C15- descending system

The motoneurons in the ventromedial portion of the spinal cord are responsible for the flexor muscles of the limbs.

Short propriospinal interneurons connect motor neurons located in adjacent spinal cord segments.

The Ia inhibitory interneuron is not involved in the stretch reflex.

Long propriospinal interneurons facilitate communication between the cervical and sacral segments of the spinal cord.

Interneurons play a minimal role in modulating the signals within the spinal cord.

The corticospinal system allows for purposeful use of the hand and arm under the control of the spinal cord.

In cats, 40% of the frontal lobe is dedicated to the primary motor functions.

The layer that originates corticospinal fibers is predominantly the 4th layer of the cerebral cortex.

The majority of corticospinal fibers in primates are uncrossed.

In humans, corticospinal fibers directly interact with all motor neurons, including axial muscles.

Termination of the corticospinal tract in goats occurs mainly in the lumbar region.

The largest termination of the corticospinal fibers occurs in the thoracic region.

Sherrington emphasized the role of the cortex in reflex actions, stating that reflexes can only be controlled by spinal mechanisms.

The Ib interneuron is positioned directly between Ib fibers and sensory neurons.

Autogenic inhibition operates with increased intensity as muscle force increases, preventing over-exertion.

Renshaw cells are excitatory interneurons responsible for enhancing motoneuron activity.

Humans possess a unique descending system that enables them to perform voluntary movements with high precision.

All mammals exhibit the same dexterity and voluntary movement capabilities as humans.

Independent movements of fingers in humans are solely dependent on anatomical structures.

The first step in assessing hand function after a stroke is to check for independent finger movements.

The precision grip in humans is facilitated by the anatomical independence of hand muscles.

The motor neurons communicate only with short proprio spinal neurons.

The circuitry for locomotion is entirely independent of any brain modulation.

The spinal cord does not play a role in organizing voluntary movements.

Motor neurons are the final common path to skeletal muscles.

The cortex operates at a low organizational level compared to the brainstem.

The muscle's force production is the same at all lengths regardless of motor neuron discharge frequency.

The stretch reflex involves direct signaling from Ia fibers to motoneurons.

The spinal cord's motoneuron pools are disorganized without somatotopic arrangement.

The brain cannot modulate the force exerted by muscle fibers through the frequency of discharge.

Ib fibers have a role in preventing excessively high force by causing muscle relaxation.

The ventral horn of the spinal cord is comprised solely of a dorsolateral section.

The sensor and motor systems do not need to communicate for proper movement functioning.

The diencephalon and telencephalon do not communicate with the spinal cord.

The ventral corticospinal tract accounts for 20% of the corticospinal system and is homolateral.

The primary motor cortex is exclusively responsible for sensory input in the brain.

Macaques are chosen as animal models for research on the corticospinal system due to their close proximity to human brain functions.

The lateral corticospinal tract does not decussate before innervating the spinal cord.

The extended limbic system plays no role in driving human behaviors related to survival.

Neurons retrogradely labeled can show projections from various cortical areas to the corticospinal tract.

The cingulate cortex does not contribute to the corticospinal tract in humans.

The somatosensory cortex has no descending pathways to the anterior horn of the spinal cord.

The primary motor cortex is located in area 4 of the frontal lobe.