Exam 3 Flashcards
<p>Deltoid origin</p>
<p>acromial end of clavicle, the acromion, and the spine of the scapula</p>
<p>Deltoid insertion</p>
<p>deltoid tuberosity on lateral midregion of humerus</p>
<p>Deltoid action</p>
<p>anterior fibers flex and medially rotate arm; middle fibers prime mover of
arm abduction; posterior fibers extend and laterally rotate arm.
</p>
<p>Coracobrachialis action</p>
<p>works as a synergist to the pectoralis major in flexing and adducting the arm
(a) Action = adducts and flexes arm</p>
<p>Teres major</p>
<p>Latin for “round” and “greater”) works synergistically with the latissimus dorsi by extending, adducting, and medially rotating the arm.
(a) Action = same as latissimus dors</p>
<p>4 rotator cuff muscles</p>
<p>Subscapularis Supraspinatus Infraspinatus Teres minor </p>
<p>Subscapularis</p>
<p>located on the anterior surface of the scapula (between scapula
and ribs).
- Action = medially rotates arm, like when you wind up to pitch a baseball</p>
<p>Supraspinatus</p>
<p>located superior to the scapular spine.
- Action = abducts the arm as when you start to execute a pitch of a baseball, with your arm fully abducte</p>
<p>Infraspinatus</p>
<p>is located inferior to scapular spine.
- Action = adducts and laterally rotates the arm, like when you slow down your
arm after pitching a basebal</p>
<p>Teres minor</p>
<p>Latin for “round” and “lesser”) is located inferior to the infraspinatus.
- Action = same as infraspinatus (synergistic muscles)</p>
<p>2 compartments that move the elbow and forearm</p>
<p>Anterior (flexor) compartment, which contains primarily elbow flexors
- Posterior (extensor) compartment, which contains elbow extensors</p>
<p>Main flexors</p>
<p>Biceps brachii</p>
<p>Main extensor </p>
<p>Triceps brachii</p>
<p>Biceps brachii</p>
<p>Latin for “two heads” and “arm”) is a large, two-headed
muscle on the anterior surface of the humerus.</p>
<p>Biceps brachii origin </p>
<p>long head originates on the supraglenoid tubercle of scapula while the short
head originates on coracoid process of scapula</p>
<p>Biceps brachii insertion</p>
<p>radial tuberostiy and bicipital aponeurosis (</p>
<p>Biceps brachii action</p>
<p>flexes elbow joint and is powerful supinator of forearm. An example of this
supination movement occurs when you tighten a screw with your right hand. [The tendon of the long head of the biceps brachii crosses the shoulder joint, so this muscle helps flex the humerus as well, albeit weakly]</p>
<p>Triceps brachii</p>
<p>Latin for “three heads” and “arm”) is the large, three- headed muscle on the posterior surface of the arm. It is the prime extensor of the elbow joint, and so its action is antagonistic to that of the biceps brachii</p>
<p>Triceps brachii origin</p>
<p>long head originates at infraglenoid tubercle of scapula, the lateral head
originates on posterior humerus above radial groove, and the medial head originates
on posterior humerus below radial groove</p>
<p>Triceps brachii insertion</p>
<p>all three parts of this muscle merge to form a common insertion on the
olecranon of the ulna</p>
<p>Triceps brachii action</p>
<p>primary extensor of the elbow joint [only the long head of the triceps
brachii crosses the glenohumeral joint, where it helps extend the humerus]</p>
<p>Anterior compartment of the forearm</p>
<p>Most of the anterior compartment muscles originate on the medial epicondyle of
the humerus via a common flexor tendon. Muscles in the anterior compartment of the forearm tend to flex the wrist, the metacarpal joints, and/or the interphalangeal joints of the fingers.</p>
<p>Posterior muscles of the forearm</p>
<p>Most of the posterior compartment muscles originate on the lateral epicondyle of the humerus via a common extensor tendon. Muscles in the posterior compartment tend to extend the wrist, the metacarpal joints, and/or the interphalangeal joints.</p>
<p>What are the tendons surrounded by</p>
<p>The tendons of forearm muscles typically are surrounded by tendon (synovial)
sheaths and held adjacent to the skeletal elements by strong fascial structures.</p>
<p>Fibrous bands in the wrist</p>
<p>Retinacula</p>
<p>Retinacula</p>
<p>The retinacula help hold the tendons close to the bone and prevent the tendons from
“bowstringing” outward.</p>
<p>Flexor retinaculum</p>
<p>Flexor tendons of the digits and the “median nerve” pass through the tight space
between the bones and the flexor retinacula, which is called the “carpal tunnel”.</p>
<p>What are the posterior carpal bones covered in</p>
<p>Extensor retinaculum</p>
<p>Intrinsic muscles of the hand</p>
<p>The intrinsic muscles of the hand are small muscles that both originate and insert on the hand; they are housed entirely within the palm.
1) As was stated earlier, there are no muscles in the fingers (digits).</p>
<p>Anterior compartment of leg</p>
<p>extend the knee or flex the thigh</p>
<p>Lateral,compartment of leg</p>
<p>abducts the thigh</p>
<p>Posterior compartment of leg</p>
<p>flexors of the knee and extensors of the thigh.</p>
<p>Medial compartment of thigh</p>
<p>adductors of the thigh</p>
<p>Where do the majority of the thigh muscles originate from</p>
<p>Os coxae</p>
<p>Sartorius</p>
<p>Latin for “tailor” crosses over the
anterior thigh. It is the longest muscle in the body and it enables one to assume a cross-legged sitting position (hence the designation as the ‘tailor’s muscle”</p>
<p>Sartorius origin</p>
<p>anterior superior iliac spine</p>
<p>Sartorius insertion</p>
<p>tibial tuberosity, medial side</p>
<p>Sartorius action</p>
<p>flexes thigh and rotates thigh laterally; flexes leg and rotates leg medially</p>
<p>Gracilis action</p>
<p>adducts and flexes thigh; flexes leg</p>
<p>Tensor fasciae latae</p>
<p>t attaches to a lateral thickening of the fascia lata, called the “iliotibial tract” (iliotibial band, IT band), which extends from the iliac crest to the lateral condyle of the tibia</p>
<p>Tensor fasciae latae origin</p>
<p>iliac crest and lateral surface of anterior superior iliac spine</p>
<p>Tensor fasciae latae insertion</p>
<p>iliotibial tract (iliotibial band, IT band)</p>
<p>Tensor fasciae latae action</p>
<p>abducts the thigh; medially rotates thigh</p>
<p>Deltoid</p>
<p>The “deltoid” (Greek for “shaped like the letter delta, Δ”) is a thick, powerful
muscle that functions as the prime abductor of the arm and forms the rounded contour of the shoulder. It is also a good location for administering intramuscular (I.M.) injections.</p>
<p>Gluteus Maximus</p>
<p> (Latin for “buttock” and “largest”) is the largest and
heaviest of the three gluteal muscles. It is the chief extensor of the thigh. It is also a common site for intramuscular (I.M.) injections.</p>
<p>Gluteus Maximus origin</p>
<p>iliac crest, sacrum, and coccyx</p>
<p>Gluteus Maximus insertion</p>
<p>iliotibial tract (iliotibial tract, IT band) of fascia lata, linea aspera of
femur, and gluteal tuberosity of femur.</p>
<p>Gluteus Maximus action</p>
<p>extends and rotates thigh laterally</p>
<p>Piriformis</p>
<p>can cause pressure
on a major nerve that runs down the back of the thigh. In some persons the sciatic nerve even passes through the belly of the piriformis muscle</p>
Biceps femoris
Latin for ‘two heads” and” femur”) is a two-headed muscle that inserts on the lateral side of the leg. Its tendon of insertion is easily seen and palpated at the lateral margin of the popliteal fossa when the knee is flexed.
Biceps femoris origin
long head on ischial tuberosity (the part of the pelvis you sit on) while the
short head originates on linea aspera of femur
Biceps femoris insertion
head of fibula
Biceps femoris action
extends thigh (long head only), flexes leg (both long and short heads), and
laterally rotates leg
Semimembranosus
Latin for “half membrane”) is deep to the
semitendinosus and inserts on the medial side of the leg. Its tendon of insertion, along with that of the more superficial semitendinosus, is easily seen and palpated at the medial margin of the popliteal fossa when the knee is flexed
Semibranosus origin
ischial tuberosity
Semimembranosus insertion
posterior surface of medial condyle of tibia
Semimembranosus action
extends thigh and flexes leg; medially rotates leg
Coxal (hip) joint
Acetabulofemoral joint
Actions of the hip joint
(a) Flexion
(b) Extension
(c) Abduction/Adduction (d) Rotation
(e) Circumduction
Fibrocartilage that runs along the rim of the acetabulum
Acetabular labrum
What is the vocal joint secured by
1) A strong fibrous joint (articular) capsule 2) Several ligaments
3) A number of powerful muscles
Ligamentum teres
This ligament does not provide much strength to the joint but it does typically
contain a small artery that supplies some of the blood to the head of the femur
Knee joint
The knee joint is the largest and most complex diarthosis of the body. It is also one of the more commonly injured joints in the body.
1) It is primarily a hinge joint, but when the knee is flexed, it is also capable of slight
rotation and lateral gliding movements
Two articulations of the knee joint
1) The “tibiofemoral joint” is between the condyles of the femur and the condyles of the tibia.
2) The “patellofemoral joint” is between the patella and the patellar surface of the anterior distal femur.
Articular capsule of knee joint
The knee joint has an articular capsule that encloses on the medial, lateral, and posterior regions of the knee joint.
1) The joint capsule does not cover the anterior surface of the knee joint; rather, the
quadriceps femoris muscle tendon passes over the anterior surface.
2) The patella, which we learned earlier is a sesamoid bone, is embedded within this
tendon, and the “patellar ligament” extends inferiorly to the patella and attaches
on the anterior surface of the tibia (at tibial tuberosity).
3) Thus, there is no single unified capsule in the knee, nor is there a common
synovial cavity.
Lcl
The “lateral (fibular) collateral ligament” (LCL) reinforces the lateral surface of the
knee joint.
- This ligament runs from the femur to the fibula and prevents the lower leg from
moving too far medially relative to the thigh.
- Your authors refer to the lateral collateral ligament as preventing
“hyperadduction” of the lower leg relative to the thigh.
- An alternate term to hyperadduction of the lower leg is “varus deviation”, which
means the part distal to the joint is abnormally angulated towards the midline of
the body.
MCL
The “medial (tibial) collateral ligament” (MCL) reinforces the medial surface of the
knee joint.
- This ligament runs from the femur to the tibia and prevents the lower leg from
moving to far laterally relative to the thigh.
- Your authors refer to the medial collateral ligament as preventing
“hyperabduction” of the lower leg relative to the thigh.
- An alternative term to hyperabduction of the lower leg is “valgus deviation”,
which means the part distal to the joint is abnormally angulated away from the
midline of the body.
- The medial collateral ligament is attached to the medial meniscus (see discussion
below) of the knee joint as well, so an injury to the medial collateral ligament
usually affects the medial meniscus
C-shaped Fibrocartilage pads
2) Deep to the articular capsule and within the joint itself is a pair of C-shaped
fibrocartilage pads located on the condyles of the tibia which are called the “medial meniscus” and the “lateral meniscus”.
(a) These fibrocartilage pads help stabilize the joint medially and laterally and act as
cushions between the articular surfaces.
Cruciate ligaments
(a) These ligaments cross each other in the form of an “X”, hence the name cruciate.
(b) The “anterior cruciate ligament” (ACL) runs from the posterior femur to the anterior side of the tibia.
- When the knee is extended, the ACL is pulled tight (taut) and prevents hyperextension.
- The ACL prevents the tibia from moving too far anteriorly of the femur.
(c) The “posterior cruciate ligament” (PCL) runs from the anterioinferior femur to the
posterior side of the tibia.
- The PCL becomes taut on flexion, and so it prevents hyperflexion of the knee
joint.
- The PCL also prevents the tibia from moving too far posteriorly of the femur.
Locking the knee
1) Humans are bipedal animals, meaning that they walk on two feet.
2) An important aspect of bipedal locomotion is the ability to “lock” the knees in the
extended position and stand erect without tiring the leg muscles.
3) At full extension, the tibia rotates laterally so as to tighten the ACL and squeeze
the meniscus between the tibia and femur.
Talocrural joint
highly modified hinge joint that permits dorsiflexion and plantar flexion, and includes two articulations within one joint capsule.
1) One of these articulations is between the distal end of the tibia and the talus.
2) The other articulation is between the distal end of the fibula and the lateral
articular facets of the talus
Deltoid ligament
On the medial side, the strong “deltoid ligament” extends from the medial malleolus of the tibia to the talus, calcaneus, and another tarsal bone.
(a) This ligament prevents overeversion of the foot
3 lateral ligaments
Anterior talofibular ligament
Posterior talofibular ligament
Calcaneofibular ligament
Anthroscope
Disease of the joints can be diagnosed with a specialized flexible endoscope,
Muscle fibers characteristics
a. Excitability, which means it responds to electrical stimuli.
b. Contractility, which means it contracts to move bones or propel materials inside the
body.
c. Elasticity, which means the muscle cell will recoil to its resting length when the
applied tension is removed.
d. Extensibility, which means a muscle cell is capable of extending in length in response
to the contraction of opposing muscle cells (i.e.- the triceps brachii muscle on the back of your arm extends when the biceps brachii muscle on the front of your arm contracts).
Hypertrophy
Increase in muscle fiber size
What type of ,uncles are skeletal muscles
Voluntary muscles
bundles of muscle fibers
fascicles
circular muscles
fibers concentrically arranged around an opening or recess, also called a sphincter
parallel muscles
fascicles that run parallel to its long axis
have a “belly”
convergent muscles
widespread muscle fibers the converge on a common attachment site example is the pectoralis major
pennate
feather muscles, one or more tendons extending through their body and the fascicles are arranged at an oblique angle to the tendon
unipennate muscle
muscle fibers are on the same side
bipennate muscles
muscle fibers are on both sides, these are the most common
multipennate
tendon branches within the muscle example is the deltoid muscle
lever
elongated, rigid object that rotates around a fixed point called the fulcrum
long bone
acts as a lever that moves the resistance
a joint serves as
the fulcrum
a muscle serves as
the effort
the effort is not where the body of the muscle is located but rather…
where the muscle attaches to the bone
first class lever system
EFR
seesaw
ex. atlanto-occipital joint of the neck, muscles in the post side pull inferioirly on the nuchal lines of the occipital bone and oppose the head to tip
ex. triceps brachi
second class levers
FRE
lifting the handles of a wheelbarrow
ex. contracting the calf muscle to elevate the body onto the ball of the foot
third class levers
REF
drawbridge
most common type
ex. flexion of the elbow and elevation of the mandible to bite off a piece of food