Exam Two Flashcards
What is the relationship between cross sectional diameter and force development?
Greater cross section area means a greater potential for force development
What is the relationship between muscle length and capacity for shortening?
Longer muscles can shorten through a greater range of motion
What are the two types of muscle fiber arrangement?
Parallel
Pennate
What advantages do parallel muscle fibers have over pennate?
Greater range of motion
Run parallel to tendon
What advantages do pennate muscle fibers have over parallel?
Shorter
Increased cross sectional area = more force
Oriented obliquely to tendon
What are the different types of pennate muscle fibers?
Unipennate - Vastus medialis
Bipennate - Gastrocnemius
Multipennate - Deltoid - Greatest CSA
What are the different types of muscle fibers?
Type 1 - oxidative, slow twitch
Type 2a - Fast oxidative glycolytic
Type 2b - Fast glycolytic
What are the roles of muscles?
Agonist Antagonist Synergist Neutralizers Stabilizers
What do agonist muscles do?
Causes motion through a specific plane of motion
Prime mover
What do antagonist muscles do?
Muscle on opposite side of joint of the agonist
Causes opposite action
What do synergist muscles do?
Guiding muscles
Eliminates undesired movements
What do neutralizer muscles do?
Neutralize or counteract other muscles to prevent unwanted movement
Two joint muscles
What are the four ways to inhibit muscle contraction?
No action potential
No ATP
No calcium
No lactate and hydrogen
What are the steps of Excitation contraction coupling?
- Action potential reaches cellular membrane
- Action potential triggers calcium release from sacroplasm
- Calcium binds with the traponin protein on the actin
- Tropomyosin moves to uncover active site, allows myosin to bind to actin
- Energy release strenghtens the actin-myosin bond (powerstroke)
- Actin and myosin filaments slide together
- Muscle shortens
What are myofibrils?
Subunits of muscle cells that contain contractile units
Actin and Myosin
What is skeletal muscle composed of?
Muscle cells
Nerve tissue
Blood
Connective tissue
What are the three layers of connective tissue?
Endomysium
Perimysium
Epimysium
What are the properties of muscle tissue?
Elasticity
Excitability
Contractability
Extensibility
What is the origin of a muscle?
Less moveable bone that a muscle is attached to
What is the insertion of a muscle?
More moveable bone that a muscle is attached to
What is the sarcoplasmic reticulum?
Storage tubules in sarcoplasm
Stores calcium
What is a motor unit?
Alpha motor neuron and all the muscle fibers that it stimulates
What are tendons?
Fibrous connective tissue that connects muscle to bone
What is isometric contraction?
A muscle contracts producing force without changing the length of the muscle
What is isotonic contraction?
A muscle contracts producing force with a change in muscle length and joint angle
What are the two types of isotonic contraction?
Eccentric - muscle lengthens
Concentric - muscle shortens
What is isokinetic tension?
Speed of muscle length change is held constant throughout the entire contraction or extension
What is the stretch-shorten cycle?
An eccentric contraction immediately followed by a concentric contraction
What causes edema?
Accumulation of inflamatory mediators and fluids
Which of the two myofiberals move?
Actin moves
Myosin remains in its location
What is proprioception?
Sensations in the CNS that result with neuromuscular activity
What is kinesthesis?
Awareness of body in regards to space
What branch of the nervous system deals with voluntary movement?
Peripheral nervous system
Somatic nervous system
What is the reflex arc?
Sensory receptors
Afferent fibers (Sensory neuron)
Efferent fibers (Motor neuron)
Reaction
What are proprioreceptors?
Provide feedback relative to tension, length and state of involved segments with respect to contractile state
What role do muscle spindles play in propriorecption?
Sensitive to stretch and rate of stretch
Found in muscle belly
What role do golgi tendon organs play in propriorecption?
Protective in nature
In tendons
Respond to muscle tension
What is the all or none principal?
Action potential either fires or it does not
All fibers in a motor unit will contract or they will not
What is the connection between muscle spindles and the stretch reflex?
Rapid muscle stretch occurs
Sensory impulse to CNS
CNS activates motor neurons, reinforcing stretch
How can muscle fiber recruitment be increased?
Activating more motor units
Activate units containing more fibers
Increase signal frequency
What is the force velocity relationship?
In concentric contractions: as force increases, shortening velocity decreases
In eccentric contractions: as force increases, lengthening velocity increases
What is the length tension relationship?
Potential tension is greatest when muscle is stretched between 100-130% of its resting length when contraction is initiated
What factors affect tension development?
Signal strength
Frequency
What are the cranial bones?
Frontal bone Occipital bone 2 Parietal bones Sphenoid bone 2 Temporal bones Ethmoid bone
What are the sutures that the parietal bones are a part of?
Sagittal suture - seperates parietal bones
Coronal suture - seperates frontal from parietal
Lambdoid - seperates occipital from parietals
Squamous - seperates temporal and parietal
What is the difference between facial and cranial bones?
Facial bones have no direct contact with the brain or meniges
What are the features of the temporal bone?
Zygomatic process Mandibular fossa External acoustic meatus Styloid process Mastoid process
What are the four parts that the temporal bone can be divided into?
Mastoid part
Squamous part
Mastoid part
Petrous part
What are the features of the occipital bone?
Occipital condyles
Foramen magnum
What are the features of the sphenoid bone?
Center is called the sella turcica
What are the features of the ethmoid bone?
Medial crest is called: Crista galli
What is important about the crista galli?
Point of attachment for meniges
What are the facial bones?
Maxillae X 2 Nasal bones X 2 Palantine bones X 2 Inferior nasal conchae X 2 Zygomatic processes X 2 Vomer X 1 Mandible X 1 Lacrimal X 2
What is the importance of the maxillae?
Forms roof of mouth and floor of nasal cavity
What are the palantine bones split into?
Hard palate
Soft palate
What is the importance of the lacrimal bone?
Form part of the medial wall of each orbit
What is the importance of the vomer?
Forms inferior portion of the nasal
What is the importance of the mandible?
Strongest bone in skull
Only facial bone that can move
Body, angel and ramus
What are the divisions of the vertebral column?
7 Cervical 12 Thoracic 5 Lumbar 5 Sacral - fused to form sacrum 5 Coccyx - fused to form tailbone
What are the thoracic vertebrae specialized for?
Rib attachment
Have costal facets
What parts of the spine curve in a convex manner?
Cervical and lumbar
What parts of the spine curve in a concave manner?
Thoracic and pelvic
What are the abnormal spinal curvatures?
Lordosis - exagerated lumbar curviture (Dan)
Kyphosis - Exagerated thoracic curviture (hunchback)
Scoliosis - lateral deviation
What is the thoracic cage?
Bony enclosure that encloses lungs and heart
Components are strenum and 12 pairs of ribs
What are true ribs?
Attach to the sternum
How many true ribs and false ribs do humans have?
Seven pairs of true ribs
Five pairs of false ribs
What are the general vertebral features?
Body
Vertebral foramen
Spinous process
Transverse process
What are the features that only cervical vertebrae have?
Relatively small
Transverse foramen
Forked spinous process
What is the first cervical vertebrae called?
Atlas
What is the second cervical vertebrae called?
Axis
Has dens process, allows rotation
