muscular system gross anatomy Flashcards
what is the belly
largest part of the muscle between origin and insertion
what is an insertion?
muscle end attachment to bone with greatest movement
what is the origin / head?
muscle end attachment to more stationary of 2 bones
what are tendons?
attach muscles to bones
what is aponeurosis
a very broad tendon
what is agonist
muscle that causes action when it contracts
what is antagonist
a muscle working in opposition to agonist
what is synergist
muscles that work together to cause a movement
what are the 2 types of synergists?
prime mover: plays a major role in accomplishing movement
fixators: stabilize joints crossed by the primer mover; preventing movement of the origin of the prime mover
what is an example of agonist and antagonist
If bicep is contracting and causing flexion at elbow joint = agonist
Antagonist = tricep
head and neck muscles
flexion - muscles deep within the neck along anterior margins of vertrbeal bodies
extension - posterior neck muscles attached to occipital bone and mastoid process
rotation and lateral flexion - lateral and posterior groups
prime mover - Sternocleidomastoid
Causes forward flexion of head but can only do one side at a time
prime mover - Trapezius
Has fiber in many diff directions which dictates the way the muscles contract
Extension and lateral flexion
muscles that move the vertebral column
2 groups of muscles (help extend, laterally flex and rotate)
deep group:
from vertebra to vertebra
superficial group:
extend from vertebrae to ribs
what is the erector spinae
Prime movers of back extension
3 subgroups that covers different regions throughout the vertebral column
- made for maintaining posture not stretching –> injured when stretched
why is it important to lift with your legs and not your back?
b/c the muscles always contracting = slow twitch fibers => not very strong
When you bend over –> lengthening sarcomere then putting load on the muscles –> not enough overlap in actin and myosin myofil = cant produce much force
=> excessive force = hurt your back
erector spinae muscles allow for which actions?
rotation and extension of vertebral column and lateral flexion of torso
thoracic muscles
scalenes - elevate first 2 ribs during inspiration
external intercostals - elevate ribs
internal intercostals - depress ribs during expiration
diaphragm - major movements of inspiration. flattens during contraction and increases the volume of the thoracic cavity
abdominal wall muscles
rectus abdominis -
external abdominal oblique -
internal abdominal oblique -
transverse abdominis
what does the abdominal wall do
flex and rotate vertebral column, decrease volume of abdominal and thoracic cavities (compression)
help in expiration, vomiting, defection, urination and birth
crossing muscle patterns adds strength to muscles to support organs
scapular movement
muscles that attach the upper limb to the body and move or stabalize tthe scapula and clavicle
muscles involved with scapular movement
trapezius - Elevates, depresses and rotates scapula
levator scapulae - Elevate and rotate scapula
rhombodieus - Pulls scapula towards vertebrae - helps square shoulders/ not hunch
serratus anterior - Holds scapula in place on thoracic cavity
- Boxers muscle b/c helping scapula holding arms in boxing position
pectoralis minor
- Depresses scapula
pectoralis major job
flexion, adduction and medial rotation (and extension if already flexed)
latissimus dorsi
extension, adduct and medial rotation
deltoid job
sits on the cap of shoulder blade and is used for extension, abduction, medial and lateral rotation
what are the 4 rotator cuffs
subscapularis, infraspinatus, teres minor and supraspinatus
SITS
what is the function of the rotator cuff muscles
hold humerus and glenoid cavity
abduction, adduction and rotation
what does the infraspinatus muscle do? and location?
pulls humerus towards back and does lateral rotation
belly of muscle found in infraspinous fossa
what does the subscapularis muscle do? and location?
internal rotation and abduction
Insert on anterior side of humerus
what does the supraspinatus muscle do? and location?
abduction , pulls bone upwards
Inserts on top portion of humerus
what is the teres minor do? and location?
adduct, extension and lateral rotation
forearm movement - extension is preformed with which muscles
triceps brachii
anconeus
forearm movement - flexion is preformed with which muscles
biceps brachii
brachioradialis
brachialis
forearm movement - supination is preformed with which muscles
supinator
biceps brachii
forearm movement - pronation is preformed with which muscles
pronator quadratus
pronator teres
what can the muscles on the anterior surface of the forearm do?
flexion of wrist, hands and fingers
abduction and adduction of wrist
what can the muscles on the posterior surface of the forearm do?
extension of wrist, hand and fingers
abduction of wrist
where are the thenar and hypothenar intrinsic muscles location and their function?
thenar - fleshy group of muscles on thumb side
hypothenar - on pinky side
function:
- Involved in abduction or adduction of hand
- Reposition and opposition of fingers
- Help provide fine motor movement dexterity in hands
anterior muscles for thigh movement and their function
iliopsoas - posas major + iliacus
hip flexion
posterior muscles for thigh movement and their function
gluteals and tensor fasiae latae
extension and abduction of thigh and flexsion and stabilize femur
what are muscles that help move the leg
sartorius = flexes hip and knee, also laterally rotates thigh (sitting cross legged)
medial thigh muscles = adduction
posterior thigh muscle / hamstrings = flexsion of knee and extension of hip
what ae the 3 hamstring muscles
semitendinosus
bicep femoris
semimembranosus
leg movements occur with the __. what are the functions as well
quadriceps femoris
- extension at the knee
rectus femoris - also flexes at hip
vastus intermedius
vastus medialis
vastus lateralis
where do all of the quadriceps femoris muscles insert?
patellar tendon
patellar ligament extends from patella to tibial tuberosity
ankle foot and toes movement - anterior compartment
extensors involved in dorsiflexion and eversion/inversion of foot; extension of toes
ankle foot and toes movement - lateral compartment
planter flexion and eversion
ankle foot and toes movement - posterior compartment
superficial muscles:
- plantar flexion
- have common tendon insertion = calcaneal tendon (achilles)
- gastrocnemius
- plantaris
- soleus
deep muscles:
- plantar flexion, inversion of foot and flexion of toes
eversion vs inversion
eversion: Tilting of the foot so the sole faces away from the midline.
inversion: Tilting of the foot so the sole faces into the midline
