Chapter 8 - Control of Movement

Physical Actions

Skeletal muscles are responsible for ______________

Tendons

Skeletal Muscles are typically attached to _________

Flexors

Skeletal Muscles that bring limbs towards the body

Extensors

Skeletal Muscles that move limbs away from the body

Contract

Muscles do not flex, they ______

Maintaining Balance

Muscles are usually paired with an opposite. This is important to for ___________________

Muscle Fibers

Within Muscles, there are two types of ____________

Movement, Strength, Alpha

Extrafusal Muscle Fibers are important for producing _________,They possess alot of ________ Contraction of the fibers occurs after contact with _________ motor neurons

Extrafusal Muscle Fibers

Branch of muscle fibers responsible for generating strength and movement of skeletal muscle. Contracted after contact with alpha motor neurons

Intrafusal Muscle Fibers

Branch of muscle fibers found responsible for sending sensory neurons towards the brain and spinal cord to allow monitoring of the state of the muscle. Contracts after contact with gamma motor neurons

within, strength, adjust, gamma

Intrafusal Muscle Fibers are found ________ Extrinsic Muscle Fibers. They do not possess alot of ________, but are important for the brain and spinal cord to monitor the state of muscles to _________ the muscle with respect to the extrafusal muscle. Contraction of these fibers occurs via contact with ______ muscle fibers

Golgi Tendon Organs

____________________ are found within tendons and detect tension and pressure on muscles.

tension, reflex

Damage to Golgi Tendon Muscles can lead to loss of the sensation of _______ within the muscle and effects the Golgi tendon _______

Monosynaptic

The Golgi Tendon Reflex is a type of __________ reflex

Nerve endings, pain, tear

Free _______________ are found within muscle tissue, and may cause ______ following damage or a _______

Pacinian Corpuscles

_______________ are responsible for sensing pressure within muscles

Actin, Myosin, Striated

Skeletal muscle fibers are comprised of overlapping ______ and ______ filaments, giving it a _______ muscle fibers a __________ appearance

Myofibril, Proteins, Slide onto

Within muscles there are _________ that are filaments of _______. When a muscle contracts they _________ of each other, giving muscles the thicker appearance.

Cross Bridges, Pulling

Myosin filament _____________ are responsible for _________ actin filaments

Contraction, Rowing

During ____________ actin and myosin filaments slide past each other due to _______ action of cross bridges

motor endplates

Motor neurons synapse on ________________, which is the point of contact for the neuron on a muscle

Motor Neuron, Muscle Fibers, Motor Unit

A single ___________ usually activates several ___________, collectively referred to as a __________

Strength, Rate of Firing

________ of a muscular contraction is determined by the average ____________ of various motor units

depolarize, acetylcholine.

When muscles contract, many neurons __________, leading to the release of ____________ into the muscle

delayed, continuously

Effects of muscle contracts are _______, which allow muscles to be _____________ contracted

Afferent, Efferent

_________ neurons carry information from sensory receptors to the central nervous system, _________ neurons carry information from motor information away from the central nervous system to the muscles

Sensory Endings, Length

Intrafusal muscle fibers contain _____________ that are sensitive to the _______ of a muscle.

spinal reflexes, lengthens

Intrafusal muscles allow for quick ______________ when a muscle suddenly ___________

a single, correct, stretched, balance.

A Monosynaptic Reflex involves ____________ synapse, they _______ limb movements in response to the muscle being quickly _______. They are also important for the maintenance of ____________

intrafusal, Alpha, Extrafusal

Monosynaptic stretch reflexes involve the ___________ muscle releasing sensory neurons to activate _________motor neurons in the spinal cord, which are sent to __________ muscle (contracts muscle)

antagonist, inhibited

If a monosynaptic stretch reflex effects one muscle, the ___________ muscle is __________

inhibition, excitation, multiple

Polysynaptic Reflex involves ___________ of inhibitory neurons, leading to ___________. This process utilizes _________ synapses

conscious

Polysynaptic Reflexes can be inhibited via ____________ control

Monosynaptic Stretch

The patellar tendon reflex is an example of a _____________________ Reflex

Polysynaptic

The withdrawal reflex of a limb touching a dangerous surface is an example of a ___________ reflex

Primary Motor

_________________ Cortex involves planning and executing voluntary movement, located within the frontal cortex

Stronger

Flexor Muscles are usually _________

Working

Extrafusal Muscle Fibers provide _________ Strength

Fineness, Back, Fingers

Number of muscle fibers from a single motor neuron depends on the ________ of the motor movement. The _________ would have more muscle fibers than the ________

Somatotopic, mapped

The Primary Motor cortex utilizes _____________ organization, meaning the body is _______ onto the Primary motor cortex

Superior, Inferior

Regarding the somatotopic organization of the primary motor cortex: Lateral areas influence _________ body structures, Medial areas influence __________ body structures

several

All movements are caused by the contraction of _________ muscle groups

primary motor cortex, neurons, more

Different areas of the body have more area of the __________________________ dedicated to sending _________ down to the location. E.g., Hands have _____ dedication

neurons, motor neurons, spinal cord

The Primary Motor Cortex involves complex neural circuitry located between _______ in primary motor cortex and ___________ in the _____________

Sustained stimulation

Stimulation of the primary motor cortex causing complex, organized behavior

Short-term Stimulation

Stimulation of the primary motor cortex causing sudden smaller movements.

Primary Motor Cortex

Sustained stimulation and short-term stimulation occur following stimulation of what brain area?

anterior, planning

The Motor Association Cortex is located _________ to the primary motor cortex, and is involved with ___________ movements

particular

The Primary Motor Cortex is responsible for causing movements of __________ parts of the body

visual systems

The motor association cortex receives highly processed inputs from ______________.

Motor Association Cortex

The ______________ becomes active when executing sequences of movements

Supplementary Motor Area

Area of the Motor Association Cortex crucial for behavioral sequences

initiate, stop

If supplemental cortex is inhibited, may ______ first behavior, but _____ next step

non-serial

The sequence of behaviors in the Supplementary Motor Area must be organized in some respects in a _________ manner.

Premotor Cortex

Area of supplementary motor area important in learning and completing movements cued by sensory information

Non-arbitrary

Stimulus involving the location of sensory information, regarding rules, logic, or reasoning: e.g., Light in middle of traffic guiding driving

preserved

Guided behaviors from location information, which are not arbitrary, are _________

Arbitrary Stimuli

Stimuli that with no inherent relationship with unconditioned stimuli

Ventromedial Group

Group of pathways that control muscles closer to the body, essential for fundamental movements

Lateral Group

Group of pathways that control distal muscles, essential for delicate and fine movements

Superior colliculus(tectum), spinal cord

Connections of the Tectospinal Tract

Tectospinal Tract

Tract important for moving head and eyes to follow things in our environment

Vestibular Nucleus (Hind Brain), Spinal Cord

Connections of the Vestibulospinal Tract

Vestibulospinal Tract

Tract important for maintaining balance and posture, receives inputs from the inner ear.

Reticular Formation (Brainstem), Spinal Cord

Connections of the Reticulospinal Tract

Reticulospinal Tract

Tract responsible for reflexes, sneezing and coughing.

rigidity

Damage to the reticulospinal tract may lead to muscle __________

Motor Cortex, Spinal Cord

Connections of the Corticospinal Tract

Corticospinal Tract

Tract responsible for movements of hands and independent finger movements

Motor Cortex, Hindbrain(Cranial Nuclei)

Connections of Corticobulbar Tract

Corticobulbar Tract

Tract responsible for controlling muscles of the face, head and neck region

swallow

ALS has a branch effecting the Corticobulbar Tract that causes issues with mouth movement, eventually compromising the ability to ________

Red Nucleus, Spinal Cord

Connections of Rubrospinal Tract

Rubrospinal Tract

Tract responsible for controlling muscles of limbs, considered “redundant” but helps during surgical recovery

Motor Unit

An alpha motor neuron, its axon, and associated extrafusal muscle fibers make up a __________

The rate of firing of various motor units

The strength of a muscle contraction is dependant on what?

stress

Golgi tendon organ activated is proportional to the ___________ on the muscle

Premotor Cortex, Supplementary Motor Area

areas of the motor association cortex

Medial, Lateral

The Supplementary motor area is located on the ________ surface of the brain. The premotor cortex is located on the ________ surface of the brain

imagining sequential movement.

People can activate their motor association cortex by ___________________________________

sequences of movements

The supplementary motor area is involved in learning and performing behaviors that consist of __________________________

Signaled by arbitrary stimuli.

The premotor cortex is involved in learning and executing responses ________________________

low, high

In the Monkey Button experiment recording SMA activity. A monkey pressing a single button that lit up showed _______ SMA activity. A monkey pressing a sequence of buttons showed _______ SMA activity

Non-Arbitrary, Arbitrary

Waving hand when seeing someone to say hi is a ____________ movement, while waving hand when hearing a buzz is a __________ movement

Gamma Motor System, Muscle Tonus

The reticular formation controls the activity of the ________________________, regulating __________

Sneezing, Coughing, Respiration

Examples of automatic/semi-automatic actions controlled by reticular formation in the Medulla Oblongata.

Mesencephalic Locomotor Region

Region of the brain stimulated by the reticular formation that plays a role in locomotion.

80%

What percentage of the brain’s neurons is contained within the cerebellum?

 Flocculonodular Lobe

Area of the cerebellum found on the caudal aspect. Important for receiving inputs from the vestibular system and projecting to the vestibular nucleus. Additionally, important for postural reflexes

Vermis

Area of the cerebellum found on the midline. Important for receiving auditory and visual information from the colliculi of the tectum, and receiving kinesthetic and cutaneous information from the spinal cord.

Independent, Skilled Limb Movements

The lateral zone of the cerebellum is responsible for ___________________

Frontal Association Cortex, Lateral Zone of Cerebellum.

Complex and skilled limb movement is planned and initiated by the _______________ but actually completed by the ________________

Pontine Nucleus.

How information is shared between Lateral Zone of Cerebellum and Frontal Cortex for movement

Frontal Cortex, Pontine Nucleus, Lateral Cerebellum, Dentate Nucleus, Ventrolateral Thalamus, Motor Cortex, Spine (Corticospinal Tract)

Order of involved Structures regarding complex limb movement

Dentate Nucleus

How information is shared between the cerebellum and the Ventrolateral Thalamus

Red Nucleus, Ventrolateral Thalamus

The two areas of which the dentate nucleus in the cerebellum project to 

gross, timing

Damage to the lateral zone of cerebellum can cause ____________ movements, and effects the _________ of movements

predict

Neurons in dentate _______ next movement in a sequence

rapid, slower

People with degeneration of their cerebellum tend to have problems with ________ movement, but are typically okay with _________ movement

trunk and proximal limbs

The medial zone of the cerebellum typically controls the _______________