Anatomy_Key Terms_Ch11 Flashcards
circular [pattern of fascicles]
fascicles arranged in concentric rings, surround external body openings which they close by contracting, e.g. orxicularis oris muscle around the mouth and the orbicularis oculi around the eyes
convergent [pattern of fascicles]
the origin of the muscle is broad and the fascicles converge toward the tendon of insertion, triangular of fan-shaped muscle, the muscle fibers extend the length of the muscle from origin to insertion, e.g. pectoralis major muscle in the anterior thorax
parallel [pattern of fascicles]
long axes of the fascicles run papallel to the long axis of the muscle and the muscle fibers extend from origin to insertion, muscles are either fusiform with and expanded central belly like the biceps brachii of the arm or straplike like the sartorius muscle of the lower limb
pennate [pattern of fascicles]
the fascicles and the the muscle fibers are short and attach obliquely to a tendon that runs the whole length of the muscle, makes the muscle look like a feather
multipennate [pattern of fascicles]
looks like many feathers situated side by side with all the quills inserting into one large tendon, e.g. deltoid muscle
bipennate [pattern of fascicles]
fascicles insert into the tendon from both sides, e.g. rectus femoris muscle of the thigh
unipennate [pattern of fascicles]
fascicles insert into only one side of the tendon, e.g. the extensor digitorum longus muscle on the anterior leg
lever
rigid bar that moves on a fixed point, the fulcrum, when a force is applied to the lever
effort
the applied force is used to move a resistance, or load
power lever
the load to be moved is close to the fulcrum and the effort is applied far from the fulcrum so a small effort can move a large load
mechanical advantage
a small effort can move a large load
mechanical disadvantage
requires a large effort to move a small load
speed lever
the load arm is longer than the effort arm, so the load is moved over a greater distance and also at a greater speed
law of levers
when the effort arm is longer than the load arm, the lever operates at a mechanical advantage; when the effort arm is shorter than the load arm, the lever operates at a mechanical disadvantage
first-class levers
the fulcrum is located between the load and the point at which the effort is applied
second-class lever
the load and the effort are on the same side of the fulcrum, and the effort is applied farther away from the fulcrum than the load, e.g. wheelbarrow
third-class lever
the load and the effort are on the same side of the fulcrum, and the effort is appled closer to the fulcrum that the load, e.g. forceps
prime mover
aka agonist, a muscle that has the major responsibility for producing a specific movement is the agonist of that motion (can have two agonists)
antagonists
”"”against the leader””, muscles that oppose or reverse a particular movement”
fixators
synergists that hold a bone firmly in place so that a prime mover has a stable base on which to move a body part
somitomeres
”"”somite pieces””, the first seven myotome-like structures in the head collecwively are called _”
muscle of the visceral organs
smooth or cardiac, develops from the splanchnic mesoderm around the early gut
pharyngeal arch muscles
“aka brachiomeric muscles (““gill segment””), skeletal muscles of the pharynx (throat region of the digestive tract) plus some otehr muscles in the head and neck, develop around the embryonic pharynx from the fourth to seventh somitomeres”
axial muscles
skeletal muscles of the thorax, abdomen, and pelvis, plus many muscles of the neck and a few in the head, lie anterior and posterior to the bod axis (vertebral column) and their main functions are moving the trunk and maintaining posture, develop from the myotomes and some somitomeres
limb muscles
upper and lower limbs arise from the ventral region as limb buds and limb muscles develop from the lateral parts of the nearby myotomes
compartments
in the limbs, dense fibrous connective tissue divides the extensor (dorsal) and flexor (ventral) muscle masses into anatomical _
palpation
”"”touching””, feeling internal structures through the skin with the fingers”
posterior triangle
aka lateral cervical region, defined by the sternocleoidomastoid anteriorly, the trapezius posteriorly, and the clavicle inferiorly
anterior triangle
aka anterior cervical region, defined by the inferior margin of the mandible superiorly, the midline of the neck anteriorly, and the sternocleidomastoid posteriorly
midaxillary line
extends inferiorly from the center of the axilla onto the lateral thoracic wall
midclavicular line
runs from the midpoint of the clavicle and extends inferiorly to the groin, passing about 1 cm medial to the nipple
anterior superior iliac spine
most anterior point of the iliac crest, this spine is a prominent landmark that can be palpated in everyone even the overweight
inguinal ligament
indicated by a groove on the skin of the groin, runs medially from the anterior superior iliac spine to the pubic tubercle of the pubic bone
linea semilunaris
”"”half-moon line””, in the skin of lean people, the lateral margin of each rectus muscle makes a groove known as the _”
posterior median furrow
vertical groove in the center of the back
supracristal line
horizontal line through the right and left superior points of each iliac crest (rougly halfway between the posterior mediun furrow and the lateral sides of the body) intersects L4 providing a simple way to locate that vertebra
base of the axilla
the groove in which the underarm hair grows
axillary folds
two thick, rounded ridges of muscle between which is the base of the axilla
