Lab 6 Terms and Lesson Flashcards
What is the muscle formed of?
Formed by groups of fasciles
What is the epimysium?
Dense irregular connective tissue (tissue that resists tensions from all directions) surrounds muscles.
What is a facicle?
A bundle of individual muscle fibers
What is perimysium?
Dense irregular connective tissue surrpunds fascicles.
What is a muscle fiber (aka muscle cell/myocyte)
An elongated, contractile cell that is a bundle of myofibrils
What is the endomysium?
Layer of connective tissue surrounding individual muscle fibers
What are tendons formed by?
Formed from endomysium, perimysium, and epimysium that extend beyond each muscle fiber that attach the muscle to bone.
What is the structure of the muscle?
Name all parts of a sarcomere on a myofibril
- Z disk
- M line
- Thick filament
- Thin filament
- I band
- A band
- H zone
- Zone of overlap
What is the zoomed in sarcomere on a microfibril look like?
What do the following look like?
- Zone of overlap
- H zone
- Z disc
- M line
- A band
- Halves (2) of I bands
What do the following look like?
- Myosin heads
- Troponin
- Actin
- Tropomyosin
What is muscular dystrophy?
Muscular dystrophy (MD) is classified as a group of inherited diseases in which voluntary muscles weaken over time.
What are four different types of muscular dystrophy? And what two are associated with heart problems?
- Duchenne
- Becker
- Duchenne and Becker are associated with heart problems
- Myotonic (Steinart’s Disease)
- Congenital
What is Duchenne Muscular Dystrophy?
Most common in children, many young boys need a wheelchair by age 12, life expectancy = late teens, early 20s
What is Becker Muscular Dystrophy?
Similar to Duchenne but less severe. Symptoms can be later (as late as 25), can usually walk until 30’s live longer.
What is Myotonic (Steinart’s Disease) Muscular Dystrophy?
Most common in adults, affects CNS, heart, GI tract, eyes, hormone-producing glands.
- Causes myotonia - inability to relax muscles after they contract
What is Congenital Muscular Dystrophy?
Occurs around birth, muscles shrink and cause joint problems, some can die in infancy
What are causes of muscular dystrophy?
- Caused by mutations on X chromosome
- Women have a 50% chance of passing it to their sons
- Caused by absense of dystrophin, which is vital for proper muscle function
What are risk factors of muscular dystrophy?
- Depends on the type…
- Duchenne: young boys
- 3 Risk factors that led to early death for those with Duchenne
- Being underweight (measured from BMI)
- Poor lung function
- High blood concentration of a protein linked to cardia damage
- Family history of muscular dystrophy
What are some symptoms of muscular dystrophy?
- All sorts, very depending on type
- Trouble walking
- Difficulty standing up
- Loss of reflexes
- Scoliosis
- Heart and lung problems
- Issues with swallowing
What are some diagnoses of muscular dystrophy?
- DNA Testing
- Muscle biopsy
- To show if dystrophin is absent or abnormal
- Electromyography or nerve conduction tests
- Blood enzyme tests
- Look for creatine kinase, which deteriorates muscle fibers
What are some treatments for muscular dystrophy?
- Corticosteroids (for short term only)
- Heart medications (i.e. ACE inhibitors)
- Physical therapy (walking and swimming)
- Ventilator for breathing assistance
- Canes/wheelchairs/walkers
- Pacemaker for cardiac abnormalities
What are some complications of muscular dystrophy?
- Contractures: Shortening of tendons, ligaments, and muscles around joints
- This can lead to immobility
- Severe breathing problems
- Heart problems
- Can lead to death
What are some misconceptions and fun facts about muscular dystrophy?
- There are more than 30 different kinds of MD
- Dystrophin makes up .002% of total proteins in striated muscle
- DMD is the gene that encodes dystrophin, and is the largest known human gene
What is prevention for muscular dystrophy?
- There is no way to prevent MD, and there is also no cure
- Certain drugs and different kinds of therapy delay progression of symptoms and improve the affected person’s quality of life
Define origin
Nonmoving point of attachment when a muscle contracts
Define insertion
- Moves toward the origin
- Majority of tension developed when a muscle contracts is focused here
Define a muscle agonist
Prime mover
Define muscle Synergist
Helps the agonist
Define muscle antagonist
Works against the agonist
Define muscle fixator
Stabilizes the origin of the prime mover, providing efficiency
Move your head in hyperextension, extension, and flexion.
Move your arm hyperextension, extension, and flexion
Move your arm in abduction and adduction
Move your arm in circumduction
Move your forearm in flexion and extension
Move your hand in flexion, extension, and hyperextension
Move your hand in abduction and adduction
Move your digits in abduction and adduction
Move your thigh in hyperextension, extension, and flexion
Move your leg in extension and flexion
Move your thigh in abduction and adduction
Move your thigh in circumduction
Move your head in a rotation
Move your thigh of medial rotation and lateral rotation
Move your arm lateral rotation and medial rotation
Move your mandible in elevation and depression
Move your mandible in protraction and retraction
Move your foot inversion and eversion
Move your foot in dorsiflexion and plantar flexion
Move your hand in pronation and supination
Move your digits in opposition
What are the three directions of muscle fibers?
Rectus, transverse, and oblique
What are the four different sizes of muscles?
Maximus, minimus, longus, brevis
How does location relate to naming skeletal muscles?
Named by the bone to which the muscle attaches, or region within which the muscle is located
What are the three shapes of muscle?
- Deltoid
- Rhomboid
- Trapezius
What are the three number of origins?
- Biceps
- Triceps
- Quadriceps
How does action relate to naming skeletal muscles?
Named for the action that the muscle performs
Where are the frontalis and occipitalis? and what is their composite name?
Occipitofrontalis: Composite muscle that overlies the cranium; the two muscles are connected by an aponeurosis
What is the action of the frontalis?
Raises the eyebrows
What is the action of the occipitalis?
Draws scalp posteriorly
Where is the orbicularis oris located and what is its function?
It is the circular muscle that encircles the mouth and its action is to pucker the mouth as in kissing.
Where is the orbicular oculi and what is its action?
Its the circular muscle that encircles each eye and its action is that it closes each eye as in blinking.
What is the location and action of the zygomaticus major?
- Originates on the zygomatic bone and inserts on the skin at the corners of the mouth
- Pulls the corners of the mouth superiorly as in smiling
What is the location and action of the zygomaticus minor?
- Originates on the zygomatic bone and inserts on the upper lip
- Elevates the upper lip, exposes upper teeth
What is the location and action of the platysma?
- Originates on the fascia of the chest and deltoid and inserts on the mandible and skin below the mouth
- Depresses the lower lip and mandible; tenses neck skin
- ***Not in a picture but get neck angry
What is the location and action of the temporalis?
- Originates on the temporal bone and inserts on the mandible
- Elevates and retracts the mandible
What is the location and action of the Masseter?
- Originates on the maxillae and zygomatic bones and inserts on the mandible
- Elevates, protracts and retracts the mandible
What is the location and action of the sternocleidomastoid?
- Originates on the sternum and clavicle and inserts on the mastoid process of the temporal bone
- If one side contracts, the head rotates to the opposite side. if both contract, flexion of the head is the result
Contraction of the muscles of the anterior and posterior trunk creates movement of what?
The vetebral column
Why does the rectus abdominis often appear to have six different portions in lean individuals?
This appearance is due to the presence of tendinous intersections, three connective bands that extend across the rectus abdominis at three different points.
What is the location and action of the rectus abdominis?
- Originates on the pubis and inserts superiorly on the lower ribs and xiphoid process
- Flexes the vertebral column and compresses the abdomen
What is the location and action of the external oblique?
- Originates laterally on the lower ribs and inserts medially on the iliac crest and linea alba
- Rotation of the trunk results if one side contracts. If both sides contract together, flexion of the vertebral column and compression of the abdomen is the result.
What is the location and action of the internal oblique?
- Located deep to the external oblique, the internal oblique originates laterally at the iliac crests and inserts medially at the linea alba and lower ribs
- The internal oblique has the same action as the external oblique: Rotation of the trunk results if one side contracts. If both sides contract together, flexion of the vertebral column and compression of the abdomen is the result.
What is the location and action of the transversus abdominis?
- Located deep to the internal oblique, the transverse abdominis originates laterally on the iliac crest and the cartilages of the lower ribs. It inserts medially at the xiphoid process and linea alba.
- Contraction of the transverse abdominis compresses the abdomen
What is the location and action of the erector spinae and what groups are included in this?
- Made up of the Iliocostalis group, Longissimus group, and the Spinalis group.
- Composite group of muscles that individually originate on vertebral processes or ribs and insert on superior processes of the vertebral column
- When one side contracts, the muscles laterally flex and rotate the vertebral column. When both contract, the muscles extend the vertebral column and maintain erect posture.
- These muscles run along either side of the spine and contribute to extension of both the head and vertebral column.
What is considered the primary muscle of inspiration because its contraction increases the dimensions of the thorax and results in the movement of the lungs?
The diaphragm
_______ of the diaphragm causes expiration
Relaxation
The external intercostals and the internal intercostals are only active during what?
Forced inspiration and expiration
What is the location and action of the diaphragm?
- Dome shaped muscle that originates on the lower ribs and lumbar vertebrae and inserts medially at the central tendon
- During inspiration the diaphragm moves downward in the thoracic cavity, increasing the horizontal and vertical dimensions of the thorax
What is the location and action of the external intercostals?
- Located between the ribs, the external intercostals originate on the inferior border of the superior rib and insert on the superior border of the inferior rib
- Contraction pulls the ribs upward and together to expand the dimensions of the thorax during forced inspiration
What is the location and action of the internal intercostals?
- Located between the ribs, the internal intercostals originate on the superior border of the inferior rib and insert on the inferior border of the superior rib
- Contraction pulls the ribs down and together to decrease the dimensions of the thorax during forced expiration
Muscles that move the pectoral girdle insert where?
Either the clavicle, the scapula, or in some case, both bones.
What is the location and action of the pectoralis minor?
- Anterior muscle of the chest. It originates medially on the upper ribs and inserts laterally on the scapula
- Depresses and protracts the scapula
What is the location and action of the trapezius?
- Posterior muscle of the upper back. It originates medially at the occipital bone, lower cervical and thoracic vertebrae, and inserts on the clavicle and scapula
- Superior portion elevates scapula and clavicle and extends the head; middle portion adducts scapula; inferior portion depresses scapula
What is the location and action of the levator scapulae?
- Posterior muscle of the upper back that originates on the upper cervical vertebrae and inserts on the superior portion of the vertebral border of the scapula.
- Elevates the scapula
What is the location and action of the Rhomboid major?
- Posterior muscle of the upper back that originates on the upper thoracic vertebrae and inserts on the vertebral border of the scapula
- Elevates, adducts and inferiorly rotates the scapula
What is the location and action of the rhomboid minor?
- Posterior muscle of the upper back that originates on the lower cervical and upper thoracic vertebrae and insters on the vertebral border of the scapula
- Elevates, adducts, and inferiorly rotates and scapula
What is the location and action of the serratus anterior?
- Originates on ribs 1-9 and inserts on vertebral border and inferior angle of scapula
- Abducts scapula and rotates it superiorly. “Boxer’s muscle” due to punching/pushing motion
What is the location and action of the pectoralis major?
- Anterior muscle of the trunk that originates on the clavicle, sternum, and upper rubs and inserts laterally on the greater tubercle of the humerus
- Flexes, adducts, and medially rotates the arm
What is the location and action of the latissimus dorsi?
- Posterior muscle of the trunk that originates on the lower thoracic vertebrae and inserts on the anterior proximal humerus
- Adducts, extends, and medially rotates the arm
What is the location and action of the deltoid?
- Large shoulder muscle that originates on the scapula posteriorly and clavicle anteriorly. It inserts on the deltoid tuberosity of the humerus
- Medial fibers abduct arm; anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm
What is the location and action of the suprapinatus?
- Originates on the supraspinous fossa of the scapula and inserts on the greater tubercle of the humerus
- Abducts the arm
What is the location and action of the infraspinatus?
- Originates on the infraspinous fossa of the scapula and insters on the greater tubercle of the humerus
- Laterally rotates and adducts the arm
What is the location and action of the teres major?
- Originates on the inferior posterior surface of the scapula and inserts on the anterior proximal humerus
- Extends, adducts, and medially rotates the arm
What is the location and action of the teres minor?
- Originates on inferior lateral border of scapula and inserts on greater tubercle of the humerus
- Extends and laterally rotates the arm
What is the location and action of the subscapularis?
- Originates on the subscapular fossa of scapula and inserts on the lesser tubercle of the humerus
- Medially rotates the arm
What is the location and action of the biceps brachii?
- Muscle of the anterior arm with two points of origin on the scapula. It inserts on the radial tuberosity
- Flexes and supinates the forearm; flexes arm
What is the location and action of the brachialis?
- Deep to the biceps brachii, the brachialis originates on the anterior distal humerus and inserts on the proximal ulna.
- Flexes the forearm
What is the location and action of the brachioradialis?
- Originates on the distal humerus and inserts on the styloid process of the radius
- Flexes the forearm
What is the location and action of the triceps brachii?
- Muscle of the posterior arm with three points of origin on the scapula and posterior humerus. It inserts on the olecranon process of the ulna
- Extends the forearm and extends the arm
What is the location and action of the pronator teres?
- Originates on the medial epicondyle of the humerus and coronoid process of the ulna and inserts on the midlateral surface of the radius
- Pronates forearm and flexes forearm
The forearm flexors are located where?
On the anterior surface of the arm
The hand flexors are located where?
The anterior surface of the forearm
Forearm extensor and hand extensors are located where?
On the posterior surface of the forearm
What is the location and action of the flexor carpi radialis?
- Muscle of the superficial anterior forearm. originates on the medial epicondyle of the humerus. Inserts on the second and third metacarpals
- Flexes and abducts hand
What is the location and action of the flexor carpi ulnaris?
- Muscle of the superficial anterior forearm. Originates on the medial epicondyle of humerus and superior posterior border of the ulna. Insterts on the pisiform, hamate, and base of the fifth metacarpal
- Flexes and adducts hand
What is the location and action of the palmaris longus?
- Muscle of the superficial anterior forearm. Originates on the medial epicondyle of the humerus. Inserts on the flexor retinaculum and palmar aponeurosis.
- Flexes the hand
What is the location and action of the Flexor digitorum superficialis?
- Muscle of the superficial anterior forearm. Originates on the medial epicondyle of humerus, coronoid process of ulna, and ridge along lateral margin or anterior surface of radius. Inserts on the middle phalance of each finger
- Flexes the digits and hand
What is the location and action of the flexor digitorum profoundus?
- Muscle of the deep anterior forearm. Originates on the anterior medial surface of body of ulna. Inserts on the base of distal phalanx of each finger.
- Flexes the digits and hand
What is the location and action of the extensor digitorum?
- Muscle of the superficial posterior forearm. Originates on the lateral epicondyle of the humerus. Inserts on the distal and middle phalanges of each finger
- Extends the digits, and hand
What is the location and action of the extensor carpi ulnaris?
- Muscle of the superficial posterior forearm. Originates on the lateral epicondyle of the humerus and posterior border of ulna. Inserts on the fifth metacarpal
- Extends and adducts hand
What is the location and action of the extensor carpi radialis longus?
- Muscle of the superficial posterior forearm. Originates on the lateral supracondylar ridge of the humerus. Inserts on the second metacarpal.
- Extends and abducts hand
What is the location and action of the extensor carpi radialis brevis?
- Muscle of the superficial posterior forearm. Originates on the lateral epicondyle of the humerus and inserts on the third metacarpal
- Extends and abducts hand
What is the location and action of the extensor digiti minimi?
- Muscle of the superficial posterior forearm. Originates on the lateral epicondyle of the humerus. Inserts on the tendon of extensor digitorum on the fifth phalanx.
- Extends the digits and hand
What is the location and action of the Abductor pollicis longus?
- Muscle of the deep posterior forearm. Originates on the posterior surface of middle of radius and ulna and interosseous membrane. Inserts on first metacarpal
- Abducts and extends thumb/pollicis and abducts hand
What is the location and action of the extensor pollicis brevis?
- Muscle of the deep posterior forearm. Originates on the posterior surface of middle of the ulna and inserts on the distal phalanx of pollicis
- Extends thumb/pollicis and abducts the hand
