely movable joint that is usually synovial
diarthrosis
(ex. knees, elbows, shoulders)
_____ are the most movable and complex joints
synovial
what are the four main components of synovial joints
- joint capsule/cavity
- articular cartilage
- synovial membrane
- synovial fluid
______ covers bony surfaces of synovial joints, reduces friction during movement
articular cartilage
articular cartilage has no _____ (3)
blood vessels, lymph vessels, nerves
articular cartilage is insensitive to pain and regenerates ________ after injury
slowly
_________ lines the inner surface of the joint capsule
synovial membranes
______ fills the joint cavity and lubricates the joint surface
synovial fluid
(lubricates and nourishes joint surfaces)
synovial fluid contains _______ fluid
superfiltrated blood plasma fluid
synovial fluid contains _____ that phagocytize joint debris and microorganisms
leukocytes
______: bundles of muscle fibers
fascicles
________: outermost fascicle layer & forms tendons
epimysium
_____: middle fascicle layer
perimysium
_______: inner fascicle layer that surrounds muscle fascicles
endomysium
______: fibrous tissue connecting muscle to bone
tendon
_______: contractile units of muscles fibers
sarcomeres
(functional unit of the neuromuscular system)
sarcomeres act as a single entity, contracts as a whole from stimuli; “______” response
all-or-nothing
skeletal muscle is _____ movement
voluntary
skeletal muscle is striated and extrafusal; what does extrafusal mean
generate movement and provide muscle mass development
______: motor units per muscle
innervation ratio
_______ innervation ratios: prevent fatigue and have higher endurance of muscles
higher
lower innervation rations facilitate ________ and fatigue ____ than higher innervation ratios
precision movement; easier/faster
________: primary ion channels that control calcium release in muscles
ryanodine receptors (RyRs)
RyR1
skeletal muscle
RyR2
cardiac muscle
RyR3
diaphragm, smooth muscle, brain
name the four phases of contractions
- excitation (stimuli/nerve impulse)
- coupling (building of myosin)
- contraction (motor fibers full = movement) (All-or-Nothing)
- relaxation (uncoupling and return to resting position)
______: amount of oxygen needed to convert lactic acid waste to glucose and replenish fuels
oxygen debt
what two things fuel muscle contraction
ATP, phosphocreatine
isometric contraction
- Static or holding contraction
- Muscle maintains a constant length as tension is increased
- Muscle contracts, but the limb does not move
isotonic (dynamic) muscle contraction
- Lengthening (eccentric) or shortening (concentric) contraction
- Muscle maintains a constant tension as it moves
- Muscle contracts and the limb moves
______ muscle: prime mover (contraction)
agonist muscle
_____ muscle: opposite of mover (relaxation)
antagonist muscle
main test for bone function
serum calcium and phosphorus
(also fo gait analysis or imaging studies)
name three tests of joint function
- arthrography
- arthroscopy
- synovial fluid analysis
_____ is a test of muscular function because it is increased when muscles are damaged
serum creatine kinase
_________: occurs with acute muscle damage
myoglobinuria
______: age-related loss of muscles
sarcopenia