BIOL 2401 Unit #3 Lecture Exam Ch. 11

Explain the functional relationship between the muscular system and other body systems.

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Explain the role of exercise in producing various responses in other body systems.

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Identify the muscles associated with specific actions as indicated in the PowerPoint in CANVAS, with the UNIT 3 LECTURE MODULE

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Third class lever

Force (AF) is applied between the load (L) & fulcrum (F)

Origin

Less moveable end of the muscle

Second class lever

Load (L) is between the fulcrum (F) & applied force (AF)

Identify age-related changes of the muscular system.

Loss of muscle mass.Reduction in number and size of motor neurons.Changes in the type of muscle tissue fibers.Reduced reflexes.Reduction in movement.Involuntary muscle movements like fasciculations begin as we age.Fatigue is common.Changes in bones and joints.

Insertion

More movable end of a muscle

Predict the actions of a muscle on the basis of its origin and insertion, and explain how muscles interact to produce or oppose movements.

Most muscles have one end that is fixed and another end that moves toward the fixed end during a contraction. The point of attachment at the fixed end is called the origin. The point of attachment to the structure that moves is the insertion. The origin is proximal to the insertion. The movement of a muscle contraction is called its action. Actions are body movements such as flexion, extension, adduction. Most muscles either originate or insert on the skeleton. Actions are described in terms of the bone, joint or region affected. Muscles usually work in groups to maximize efficiency. The smaller muscles reach maximum tension first, followed by larger primary muscles. Muscles are described based on their functions. 1. an agonist (prime mover) is a muscle that produces a particular movement of a particular agonist. (agonists and antagonists work in pairs flexors-extensors, abductors-adductors, etc.) When one contracts, the other stretches A synergist is a small muscle that assists a larger agonist. They may help start a motion or stabilize the origin of the agonist (fixators)

Fixator

Muscle that assists an agonist by preventing movement at another joint, stabilizing the origin of the agonist

Antagonist

Muscle that opposes or reverses a prime mover

Based on patterns of fascicle organization name the four classifications of skeletal muscle tissue

Parallel muscles Convergent muscles Pennate muscles Circular muscles

Pennate muscles

Pennate: fascicles form a common angle w/ the tendon; muscle fibers pull at an angle & produce more tension

Identify six different types of descriptive information that can be used to name skeletal muscles.

Region of the body Position Direction Fascicles arrangement Structural characteristics Action

Identify the principal appendicular muscles of the body, plus their origins, insertions, actions, and innervation

The appendicular muscles position and stabilize the pectoral and pelvic girdles, and move the upper and lower limbs.• The 2 major groups of appendicular muscles are the:1. Muscles of the shoulders and upper limbs2. Muscles of the pelvis and lower limbsMuscles of the Shoulders and Upper Limbs, p. 353• Muscles of the shoulders and upper limbs are divided into 4 groups:1. muscles that position the pectoral girdle2. muscles that move the arm3. muscles that move the forearm and hand4. muscles that move the hand and fingersFigure 11-14• Muscles that position the pectoral girdle include the: trapezius:- superficial- covers the back and neck up to the base of the skull - inserts on the clavicles and scapular spinesrhomboid and levator scapulae: - deep to the trapezius- attach to cervical and thoracic vertebrae- insert on the scapular border serratus anterior:- on the chest- originates along ribs- inserts on anterior scapular marginsubclavius:- originates on the ribs- inserts on the clavicle pectoralis minor:- attaches to the scapulaTable 11-11: Note the origins, insertions, actions and innervation of the muscles that position the pectoral girdle.Figure 11-15• Muscles that move the arm include the: deltoid:- the major abductor supraspinatus:- assists the deltoid subscapularis and teres major:- produce medial rotation at the shoulder infraspinatus and teres minor:- produce lateral rotation at the shoulder coracobrachialis:- attaches to the scapula- produces flexion and adduction at the shoulder pectoralis major:- between the anterior chest and the greater tubercle of the humerus- produces flexion at the shoulder joint latissimus dorsi:- between thoracic vertebrae and the humerus - produces extension at the shoulder joint• Muscles involved in rotation of the shoulder (supraspinatus, subscapularis, infraspinatus, and teres minor) and their tendons form the rotator cuff.Table 11-12: Note the origins, insertions, actions and innervation of the muscles that move the arm.Figure 11-16• Most of the muscles that move the forearm and hand originate on the humerus and insert on the forearm, except the major flexor (the biceps brachii) and the major extensor (the triceps brachii). Extensors lie mainly on the posterior and lateral surfaces of the arm, and flexors lie mainly on the anterior and medial surfaces.biceps brachii:- flexes the elbow- stabilizes the shoulder joint- originates on the scapula, inserts on the radial tuberosity triceps brachii:- extends the elbow- originates on the scapula, inserts on the olecranon brachialis and brachioradialis:- flex the elbow anconeus:- opposes the brachialis flexor carpi ulnaris- superficial- flexes the wrist- adducts the wristflexor carpi radialis, - superficial- flexes the wrist- abducts the wrist palmaris longus:- superficial- flexes the wrist extensor carpi radialis:- superficial- extends the wrist - abducts the wristextensor carpi ulnaris - superficial- extends the wrist - adducts the wristpronator teres and supinator:- originate on the humerus and ulna - rotate the radiuspronator quadratus:- originates on the ulna- assists the pronator teresTable 11-13: Note the origins, insertions, actions and innervation of the muscles that move the forearm and hand.Figure 11-17• The muscles of the forearm that move the hand and fingers lie entirely within the forearm. Only their tendons cross the wrist (in bursae sheaths called synovial tendon sheaths). These are called the extrinsic muscles of the hand.• The wide band of connective tissue on the posterior surface of the wrist, which holds the tendons of the extensor muscles in place, is the extensor retinaculum. On the anterior surface, the flexor retinaculum stabilizes the tendons of the flexor muscles.Table 11-14: Note the origins, insertions, actions and innervation of the muscles that move the hand and fingers.Figure 11-18• The intrinsic muscles of the hand.Table 11-15: Note the origins, insertions, actions and innervation of the intrinsic musclesof the hand.Muscles of the Pelvis and Lower Limbs, p. 363• The pelvic girdle is tightly bound to the axial skeleton, permitting little movement (few muscles).• The muscles that position the lower limbs are divided into 3 groups:1. muscles that move the thigh2. muscles that move the leg3. muscles that move the foot and toesFigure 11-19• The muscles that move the thigh can be subdivided into 4 groups: (1) the gluteal muscles cover the lateral surfaces of the iliaa. gluteus maximus:- the largest, most posterior gluteal muscle- produces extension and lateral rotation at the hipb. tensor fasciae latae:- works with the gluteus maximus- stabilizes the iliotibial tract- (band of collagen fibers that braces the knee)c. gluteus medius and gluteus minimus:- originate anterior to the gluteus maximus - insert on the trochanter(2) the lateral rotators are 6 muscles including: a. piriformisb. obturator(3) the adductors include:a. adductor magnus:- produces adduction, extension and flexionb. adductor brevis:- hip flexion and adductionc. adductor longus- hip flexion and adductiond. pectineus- hip flexion and adductione. gracilis- hip flexion and adduction(4) the iliopsoas muscle (2 hip flexors that insert on the same tendon) a. psoas majorb. iliacusTable 11-16: Note the origins, insertions, actions and innervation of the muscles that move the thigh.Figure 11-20• Muscles that move the leg are divided into flexors of the knee and extensors of the knees.(1) flexors of the knee a. biceps femorisb. semimembranosus c. semitendinosusd. sartorius:- originates superior to the acetabulum e. popliteus:- rotates the tibia to unlock the knee (2) extensors of the knee insert on the patellaa. vastus musclesb. rectus femoris muscle• Most flexors originate on the pelvic girdle. Most extensors originate on the femoral surface.• The biceps femoris, semimembranosus and semitendinosus muscles make up thehamstrings.• The 3 vastus muscles and the rectus femoris make up the quadriceps femoris.Table 11-17: Note the origins, insertions, actions and innervation of the muscles that move the leg.Figure 11-21• The extrinsic muscles that move the foot and toes include: (1) muscles that produce extension at the ankle:a. gastrocnemius b. soleusc. fibularisd. tibialis posterior(2) muscles that produce flexion at the ankle: a. tibialis anterior:- opposes the gastrocnemius (3) muscles that produce extension at the toes:a. extensor digitorum longumb. extensor hallucis longus(4) muscles that produce flexion at the toes:- opposing the extensors.• The gastrocnemius and soleus share the calcaneal tendon (Achilles tendon).• The fibrous sheaths that hold the tendons of the toes in place as they cross the ankle are the extensor retinacula.Table 11-18: Note the origins, insertions, actions and innervation of the muscles that move the foot and toes.Figure 11-22• The intrinsic muscles of the foot.Table 11-19: Note the origins, insertions, actions and innervation of the intrinsic musclesof the foot.V. Aging and the Muscular System, p. 371• The effects of aging on the muscular system include:1. Skeletal muscle fibers become smaller in diameter.2. Skeletal muscles become less elastic.3. skeletal muscles develop increasing amounts of fibrous connective tissue(fibrosis).4. Tolerance for exercise decreases.5. The ability to recover from muscular injuries decreases.

first class lever

The fulcrum (F) is between the load (L) & applied force (AF)

Explain how the name of a muscle can help identify its location, appearance, or function.

The name of skeletal muscles includes descriptive information about 1: location in the body -identified by body regions -e.g. temporalis muscle 2. origin and insertion -the first part of the name indicates the origin -the second part of the name indicates the insertion e.g. genioglossus muscle 3. fascicle organization -describes the fascicle orientation within the muscle- i.e. rectus (straight), transversus, and oblique 4. relative position -externus (superficialis) are visible at the body surface- internus (profundus) are deep muscles -extrinsic muscles are outside an organ -intrinsic muscles are inside an organ 5. structural characteristics -such as number of tendons (bi=2, tri=3) -shape (trapezius, deltoid, or rhomboid) -or size longus (long) longissimus (longest) teres (long and round) brevis (short) magnus (large) major (larger) maximus (largest) minor (small) minimus (smallest) 6. action -muscles may be named after movements (flexor, extensor, retractor, etc.) -or common occupations and habits (e.g. risor laughter)

Parallel muscles

fascicles are arranged parallel to the long axis of the muscle; when it contracts it shortens & gets larger in diameter

Circular muscles

fascicles arranged concentrically around an opening; muscle contracts & opening becomes smaller

Convergent muscles

fascicles extend over a broad area & come together/converge at a common attachment site; adaptive to diff. activities bc the stimulation of diff. portions of the muscle can change the direction it pulls

Synergist

muscle that aids a prime mover in a movement

Agonist (prime mover)

the muscle that is most responsible for a particular movement when that muscle contracts.

Compare the major functional differences between the upper and lower limbs.

upper limbs are designed for mobility and dexterity, relatively unstable but flexible lower limbs are designed for locomotion and weight bearing, thus relatively stable but less flexible

Identify the principal axial muscles of the body, plus their origins, insertions, actions, and innervation.

• Axial muscles can be divided into 4 groups based on location and function: 1. muscles of the head and neck2. muscles of the vertebral column3. oblique and rectus muscles4. muscles of the pelvic floor Muscles of the Head and Neck, p. 336• Muscles of the head and neck are subdivided into 6 groups:1. muscles of facial expression2. extrinsic eye muscles3. muscles of mastication4. muscles of the tongue5. muscles of the pharynx6. anterior muscles of the neckFigure 11-4• Muscles of facial expression originate on the skull: orbicularis oris constricts the mouth openingbuccinator moves food around the cheeks• Muscles of the epicranium (scalp) include: temporoparietalisoccipitofrontalisthe platysma covers the anterior surface of the neck• frontal and occipital bellies are separated by the epicranial aponeurosis) Table 11-2: Note the origins, insertions, actions and innervation (nerve supply) of themuscles of facial expression.Figure 11-5• The six extra-ocular or extrinsic eye muscles originate on the surface of the orbit and control the position of the eye:inferior rectus medial rectus superior rectus lateral rectus inferior obliquesuperior obliqueTable 11-3: Note the origins, insertions, actions and innervation of extrinsic eye muscles.Figure 11-6• The muscles of mastication move the mandible. masseter, the strongest jaw muscletemporalis helps lift the mandiblepterygoid muscles position the mandible for chewingTable 11-4: Note the origins, insertions, actions and innervation of the muscles of mastication.Figure 11-7• Names of the muscles of the tongue end in "glossus." palatoglossus originates at the palatestyloglossus originates at the styloid process genioglossus originates at the chin hypoglossus originates at the hyoid boneTable 11-5: Note the origins, insertions, actions and innervation of the muscles of the tongue.Figure 11-8• The muscles of the pharynx begin the swallowing process. pharyngeal constrictor muscles move food into the esophagus laryngeal elevator muscles elevate the larynxpalatal muscles lift the soft palateTable 11-6: Note the origins, insertions, actions and innervation of the muscles of the pharynx.Figure 11-9• Anterior muscles of the neck control the position of the larynx, depress the mandible, and support the tongue and pharynx.digastric, from chin to hyoid, and hyoid to mastoidmylohyoid, floor of the mouthgeniohyoid, between hyoid and chinstylohyoid, between hyloid and styloidsternocleidomastoid, from the clavicle and sternum to the mastoid omohyoid, attaches scapula, clavicle, 1st rib and hyoidTable 11-7: Note the origins, insertions, actions and innervation of the anterior muscles of the neck.Muscles of the Vertebral Column, p. 344Figure 11-10• The muscles of the vertebral column are divided into spinal extensors (superficial and deep) and spinal flexors.• The spinal extensors or erector spinae muscles are subdivided into superficial and deep spinal extensors:- the superficial muscles include the:a. spinalis groupb. longissimus group c. iliocostalis group- the smaller, deep muscles (transversospinalis) include the: a. semispinalis groupb. multifidus musclec. interspinalis musclesd. intertransversarii muscles e. rotatores muscles• The vertebral column has few spinal flexors. In the neck, the longus capitis and longus colli rotate and flex the neck. The lumbar quadratus lumborum muscles flex the spine and depress the ribs.Table 11-8: Note the origins, insertions, actions and innervation of the muscles of the vertebral column.Oblique and Rectus Muscles, p. 346Figure 11-11• The oblique and rectus muscles lie within the body wall.- oblique muscles compress underlying structures or rotate the vertebral column - rectus muscles flex the vertebral column, opposing the erector spinae.• The oblique muscle group, divided by region, includes: Cervical region:- scalene muscles, flex the neck Thoracic region:- intercostal muscles (external and internal intercostals), respiratory movements of the ribs- transversus thoracis, cross the inner surface of the ribsAbdominopelvic region (the same pattern as the thoracic region): - external and internal oblique muscles- transversus abdominis• The rectus group includes the rectus abdominis, the "six-pack" between thexiphoid process and the pubic symphysis. The rectus abdominis is divided longitudinally by the linea alba, and transversely by the tendinous inscriptions.• The diaphragmatic muscle or diaphragm divides the thoracic and abdominal cavities, and performs respiration.Table 11-9: Note the origins, insertions, actions and innervation of the oblique and rectus muscles.Muscles of the Pelvic Floor, p. 349Figure 11-12• The muscles of the pelvic floor:1. support the organs of the pelvic cavity2. flex the sacrum and coccyx3. control movement of materials through the urethra and anus• The perineum (the muscular sheet which forms the pelvic floor) is divided into the anterior urogenital triangle and the posterior anal triangle.• External genitalia are supported by the superficial muscles of the urogenital triangle.• The deep muscular layer between the public bones that supports the pelvic floor and muscles of the urethra is the urogenital diaphragm.• The deep muscular layer extending to the pubis, that supports the anal triangle, is the pelvic diaphragm.