Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
|
What is dance? |
- Can be defined as rhythmically timed form of spatially patterned body movements in which a musical beat generally serves as a timekeeper - It is universal (human), often associated with ceremonial rituals. It almost always involves music. - Takes full advantage of the human capacity for recreation, narrativity, gesturing, mime etc. - May be as ancient as the human capacity for bipedality, although you don't need legs to dance. |
|
|
Classification of dance |
Number of Dancers (solo, pair, group) Configuration (face to face; side by side; line; circle; ring) Status/Gender/Age of Dancers Function (context, contents) Narrative (Ballet) vs. Abstract (Robot and Merengue) Rhythm (march vs. waltz -- 2/4 vs 3/4) Most Active Body Parts Functional joints (extremeties vs core) Shape of movement = trajectory Energy (tempo, constant/smooth) Spread of Flow Throughout the Body |
|
|
What are m |
Muscles are attached to bones via connective tissues called tendons. Contraction of muscle leads to flexion or extension of a joint |
|
|
s |
The muscle fiber is the basic cell types of muscle tissue. Muscles are made up of hundreds of thousands of muscle fibers, arranged in parallel and in series. |
|
|
m |
A typical large muscle (e.g. thigh) is controlled by about 100 ventral horn alpha motor neurons. Each muscle fiber is innervated by only one motor neuron. That motor neuron innervates 100-1000 muscle fibers. |
|
|
d |
A "motor unit" consists of one motor neuron + the muscle fibers it innervates. The innervation ratio varies across muscle types. - A small ratio (e.g. 1:3) in small muscles requiring fine control (fingers, larynx, eyes). - A large ratio (e.g. 1:1000) in large muscles requiring only gross control (thighs, trunk). |
|
|
What are the three types of muscles and motor units |
Slow (continuous activity- thighs - red muscles, must generate a lot force; posteral), Fast "Fatigue resistant" (same as slow), fast "fatigable" (breast muscle - white |
|
|
Slow |
Low strength/force, resistant to fatigue, slow contraction rate. etcTakes the least amount of stimulation |
|
|
Fast "fatigue resistant" |
Active all the time; sustained activation |
|
|
Fast "fatigable" |
Takes the most amount of stimulation |
|
|
What does this graph demonstrate? Three tyoes of motor neurons |
Three types of motor units: Green = fatigue resistant Red = fast fatigue-res Blue = fast fatigableAmount of force produced in response to a single AP in the motor neuron. |
|
|
l |
Motor units are recruited in a fixed order from weakest to strongest - When only a small amount of force is requ |
|
|
w |
s |
|
|
s |
The "size principle" : the order of recruitment is highly correlated with the size od the motor neuron cell bodies, as well as their axons. |
|
|
s |
Slow motor units consist of smaller motor neurons that innervate smaller muscle fibers, and thereby generate a smaller force output. This is where the "size" aspect of the size principle comes in. |
|
|
CAt |
s |
|
|
Motor units are recruited in a fixed order from weakest (smallest to strongest (.... |
e |
|
|
Rate code for muscle Force |
As AP freq is unc in a motor unit, muscle contractions are able to summate, thereby generating larger forces. At the highest rates, individual contractions are no longer apparent .... |
|
|
Rate Code for Muscle Force |
Each set of connected dots is a single motor unit. The number of motor units and the firing rate of each unit increase as more force is generated by the subject. |
|
|
Central Pattern Generators - Walking |
Humans: Stance (extension) vs swing phase (flexion), alternate between each when walking. Cats is more complicated with 4 legs. |
|
|
Central pattern gen for locomotion |
A central pattern generator (CPG) is an oscillatory spinal cord or brain stem circuit responsible programmed, typically rhythmic, movement, such as locomotion. E.g. taking out the spinal cord of fish and placing it in a bowl -- SC itself produces swimming motion alternations. something else. |
|
|
CAT |
Lesion at the level of thoracic SC (since lumbar part is there - humans dont recover here well either here, but cats are different), allow cat to recover, place cat on treadmill. |
|
|
Cat |
Each limb has its own CPG for alternating flexion and estension of the limb during lcoomotion sklfskjd |
|
|
kf |
Metric motion requires nothing more than CPG's in the spinal cord. No brain is necessary! Not surprisingly, metric locomotion is found in most animals. What is special about dance is entrainment not meter. |
|
|
The Descending Motor Pathways |
lol |
|
|
ks |
TWo divisions of the body motor system: 1) one of the proximal (trunk) muscles. It is mainly involved in posterual control. 2) One of the distal (limb) muscles (feet as well as hands). It is involved in skilled voluntary movement etc. |
|
|
Step 1: experiment |
Postural Control precedes fine motor control. Before biceps are activated, the calf muscles activate first in order to counter the power of the biceps. It is setting up postural control FIRST. |
|
|
lol |
1) 2) |
|
|
Two motor systems |
Lateral voluntary system and Medial Postural system |
|
|
Lateral Voluntary System |
M1 direct pathway Corticospinal Pyramidal Pathway ----> Lateral Spinal Cord; Distal Muscles; Limb Muscles |
|
|
Medial/Postural Systems |
M1 Indirect Pathway (cortico)bulbospinal Extrapyramidal Pathway ----> Medial Spinal Cord; Proximal Muscles; Trunk/Axial Muscles |
|
|
Primary Motor Cortex |
Goes down (controls contralaterally) ti pyramidal decussation, hence called pyr tract -- the direct pathway is 'direct' in that it projects directly to ventral horn LMN's w/o having relays in the brain stem. This pathway is called the corticospinal tract. It is also called the pyra because the axons decussate lol |
|
|
sf |
Because of this decussation, control of the limbs by the motor cortex is strictly contralateral. |
|
|
Supplementary Motor Area (SMA) |
The SMA is thought to play a role in interlimb coordination, such as bimanual or bipedal coordination. In other words, |
|
|
ksj |
ex, the sMA |
|
|
When another person becomes an extension of your own body ... |
l |
|
|
Goal directed vs stimulus directed behaviour |
Think Tango dancing GD: Internally-guided self-motivated action, related to the initiation of movement (e.g. dancing the leader's part in a tango); is associated with the SMA, via its connections with the basal ganglia SD: Externally-guided action based on sensory cues (e.g. dancing the follower's part in a tango); is associated with the lateral premotor cortex, via its connections with the cerebellum. |
|
|
For the |
Body system, there are additional upper motor neurons outside the motor cortex. They are located in the brain stem and comprise the extra pyramidal motor pathways. These are true UMN's: they project to LMN's in the ventral horn of the spinal cord. The motor cortex projects to these extrapyramidal.... |
|
|
s |
The extrapyramidal motor nuclei are UMN's but are located in the brain stem, rather.. |
|
|
2 extrapyramidal pathways |
c |
|
|
image |
lol |
|
|
the indirect cortical pathway |
The extrapyramidal motor nuclei in the brain stem are influenced by M1 through the "indirect cortical pathway". The main projection is the cortico... |
|
|
a |
SC, distal muscle occur laterally but prox occur medially. |
|
|
ok |
d |
|
|
d |
s |
|
|
d |
Combining the tuning curves for hundreds of motor neurons gives rise to what is called a population vector.
|
|
|
4 neurons |
The direction of the vector is the neuron's preferred direction. The length of the vector is the neuron's firing rate for the target direction. |
