Musch/ Wangemann Test Flashcards
Sacromere??
- contractile units in myofibrils
- defined as z-line to z-line
Myofibrils??
contained within each muscle cell
What surrounds each muscle fiber?
endomysium
What is a fasiculi??
bundle of muscle fibers
What surrounds a fasiculus??
perimysium
What surrounds the whole muscle and coalesces with the CT, becoming part of the tendon?
epimysium
Between efferent nerve fibers and afferent nerve fibers, what percentage goes with each?
60% efferent
40% afferent
What things are efferent nerve fibers?
alpha motor neurons
What things are afferent nerve fibers?
mechanoreceptors and chemoreceptors
What is a triad??
cisternae and t-tubule and cisternae
Cisternae
- assoc. w/ Ca2+ release
- longitundinal or light SR
- Ca2+ reuptake = Ca2+ binds to calsequestrin
Calsequestrin??
binding protein, reduces gradient
Optimal length of z-line to z-line??
2.0-2.2 micrometers
How many actin filaments will one myosin filament interact with??
6 actin filaments
Titin??
acts like anchor and spring
keeps myosin filament in place
Rebulin??
molecular ruler in assembly of actin
Dystrophin??
anchors contractile proteins to the cellular membrane
Alpha-actinin??
located in the z-line and connects actin filaments together
Motor unit??
innervates one or more muscle fibers
All muscle fibers connected to motor unit have:
same contractile properties
same metabolic properties
What does DHP do??
Blocks voltage sensitive Ca2+ channel
What does Ryanodine do??
blocks Ca2+ release channel
T/F: Z-line gets bigger during contraction
False.
It gets smaller
T/F: H zone and I zone get smaller during contraction
True
T/F: The A band does not change length during contraction??
TRUE
What is the A band made of?
thin filaments(actin) and thick filaments(myosin)
What does the hinge region do??
active in coupling chemical to mechanical energy
Isoenzymes for Myosin Thick Filaments
- fast-fast twitch = locomotion
2. slow-slow twitch = postural
Length of an actin thin filament??
one micrometer
what does the z-line equal??
alpha-actin
Tropin I (TN-I)??
inhibits active binding site
Tropin C (TN-C)??
contains binding site for Ca2+
Tropin T (TN-T)??
binds to tropomyosin
Fine motor control = ________ amount of innervation
greater
A lesser amount of innervation is assoc. with?
gross motor control
T/F: Muscle spindles run parallel w/ extrafusal fibers??
True
Primary annulospinal ending??
quick responders to changes in muscle length (dynamic)
Secondary flower-spray endings??
tonic input to muscle length (static)
What does acetylcholinesterase do??
cleaves off Ach
Ach binding to the motor end plate leads to what??
Na+ influxes via gated cation channels
depolarization (end plate potential)
EEP comes out of cleft and starts AP across cell membrane
T/F: Golgi tendon organ set in series w/ muscle fibers??
True
What determines the speed of contractions?
Myosin ATP found on thick filament
What determines the speed of relaxation? Is energy involved?
Ca2+ pumped back into SR at a rate of Ca2+/ATP
It is energy dependent!
Series Elastic Elements
tendon
hinge region
Contractile Elements
sarcomeres
Parallel Elastic Elements
sarcolemmas
blood vessels and nerves
CT
Types of Muscle Contraction
isometric
isotonic
Force of weight > force being produced by muscle??
Weight doesn’t move (Isometric)
Force being produced by muscle > force of weight??
Muscle shortens and weight moves (Isotonic)
What is the total force production dependent on??
the cross-sectional area of the muscle
INDEPENDENT OF MUSCLE FIBER TYPE!!
What does maximal velocity of contraction depend on??
cross bridge cycling
Temporal summation?
frequency of firing of an alpha-motor neuron
Spatial summation?
recruitment of different alpha-motor neurons
What are the additive colors? What do they add up to?
RGB
Add up to white
What are the subtractive colors? What do they subtract to?
CMYK (Cyan Magenta Yellow Black)
Subtract to black
Is the focal distance for convex lens positive or negative?
positive
Is the focal distance for concave lens positive or negative?
negative
What is emmetropia?
normal vision for far objects
NO ACCOMMODATION!!!!
4 things about emmetropia
- far objects (>7m)
- ciliary muscles relaxed
- zonular fibers under tension
- lens flattened
4 things about accommodation
- near objects
- ciliary muscle contracted
- zonular fibers relaxed
- lens rounded
Presbyopia
- d/t: aging - stiff lens
- reduced accommodation
- correction: reading glasses or bifocals
Far: Clear Near: Blurry
Convex lens needed
Hyperopia
- d/t: farsighted
- bulbus too short
- correction: reading glasses or bifocals
Far: Clear Near: Blurry
-Convex lens needed
Myopia
- d/t: nearsighted
- bulbus too long
- correction: driving glasses or bifocals
Far: Blurry Near: Clear
-Concave lens needed
Cornea epithelium
- barrier between tear fluid and stroma
- multi-layer epithelium
- cells regenerate (turnover: 7 days)
- active ion transport necessary to maintain transparency of stroma
Cornea endothelium
- barrier between stroma and aqueous humor
- single layer epithelium
- cells DO NOT regenerate (can stretch to maintain barrier)
- active ion transport necessary to maintain stroma transparency
- active transport prevents swelling of stroma. swelling leads to loss of transparency and clouding of cornea
CN involved with Gustation
CN VII = facial nerve; taste buds on tip of tongue
CN IX = glossopharyngeal nerve; taste buds on back of tongue
CN X = vagus nerve; taste buds on epiglottis
What are the 6 tastes?
sweet, salty, bitter, sour, umami, fatty
What does flavor add to taste?
smell, temperature, pungency, freshness, and texture
Type I taste receptor cells
Glia cells
- ensheathe Type II cells
- express exto-ATPase to limit extracellular ATP
Type II taste receptor cells
Receptor cells
- subset for sweet, umami, bitter, and possibly fatty
- release ATP via channels in response to ligand
Type III taste receptor cells
Presynaptic cells
- subtypes for salty and acid taste
- release serotonin and norepinephrine in response to activation
- DO FORM SYNAPSES w/ gustatory afferents!
Type IV taste receptor cells
Basal cells
-stem cells for taste bud regeneration
taste cell turnover: 2 weeks
