Module 3 - Muscular system Flashcards
where is the pectoralis major and what does it do
it attaches to the anterior chest wall, and runs laterally over the shoulder joint and attaches to the upper humerus
when it contracts/shortens it results in adduction of the arms
what is the name of the abdominal muscle with vertical fibres
rectus abdominis (nicknamed 6 pack)
what are the 4 layers of abdominal muscles called
- rectus abdominis (vertical)
- transverse abdominis (horizontal)
- external oblique
- internal oblique
what happens when the abdominal muscles contract
compress abdominal cavity and increase pressure
what are the 2 most superficial muscles of the back
- trapezius
- latissimus dorsi
where do the superficial muscles of the back join medially
spinous process of the vertebrae
the trapezius muscle has 3 fibre directions. What are they and what are their actions
superior (scapula up to cervical spine/head) - elevate scapula
horizontal (scapula to upper thoracic spine) - retract the scapula
inferior (scapula down to lower thoracic spine) - depress the scapula
what muscles work to keep the spine upright/erect
erector spinae
what are the 3 muscle that make up the glutes and what distinguishes them (why are they named that)
they are named by their size (which also happens to be outermost to innermost)
gluteus maximus
gluteus medius
gluteus minimus
how does the gluteus maximus cross the hip joint and consequently what is its function
it crosses posteriorly and extends the hip joint
how do the gluteus medius and gluteus minimus cross the hip joint and what is their function
they cross the hip joint laterally and abduct the hip
what are the 3 positions of muscle fibres in the deltoid, how do they cross the joint and what do they do
position: anterior - flexion of shoulder
position: middle (crosses the shoulder laterally- abduction
position: posterior - extension of the shoulder joint
which muscles are used to flex and extend the elbow and where are they found
flexion = biceps brachii - found anterior to the elbow joint
extension = triceps brachii - found posterior to the elbow joint
note: brachii translates to “of the arm”
bicep translates to “2 headed” and tricep is “3 headed”
what is the name of the group of muscles on the posterior side of the forearm and what is their role
extensors of the wrists and digits
(extend wrists and digits)
what is the name of the muscle group on the anterior side of the forearm and what is their role
flexors of the wrists and digits
(flex wrists and digits)
where are the pronators and supinators located and what do they do
supinators - on top of the radius just below the elbow - they rotate the forearm so the palms face forward in an anatomical position
pronators - just below the elbow and just above the wrist - rotate the wrist so the palm faces backwards in the anatomical position
what is the name of the group of 4 muscles on the anterior side of the thigh and what do they attach to
quadriceps - attach to the femur proximally and tibia distally (over the knee)
the 3 muscles on the posterior aspect of the thigh are known collectively as what
hamstrings
what are the names of the 3 muscles in the hamstring and what is a defining feature of each
from medial to lateral:
semimembranosus - has a flat tendon of origin (originate at ischium of pelvis)
semitendinosus - has a long tendon of insertion (to the tibia)
Biceps femoris - has 2 heads
the hamstrings cross the hip and knee posteriorly. what is their action when contracted
extension of the hip
flexion of the knee
which joint in the body has an opposite naming of flexion and extension
knee
what is the name of the muscles inside your thigh, what joint do they cross and how to they act on it
adductors of the hip
cross the hip joint medially
adduct the hip
what is the muscle on the anterior aspect of the leg, attaching to the tibia and crossing the ankle joint anteriorly and what is it’s role
- it crosses the joint obliquely and attaches to the medial side of the foot
- it is called the tibialis anterior
- it can pull the foot upwards (dorsiflexion of the ankle) or it can turn the plantar surface medially (inversion of the ankle)
what is the name of the main muscle in the calf and what does it attach to posteriorly
it is called the gastrocnemius and attaches to the calcaneus (heel bone) via the achilles tendon