Extrinsic Back Flashcards
Muscle type found in the walls of hollow organs
Smooth muscles
Contractions of smooth muscles are _____ movements triggered by impulses from _____ nervous system
- Involuntary
- Autonomic
Cardiac muscle fibers are made up of cells called:
Cardiomyocytes
Function of contraction of cardiac muscle fibers
Pumps the heart
Thin connective tissue that wraps around the whole muscle
Epimysium
Connective tissue surrounding a fascicle
Perimysium
CT surrounding muscle fiber
Endomysium
Where muscle attaches to a bone
Attachment sites
Attachment site where bone remains immobile during action
Origin
Place on the bone that moves during an action
Insertion
Muscle that is performing an action
Agonist
Muscle that performs opposite action is relaxing
Antagonist
Muscle types circular in shape
Circular muscles
Circular muscle examples
- Orbicularis oris
- Orbicularis oculi
- Sphincters of bowels, bladder
Muscle types wider than the point of insertion
Convergent
What does convergent fiber arrangement allow for
Maximum force production
What is convergent muscle sometimes called?
Triangular muscles
Convergent muscle example
Pectoralis major
Muscles which fibers run parallel to each other
Parallel
What are parallel muscles also called?
Strap
Parallel muscle features
- Long muscles, large movements
- Lower strength, higher endurance
Parallel muscle example
Sartorius
Muscle type that is sometime included in parallel muscle group
Fusiform
Fusiform muscle shape
Spindle
Muscle belly is wider that origin and insertion
Fusiform
Fusiform example
Biceps brachii
Skeletal muscle type defined as a large number of muscle fibers, high strength
Pennate
Skeletal muscle type in which fibers are arranged to inset in a diagonal direction onto the tendon
Unipennate
Unipennate examples
- Lumbricals
- Extenson digitorum longus
Skeletal muscle type in which two rows of muscle fibers are facing in opposite directions
Bipennate
Where do bipennate muscle fibers insert onto?
Central tendon
Bipennate muscle features
- Greater power
- Less ROM
Bipennate example
Rectus femoris
Skeletal muscle type in which there are multiple rows of diagonal fibers
Multipennate
Multipennate example
Deltoid
Types of muscles by inneravation
- Hypaxial
- Epaxial
Extrinsic back muscles
Hypaxial
Intrinsic back muscles
Epiaxial
What are hypaxial muscles innervated by?
Ventral rami
What are epiaxial muscles innervated by?
Dorsal rami
Superficial, extrinsic back muscles (hypaxial, ventral rami)
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid major
- Rhomboid minor
Intermediate hypaxial back muscles
- Serratus posterior superior
- Serratus posterior interior
Deep/intrinsic epiaxial back muscles
- Erector spinae group
- Transversospinalis group
- Others
Flat sheet or ribbon of tendon like tissue that anchors a muscle
Aponeurosis
Purpose of aponeuronsis
Takes place of tendon or bone in sheet like muscles having wide area of attachment
Thoracolumbar aponeurosis blends laterally with aponeurosis of which muscle?
Transversus abdominus muscle in the lumbar region
The anterior layer of the thoracolumbar aponeurosis is anterior to:
Quadratus lumborum muscle
The anterior layer of the thoracolumbar aponeurosis ends where?
Medially in TPs of lumbar vertebrae
The middle layer of the thoracolumbar aponeurosis is posterior to:
Quadratus muscle, attaches to TP
The middle layer of the thoracolumbar aponeurosis is anterior to:
Intrinsic muscles of the back
What does the posterior layer of the thoracolumbar aponeurosis cover?
Erector spinae group
Where does the thoracolumbar aponeurosis end?
Laterally in lumbar by blending with aponeurosis of transverse abdominis muscle
Principal actions of the superficial back muscles
Motions of the upper limbs
Superficial back muscles are innervated by:
Ventral rami of spinal nerves, hypaxial
