Anatomy and Physiology Bone Muscle Lecture Test
Heat Production During Muscle Activity
~ 40% of the energy released in muscle activity is useful as work Remaining energy (60%) given off as heat Dangerous heat levels are prevented by radiation of heat from the skin and sweating
dorsiflexion
bending of the foot or the toes upward
plantar flexion
bending of the sole of the foot by curling the toes toward the ground
Wolff's Law
bone grows or remodels in response to the demands placed on it
inversion
Turning the sole of the foot inward
Effort
the applied force used to move a resistance
appositional growth
"growth from outside"- cartilage forming cells in surrounding perichondrium secrete new matrix against the external face of existing cartilage tissue
intersitial lamellae
- Incomplete lamellae lying between intact osteons - Fill gaps between forming osteons or are remnants of osteons that have been cut through by bone remodeling
3 steps process in generation and propagation of an action potential
- depolarization and generation - action potential is propagated - repolarization
aerobic respiration
95% of ATP used for muscle activity during rest and light to moderate exercise
Actin
A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.
Troponin
A protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the interaction of actin and myosin and that when combined with calcium ions permits muscular contraction
Myosin
A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber
lever
A rigid bar that is free to move around a fixed point
cocking of myosin head
As ATP is hydrolyzed to ADP and Pi, the myosin head returns to its prestroke high-energy, or "cocked" position
cross bride detachment
As a new ATP molecule binds to the myosin head, myosin holds on actin looses and bridge detached from actin
cardiac muscle
Beating of cardiac Muscle
closed
Bone ends are coaxed together by doctor
open
Bone ends are surgically wired or pinned together
thick filaments
Central, extends the entire length of A band Myosin
Perimysium
Connective tissue surrounding a fascicle
Endomysium
Connective tissue surrounding a muscle fiber
flexion
Decreases the angle of a joint
Alkaline phosphatase
Enzyme shed by osteoblasts, essential for mineralization and part of matrix proteins that bind and concentrate calcium
thin filaments
Extends across the I band and partway into the A band Actin Z disc coin shape - Composed of Nebulin
Osteon
Groups of hollow tubes of bone matrix
regulating proteins
Help control the myosin actin interactions involved in contractions
blood cell formation
Hematopoiesis occurs in marrow cavities of certain bones
Control of Remodeling
Hormonal mechanisms that maintain calcium homeostasis in the blood Mechanical and gravitational forces
Linear
If the break is parallel to the long axis
Transverse
If the break is perpendicular to the bones long axis
hinge joint
Joint between bones (as at the elbow or knee) that permits motion in only one plane
terminal cisternae
Large perpendicular cross channels at the A band and I band junction
spongy bone
Layer of bone tissue having many small spaces and found just inside the layer of compact bone.
Lamella
Layers of bone matrix
calcification front
Located between osteoid seam and older mineralized bone
Skeletal
Locomotion or Manipulation
compact bone
Looks solid and dense but riddled with passageways that serve as conduit for nerves, blood vessels and lymphatic
abduction
Movement away from the midline of the body
opposition
Movement of the thumb to touch the fingertips
adduction
Movement toward the midline of the body
indirect
Muscle CT wrapping extend beyond the muscle
bone deposit
Occurs where bone is injured or added strength is needed; Requires a diet rich in protein; vitamins C, D, and A; calcium; phosphorus; magnesium; and manganese
muscle fiber contraction
Once myosin binding sites on actin are exposed 4 events occur
condyloid joint
Oval articular surface of one bone fits into a complementary depression in another ex. knuckles
Smooth
Propels or squeeze substances through organs and along a tract
muscle metabolism
Providing energy for contraction
incomplete tetanus
Quivering contraction due to stimulus coming at faster rates so that the relaxation phase between the twitches are shorter
Fibrocartilagenous callus formation
Restructure, Splints the bone, formation of soft granulation tissue (Callus)
Movement
Skeletal muscles which attach to bones by tendons use bones as levers to move the body
synaptic cleft
Space separating axonal ending and muscle fibers
Haversian system or Osteon System
Structural unit of bone
support
Supports the body and cradles it's soft organs
bone remodeling
The continuous turnover of bone matrix and mineral that involves first, an increase in resorption and osteoclast activity, and later, reactive bone formation by osteoblast activity.
fulcrum
The fixed point around which a lever pivots
protection
The fused bones of the skull protect the brain.
Depolarization
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.
Osteiod seam
Unmineralized band of gauzy-looking bone matrix
origin
When muscle contracts the insertion moves toward the origin
hematoma formation
a mass of clotted blood, forms at the fracture site
motor unit
a motor neuron and its associated muscle fibers
primary ossification center
a region where bone tissue will replace most of the cartilage (Hyaline)
Tropomyosin
a rod-shaped protein, spiral about the actin core and help stiffen and stabilize it
Stored ATP
a small amount of ATP is stored in muscles -used for first few seconds of exercise
Elasticity
ability of a muscle fiber to recoil and resume its resting length after being stretched
Excitability (irritability)
ability to receive and respond to stimuli
Contractility
ability to shorten forcibly when stimulated
medial rotation
anterior surface moves toward midline
Bone repair
blood clot formation, fibrocartilage callus, bony callus, bone remodeling
intramembranous ossification
bone develops from a fibrous membrane (Cranial Bones of the skull- Frontal Parietal Occipital Temporal)
displaced fracture
bone ends are out of normal alignment
nondisplaced fracture
bone ends retain their normal position
Osteoblasts
bone forming cells
lever system
bone-muscle relationship
bony callus formation
bony tissue fills the area, creating a hard callus
Osteoclasts
break down bone matrix
closed (simple) fracture
break that does not penetrate the skin
complete fracture
broken all the way through
open (compound) fracture
broken bone penetrates through the skin
Fascicle
bundle of muscle fibers
elastic filaments
composed of the protein Titin which anchors the Thick Filaments
Bone Homeostasis
consists of bone remodeling and bone repair. (Recycle 5-7% of our bone mass every week)
Haversian canal
contains small blood vessels & nerve fibers
generating heat
contracting muscle produces heat shivering increases heat production
period of contraction
cross bridges are active, from the onset to the peak of tension development, and the myogram tracing rises to a peak
second class lever
effort is applied at one end of the lever and the fulcrum is located at the other, with the load between them (ex: wheelbarrel)
third class lever
effort is between the fulcrum and the resistance
tendon sheath
elongated bursa that wraps completely around a tendon
T tubules
elongated tube; formed by the cell interior in sarcolemma of cell muscle that protrudes deep into cell interior; increase muscle fibers surface area
direct (fleshy) attachment
epimysium fused to periosteum of bone or perichondrium of cartilage
Myofilaments
filaments of myofibrils, constructed from proteins, principally myosin or actin
hormonal regulation
growth hormone, thyroid hormone, testosterone and estrogen, PTH, and calcitonin
postnatal bone growth
growth in length of long bones
cross bridge formation
high-energy myosin head attaches to actin thin filament active site
connective tissue sheaths
hold together and wrap around individual muscle fibers; support each cell and reinforce the muscle as a whole ( Endomysium, perimysium, fascicles, Epimysium)
extension
increases the angle of a joint
period of relaxation
initiated by reentry of Ca in the SR
intersitial growth
lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within
Volkmann's canals
lie at right angles to the long axis of the bone and connect the blood and nerve supply of the medullary cavity to the central canals
Elevation
lifting a body part superiorly
circumferential lamellae
located deep to periosteum and superficial to endosteum and extend around entire circumference of the diaphysis and resist twisting of long bone
Osteocytes
mature bone cells
Insertion
movable bone
circumduction
movement of a limb so that it describes a cone in space
protraction
moving a body part forward
Depression
moving a body part inferiorly
depression
moving a body part inferiorly
retraction
moving a part backward
eccentric
muscle contractions lengthen
concentric
muscle shortens and does work
isotonic contraction
muscles contract and shorten
working stroke
myosin head pivots and pulls thin filament toward M line
complete tetanus
no relaxation between contractions
Protraction
nonangular anterior movements in a transverse plane
Retraction
nonangular posterior movement in a transverse plane
incomplete fracture
not broken all the way through
Epimysium
overcoat of dense irregular connective tissue that surrounds the whole muscle
weeping lubrication
pressure on joints squeezes synovial fluid into and out of articular cartilage
endochondral ossification
process in which bone forms by replacing hyaline cartilage
collagen fibers
provides flexibility and strength
elevation
raising a body part superiorly
reduction
realignment of broken bone ends
Sacromere
region between two successive Z discs Contains A band and 1/2 i band Functional unit of skeletal muscle
neuromuscular junction
region where a motor neuron comes into close contact with a skeletal muscle cell
Striations
repeating series of dark and light bands
mineral storage
reservoir for minerals, especially calcium and phosphorus
load
resistance
maintain posture
skeletal muscles maintain constant tone
Myofibrils
rodlike and run parallel to length of muscle fibers
pivot joint
rotating bone turns around an axis; ex. connection between radius/ulna and humerus
lateral rotation
rotation away from the midline
Pronation
rotation of the hands and forearms so that the palms face downward
Supination
rotation of the hands and forearms so that the palms face upward
medial rotation
rotational movement towards the midline
plane joint
short slipping or gliding movements; ex. carpals
gliding movements (translation)
simplest joint movement since a flat bone moves or slips over another
synaptic vesicles
small membranous sacs containing neurotransmitter
Inversion
sole of foot inward
Eversion
sole of foot turns laterally
sacroplasmic reticulum
specialized smooth endoplasmic reticulum, releases calcium on demand when the muscle fiber is stimulated to contract
ball and socket joint
spherical head of one bone fits into a round socket in another ex. shoulder, hip
Treppe
stepwise increase in contraction tension
maximal stimulus
strongest stimulus that increases contractile force
Extensibility
the ability to be stretched or extended
oxygen debt
the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose
bone resorption
the breakdown of bone extracellular matrix by osteoclasts that is part of the normal development, maintenance, and repair of bone tissue
first class lever
the effort is applied at one end of the lever and the load is at the other, with the fulcrum somewhere between
Acetylcholinesterase
the enzyme that breaks down acetylcholine in the synaptic cleft (located neuromuscular junction )
Triads
the grouping of one T-tubule and two terminal cisternae
muscle fatigue
the physiological inability of a muscle to contract
Repolarization
the process of restoring the normal resting membrane potential after depolarization
muscle twitch
the response of a muscle to a single brief threshold stimulus
muscle tone
the state of balanced muscle tension muscle tendons that cross the joint are the most important stabilizing factor
threshold stimulus
the stimulus at which the first observable contraction occurs
isometric contraction
the tension generated is not enough to exceed the resistance of the object to be moved, and the muscle does not change its length
wave summation
this occurs when a second stimulus is received before the muscle fiber has relaxed, creating a second contraction that is stronger than the first
latent period
time between stimulus and contraction
motor end plate
troughlike part of the muscle fiber's sarcolemma that helps form the neuromuscular junction
pronation
turning the palm downward
supination
turning the palm upward
eversion
turning the sole of the foot outward
saddle joint
type of joint found at the base of each thumb; allows grasping and rotation
graded muscle responses
variations in the degree of muscle contraction by changing either the frequency or strength of the stimulus