8. Muscular System Flashcards
How is cardiac muscle similar to skeletal muscle?
Besides the mechanism of contraction, it also stores calcium, has a sacroplasmic reticulum, many mitochondria and a system of transverse tubules.
How is cardiac muscle similar to smooth muscle?
The mechanism of contraction is essentially the same
What is the function of intercalated disks?
They allow muscle impulses to pass freely so that they travel from cell to cell, triggering contraction.
What characteristic of cardiac muscle contracts the heart as a unit?
when one portion of the cardiac muscle is stimulated, the impulse travels to other parts of the network, cell to cell.
Distinguish between the origin and the insertion of a muscle.
The immovable end of the muscle is the ORIGIN.
The movable end is its INSERTION.
When a muscle contracts, the insertion is pulled towards its origin
Define Prime Mover
The muscle that provides most of the movement, also called agonist.
What is the function of a synergist? An antagonist?
Synergists contract and assist a prime mover so that it’s actions are more effective.
Antagonists resist a prime movers action and cause movement in the opposite direction.
What information is imparted in the muscle’s name?
the muscle’s relative size, shape, location, action, number of attachments, or the direction of its fibers.
Which 6 muscles provide facial expressions?
Epicranius (raises eyebrow) Orbicularis Oculi (closes eye) Orbicularis Oris (closes and protrudes lips) Buccinator (compresses cheeks inward) Zygomaticus (raises corner of mouth) Platysma (draws angle of mouth downward)
Which muscles provide the ability to chew?
Masseter (elevates mandible)
Temporalis (elevates mandible)
Which 3 muscles provide head movements?
Sternocleidomastoid (pulls head to one side, pulls head toward chest or raises sternum)
Splenius capitis (Rotates head, bends head to one side or brings head into upright position)
Semispinalis capitis (extends head, bends head to one side or rotats head)
Which 5 muscles move the pectoral girdle?
Trapezius (Rotates scapula and raises arm; pulls scapula medially or pulls scapula and shoulder downward).
Rhomboid major (raises and adducts scapula)
Levator scapulae (elevates scapula)
Serratus anterior (pulls scapula anteriorly and downward)
Pectoralis minor (pulls scapula anteriorly and downward or raises ribs)
Which muscles move the abdominal wall?
External oblique (tenses abdominal wall and compresses abdominal contents)
Internal oblique (tenses abdominal wall and compresses abdominal contents)
Transversus abdominis (tenses abdominal wall and compresses abdominal contents)
Rectus abdominis (tenses abdominal wall and compresses abdominal contents; also flexes vertebral column
Three types of muscle tissue
Skeletal
Cardiac
Smooth
Broad fibrous sheets of connective tissue that attach to bone or to the coverings of adjacent muscles are called:
Aponeuroses
What is the name of the connective tissue covering the entire muscle
Epimysium
Want connective tissue separates muscle tissue into compartments called fascicles?
Perimysium