BIO 101 Unit 7 Muscular System

Cardiac Muscle Tissues features:

Automacity (pacemaker) Longer Contractions No Tetanus Extracellular Calcium Ions Reliance on Aerobic Metabolism

The skeletal muscle is a voluntary muscle. (True or False)

True

A __________________, is a muscle whose contraction is chiefly responsible for producing a particular movement. The biceps brachii muscle is a _____________ that flexes the elbow.

agonist (prime mover)

In the ______________ ___________, tension rises to a peak. Throughout this period the cross-bridges are interacting with the active sites on the actin filaments.

contraction phase (Page 205, figure 7-7)

When the myosin heads interact with thin filaments during a contraction, they are called ____________ ____________.

cross-bridges

surrounds each skeletal muscle fiber and ties adjacent muscle fibers together. The _______________ also contains capillaries that supply blood to the muscle fibers, and nerve fibers that control the muscle.

endomysium

The _________ ____________ act to maintain an erect spinal column and head. Which has three parts: ___________, _____________, and ______________.

erector spinae(spinal extensors) spinalis, longissimus, and iliocostalis (page 221, figure 7-15)

Most of the skeletal muscle fibers in the body are called ____________ fibers because they can reach peak twitch tension in 0.01 second or less after stimulation. They are large in diameter and contain densely packed myofibrils, large glycogen reserves, and relatively few mitochondria. (POWERFUL CONTRACTIONS)

fast (WHITE)

Agonists and antagonists are functional opposites—if one produces ___________, the other's primary action is _____________.

flexion extension

the pyruvate is converted to ____________ ______________, a related three-carbon molecule

lactic acid (THE BURN)

- begins at stimulation and typically lasts about 2 msec. - Over this period the action potential sweeps across the sarcolemma, and calcium ions are released by the sarcoplasmic reticulum. - No tension is produced by the muscle fiber because contraction has yet to begin.

latent period (Page 205, figure 7-7)

The adductors of the thigh include the adductor ____________, the adductor ___________, the adductor __________, the ____________, and the ____________.

magnus brevis longus pectineus gracilis (page 233, Figure 7-21)

Each skeletal muscle fiber is controlled by a nerve cell called a ____________ _____________. ________________ is a neurotransmitter, a chemical released by a neuron to communicate with other cells. The release of _________________ from the axon terminal results in changes in the sarcolemma that trigger the contraction of the muscle fiber. Neurons control skeletal muscle fibers by stimulating the production of an _________________ _______________, or electrical impulse, in the sarcolemma.

motor neuron Acetylcholine(2x) action potential (page 198-199) (see page 204, figure 7-6 for steps in skeletal muscle contraction and relaxation)

A___________ ___________ is a single motor neuron and all the muscle fibers it innervates. The activation of more and more motor units is called _______________, and the result is a smooth, steady increase in muscular tension.

motor unit recruitment

A skeletal muscle contains 4 things:

muscle tissue connective tissues blood vessels nerves

Resting tension in a skeletal muscle is called __________ __________. (T or F): A muscle with little muscle tone is limp and flaccid, whereas one with moderate muscle tone is quite firm and solid. A skeletal muscle that is not regularly stimulated by a motor neuron; muscle fibers will become smaller and weaker: ______________

muscle tone. T Atrophy

During the _____________ ____________, muscle tension falls to resting levels as calcium levels drop, active sites are being covered, and the number of cross-bridges declines.

relaxation phase (Page 205, figure 7-7)

Inversion of the foot is caused by contraction of the __________ muscles; the large ___________ ______________ dorsiflexes the ankle and opposes the gastrocnemius.

tibialis tibialis anterior (Page 235, figure 7-23)

The large, superficial _____________ muscles cover the back and portions of the neck, reaching to the base of the skull. These muscles form a broad diamond. Its actions are quite varied because specific regions can be made to contract independently. The _____________ muscles and the __________ ___________ are covered by the trapezius. Both originate on vertebrae and insert on the scapula.

trapezius rhomboid levator scapulae (page 226, figure 7-18)

A __________ is a single stimulus-contraction-relaxation sequence in a muscle fiber. Its duration can be as brief as 7.5 msec

twitch (Page 205, figure 7-7)

The axial muscles of the trunk include:

(1) the external and internal intercostals (2) the muscular diaphragm that separates the thoracic and abdominopelvic cavities (3) the external and internal obliques (4) the transversus abdominis (5) the rectus abdominis (6) the muscles that form the floor of the pelvic cavity. (page 222, figure 7-16)

5 functions of the skeletal muscle

1. Produce movement of the skeleton. 2. Maintain posture and body position. 3. Support soft tissues. 4. Guard entrances and exits. 5. Maintain body temperature.

Knee extensors is known as the quadricep femoris. What are the parts of this? Quad(4)

3 Vastus and 1 rectus femoris (page 234, figure 7-22)

Aerobic metabolism normally provides ______ percent of the ATP needed by a resting cell. (T or F): Resting skeletal muscle fibers rely primarily on the aerobic metabolism of fatty acids to make ATP

95 T

__________________ is the energy source for muscle contraction ATP transfers energy to ____________, a small molecule muscle cells assemble from fragments of amino acids. Cells in the body generate ATP through ______________ metabolism in mitochondria and through glycolysis in the cytoplasm. Glycolysis is an _____________ process.

Adenosine Triphosphate (ATP) creatine Aerobic (oxygen required) Anaerobic (non-oxygen required) (page 208, figure 7-10: Muscle Metabolism)

___________________ endurance is the length of time muscle contractions can be supported by glycolysis and existing energy reserves of ATP and CP. Examples of activities that require anaerobic endurance are a 50-yard dash or swim, a pole vault, and a weight-lifting competition.(DOESN'T NEED OXYGEN) ________________ endurance is the length of time a muscle can continue to contract while supported by mitochondrial activities. Aerobic endurance is determined by the availability of substrates for aerobic metabolism from the breakdown of carbohydrates, lipids, or amino acids. Aerobic activities do not promote muscle hypertrophy. (NEEDS OXYGEN) Getting swole, enlarging muscle

Anaerobic Aerobic Hypertrophy

_______________ are muscles whose actions oppose the movement produced by another muscle. An _____________ may also be a prime mover. For example, the triceps brachii muscle is a prime mover that extends the elbow. It is, therefore, an ______________ of the biceps brachii, and the biceps brachii is an ___________ of the triceps brachii.

Antagonists(4x)

_____________ muscles arise on the axial skeleton. They position the head and the spinal column and also move the rib cage, assisting in the movements that make breathing possible. This category includes roughly ______ percent of the skeletal muscle in the body. ________________ muscles stabilize or move components of the appendicular skeletor

Axial 60 Appendicular

Muscles of the anterior neck:

Digastric Mylohyoid Stylohyoid Sternocleidomastoid Omohyoid (page 220, figure 7-14)

is a layer of collagen fibers that surrounds the entire muscle. It separates the muscle from surrounding tissues and organs.

Epimysium

Three layers of connective tissue

Epimysium Perimysium Endomysium (page 193, figure 7-1)

________________ + __________________= scalp or ________________ The ____________ covers the ventral surface of the neck, extending from the base of the neck to the mandible and the corners of the mouth.

Frontalis + Ocipitalis = Epicranium (Scalp) platysma (page 218, figure 7-13)

____________ muscles cover the lateral surfaces of the ilia. The __________ __________ is the largest and most posterior of the gluteal muscles, which produce extension, rotation, and abduction at the hip joint.

Gluteal gluteus maximus (page 233, Figure 7-21)

_______________ is the breakdown of glucose to pyruvate in the cytoplasm of the cell

Glycolysis

Two types of muscle contraction: _______________ & _______________. tension rises and the skeletal muscle's length changes. Tension in the muscle remains at a constant level until relaxation occurs. Lifting an object off a desk, walking, and running involve _____________ contractions. the muscle as a whole does not change length, and the tension produced never exceeds the load. Examples of ______________ contractions are pushing against a closed door and trying to pick up a car.

Istonic and Isometric Contraction Isotonic isometric

____________ _______________ is caused by the exhaustion of energy reserves or the decline in pH due to the production and dissociation of lactic acid. Under these conditions, __________ _____________ will not occur until glycogen and other reserves such as lipids and amino acids are depleted. During the ______________ ______________, conditions within the muscle are returned to normal pre-exertion levels. The muscle's metabolic activity focuses on the removal of lactic acid and the replacement of intracellular energy reserves, and the body as a whole loses the heat generated during intense muscular contraction.

Muscle fatigue (2x) recovery period

Smooth Muscle Tissue Features:

No Sacromeres Scattered Thick Filaments Cells Bound together Contractions triggered differently Contraction over a greater range of lengths Automacity or neural or hormonal stimulation

_______________ ________________ are organs composed primarily of skeletal muscle tissue, but they also contain connective tissues, nerves, and blood vessels. These muscles are directly or indirectly attached to the bones of the skeleton. The muscular system includes approximately ______________ skeletal muscles

Skeletal muscles 700

__________ fibers are only about half the diameter of fast fibers, and they take three times as long to reach peak tension after stimulation. These fibers are specialized to continue contracting for extended periods, long after a fast muscle would have become fatigued.

Slow (DARK)

At Thanksgiving, many people prefer white meat, while others prefer dark meat. Which type is composed of mostly fast fibers and which mostly slow fibers?

The more myoglobin, the darker the meat. This means that since slow fibers have more myoglobin, the dark meat will be mostly slow fibers. In contrast white meat will be mostly composed of fast fibers. WHITE = FAST DARK = SLOW

The _________ ______________ and the long head tendon of the ____________ _______________ originate on the scapula and insert on the bones of the forearm.

biceps brachii triceps brachii

The flexors of the knee include three muscles collectively known as the hamstrings: the _________ ____________, the ____________, and the ______________ and the ______________.

biceps femoris semimembranosus semitendinosus sartorius (page 234, figure 7-22)

The_____________ and ____________ also flex the elbow, opposed by the triceps brachii.

brachialis brachioradialis (page 230, figure 7-20)

A band is _________ (color) I band is ________ (color) Boundaries of each Sarcomere: _______________ What band stays the same when contractions begin? ________________

dArk (THICK FIBERS) lIght (THIN FIBERS) Z Lines A Bands (page 195, figure 7-2)

The __________ is the major abductor of the arm, and the ___________ assists at the start of this movement. The ____________, __________ ____________, _____________, and_________ ____________ rotate the arm.

deltoid supraspinatus subscapularis teres major infraspinatus teres minor (ROTATOR CUFF) (page 228, figure 7-19)

The __________ _________ __________, the ___________ __________ ____________, and the ____________ _____________ are superficial muscles that work together to produce flexion of the wrist. Because they originate on opposite sides of the humerus, the ___________ ___________ ____________ flexes and abducts the wrist, whereas the _____________ ___________ _______________ flexes and adducts the wrist.

flexor carpi ulnaris flexor carpi radialis palmaris longus flexor carpi radialis flexor carpi ulnaris (page 230, figure 7-20)

Muscle performance can be considered in terms of ____________, the maximum amount of tension produced by a particular muscle or muscle group, and _____________, the amount of time over which the individual can perform a particular activity.

force endurance

The muscles of the _____________ flex and extend the finger joints

forearm

The large ________________ of the calf is assisted by the underlying __________ muscle. These muscles share a common tendon, the calcaneal tendon, or Achilles tendon.

gastrocnemius soleus (Page 235, figure 7-23)

The largest hip flexor is the ___________, which is the combination of the ____________ and ____________ _____________

iliopsoas Iliacus Psoas Major (page 233, Figure 7-21)

Inside each muscle fiber, branches of T tubules encircle cylindrical structures called ____________. They are bundles of thick and thin ______________, protein filaments consisting primarily of the proteins actin and myosin. _______________ molecules are found in thin filaments, and _____________ molecules in thick filaments

myofibrils myofilaments Actin myosin (page 195, figure 7-2)

Communication between the nervous system and skeletal muscles occurs at _________________ _______________

neuromuscular junctions (NMJ)

The _________ muscles and the ___________ muscles form the muscular walls of the thoracic and abdominopelvic cavities between the first thoracic vertebra and the pelvis. The ____________ muscles can compress underlying structures or rotate the spinal column, depending on whether one or both sides are contracting. The __________ muscles are important flexors of the spinal column; they oppose the erector spinae.

oblique rectus oblique rectus (page 222, figure 7-16)

The ____________ ______________ constricts the opening, and other muscles move the lips or the corners of the mouth. The ___________ muscle compresses the cheeks, as when pursing the lips and blowing forcefully. During chewing, contraction and relaxation of the ____________ move food back across the teeth from the space inside the cheeks. The chewing motions are primarily produced by contractions of the ____________, assisted by the ______________ and the _____________ muscles used in various combinations.

orbicularis oris buccinator masseter temporalis pterygoid (page 218, figure 7-13)

Each muscle begins at an _________, ends at an _________, and contracts to produce a specific _________.

origin insertion action

divide the skeletal muscle into compartments. Each compartment contains a bundle of muscle fibers called a fascicle. In addition to collagen and elastic fibers, the ___________________ contains blood vessels and nerves that supply the fascicles.

perimysium

The floor of the pelvic cavity is called the ________________. It is formed by a broad sheet of muscles that connects the sacrum and coccyx to the ischium and pubis. These muscles support the organs of the pelvic cavity, flex the coccyx, and control the movement of materials through the urethra and anus.

perineum (page 224, figure 7-17)

The ___________________, of a muscle fiber surrounds the ___________________. Filled with extracellular fluid, the _____________ _____________ form passageways through the muscle fiber, like a series of tunnels through a mountain. They play a major role in coordinating the contraction of all regions of the muscle fiber at the same time. (Think organization of skeletal muscle fiber)

sarcolemma (plasma membrane) sarcoplasm (cytoplasm) T tubules (transverse tubules) (page 195, figure 7-2)

Myofilaments (thin and thick filaments) are organized into repeating functional units called ___________.

sarcomeres (page 195, figure 7-2)

Wherever a T tubule encircles a myofibril, the tubule is tightly bound to the membranes of the ______________ _______________, a specialized form of smooth endoplasmic reticulum

sarcoplasmic reticulum (SR) (page 195, figure 7-2)

If a second stimulus arrives before the relaxation phase has ended, a second, more powerful contraction occurs. The addition of one twitch to another in this way is called ____________. A muscle producing almost peak tension during rapid cycles of contraction and relaxation is said to be in ________________ _______________. _______________ __________________ occurs when the rate of stimulation is increased until the relaxation phase is completely eliminated, producing maximum tension

summation incomplete tetanus Complete tetanus (page 205, figure 7-8)

A ____________ is a muscle that helps a prime mover work efficiently. ____________ may either provide additional pull near the insertion or stabilize the point of origin. For example, the deltoid muscle acts to lift the arm away from the body (abduction). ____________ are synergists that stabilize the origin of a prime mover by preventing movement at another joint.

synergist(2x) Fixators

At each end of the muscle, the colagen fibers of the three layers (epi,peri,endo-mysium) come together to form a _____________, or a broad sheet called an _________________.

tendon aponeurosis

When muscle cells contract, they pull on collagen fibers, producing an active force called ____________. ______________ applied to an object tends to pull the object toward the source of the tension. However, before movement can occur, the applied tension must overcome the object's __________________, a passive force that opposes movement. The amount of ______________ can depend on an object's weight and shape, friction, and other factors. a push applied to an object: __________________

tension (2X) resistance(2x) Compression