Skeletal Muscles Anatomy & Joint Movement Flashcards
Origin/ head
- muscle end attaches to more stationary of two bones
Insertion
- muscle end attaches to bone with greatest movement
Belly
- Largest portion of the muscle between the origin and insertion
Tendon & aponeurosis
- Muscle attaches to bone
- Aponeurosis is a very broad tendon
Agonist
- Muscle that, when contracted, causes an action
Anatgonist
- Muscle working in opposition to angonist
Synergist
Prime movers, fixators
- A synergist muscle assists the agonist muscle or “primary mover” for a specific action at a joint
- Prime mover plays a major role in helping primary mover accomplish movement
- Fixators stabalize the joint crossed by the primary mover, preventing moving of the origin.
Muscles are named according to:
7 points
- Location: Pectoralis
- Size: Maximus
- Shape: Deltoid (delta)
- Action/ function: Abductor, masseter
- Orientation direction of fibers: rectus (fibers that run parallel to midline)
- Origins and insertion: sternocleidomastoid
- Number of heads: Biceps
Sternocleidomastoid
Head and Neck
- Mandibrium of sternum, clavicle, mastoid process.
- Lateral muscle
- Causes flexion: muscles deep into the neck along the anterior margins of the vertebral bodies
Trapezius
Head and Neck
- Shaped like trapezoid…broad origin from the vertebae to the occipital bone.
- Fibers in many direction allows for alot of movement
- Movements include extension and lateral flexion of the neck
Deep group
Vertebral Column
- from vertebra to vertebra
- Involved in movement of vertebral column
Superficial group, erector spinae
Vertebral Column
- Extend from vertebrae to ribs
- 3 subgroups
- Maintain posture
- Always contracting…made with slow-twitch fibers
- Main movements are extension and lateral flexion
Scalene
Thoracic Muscle
- Anterior, middle, posterior
- Grabs on to the first two ribs to help them move upwards when taking a deep breath
Internal Intercostal
Thoracic Muscle
- Deep muscles within the rib
- Depresses the ribs during expiration
External Intercostal
Thoracic Muscle
- In between the ribs
- Elevates rib during inspiration.
Transversus thoracis
Thoracic Muscle
- Attached to the cartilage part
- Depresses ribs during expiration
Diaphragm
Thoracic cage
- Flattens during contraction and increases the volume of the thoracic cavity and vice versa.
- Major movmeent of inspiration
External abdominal oblique
Abdominal wall
- Fibers run at an oblique angle
- Flex and rotate vertebral column and compression.
- Lateral to medial
Internal abdominal oblique
Abdominal wall
- Flexion, rotation, compression
- muscle fibers running in the opposite direction to the external oblique
Transversus abdominis
Abdominal wall
- Runs in transverse plane
- only job is compression
Trapezius
Scapular Movement
- Posterior scapular muscle
- responsible for elevation, depression, rotate and rectraction the scapula
Pectoralis Minor
Scapular Movement
- From rib 3-5
- Attaches to the corachoid process
- Depresses scapula
Serratus anterior
Scapular movement
- Anterior to scapula, under the scapula to the medial boarder.
- Holds scapula in place on the thoracic cage
- also known as the boxer muscles –> holds arm in this position
Levator scapulae
Scapular movement
- Deep to the traps
- Elevate and rotate scapula
Rhomboideus
- Located deep in the traps muscles
- Helps square the scapula
- From vertebrae to medial boarder of scapula
Deltoid
- Triganular shaped, sits overtop should joint
- Abduction and medial/lateral rotation
Pectoralis major
- Broad origin from the thoracic cage
- Flexion, extension, adduction and medial rotation
Latissimus Dorsi
- Attached to the auxillary region of the arm, attachingto the anterior side of the humerous
- Allows extension (pulls arm backwards), adduct (brings arm back towards the body), and medial rotation
Subscapularis
- Located in the subscapular fossa (front)
- Pulls the humerus to the front of the body to perform medial rotation
Infraspinatus
- Belly found in the infraspinatus fossa of the scapula
- Pull the humerus towards the back to do lateral rotation
Tere minor
- Round muscle belly
- Adduct and lateral rotation which will rotate humerus away from the body
Superspinatus
- ## Located at the superspinaous fossa
Intrinsic muscles of the foot
- Flexsion
- Extension
- Abduction and adduction of toes
Anterior compartment
- dorsi flexion
- Eversion and inversion of foot
- Extension of toes
Lateral compartment
- Plantar flexion
- Eversion of toes
Posterior Compartment
- Superficial
- Deep
Superficial: Plantar flextion, flexes knee
Deep: Flexes knee, plantar flexion, inversion foor
toe flexion
Quadriceps
- Rectus femoris (only one that inserts at the hip, causes flexsion of hip)
- Vastus intermedius (deep to rectus femoris)
- Vastus medialis
- Vastus lateralis
- Extension of leg at the knee
Sartorius
- Flexes hip and knee
- laterally rotates thigh
Posterior thigh muscle: hamstring
- Semitendonosus
- Biceps femoris
- Semimembranosus
- Flexion of the knee, extension of the hip
Gluteal and tensor fasciae latae
- extension of thigh and abdction, flexion and stabilize femur
Intrinsic muscles of the hand
- Opposition and reposition
- Thenar muscles (thumb)
- Hypothenar muscles (pinky)
Muscles on anterior surface of the forearm
- flexion of wrist, hand, fingers
- Adduction and abduction of wrist
Muscle on posterior surface of the forearm
- Extension of the wrist, forearm, hand, and figers
- Abduction of the wrist
Extension
- Triceps brachii
- Anconeus
Flexion
- Biceps brachii
- Brachioradialis
- Brachialis
Supination
- Supinator
- Biceps brachii
Pronation
- Pronator quadratus
- Pronator teres
Types of movement
- Gliding (carpals)
- Angular (flexion, extension, hyperextension) (planar flexion, dorsiflexion) (Abdunction and adduction)
- Circular (Rotation) (pronation, supination) (Circumduction)
- Special movement (Evelation, depression) (Protaction, retraction) (Opposition, reposition) (Inversion, eversion)
