Anatomy Study Guide- Muscular System Test(U6)
Name the two ways graded responses can be produced.
1. By changing the frequency (how fast) of muscle stimulation 2. By changing the number of muscle cells being stimulated at one time
Name the three main energy systems that resupply muscle with ATP in order from using maximal physical effort to minimal physical effort.
1. Direct phosphorylation of ADP by creatine phosphate (ATP-CP System) 2. Anaerobic glycolysis and lactic acid formation 3. Aerobic Respiration
What are the three types of muscle tissue?
1. Skeletal 2. Cardiac 3. Smooth
What are the three key roles of skeletal muscle?
1. To maintain posture and body position 2. To stabilize joints 3. To generate heat
Name the four main types of graded responses.
1. Twitch 2. Summing of Contractions 3. Unfused (Incomplete Tetanus) 4. Fused (Complete Tetanus)
What is abduction?
> A type of body movement of a limb away from the midline
What is eversion?
> A type of body movement turning the sole of the foot laterally
What is inversion?
> A type of body movement turning the sole of the foot medially
Describe Cardiac Muscle tissue. (What are the cells' shape? How many nuclei do cells have, striations? etc.)
> Branching chains of cells with intercalated discs > Uninucleate > Has striations > They are involuntary muscles > Line the walls of the heart
Describe the steps to the Sliding Filament Theory.
> Calcium ions (Ca2+) bind regulatory proteins on actin filaments and expose myosin-binding sites, allowing the myosin heads on the thick filaments to attach >Each actin-myosin cross bridge pivots, causing the thin filaments to slide toward the center of the sarcomere >As a result, contraction occurs, and the cell shortens >During a contraction, a cross bridge attaches and detaches several times >ATP provides the energy for the sliding process, which continues as long as calcium ions are present
Describe Smooth Muscle tissue. (What are the cells' shape? How many nuclei do cells have, striations? etc.)
> Cells are spindle shaped > Have a single, centrally located nucleus > Lack striations >They are involuntary muscles >Line the walls of hollow visceral organs
Skeletal muscle cells are surrounded and bundled by connective tissues. Name the four that lie inside skeletal muscle and define them.
> Endomysium: encloses a single muscle fiber > Perimysium: wraps around a fascicle (bundle) of muscle fibers > Epimysium: covers the entire skeletal muscle (blends into a connective tissue attachment) > Fascia: on the outside of the epimysium
Describe the structure of a sacromere.
> I band - light band, thin filaments > A band - dark band, thick filaments (Light (I) bands and dark (A) bands give the muscle its striated (banded) appearance)( On one sarcomere, they appear A, (I, A, I ), A) > Z disc: a midline interruption an the I bands (appears very dark) >H zone: a lighter central area on A bands >M line: in the center of H zones
What is muscle tone a result of, physiologically?
> It is a result of different motor units being stimulated in a systematic way to produce a state of continuous partial contractions >Muscle remains firm, healthy, and constantly ready for action
Describe Skeletal Muscle tissue. (What are the cells' shape? How many nuclei do cells have, striations? etc.)
> Large cylindrical shaped cells > Multinucleate > Has striations > They are voluntary muscles
Describe the organization of skeletal muscle in order from inside to outside "layers".
> Muscle fiber (Muscle cell) >Endomysium > Fascicle (contains multiple muscle fibers) > Perimysium > (Blood vessels) > Epimysium > Fascia
Define the components in the microscopic anatomy of a muscle fiber.
> Myofibrils - long organelles inside muscle cell. (about 2000 in typical adult) > Sarcomere - the smallest and a contractile unit of a muscle fiber. It is the structural and functional unit of skeletal muscle (and is characterized as a portion of myofibrils) > Sarcolemma - specialized plasma membrane around muscle fibers (contains all myofibrils and such that lie inside of muscle cells > The sarcoplasmic reticulum (specialized smooth endoplasmic reticulum):surrounds the myofibril
What is this muscle that moves the head?
> Orbicularis oculi
Describe actin filaments.
> Thin filaments composed of the contractile protein actin > At rest, H zone in A band lacks actin filaments > Actin is anchored to the Z disc
Muscle fibers contract in an _________ fashion, meaning they will maximally contract stimulated fibers adequately.
>"all-or-none"
What is the definition of a neurotransmitter?
>A chemical released by neurons upon arrival of nerve impulse in the axon terminal.
What is a synaptic cleft?
>A gap between nerve and muscle filled with interstitial fluid; the nerve and muscle do not make contact
What physiologically happens during muscle fatigue?
>A muscle is unable to contract even when it is being stimulated >Without rest a muscle contractions will become weaker until failure
What is a synergist in a group of muscles?
>A muscle that aids a prime mover in a movement or reduces undesirable movements
What is an antagonist in a group of muscles?
>A muscle that opposes or reverses a prime mover
What is a "prime mover" in a group of muscles?
>A muscle with the major responsibility for a certain movement.
Describe a muscle twitch.
>A single, brief, jerky contraction >A single stimulus causes a single muscle contraction and relaxation >Not a normal muscle function resulting from a nervous system abnormality
What is depression?
>A type of body movement in which a body part is lowered inferiorly
What is supination?
>A type of body movement in which the forearm rotates laterally so palms face anteriorly, radius and ulna are parallel
What is pronation?
>A type of body movement in which the forearm rotates medially so palms face posteriorly, radius and ulna cross each other like an X
What is opposition?
>A type of body movement in which the thumb touches the tips of other fingers on the same hand.
What is dorsiflexion?
>A type of body movement lifting the foot so that the superior surface approaches the shin (toward the dorsum)
What is rotation?
>A type of body movement of a bone around its longitudinal axis >Common in ball-and-socket joints >Example: moving the atlas around the dens of axis (i.e., shaking your head "no")
What is adduction?
>A type of body movement of a limb toward the midline >Opposite of abduction
What is plantar flexion?
>A type of body movement pointing the toes away from the head
What is flexion?
>A type of body movement that decreases the angle of the joint >Brings two bones closer together >Typical of bending hinge joints (e.g., knee and elbow) or ball-and-socket joints (e.g., the hip)
What is extension?
>A type of body movement that increases the angle between to bones >Opposite of flexion >Straightening the elbow or knee or standing up Extension beyond 180º is hyperextension
What is circumduction?
>A type of body movement that is a combination of flexion, extension, abduction, and adduction >Common in ball-and-socket joints >Proximal end of bone is stationary, and distal end moves in a circle
What is elevation?
>A type of body movement un which a body part is raised superiorly
What is the energy source for muscle contractions?
>ATP (Adenosine Triphosphate)
In the talk test, if someone can speak 1-2 words before needing to take a breath, their ______________ [insert energy pathway here] pathway is dominant.
>ATP-CP/Direct Phosphorylation
Describe fused (complete) tetanus.
>Achieved when the muscle is stimulated so rapidly that no evidence of relaxation is seen >Contractions are smooth and sustained
Name the 5 adductor muscles of the hip/thigh.
>Adductor longus >Adductor brevis >Adductor magnus >Gracilis >Pectineus
In the talk test, if someone can speak normally without difficulty breathing, their ______________ [insert energy pathway here] pathway is dominant.
>Aerobic
_________________ (resistance (isometric)/ aerobic (endurance)) exercise (e.g. biking, jogging) results in stronger, more flexible muscles with greater resistance to fatigue.
>Aerobic (endurance)
What is this muscle of the trunk?
>Anterior serratus muscle
Which 3 muscles are involved in the hamstrings?
>Biceps femoris >Semitendinosus >Semimembranosus
What is this muscle of the (left) forearm?
>Brachioradialis
What is this muscle that moves the head?
>Buccinator
Muscles are named on the basis of which 7 criteria? List them.
>By direction of muscle fibers (Example: rectus (straight)) >By relative size of the muscle (Example: maximus (largest)) >By location of the muscle (Example: temporalis (temporal bone)) >By number of origins (Example: triceps (three heads)) >By location of the muscle's origin and insertion (Example: sterno (on the sternum)) >By shape of the muscle (Example: deltoid (triangular)) >By action of the muscle (Example: flexor and extensor (flexes or extends a bone))
What nerve connects to the gluteus maximus? (What spinal vertebra?)
>C5 & S1-S2 Nerve [sciatic nerve at sacral plexus]
What are all four types of muscle contraction defined by?
>Changes in length of the muscle during contraction
What is this muscle that moves the head?
>Corrugator supercilii
What is this superficial muscle of the upper back?
>Deltoid
Describe the Direct phosphorylation (ATP-CP) process. How many ATP is produced per creatine phosphate (CP) molecule? In what type of exercise would this process be utilized to provide energy?
>Direct phosphorylation of ADP by creatine phosphate (CP) occurs supplies quick energy to working muscle cells >Muscle cells store CP, a high-energy molecule >After ATP is depleted, ADP remains >CP transfers a phosphate group to ADP to regenerate ATP >1 ATP is produced per CP molecule >CP supplies are exhausted in less than 15 seconds >Main energy pathway during near or at maximal physical effort >100 meter sprint, football...
What is this connective tissue that moves the head?
>Epicranial aponeurosis
What are four general effects of exercise on muscle?
>Exercise increases muscle size, strength, and/or endurance depending on the type >Makes body metabolism more efficient >Improves digestion and coordination >Individual muscle fibers enlarge
What is this muscle of the trunk?
>External oblique
Different combinations of muscle fiber contractions will give the same responses. True or False?
>False, different combinations of muscle fiber contractions may five different responses.
All fibers within an entire skeletal muscle are stimulated at the same time. True or False?
>False, not all fibers within an entire skeletal muscle are stimulated at the same time.
In the talk test, if someone can speak 1-2 sentences before needing to take a breath, their ______________ [insert energy pathway here] pathway is dominant.
>Glycolytic (Anaerobic)
What are graded responses?
>Graded responses are responses that muscle might have to stimulation from the nervous system.
What is this deep abdominal muscle?
>Illacus
What is this muscle of the posterior shoulder?
>Infraspinatus
What is this muscle of the trunk?
>Internal oblique
Muscle fatigue results from imbalances in...
>Ions (Ca2+, K+)
What does Acetylcholine (ACh) do?
>It is a neurotransmitter that stimulates skeletal muscle.
What is the function of the sarcoplasmic reticulum?
>It stores and releases calcium.
What nerve connects to the hamstrings (What spinal vertebra?)
>L4-S3 [sciatic nerve at sacral plexus]
What is this muscle of the back?
>Latissimus dorsi
What is this muscle of the trunk?
>Linea alba
What are the four types of muscular exercise? Describe them.
>Mobility-Flexibility Exercise: for proper range of motion (ROM) and maintenance of stable strength-tension relationships between muscle pairs, synergists, and antagonists >Resistance Exercise: for maintenance of muscle and joint stability, endurance, strength, and power >Agility Exercises: enhance dynamic muscular movements over time >Balance and Coordination Exercises: train neuromuscular communication, connections, and responses to internal and external changes in movement
A muscle fiber generates tension through actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same. How would muscle contraction be defined?
>Muscle contraction is the generation of tension within a muscle fiber.
Describe and give examples of isometric contractions.
>Muscle filaments are trying to slide, but the muscle is pitted against an immovable object >Tension increases, but muscles do not shorten, no movement occurs > e.g. Plank, static exercises, pushing an immoveable wall...
What is the main function of muscle?
>Muscles are responsible for body movements and movement of substances within and through the body.
Describe and give examples of isotonic contractions.
>Myofilaments slide past each other during contractions >Muscle shortens, movement occurs >e.g. bending the knee, lifting weights, smiling
What are the two types of filaments found on a sarcomere?
>Myosin and Actin Filaments
What is this muscle that moves the head?
>Occipitofrontalis (frontal belly)
What is this muscle that moves the head?
>Occipitofrontalis (occipital belly)
Describe a summing of contractions.
>Occurs when nerve impulses are delivered more frequently so that the muscle does not have time to completely relax >As a result, contractions are added together, and one contraction is immediately followed by another
Describe unfused (incomplete) tetanus.
>Occurs when stimulations become more frequent >Muscle contractions get stronger and smoother
Define "motor unit".
>One motor neuron and all the skeletal muscle cells innervated by that neuron
What is this muscle that moves the head?
>Orbicularis oris
Name the origin, insertion and primary actions of the Frontalis (of the Head/Neck muscles).
>Origin: Cranial aponeurosis >Insertion: Skin of eyebrows >Primary action(s): Raises eyebrows
Name the origin, insertion and primary actions of the gastrocnemius (of the hip/thigh/leg muscles)
>Origin: Distal femur >Insertion: Calcaneus (heel via calcaneal tendon) >Primary action(s): Plantar flexes foot and flexes knee
Name the origin, insertion and primary actions of the Brachialis (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: Distal humerus >Insertion:Proximal ulna >Primary action(s): Flexes elbow
Name the origin, insertion and primary actions of the fibularis muscles (of the hip/thigh/leg muscles)
>Origin: Fibula >Insertion: Metatarsals of foot >Primary action(s): Plantar flex and evert foot
Name the origin, insertion and primary actions of the Orbicularis oculi (of the Head/Neck muscles).
>Origin: Frontal bone and maxilla >Insertion: Tissue around eyes >Primary action(s): Blinks and closes eyes
Name the origin, insertion and primary actions of the Erector spinae (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: Iliac crests, ribs 3-12, and vertebrae >Insertion: ribs, thoracic and cervical vertebrae >Primary action(s): extends and laterally flexes spine
Name the origin, insertion and primary actions of the Gluteus medius (of the hip/thigh/leg muscles)
>Origin: Ilium >Insertion: Proximal femur >Primary action(s): Abducts thigh, steadies pelvis during walking
Name the origin, insertion and primary actions of the Iliopsoas (of the hip/thigh/leg muscles)
>Origin: Ilium and lumbar vertebrae >Insertion: Femur (lesser trochanter) >Primary action(s): Flexes hip
Name the origin, insertion and primary actions of the hamstrings (of the hip/thigh/leg muscles)
>Origin: Ischial tuberosity >Insertion: Proximal tibia (head of fibula in the case of biceps femoris) >Primary action(s):Flex knee and extend hip
Name the origin, insertion and primary actions of the Latissimus dorsi (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: Lower spine and iliac crest >Insertion: Proximal humerus >Primary action(s): Extends and adducts humerus
Name the origin, insertion and primary actions of the Orbicularis oris (of the Head/Neck muscles).
>Origin: Mandible and maxilla >Insertion: Skin and muscle around mouth >Primary action(s): Closes and protrudes lips
Name the origin, insertion and primary actions of the Buccinator (of the Head/ Neck muscles.
>Origin: Maxilla and mandible near molars >Insertion: Orbicularis oris >Primary action(s): Compresses cheek, holds food between teeth during chewing
Name the origin, insertion and primary actions of the Trapezius (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: Occipital bone and all cervical and thoracic vertebrae >Insertion: Scapular spine and clavicle >Primary action(s): Raises, retracts, and rotates scapula
Name the origin, insertion and primary actions of the adductor muscles (of the hip/thigh/leg muscles)
>Origin: Pelvis >Insertion: Proximal femur >Primary action(s): Adduct and medially rotate thigh
Name the origin, insertion and primary actions of the Tibialis anterior(of the hip/thigh/leg muscles)
>Origin: Proximal tibia >Insertion: First cuneiform (tarsal) and first metatarsal of foot >Primary action(s): Dorsiflexes and inverts foot
Name the origin, insertion and primary actions of the soleus (of the hip/thigh/leg muscles)
>Origin: Proximal tibia and fibula >Insertion: Calcaneus >Primary action(s): Plantar flexes foot
Name the origin, insertion and primary actions of the Rectus abdominis (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: Pubis >Insertion: Sternum and 5-7 ribs >Primary action(s): Flexes vertebral column
Name the origin, insertion and primary actions of the Sternocleidomastoid (of the Head/Neck muscles)
>Origin: Sternum and clavicle >Insertion: Temporal bone (mastoid process) >Primary action(s): Flexes neck, laterally rotates head
Name the origin, insertion and primary actions of the Pectoralis Major (of the Trunk muscles)
>Origin: Sternum, clavicle, and ribs 1-6 >Insertion: Proximal humerus >Primary action(s): Adducts and flexes humerus
Name the origin, insertion and primary actions of the Masseter (of the Head/Neck muscles)
>Origin: Temporal bone >Insertion: Mandible >Primary action(s): Closes jaw
Name the origin, insertion and primary actions of the Temporalis (of the Head/Neck muscles)
>Origin: Temporal bone >Insertion: Mandible >Primary action(s): closes jaw
Name the origin, insertion and primary actions of the Zygomaticus (of the Head/Neck muscles)
>Origin: Zygomatic bone >Insertion: Skin and muscle around mouth >Primary action(s): Raises corner of mouth
Name the origin, insertion and primary actions of the Platysma (of the Head/Neck muscle)
>Origin: connective tissue covering of superior chest muscles >Insertion: tissue around mouth >Primary action(s): Tenses skin of neck
Name the origin, insertion and primary actions of the Extensor digitorum(of the arm/forearm muscles)
>Origin: distal humerus >Insertion: Distal phalanges of fingers 2-5 >Primary action(s): extends fingers
Name the origin, insertion and primary actions of the Quadratus lumborum (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: iliac crest, lumbar fascia >Insertion:transverse processes of upper lumbar vertebrae Primary action(s): flexes spine laterally, extends spine
Name the origin, insertion and primary actions of the sartorius (of the hip/thigh/leg muscles)
>Origin: ilium >Insertion:Proximal tibia >Primary action(s): flexes thigh on hip
Name the origin, insertion and primary actions of the External oblique(of the Head/Neck/Trunk/Shoulder muscles)
>Origin: lower eight ribs >Insertion: Iliac crest >Primary action(s): flexes and rotates vertebral column
Name the origin, insertion and primary actions of the Occipitalis (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: occipital and temporal bones >Insertion: cranial aponeurosis >Primary action(s): Fixes aponeurosis and pulls scalp posteriorly
Name the origin, insertion and primary actions of the Gluteus maximus (of the hip/thigh/leg muscles)
>Origin: sacrum and ilium >Insertion: proximal femur (gluteal tuberosity) >Primary action(s): Extends hip (when forceful extension is required)
Name the origin, insertion and primary actions of the Biceps brachii (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: scapula of shoulder girdle >Insertion: proximal radius >Primary action(s): Flexes elbow and supinates forearm
Name the origin, insertion and primary actions of the Deltoid (of the Head/Neck/Trunk/Shoulder muscles)
>Origin: scapular spine and clavicle >Insertion: humerus (deltoid tuberosity) >Primary action(s): abducts humerus
Name the origin, insertion and primary actions of the Triceps brachii (of the arm/forearm muscles)
>Origin: shoulder girdle >Insertion: Olecranon process of ulna >Primary action(s): Extends elbow
Describe the Anaerobic Respiration process. What is this process also called? How many ATP is produced per glucose molecule? In what type of exercise would this process be utilized to provide energy?
>Oxidative phosphorylation is a series of metabolic pathways occurring in the mitochondria in which oxygen and nutrients are used to break down glucose into carbon dioxide and water, releasing energy >Produces 32 ATP molecules for each molecule of glucose >Slower reaction that requires continuous delivery of oxygen and nutrients >Dominant energy pathway at rest and during light to moderate exercise
What is this muscle of the pectoral girdle?
>Pectoralis major
Describe the Anaerobic Glycolysis process. How many ATP is produced per glucose molecule? In what type of exercise would this process be utilized to provide energy?
>Produces ATP in the cytosol without oxygen (Anaerobic) >Glucose is broken down to pyruvic acid to produce 2 ATP (2 molecules of ATP per 1 glucose molecule) >Supplies ATP for up to 30 - 40 seconds during activities requiring vigorous physical effort >2.5 times faster than aerobic respiration >Pyruvic acid is converted to lactic acid, which causes muscle soreness >Not sufficient to meet the ATP demands of the human body >400 meter run, vigorous running, soccer...
What is this muscle of the (right) forearm?
>Pronator teres
What is this deep abdominal muscle?
>Psoas major
What is this muscle of the trunk?
>Rectus abdominis (which is enclosed within rectus sheath)
_________________ (resistance (isometric)/ aerobic (endurance)) exercise (e.g. weight lifting) increases muscle size and strength.
>Resistance (isometric)
What is this superficial muscle of the upper back?
>Rhomboid major
What is this superficial muscle of the upper back?
>Rhomboid minor
What nerve connects to the gastrocnemius? (What spinal vertebra?)
>S1-S2 nerve [tibial nerve at sacral plexus]
What is a fixator in a group of muscles?
>Specialized synergists that hold a bone still or stabilize the origin of a prime mover
What is this muscle of the (right) forearm?
>Supinator
What is this muscle of the posterior shoulder?
>Supraspinatus
Most skeletal muscle fibers are attached by ______________ to bones. (Then define this term)
>Tendons: cordlike structures made up mostly collagen fibers and attach muscle to a joint because they facilitate movement
What is this muscle of the posterior shoulder?
>Teres major
What is this muscle of the posterior shoulder?
>Teres minor
What nerve connects to the trapezius? (What spinal vertebra?)
>The C1-C5 nerve [cervical nerve]
What nerve connects to the deltoid? (What spinal vertebra?)
>The C5-C6 nerve [axillary nerve at brachial plexus]
What nerve connects to the biceps brachii? (What spinal vertebra?)
>The C5-C6 nerve [musculocutaneous]
What nerve connects to the pectoralis major? (What spinal vertebra?)
>The C6-C8 nerve [medial pectoral nerve on brachial plexus]
What nerve connects to the triceps brachii? (What spinal vertebra?)
>The C7-C8 nerve [radial nerve on brachial plexus]
What nerve connects to the quadriceps? (What spinal vertebra?)
>The L2-L4 nerve [femoral nerve at lumbar plexus]
What nerve connects to the latissimus dorsi? (What spinal vertebra?)
>The T6-T8 nerve
What nerve connects to the rectus abdominal? (What spinal vertebra?)
>The T7-T12 nerve
What is this superficial muscle structure of the upper back? (labeled G)
>The acromion process of scapula
What is this muscle structure of the upper back?
>The coracoid process of scapula
What is the neuromuscular junction?
>The point of contact between an axon terminal of a motor neuron and sarcolemma of a muscle.
Describe myosin filaments.
>Thick filaments composed of the protein myosin >Contain ATPase enzymes to split ATP to release energy for muscle contractions >Have projections known as myosin head (called cross bridges when they link thick and thin filaments during contraction)
What is this muscle of the trunk?
>Transversus abdominis
What is this superficial muscle of the upper back?
>Trapezius
What is this muscle of the posterior shoulder?
>Triceps brachii
All muscle types produce movement. True or False?
>True
Name the origin, insertion and primary actions of the quadriceps (of the hip/thigh/leg muscles) (Vasti and Rectus femoris origins are different)
>Vasti Origin: femur >Rectus femoris Origin: pelvis >Insertion: Tibial tuberoisty via patellar ligament >Primary action(s): All extend knee, rectus femoris also flexes hip on thigh
What are the 4 muscles involved in the quadriceps?
>Vastus medialis >Vastus intermedius >Vastus lateralis >Rectus femoris
Describe the steps to muscular contraction in terms of nerve stimulus and action potential.
>When a nerve impulse reaches the axon terminal of the motor neuron, the following steps take place in sequence: >Step 1: Calcium channels open, and calcium ions enter the axon terminal >Step 2: Calcium ion entry causes some synaptic vesicles to release acetylcholine (ACh) >Step 3: ACh diffuses across the synaptic cleft and attaches to receptors on the sarcolemma of the muscle cell >Step 4: When enough ACh is released, the sarcolemma becomes temporarily more permeable to sodium ions (Na+), Potassium ions (K+) diffuse out of the cell, More sodium ions enter than potassium ions leave, Interior is depolarized (has more positive ions than exterior), More Na+ channels open >Step 5: Depolarization opens more sodium channels that allow sodium ions to enter the cell, An action potential is created, An electrical impulse is conducted from one end of the cell to the other >Step 6: Acetylcholinesterase (AChE) breaks down acetylcholine into acetic acid and choline, AChE ends muscle contraction, One nerve impulse produces one contraction > Cell returns to its resting state when: Potassium ions (K+) diffuse out of the cell, Sodium-potassium (NA+-K+ ) pump moves NA+ and K+ ions back to their original positions
Maximal muscle contraction is reached when all motor units that have been stimulated are _________ (active/inactive)
>active
Muscular exercise _________(decreases/increases) the risk of broken bones, osteoporosis, falls, and body pains.
>decreases
Muscular exercise __________(does/does not) reduce the risk of chronic disease, cancer, obesity, diabetes, metabolic syndrome, stroke, heart attack, Alzheimer's, dementia, and other lifestyle related conditions.
>does
Muscular exercise ____________ (does/does not) improve memory, intelligence, self-confidence, and cognitive performance.
>does
Light resistances results in __________ (greater/fewer) muscle fiber recruitment.
>fewer
Oxygen deficit and _________ accumulation result in decrease in ATP supply.
>lactic
Skeletal muscles must be stimulated to contract by a ______________ (nerve cell).
>motor neuron
Muscular contractions must be systematic and organized to produce proper movement. In general, groups of muscles that produce opposite actions lie on ___________ (the same/opposite) sides of a joint.
>opposite
Small amounts of ATP is stored in muscle fibers but is depleted within _______ [insert time unit here].
>seconds
Aponeuroses are...
>sheetlike structures that attach muscles indirectly to bones, cartilages, or connective tissue coverings
Contraction of more motor units results in contraction of all fibers innervated by those motor units (all or none). This results in greater muscle ___________.
>tension
Muscle force depends upon...?
>the number of fibers stimulated (motor units)
List the four types of muscle contraction and define them.
1. Isometric: A muscular contraction in which the length of the muscle does not change. 2. Isotonic: A muscular contraction in which the length of the muscle changes. There are two phases during an isotonic contraction: 3. Eccentric: An isotonic contraction where the muscle lengthens. 4. Concentric: An isotonic contraction where the muscle shortens.
List the Five Golden Rules for understanding skeletal muscle activity.
1. Muscles are attached at least two points >Origin: attachment to an immovable or less movable bone >Insertion: attachment to a movable bone 2. When muscles contract, the insertion moves toward the origin 3. Body movement occurs when muscles contract across joints 4. Muscles work in pairs in an agonist-antagonist relationship 5. Muscles pull, never push
What is the talk test?
A test which measures how much you're able to talk, determining the intensity of the exercise.
What is this deep abdominal muscle?
Quadratus Lumborum
