Exam 1 Flashcards
Basic structure unit of a muscle is the ___________
Muscle Fiber (cell)
Muscle fibers are grouped into bundles known as ______
Fasciculi
Muscles fibers & fasciculi are bound together by:
Connective tissue
3 layers of connective tissue
Endomysium, Perimysium, Epimysium
Endomysium
Delicate connective tissue sheath which surrounds each individual muscle fiber & connects it to adjacent muscle fibers.
Perimysium
More dense layer which surrounds each fasciculi & divides the muscle into a series of separate compartment
Epimysium
Dense layer of connective tissue which surrounds the entire muscle & separates the muscle from surrounding tissue, organs & other muscles. The epimysium is continuous w/ deep fascia in the area & will continue as the tendon of the muscle.
The contractile units of the muscle
Myofibrils
Each fiber is contained w/in a tough, specialized membrane known as the _____________
Sarcolemma
Exercise may increase muscle size up to an average of about _____
25%
Type of increase in the size of a muscle which is due to an increase in the size of each INDIVIDUAL muscle fiber.
Hypertrophy
An increase in the size of a muscle due to an actual increase in the number of muscle fibers
Hyperplasia
Due to subjecting the muscle fibers to HIGH tension overload (high resistance), which includes injury to the individual fibers, which is fallowed by a regenerative period
Hyperplasia
The designation of muscles being red (dark) or white (light) is based on the amount of the _______ w/in the majority of fibers found in the respective muscle
Sarcoplasm
Type 1 Fibers (dark)
fibers associated with endurance activities
Are associated w/ relatively higher levels of continuous metabolic activity & thus associated w/ aerobic metabolism
Type 1 Fibers
Type 2 Fibers (light) Activities:
Found in muscles that are utilized for quick, more powerful activities & related to speed & strength. Used in sprinting, weightlifting
Which muscle fibers are anaerobic metabolism
Type 2 Fibers
- Exhibit characteristics which are b/t type 1 & type 2 fibers
- Contract faster than type 1 but slower than type 2
- have a greater resistance to fatigue but resemble type 2 fibers
Intermediate fibers
Weight lifters & sprinters contain a higher proportion of what type of muscle fiber?
Type 2 fibers
Marathon runners contain a higher proportion of what type of muscle fibers?
Type 1 fibers
The cell membrane ________
Sarcolemma
Elaborate, continuous tubular network that runs both parallel & perpendicular to the myofibrils
Sarcoplasmic reticulum
Function to store & transport calcium ions
Sarcoplasmic reticulum
Tubular invaginations of the sarcolemma which allow electrical impulse to enter the muscle fiber & make their way to the myofibrils
Transverse Tubules (T-system)
Myoglobin
red protein pigment found in the sarcoplasm of the fiber
Gives color to the muscle & stores needed oxygen the fibers utilize for its metabolism
Myoglobin
Has greater affinity for oxygen that that of hemoglobin
Myoglobin
Contractile apparatus of the muscle fibers. Formed from longitudinally oriented bundles of thick & thin filaments known as myofilaments
Myofibrils
I- bands
Light areas where actin is found
A -Bands
Dark areas where myosin is found
H-bands
Light areas in the middle of each dark band
M- bands
Thin dark line down the center of each H- band
Z-lines (discs)
Thin dark line in the middle of each I-band
- Main protein elements of the skeletal muscle fibers & consist of Actin
- Found mainly in the I-bands & myosin
- Found mainly in the A- bands
- They have the ability to interact w/ each other & thus create movement
Contractile Proteins
These proteins act to inhibit the interaction of actin & myosin & prevent indiscriminate movement.
Regulatory Proteins
Troponin & tropomyosin
2 most common regulatory proteins
Both of these regulatory proteins recognize calcium as the signal to allow actin & myosin to interact w/ one another
Eliminates the inhibition caused by the regulatory proteins & allow subsequent muscular contractions to occur
Calcium
The nerve impulse from the transverse tubules stimulate the release of _______ from the sarcoplasmic reticulum
Calcium
The released ______ than binds w/ the troponin molecules on the actin filament
Calcium
Binding of _____ w/ troponin actually changes the shape of the nearby tropomyosin molecule & exposing the myosin binding site on the actin molecule
Calcium
Meaning of ATP
Adenosine Triphosphate
The addition of ____ allows the system to operate, by allowing myosin to interact w/ actin
ATP
Energy is provided by the breakdown of ________ into ______ & a free phosphate ion. This reaction releases a large amount of energy (heat)
Adenosine-tri-phosphate (ATP) into Adenosine-di-phosphate (ADP)
The movement of a muscle is the result of the continuous breakdown & reconstruction of ____
ATP
Muscles use 2 general metabolic methods to provide ATP one works _______ and the other works _______
Aerobically and the other works anaerobically
- Takes place in the mitochondria
- More efficient way to produce ATP in a muscle fiber
Aerobic Pathway
- The pathway creates more energy than is needed for the production of ATP & excess energy is released as heat & contribute to keeping the body at its most efficient temp
- Pathway prefers fatty acids to produce ATP
- Fatty acids are stored in body’s fat cells as triglycerides & released in the blood during exercise
Aerobic pathway
Exercise from a metabolic point of view: Phase 1
Will last for the 1st few minutes & creatine phosphate & glycogen are the primary fuel sources. As much as 20% of the total glycogen that is stored in a muscle may be utilized during this phase
Exercise from a metabolic point of view: Phase 2
See a shift in metabolism to the more efficient aerobic metabolism & the use of fatty acids to produce ATP
Exercise from a metabolic point of view: Phase 3
Occurs as exercise intensifies, will see muscle fibers going back to the anaerobic production of ATP & thus the utilization of the remaining stored glycogen, During this phase that lactic acid can accumulate w/in the fibers
Muscle fibers run approximately the whole length of the muscle. PARALLEL to the long axis
Paralle or strap (power)
Muscle fibers run OBLIQUE to the long axis of the muscle
Pennate
Tendon lies along one side of the muscle & the fibers pass obliquely to the tendon
Unipennate (endurance)
Tendon lies in the center of the muscle & the fibers pass to it from each side
Bipennate
A muscle built for ________ has fibers that are short, more numerous & in the pennate arrangement
Endurance (type I)
Muscle built for _______ has fibers that are longer, less numerous & in parallel arrangement
Power (type II)
Muscle or muscles which are most responsible for carrying out a particular action
Prime mover or Agonist
Assist the prime mover in performing an action.
- Stabilize a joint which is the mover pass but do not move
-
Synergist
Muscle that produces the opposite e effect from the agonist
Antagonist
When a muscle contracts, its antagonists automatically relaxes
Reciprocal Innervation
In a newborn, both agonists & antagonists contract @ the same time. Also seen in individuals w/ sensory nerve damage
Co-reflex phenomenon
Pathology of the central nervous system
Amyotropic lateral sclerosis (ALS)
Pathology of the peripheral nervous system
Guillan- Baree syndrome starts off w/ flu like symptoms
Pathology of the neuromuscular junction
Myesthemia Gravis, Botulism
Pathology of the individual muscle fibers
Muscular dystrophies (Duchenue Found in males)
Prolonged immobilization of the joints or chronic joint disorder (arthritis)
Atrophy
Term used to designate any diminishing of the vascular supply to a muscle, which will result in the loss of the muscle fiber w/in a few hours. May be due to an obstruction or trauma
Ischemic Necrosis (Ischemia)
If a muscle remains in a shortened state for a prolonged period of time, it will develop a persistent & sometime permanent shortening. This may develop in certain types of disease
Contracture
In the condition known as _________ ________, satellite cells are prevented from replacing damaged muscle fibers
Muscular dystrophy
Shoulder girdle consist of:
Scapula & clavicle
_________ ossification in which the bone cells replace a primitive type of connective tissue known as __________
Intramembranous; mesenchyme
Ossification of the clavicle
- 1st bone to undergo ossification
- undergoes both intramembranous & endochondral
Ossification of the scapula
- 7 centers of ossification (1 primary & 6 secondary)
- primary center develops around the 8th week of development
- 6 secondary ossification - 2 for the acromion process, 2 for the coracoid process, 1 each for the medial border and inferior angle
Ossification of the humerus
8 ossification centers (1 primary 7 secondary)
- primary for the shaft which develops early in fetal development
- Secondary occurs after birth to late adolescents & include centers for the head, greater tuberosity, lesser tuberosity, medial epicondyle, lateral epicondyle, capitulum & trochlea
- Bone completes ossification about 18-20 years of age
This artery is direct continuation of the subclavian artery, the vessel will become the brachial artery
Axillary artery
Axillary artery has 6 specific branches:
- Superior Thoracic
- Thoracoacromial
- Lateral Thoracic
- Subscapular
- Anterior Humeral Circumflex
- Posterior Humeral Circumflex
- 1st branch to come off of the axillary artery, just as the vessel emerges from under the clavicle.
- Supplies the pectoralis major/ minor, Subclavius muscle, and the wall of the thorax
Superior Thoracic supplies
Short truck which curls around the upper border of the pectoralis minor & divides into 4 branches (acromial, pectoral, clavicular, deltoid)
Thoracoacromial
- Appears along the lateral border of the pectoralis minor.
- Supplies the Serratus Anterior, both pectoral muscles, mammary gland, and the intercostal muscles
Lateral Thoracic
- Largest branch of the axillary artery & found parallel & lateral to the lateral thoracic branch, divides into 2 branches
- Thoracodorsal and Circumflex scapular
Subscapular
Arteries form a ring around the surgical neck of the humerus. Run w/ the axillary nerve & supply the deltoid muscle, shoulder joint, teres muscles & the proximal part of the humerus
Anterior and posterior Humeral circumflex arteries