Glossary of kt AP exam 2

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a stem cell that produces osteoblasts
immature bone cells that secrete organic components of matrix
mature bone cells that maintain the bone matrix
multinucleated cells that secrete acids and enzymes to dissolve bone matrix
interconnecting tiny arches of bone tissue found in spongy bone are called
the lining of the medullary cavity is called the
what is the organic component of the matrix in developing or repairing bone?
that carpal bones are examples of what type of bone?
short bones
the medullary cavity of bones contains
what structure allows a bone to grow in length?
epiphyseal plate
blood cell formation occurs in the
red bone marrow
what makes up two-thirds of the weight of bone?
crystals of calcium phosphate
the membrane found wrapping the bones (except at the joint cavity)
the periosteum
the basic functional unit of compact bone is the haversian system or
vitamins essential for normal adult bone maintenance and repair are
vitamins C & D
hormones that coordinate the storage, absorption, and excretion of calcium ions are
calcitonin and parathyroid hormone
the humerus is an example of what type of bone?
long bone
the parietal bone is an example of what type of bone?
the presence of an epiphyseal line indicates that
epiphyseal growth has ended
the primary reason osteoporosis accelerates after menopause in women is
reduced levels of circulating estrogens
the nonpathologic loss of bone that occurs with aging is
how many bones are there?
what are the 2 skeletons?
axial and appendicular
what is the axial skeleton?
everything down the middle
what is the appendicular skeleton?
sasamoid bones form where?
what are sutural bones?
form between flat bones of the skull, borders are like a puzzle piece
what are the main functions of the bones? (5)
support, protection, movement, mineral storage, blood cell formation
what are the 2 kinds of bone textures?
compact and spongy
what is osteomalacia?
what happens to the osteoid in ricketts?
formed but not calcified
what happens in ricketts?
bones become softened and often bend because there is a calcium/vitamin D deficiency
what is osteoporosis
reabsorption faster than its being replaced
what is paget's disease?
excessive osteoblast and osteoclast activity; woven bone that's taking up more space (can cause deformation like protrusion of the forehead)
what is a nondisplaced fracture?
retains normal alignment
what is a displaced fracture?
bone ends don't match up
what is a complete break?
all the way through the bone
what is an incomplete break?
break doesn't go through the bone
what is a green stick fracture?
often in kids, incomplete fracture
if a broken bone penetrates the skin it is
open or compound
if a bone breaks but doesn't penetrate the skin, it is
closed or simple
what is a closed reduction for?
a simple fracture - when you manipulate outside the skin
what is an open reduction?
involves surgery-needs to be put back into place with pins or plates
what are the stages of healing of a bone fracture? (4)
hematoma formation, fibrocartilaginous callus formation, bony callus formation, bone remodeling
osteomilitus is
infection/inflammation of the bone
osteocarcoma is
bone cancer
bone cancer is most common in what age group?
10-25 years old
what is a pathological fracture?
fracture because of a disease
what is a hematoma?
large blood clot
why does a hemotoma form in a bone fracture?
to block the osteoclasts from getting what they need and killing them so it stops eating the bone
what is a fibrocartilaginous callus formation?
an internal callus forms and the external callus stabilizes the outer edge
bony callus formation produces what?
spongy bone and unites broken ends
what are bones stronger after you break them?
there is extra material
what is the diaphysis?
shaft of the bone
spongy bone filled with red marrow is called
an epiphyseal line indicates what?
where the growth plate had been but has calcified over
what is articular cartilage?
where 2 bones are coming together
what covers articular cartilage?
hyaline cartilage
what are the 3 functions of the periosteum?
isolates the bone, provides route for blood vessels and nerves, assists in repair
what kind of tissue is the periosteum?
dense irregular connective tissue
what does the fibrous layer of the periosteum do?
helps keep everything together and keeps periosteum attached
what produces new osteoblasts?
osteoprogenitor cell
the periosteum secures the bone to the
true or false: osteoblasts divide
the endosteum contains what?
osteoblasts and osteoclasts
the marrow cavity of a long bone contains what marrow?
yellow marrow for fat storage
is the endosteum complete or incomplete?
short, irregular and flat bones have an outer layer of ______ and an inner layer of _______
compact bone; spongy bone
what is diploe?
the inner layer of spongy bone
what is the diploe covered by?
what does hematopoietic tissue do?
grows red blood cells
where is the hematopoietic tissue in bones in infants?
medullary cavity and all areas of spongy bone
what is the lamellae?
one right within the osteon made of collagen fibers that has been calcified
what is the central haversian canal?
opening in the middle for blood vessels, nerve fibers, lymphatic vessels
what are perforating canals?
bring blood cells to central canal; connects the central canal to periosteum
what are osteocytes?
mature bone cells located in their own lacunae pockets
what are lacunae?
pockets that contain osteocytes
what are canaliculi
tiny canals that penetrate the lamellae and connect the lacunae with each other
spongy bone does not form via
what is trabeculae?
meshwork, the framework of spongy bone
osteoblasts form _____, osteoblasts become ______
osteoids, osteocytes
the plasma membrane of skeletal muscle is
the storage and release site for calcium ions is
sarcoplasmic reticulum
the region of the sarcomere containing thick filaments is the
A band
each skeletal muscle fiber is controlled by a motor neuron at a single
neuromuscular junction
receptors for acetylcholine are located on the
motor end plate
at rest, active sites on the actin are blocked by
tropomyosin molecules
the narrow space between the synaptic terminal and the muscle fiber is
synaptic cleft
what are the 3 kinds of muscle tissue?
skeletal, cardiac, smooth
what is skeletal muscle?
striated, multi-nucleated; voluntary
cardiac muscle has how many nuclei?
where is smooth muscle found?
walls of hollow organs
is smooth muscle non-striated?
what are the skeletal muscle functions? (6)
produce movement, maintain posture, support soft tissue, generate heat, guard entrances and exits, store nutrient reserves
what are contractile muscles made of?
what is wrapped around each individual muscle cell?
a muscle cell is also called a
muscle fiber
endomysium contain
capillary beds and myosatellite cells
myosatellite cells are what
stem cells that assist in repairing damaged muscle fibers
what is the perimysium
collagen and elastic fibers that surround a bundle of muscle fibers called a fascicle
is the perimysium the inner or outer layer of bone?
what is a fascicle?
a bundle of muscle fibers
what is the origin attachment?
bone not moving
what is the insertion attachment
bone moving a lot
what is a direct attachment?
epimysium fused to perimysium; muscle to bone (ribs)
what is an indirect attachment?
connective tissue wrappings extend beyond the fiber of the muscle and connect to other muscles - form tendon or aponerurosis to connect
what is an aponerurosis?
indirect attachment - connects like a sheet of connective tissue
what is the blood supply like in skeletal muscle tissue?
capillary bes are long and winding and cross-linked
osteogenesis is
bone development
what is the blueprint for your bones?
what are dermal bones?
bones right under your skin (skull, clavicle)
dermal bones use what kind of ossification?
what happens during intramembraneous ossification?
1. ossification center appears in fibrous CT membrane
2. formation of bone matrix (osteoid) within CT membrane
3. formation of woven bone and the periosteum
4. rearrangement of bone

_______ cells are stem cells that become ________
messenchimal cells; osteoblasts
all bones below the skull (except the clavicle) use this method of ossification
how many ossification centers do long bones have?
where does growth of long bone occur?
epiphyseal plates
what is oppositional growth?
the bone gets more hollow as it gets wider
why are bones hollow?
to reduce the weight
gigantism has excess:
growth hormone
thyroid hormones stimulate what?
metabolism and osteoblast activity
what does testosterone do to bones at puberty?
cause epiphyseal closure and cause huge initial growth spurt
what does estrogen do to bones at puberty?
epiphyseal closure and growth spurt but growth spurt is faster in girls
what vitamin does osteoblasts and osteoclasts need to remodel bone?
vitamin A
what does bone desposition entail?
laying down and depositing material
how does bone deposition?
1. amino acids, vitamins, calcium, phosphorus, magnesium from the diet are used
2. osteoblasts form osteoid by laying down collagen fibers and ground substance
3. calcium salts crystalize within the osteod to become hardened

what occurs during bone resorption?
1. osteoclasts degrade the osteoid by dissolving collagen fibers
2. calcium salts are converted into their ionic forms and reabsorbed into the bloodstream
what are the 5 reasons it's important to regulate calcium?
1. nerve impulse transmission
2. muscle contractions
3. blood coagulations
4. secretions by glands
5. involved in cell division

parathyroid hormone is released when?
if there is a DECREASE in calcium ion concentration in the blood
calcitonin is released when:
there is an INCREASE of calcium in the blood
what does the parathyroid hormone do to bone?
stimulates osteoclasts to degrade bone and release calcium ions into the blood to raise the blood calcium level
what does calcitonin do to the bone?
secreted by the thyroid gland, inhibits osteoclast activity and stimulates bone deposition which removes calcium from the blood, lowers the calcium level because it gets absorbed by the kidney and GI
what is wolf's law?
a bone will deposit bone tissue in proportion to the mechanical stresses placed on the bone (ex: a parapalegic will have very small leg bones but a huge upper body)
what is an example of a flat bone?
sternum, rips, scapulae
what is an example of an irregular bone?
spinal vertebrae, pelvis
what is an example of a sesamoid bone?
patella, near joints of hands and feet
the vitamins essential for normal bone maintenance and repair are:
vitamins A & D
what is the primary reason that osteoporosis accelerates after menopause?
decrease in estrogen hormone
the command to contract is distributed deep into a muscle fiber by the
transverse tubules
the connective tissue coverings of a skeletal muscle (from superficial to deep) are:
epimysium, perimysium, endomysium
the detachment of the myosin cross-bridges is directly triggered by
hydrolysis of ATP
a muscle producing near-peak tension during rapid cycles of contraction and relaxation is said to be in
incomplete tetanus
the type of contraction in which the tension rises, but the load does not move is
an isometric contraction
an action potential can travel quickly from one cardiac muscle cell to another because of the presence of:
gap junctions and intercalated discs
parasitic round worm from pork that infects muscle tissue and causes soreness
musculo-skeletal pain and fatigue
muscular dystrophies
genetically inherited muscle disease, characterized by progressive degenerative muscle
what is duchenne's md?
most common childhood MD, carried on X chromosome, more prevalent in males; excessive calcium ions in sarcolemma damages the cell and kills it
which muscle fiber has no t-tubules, myofibrils or sarcomeres?
is the smooth muscle striated?
which muscle cell has an intercalated disc that allows action potential to move from one to another?
which muscle cell requires no neural stimulation?
which muscle cell has plasticity?
smooth muscle
T/F: the skeletal muscle is striated
what are the 6 major skeletal muscle functions?
1. movement
2. posture
3. support soft tissue
4. generate heat
5. guard entrances and exits
6. store nutrient reserves

the inner most CT wrapped around an individual muscle cell
stem cells that assist in repairing damaged muscle fibers
myosatellite cells
collage and elastic fibers that surround a bundle of muscle fibers called a fascicle
bundle of muscle fibers
outer layer made of dense irregular tissue surround entire muscle
where does muscle nerve and blood supply come from
perimysium and epimyseium
origin is where the bone:
moves or does not move?
does NOT move
insertion is where the bone: moves or does not moves?
what are direct muscle attachments?
epimysium is fused to perimysium; muscle and bone are fused together; RIBS
what are 2 types of indirect attachments?
tendons and aponerurosis
what are indirect attachments made of?
attach muscle to bone; CT wrappings extend beyond the fiber of the muscle and connect it to the bone
what is the cell membrane of a skeletal muscle fiber?
these are found in the sarcolemma and help electrical impulses travel
this is the cytoplasm of a skeletal muscle cell
what 2 things are found in the sarcoplasm?
myoglobin and glycogen
myoglobin is:
oxygen-binding protein, red pigment
what makes our meat look red?
glycogen is:
stored sugar; stored in glycozomes
each muscle fiber has hundreds to thousands of these in them
what is a sarcomere?
functioning unit of a myofibril made of thick and thin filaments, bound by z-lines
what are myofilaments?
thick or thin
a thick filament is made of
500 myosin molecules
what does a thick filament do?
forms a cross-bridge with the active site on actin
what are thin filaments composed of?
actin molecules, tropomyosin molecules, toponin molecules, z lines
why do skeletal and cardiac muscle have striations?
thick and thin filament organization
what are actin molecules?
G actin is strung together and twisted to form F actin. On each G actin there is an active site
what does a tropomyosin molecule do?
covers the active site; long, double-stranded protein covers it when it's at rest
what does a troponin molecule do?
3 polypeptide complex with 3 binding sites
what do the 3 binding sites of troponin do?
1st: binds to tropomyosin to form the troponin-tropomyosin complex
2nd: binds to actin
3rd: binds to calcium ions (when NEEDED, NOT @ rest)

what are z-lines?
boundary of the sarcomere; the thin filament goes to a z-line
what are A bands?
darker striations that contain thick filaments
what is within the A band?
m-line, h-zone, zone overlap
What are M-lines?
@ the middle of the A-band
what is the H-zone?
lighter middle area of A-band; thick filament only
what is the zone overlap?
where the thick and thin filaments overlap
what are I bands?
repeating series of light bands made of thin filaments that cross the boundary of the sarcomere over the z-line
what is the smooth ER in a skeletal muscle cell?
sarcoplasmic reticulum
what does the SR contain?
terminal cisternae
what are terminal cisternae?
large, perpendicular pairs of channels occur at the A-I junction
what are t-tubules?
wrap around myofibrils at the A-I junction
what is the role of the SR?
to regulate calcium ion concentration in the cytoplasm and store and release ions on demand
what is a triad?
2 terminal cisternae and a t-tubule
what is the sliding filament theory?
says thin filaments must be sliding closer together during a contraction and the H zone gets smaller
what 2 things does a myosin head bind to?
actin and ATP
does relaxing a muscle take energy?
NO - it is a PASSIVE process
what are the 5 steps to the contraction cycle of the SFT?
1. calcium ions enter sarcoplasm, bind to troponin and cause the troponin-tropomyocin complex to pull off active sites
2. cross bridge attachment - myosin head binds to the active site on actin to form a bridge (moves upwards in diagram)
3. the power stroke of the myocin head that causes sliding of thin filaments inward and new ATP comes
4. cross bridge detachment - ATP has attached to myocin head and causes cross bridge to detach, thin filaments go back
5. cocking of the myosin head - actin's active site allows it again to get ready to repeat the process

what is hydrolysis?
ATP into ADP + P
as you are contracting your muscle, your H zone will get:
what is rigor mortis?
when muscles contract after death; ATP is no longer produced and cross bridge detachment can't happen/myosin heads cannot be released
his is the sac-like region of the SR that serves as specialized reservoirs of calcium ions
terminal cisternae
this an invagination of the sarcolemma that projects deep into the muscle cell's interior
what is the purpose of the NMJ?
communication point between the nervous system and the muscular system
each muscle fiber is controlled by 1
where is the NMJ usually found?
midway between each muscle fiber
the synaptic terminal is part of what
nervous system
the portion of the sarcolemma under the synaptic terminal that contains lots of ACh receptors is
motor end plate
what is ACh?
the messenger; a chemical released by a neuron that changes the membrane of another cell and allows a message to pass
where is ACh stored?
synaptic vesicles
what is the series of events that occurs at the neuromuscular junction?
1. synaptic vesicles release ACh
2. ACh changes the transmembrane potential, creating an action potential along the entire surface of the sarcolemma and t-tubules
3. SR releases calcium ions
4. Calcium binds to troponin-topomyosin complex, starts contraction
5. action potential ceases as AChE breaks down ACh (when we release contraction)
6. SR reabsorbs calcium ions
7. Active sites covered back up
8. muscle relaxes

what is botulism?
nerve toxin produced by bacteria to prevent the release of ACh; muscles can't move
what is myasthenia gravis?
autoimmune disorder; ACh receptors sites are attacked and destroyed - leads to inability to contract muscles
what is action potential?
the regulation of movement; moving transmembrane potential that is constantly changing
when action potential arrives at the NMJ, what happens?
ACh is released
what causes the terminal cisternae to release calcium?
action potential traveling through t-tubule
tension is:
forces exerted by a contracting muscle on an object
load is:
opposing force exerted on a muscle by the weight of an object
if tension overcomes load, what happens?
movement occurs
what is a length tension relationship?
tension a muscle can generate when it's at different lengths
what is the all-or-none principle?
when a motor neuron fires and sends action potential, all the fibers in that unit contract
what are the 3 parts of a twitch?
single stimulation, contraction, relaxation
what occurs in a latent period of a twitch?
beings at stimulation, no tension, everything that happens BEFORE myosin head pivots
what happens during the contraction phase?
myosin head pivots, new cross bridge attachment, sarcomere shortens, tension and contraction builds
what happens during the relaxation phase?
action potential is gone, calcium back into the SR, active sites are covered, tension falls
wave summation is:
addition of one twitch to another before relaxation period is complete
what is tetanus?
fused twitch together; incomplete and complete
incomplete tetanus:
muscle producing near peak tension during rapid cycles of contractions
complete tetanus:
increasing rate of stimulation until there is no relaxation period
stimuli immediately after relaxation
what does multiple motor unit summation of recruitment do?
affects the force of the contraction (ex: how hard you clap)
which motor units will be used first?
smaller ones - they are slower to contract and respond to weaker CNS stimulus
once an action potential reaches the sarcolemma, which motor units are used?
fast/large ones
what does asynchronous motor unit summation do?
sustain muscle activity for a long period of time because they're not recruited at the same time (you use up one, then another) ex: holding your head up
muscle tone allows us to do what?
be upright
are some muscle units always active?
YES - keeps us upright
what are the 2 types of muscle contractions?
isotonicc and isometric
what is an isotonic contraction?
tension increases and skeletal muscle length changes
the two types of isotonic contractions are:
concentric and eccentric
a concentric contraction is:
peak tension exceeds the load - muscle shortens (bicep curls)
an eccentric contraction is:
peak tension is less than the load; muscle elongates and extends (like tug of war with a car)
an isometric contraction is:
muscle as a whole does not change length because the tension produced doesn't exceed the load (ex: trying to lift a weight that is too heavy)
during anaerobic glycolysis, glucose will break into:
pyruvic acid (2) and ATP (2)
excess pyruvic acid is converted into:
lactic acid
we experience muscle fatigue when the muscle can no longer
what does lactic acid do to a muscle cells?
decreases the pH in sarcoplasm and prevents calcium bonding
during the recovery period of muscle fatigue, what happens to lactic acid?
it's recycled or released to liver and turns it back into ATP
what is a fast fiber type?
contracts quickly, fatigues quickly; white fibers
what are slow muscle fibers?
dark/red; used when you need long periods of contraction and are slower to contract, slower to fatigue
what is an intermediate fiber?
looks like a fast fiber, but it has a more extensive capillary bed than a fast fiber and is more resistant to fatigue
what is muscle hypertrophy?
repeated exhaustive stimulation of muscle fibers will increase the number of mitochondria, glycogen storage, myofibrils and filaments within the myofibrils (body building) - you increase the diameter of cell size
anaerobic exercise training is:
frequent, brief, intense workouts
aerobic exercise is:
warm-up to get blood flow to myofibrils, low level exercises
can atrophy be reversed?
yes, as long as the muscle fiber doesn't die.
is glycolysis aerobic?
is the kreb's cycle aerobic?

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