A+P 8-9 Flashcards
articulation
place where two bones come together.
freely movable, limited, or no apparent movement
What are the three ways articulations are named
according to bones, parts united
according to only one of bones
by latin equivalent of common name
how are joints classified
fiberous, cartilege, synovial.
what are fiberous joints
synarthrosis-
have little or no movement
united by fibrous connective tissue
no joint cavity
what are the types of fiberous joints
sutures, syndesmoses, gomphoses
what are sutures
seams found between bones of the skull
What is the sutural ligament
two periostea and connective tissue
what is synostosis
fully ossified suture. two bones grow together across a joint to form a single bone
what is syndesmoses
slightly movable type of fiberous joint
bones are father apart than in suture joints
joints of mandible and maxillae
specialized
pegs fit into sockets
what is gomphoses
peridontal ligaments
keep teeth in place- connective tissue bundles between teeth and sockets
cartilegous joints
united by hyaline cartilege or fibrocartilege
what are the two types of cartilegoues joints
synchondroses
symphyses
what is synchondroses
hyaline cartilege
little or no movement
temprary
costochondral joints develop into synovial joints
what is symphyses
fibrocartilege
slightly movable
what are the six types of synovial joints
plane, saddle, hinge, pivot, ball and socket, ellipsoid.
what is the only change in the symphysis
pregnancy- becomes more stretchable
joint can relax some
joint goes back to original condition
what are the characteristics of synovial joints
synovial fluid
considerable movement
complex
most joints of the appendicular skeleton.
what is articular cartilege
smooth surface- where bones meet
what is the joint cavity
encloses articular surfaces
what is joint capsule
space around articular surfaces of bones in synovial joint
what is fiberous capsule
outer layer of joint capsule
what is synovial membrane
membrane lines inside of joint capsule
a prominent area of adipose tisse, lie between fiberous capsule and synovial membrane. cushion around joint.
what are fat pads
what are two parts of joint capsule
fiberous capsule
synovial membrane
what is bursae
pockets of synovial membrane
provides cushion between structures
what is purpose of articular discs
improve stability reduce wear on articular cartilege
what are menisci
fibrocartilaginous pads
what are tendon sheaths
synovial sacs surrond tendons
what is plane joint
two flat bonee surfaces of about equal size between which gliding motion occurs
unaxial
intervertebral
what is saddle joint
consists of two saddle shaped articulating surfaces oriented at right angle so complementary surfaces articulate
biaxial
what is ahinge joint
uniaxial
convex cylinder in one bone, corresponding concavity in the other.
what is pivot joints
unaxial. rotation around a single axis
cylindrical bony process rotating within a circle of bone and ligament
dens of axis and atlas, proximal radioulnar.
what is ball joint
multiaxial
wide range of movement
what is ellisoid joint
modified balla nd socket
articular surfaces are ellipsoid
biaxial
atlantooccipitial
what are the three types of movement3
gliding
angular
circular
what is angular movement
involve change in angle between bones in joint
what are the two types of angular movement
flexion/extension
abduction and adduction
what are the two types of flexion
hyperextension
plantar and dorsiflexion
what is hyperextension
extension of joint beyond anatomical position
what is plantar
walking o heals
what is flexion
bending movement that decreases angle of joint to bring articulating bones together
what is extension
straightening movement increase angle of joint to straighten articulating bones
what are three types of circular movement
rotational
pronation
circumduction
what is abduction
take awat from midline
what is adduction
bring toward midline
what is a rotation
turning of a structure on its long axis
what are two types of rotation
medial
lateral
what are the ypes of special movement
elevation and depression protraction and retraction excursion opposition inversion and eversion
what is elevation
moves structure superiorly or inferiorly
what is protraction
gliding motion moving structure anterioirly or posteriorly
what are two types of excursion
lateral
medial
what is opposition
thumb and finger are brought together or apart
what is inversion
turns ankles toward midline or return to AP
what is range of motion
describes the amount of mobility
what is active and passive motion influenced by
the shape of articular surfaces strength location of ligaments and tendons location of muscles associated with joint fluid or pain in and around joint use of joint
what is dislocation
occurs when articulating surfaces of bones are moved out of proper alignment
what is subluxation
partial dislocation
what is glenoid labrum
rim of fibrocartilage around the glenoid cavity.
rotator cuff
four muscles add stability to the joint
what are the three parts of the knee joint
menisci
cruciate ligaments
collateral ligaments
what is the menisci
fibrocartilage articular disks build up in the margins of the tibia and deepen the articular surface
traditionally considered a modified hinge joint but actually a complex ellipsoid joint
what is anterior cruciate ligament
prevents anterior displacement of tibia
what is posterior cruciate ligament
prevents posterior displacement
what is purpose of collateral ligaments
helps strenghen joint
what is a sprain
damaged ligaments, inflammation, swelling, pain.
what are the effects of aging on the joints
tissue repair slows rate of new blood vessels decreases articular cartilege wears down matrix becomes more rigid production of synovial fluid declines ligaments and tendons become shorter less flexiable muslces around joints weaken decreased activity
what is arthritus
inflammation of any joint
what ajre the two kind sof arthritus
osteoarthritis
rheumatoid
what is the ankle joint
talocrucal- highly modified hinge joint formed by two articulations
what is purpose of the arches of the ankle
hold bones in proper relationshiop as segments of arch and provide ties across arch
what is plantar fasciitis
inflammation of plantar fascia.
what are the functions of the muscular system
body movement maintenence of posture respiration production of body heat communication constriction of organs and vessels heart beat
what are the properties of muscles
contractility
excitability
extensibility
elasticity
contractility
muscle shortens with force or contract
excitability
respond to a stimulis
extensibility
muscle can be stretched beyond its normal resting length and still contract
elasticity
recoil to original resting lenght after stretched.
what are the three types of muscle tissue
skeletal- voluntary- locamotion, facial expression, posture, respirations
smooth- involuntary
cardiac- involuntary
what are the characteristics of smooth muscle
walls- hollow organs, blood vessels, glands skin.
some functions: propel urine, mix food, pupils, regulate blood flow
some is autorhythmic
control- endocrine and autonomic nervous systems.
what are characteristics of cardiac
heart
autorhythmic
control- endocrine and autonomic nervous systems.
what are the connective tissue layers
sarcolemma- surronds muscle cell
endomysium- also around muscle cell
perimysium- denser CT surronding group of muscle fibers
epimysium- CT that surronds whole muscle
what is fascia
connective tissue sheet
what is endomysium
delicate layer tissue that seperates individual muscle fibers within fasicle
what is epimysium
layer of dense irregular connective tissue, protein fibers gradually merge with muscular fascia.
what is muscular fascia
layers of connective tissue between adjacent muscles and between muscles and skin.
what are the characteristics of fascia
forms layer under skin hold muscles together separates them into functional groups allows free movement or muscles carries nerves, blood vessels and lymphatic continuous with tendons and periosteum
what are motor neurons
stimulate muscle fibers to contract
what are axon branches
each muscle fiber is innervated
what are myofilaments
threadlike, protein
what are sarcomeres
repeating units of myofilaments
myoblasts
fusion of several hundred embryonic cells
tropomyosin
long protein covers active binding sites on actin
troponin
binds to actin, tropomyosin, and Ca++
tropomyosin
regulates the interaction of active sites on actin
what does striated mean
alternating light and dark bands of muscle fibers
what are myosin heads
binds to active sites on actin- forms cross bridges
hinge region- bends during contraction
breaks down ATP releasing energy.
what are sacromeres
highly ordered units, structural and functional units of skelteal muslces
what is hypertrophy
enlargement
what happens in a sliding filament model
actin and myosin do not change lenght
shortening sacromeres leads to skeletal muscle contraction
relaxation- sacromeres lenghten by antagonistic muscles.
what does the nervous system do
controls muscle contractions with action potenetials
what is the membrane volatege difference across membranes
inside some cells more negative. More K+ on the inside
more Na on the outside. Na/K maintians concentrations of ions.
what are the two types of ion channels
ligand gated- neurotransmitter attackes to receptor and gate opens, Na moves into cell
voltage gated- voltage changed open gates. gates only for Na+ and gates for only K+
what are the two action potentials
depolarization- inside plasma membrane becomes less negative
repolarization- return to resting membrane potential
what is action potential
if charge reaches the membrane potential
what is propagate
spread from one location to another. action potentials does not move aong the membrane.
what is frequency of action potentials
number of action potentials per unit of time.
what are the muscle contraction factors
the amount of force in individual muscle fiber, amount of force in whole muscle.
what happens in a single contraction
each myosin myofilament undergoes cross bridge formation, movement, release in return.
what is synapse
axon terminal resting in depression of the arcolemma.
what is presynaptic terminal
axon terminal with synaptic vesicles
what is synaptic cleft
space betweeen presynaptic terminal and muscle fiber
what is postsynaptic membrane or motor end plate
muscle plasma membrane in area of junction
what are the sections of the neuromuscular junction
presynaptic
synaptic
postsynaptic
what happens in synaptic vesicles
neurotransmitter released from presynaptic terminal membrane, diffuses across synaptic cleft
it stimulates action potentials in postsynaptic membrane.
what is acetylcholinesterase
degrading enzyme in synaptic cleft
what is excitation
mechanism where action potentials causes muscle fiber contraction
what does excitation involve
sarcolemma
transverse tubules
terminal cisternae of the sarcoplasmic reticulum
Ca2+
tropomyosin complex reestablishes its position and blockes binding sites on actin.
what happens if something blockes the receptor site for acetycholine in the neuromuscular junction
myasthenia gravis
what are the results of the resting membrane potential
K+ concentration higher than outside membrane
Na+ concentration outside is higher than inside
more permeable to K+ than Na+
what do sodium potassium pumps maintain
uneven distribution of Na+ and K+ across plasma membrane
what is power stroke
movement of myosin head
what is recovery stroke
breakdown of ATP by myosin head supplies energy
what does depolarization in one action potential trigger
opening of nearby voltage gated Na+ single action potential
what is action potential frequency
number of action potentials produced in certian amount of time. can affect strenght of muslce contraction.
what is amuscle twitch
muscle contraction from stimulus that casues action potential in one or more muscle fibers.
what are the phases of muscle twitch
lag
contraction
relaxation
what is the lag phase in muscle twitch
gap between time of simulation to motor neuron and beginning of contraction.
what are motor units
a single motor neuron and all muscle fibers innervated by it.
what does size of motor units depend on
number of muscle fibers in unit.
what is all or noen principle
contraction of equal force to each action potential
what is muscle tetany
the frequency potentials increase, the frequency of contraction increases.
muscle fibers partially relax between contractions
what is imcomplete tetanus
what is complete tetanus
no relaxation between contractions
what are the types of muscle contraction
isometric
isotonic
muslce tone
what is isometric
no change in length but tension increases
what is isotonic
change in lenght but tension constant
what is muscle tone
relatively constant tension y muscles over a long time
what is treppe
stimulis frequency must allow muscle fiber to completely relax followed by another immediate stimulation
what is fatigue
decreaased capacity to work and reduced efficiency of performance
what are the types of fatigue
psychological- depends on emotional state of individual
muscular- results from ATP depletion
synaptic- occurs in NMJ due to lack of acetycholine
what is rigor mortis
rigid muscles several hours after death. CA+ leaks into sarcoplasm and attaches to myosin heads
what is creatine phosphate
during resting conditions stores energy to synthesize ATP - 10 seconds
what is anaerobic respiration
no oxygen- breakdown of glucose- lasts up to 3 seconds
what is aerobic respiration
rewuires oxygen- breakdown of glucose- lasts hours
what does a motor unit consist of
single motor neuron and all muscle fibers
what is oxygen debt
oxygen taken in by the body, above that required for resting metabolism after excersize.
what happens in a slow twitch
contract slowly, smaller in diameter, better blood supply, more mitochondria, more fatigue resitant than fast twith, large amount of myoglobin.
where is slow twitch found
postural muscles, more in lower limbs
what is fast twitch
rapid response to nervous stimulation, less blood supply, few number of mitochondria
where is fast twitch found
lower limbs in sprinter, upper limbs of most poeple.
what is hpertrophy
increase in muscle size
increase in myofibrils
increase in nuclei
increase in strenght
decrease in muscle size
what is anabolic steriods
increase muscle mass
skelatal muscle hypertrophies
what is side effect of anabolic steriods
irratability, testicular atrophy, Cv disease, liver disease
what are characteristics of smooth muscles
not straited, fibers smaller than those in skeltal muscle
spindle shaped
dense bodies
Ca2+ required to initiate contractions. binds to calmodulin.
cross bridges occurs
what are types of smooth muscles
visceral- cells in sheets function as a unit. numerous gap junctions- waves of contraction
autorythmic
multiunit- cells groups of cells act independently
sheets, bundles
what are the electrical properties of smooth muscles
slow waves of depolarization- cell to cell
does not follow all or none principle
may have pacemaker cells
contraction regulated by nervous system and hormones
what is depolarization
spontaneous diffusion of Na+ and Ca2+ into cell
what is smooth muscle regulation
receptors on plasma membrane respond not certain neurotransmitters or hormones
innerverted
neurotransmitters
hormones
what are characteristics of the cardiac muscle
only in heart each cell usually one nucleus intercalculated disksa nd gap junctions autorythmic cells action potentials have longer duration and longer refractory period Ca2+ regulates contraction
what is myopathy
degeneration of muscle cells
replaced by connective tissue
progressive
what does inflammation cause
lactic acid
what is fibrositis
reflex contraction of muscle fibers
what is effects of aging on skeletal muscle
less muscle mass
increased time for muslce to contract in response to nervous stimuli
reduced stamina
increased recovery time
loss of muscle fibers
decreased density of cappillaries in muscle
what is a joint or articulation
is place wher two bones come together
how are joints named
according to the bones or parts of bones involved
how are joints classified
structurally according to the type of connective tissue that binds them together and whether fluid is present betwene the bones.
what is fiberous joint
bones are connected by fiberous tissue with no joint cavity, and little movement
what are sutures
interdigitating bones held together by dense fiberous connective tissue.
what are syndesmoses
joints consisting of fiberous ligaments
what are gomphoses
joints in which pegs fit into sockets and are hed in place by peridontial ligaments
what is synotoses
sutures and other joints can become ossified
what are synchondroses
immovable joints in which bones are joined by hyaline cartilege
what are symphyses
slightly movable joints made of fibrocartilege
what are bursea
extensions of synovial joint cavities that protect skin, tendons, or bone from structures that could rub against them.
what is range of motion
the amount of movement, active or passive, tha can occur iat a joint
What can range of motion be affected by
several properties of the joint and surrounding tissues
what is the temporomandibular joint
complex hinge and gliding jint between the temporal and mandibular bones
what is the shoulder joint
balls and socket joint between the head of the humerous and the glenoid cavity of the scapula that permits a wide range of motion
what is elbow joint
compound hinge joint between the humerus, the ulna, and the radius.
what is the hip joint
ball and socket joint between the head of the femur and the acetabulum of the hip bone
what is flexion
bending movement that decreases the angle of the joint to bring the articulating bones closer together.
what is extensions
straightening movement that increases the angle of the joint to straighten the articulating bones
what is dorsiflexion
movement of the foot toward the shin
what is abduction
movement away from midline
what is adduction
movement towrad the midline
what is elevation
structure moves superiorly
what is depression
structure moves anteriorly
what is protraction
gliding motion that moves a structure in a anterior direction
what is retraction
gliding motion that moves a structure in a posterior direction.
what is lateral excursion
moving the mandible to either the right or left of the midline
what is medial excursion
returns the mandible to the midline position
what is opposition
movement of the thumb to touch the pinky
what are muscles responsible for
maintenance of posture, respiration, production of body heat, communication, contriction of organs and vessels, heartbeat.
what are the three types of muscle tissue
skeletal, smooth, cardiac
What is skeletal muscle responsible for
most body movements, smooth muscle found in walls of hollow oragans and tubes and moves substances through them, cardiac muscle is in the heart and pumps blood
what are the general properties of muscle tissue
contractility (shortens forcefully), excitability (respond to stimuli), extensibility (stretched and still contract), elasticity (recoilds to resting)
what is perimysium
covers connective tissue
what is epimysium
entire muscle surronded by connective tissue layer
what is a muscle fiber
a single cell consisting of a plasma membrane, cytoplasm, several nuclei, and myofibrils.
what are myofibrils
composed of two major protein fibers. actin and myosin.
what are actin fibrils
consist of a double helix of f actin, tropomyosin, and troponin.
what are myosin molecules
consist of two globular heads and a rodlike portion, constitute myosin myofilaments
when does a cross bridge form
when the myosin binds to the actin
what are sacromeres
actin and myosin
what surronds a myosin myofilament
six actin myofilaments
why do myofibrils appear straited
becuase of a bands and i bands.
what does it means when a plasma membrane is polarized
there is a charge difference, called the resting membrane potential, exist across the PM
why does the psma membrane become polarized
the tendency for K+ to diffuse out of the cell is resisted by the negative charges of ions and molecules inside the cell.
what are ion channels responsible for
membrane permeability and the resting membrane potential
what are two types of membrane potentials
ligand gated and voltage gated
what are ion channels responsible for
producing action potentials.
what is the resting membrane potential
the charge difference across the PM of cells
what is depolarization
results from an increase in the permeability of the PM to NA+
when is a all or none action potential produced
if depolarization reaches threshold
when does the depolarization phase result
many Na+ channels open in an all or none fashion.
when does repolarization phase occur
when the Na+ channels close and the K+ channels open breifly
what does a synaptic cleft seperate
the presynaptic terminal of the axon from the motor end plate of the muscle fiber.
what happens when acetylcholine is released fro the presynaptic terminal and binds to receptors of the motor end plate
changes membrane permeability and producing an action potential.
when does contraction occur
mysoin heads bind to active sites on actin, myosin changes shape, and actin is pulled past the myosin.
when does relaxation occur
when calcium is taken up by sarcoplasmic reticulum, ATP binds to myosin, and tropomyison moves back so that active sites on actin are no longer exposed to myosin.
what is ATP required for
the cycle of cross bridge ofrmation, movement, and release, transport Ca2+ into sarcoplasmic reticulum, maintain normal concentration gradients
what is a muscle twitch
the contraction of a single muscle fiber r a whole muscle in response to a stimulus.
what are the parts of a muscle twitch
lag, concentration, relaxation
what is a motor unit
one motor neuron and all the muscle fibers it controls.
when does a muscle contract with less than maximum force
if its inital lenght is shorter or longer than optimum
what are isometric contraction
cause a change in muscle tension but no change in muscle lenght
what are isotonic contractions
cause a change in muscle lenght but no change in muscle tension.
what is treppe
an increase in the force of contraction during the first few contractions of a rested muscle
what is incomplete tetanus
partial relaxation between contractions, complete tetanus is no relaxtion between contractions.
what do concentric contractions cause
muscle s to shorten and tension to increase
what do eccentric condition cause
muscle lenghten and tension to decrease gradually
what is muscle tone
the maintenance of steady tension for long periods
what are asynchronous contractions
motor units produce smooth, steady muscle contractions
what are slow twitch muscle fibers
break down ATP slowly and have a well developed blood supply, many mitochondria, and myoglobin.
what do type 2a muscle fibers have
well developed blood supply, more mitochondria, and more myoglobin.
what do type 2b muscle fibers have
large amounts of glycogen, a poor blood supply, fewer mitochondria, and little myoglobin.
what muslce fibers does anaerobic exercise develop
type 2b
what muslce fibers does aerobic exercise produce
type 1 and changed type 2b into type 2a fast twitch
where does energy for muscle contraction come from
ATP
what is fatigue
the decreased ability to do work, can be caused by the central nervous system, depletion of ATP in muscles, or depletion of acetylcholine in neuromuscular junction.
what is shape of smooth muscles
spindle shaped
What do smooth muscles contain
actin myofilaments and myosin myofilament but are not straited.
what are the two types smooth muscle
visceral and multiunit
what are visceral smooth muscle fibers
contract slowly, have gap junctions and can be autorythmic
what are multi unit smooth muscle fibers
contract rapidly in response to stimulation by neurons and function independently
what do spontaneous contractions result from
Na_ and Ca2+ leakage into cells.
what do smooth muscle contract autorythmically in response to
stretch or when stimulated by the autonomic nervous system or hormones
what is important in regulating smooth muscle
hormones
what are components of cardiac muscle
muscle fibers are straited, have a single nucleus, are connected by intercalculated disks and are capable of autorythmicacy.
