The Muscular System Flashcards
Describe the interaction of skeletal muscles?
They can work together or opposite to undo each other’s movements. They also can only ever pull on bones, they cannot push. They pull in a way that the insertion will move towards the origin.
List and describe the functional groups of skeletal muscles?
Prime Mover (Agonist) - provides the most force for a particular action
- Antagonist - Opposes or reverses a particular action
- Synergists - Muscle that are ‘on” or contracting, together. Help prime movers or reduce undesirable movement
- Fixators - Synergist that immobilize a bone
Describe the various ways the skeletal muscles are named?
- Location - Where it is on the body
- Shape
- Size
- Direction of the fibers - Transversus, Oblique, Rectus
- Number of origins - how many heads form the nuscles origin
- Location of the attachment
- Action the muscle will perform
- Any combination of the above
List and describe the arrangement of fascicles in skeletal muscles?
Circular - Usually a round muscle with fibers in a circular pattern
- Convergent - fibers start at a broad origin and run to a common point
- parallel - fibers running in the same direction along a long, strap-like muscle
- Fusiform - Fibers running in the same direction along a long muscle with a thicker middle portion
- Pinnate - obliquely running fibers, Uni- one set Bi- two sets; Multi - Three or more sets
List and describe the three components to a lever system?
Lever - Bar that rotates around a point; our bones
Fulcrum - point in which the lever rotates about; our joints
Force - Effort - a force that provides the movement - our muscle Load - Mass being moved - our body mass and potentially an external object
Frontalis
Origin: Galea aponeurotice
Insertion : Eyebrow
Primary Action : Raises eyebrows, wrinkles forehead
Occipitalis
Origin: Occipital and Temporal Bones
Insertion: Galea aponeurotica
Primary Action: Pull scalp posteriorly
Oribicularis oculi
Origin : frontal and maxillary bones
Insertion: eyelids
Primary action: blinking and squinting
Orbicularis oris
Origin : maxilla and mandible
Insertion : Muscle and skin of mouth
Primary action: Closes, purses and protrudes lipds
Buccinator
Origin : Molar region of maxilla and mandible
Insertion: orbicularis oris
Primary action: Draws corners of mouth laterally, chewing
Temporalis
Origin : Temporal bone
Insertion : Mandible
Primary action : Elevates and retracts mandible
Masseter
Origin : Zygomatic Arch/Maxilla
Insertion : mandible
Primary action: Primary elevator of mandible
Digastric
Origin : Temporal bone and mandible
Insertion : hyoid
Primary action : swollowing and speech
Mylohyoid
Origin : Mandible
Insertion : Hyoid
Primary action : Elevates hyoid and floor of mouth
Sternohyoid
Origin : Sternum
Insertion : hyoid
Primary action : Depresses hyoid and larynx
Sternothyoid
Origin : Sternum
Insertion : Thyroid cartilage
Primary action : Pulls thyroid cartilage inferiorly
Thyrohyoid
Origin : Thyroid Cartilage
Insertion : Hyoid
Primary action : Depresses hyoid and elevates larynx
Sternocleidomastoid
Origin : Sternum/Clavicle
Insertion: Temporal and Occipital bones
Primary action : Both - neck flexion; Singular - rotates head to opposite side
Scalenes (anterior, medial, posterior)
Origin : cervicle
Insertion : Ribs 1 & 2
Primary action : Elevates ribs 1 , 2; flex and rotate neck
Splenius Capitis
Both - extend/hyperextend head ; single -rotate and lateral flexion
Splenius cervicis
Both - extend/hyperextend head ; single -rotate and lateral flexion
lliocostalis cervicis
Both - extend vertebral column; single - lateral flexion
lliocostalis thoracis
Both - extend vertebral column; single - lateral flexion
lliocostalis lumborum
Both - extend vertebral column; single - lateral flexion
Longissimus capitis
Both - extend head; single turns head
Longissimus Cervicis
Both - extend head; single turns head
Longissimus Thoracis
Both - extend head; single turns head
Spinalis thoracis
Extends vertebral column
spinalis cervicis
Extend vertebral column