which statement is true regarding upper motor neurons course hero

Where are the C.Upper motor neurons located?

c.Upper motor neurons are located in the gray matter of the spinal cord.

Which part of the body is responsible for conscious and unconscious muscle synergy and for maintaining balance and posture?

The cerebellum is responsible for conscious and unconscious muscle synergy and for maintaining balance and posture.

What is the primary response of norepinephrine?

The primary response from norepinephrine is the stimulation of the α1-adrenergic receptors that cause vasoconstriction.

What is the membrane that separates the cerebellum below from the cerebral structures above?

The tentorium cerebelli is a membrane that separates the cerebellum below from the cerebral structures above.

How much blood flow does the brain get?

The brain receives approximately 20% of the cardiac output, or 800 to 1000 ml of blood flow per minute.

Which nerves carry sensory impulses toward the CNS?

Peripheral nerve path ways can be afferent (ascending) pathways that carry sensory impulses toward the CNS.

Which part of the brain controls respiration?

The medulla oblongata makes up the myelencephalon and is the lowest portion of the brainstem. Reflex activities, such as heart rate, respiration, blood pressure, coughing, sneezing, swallowing, and vomiting, are controlled only in this area.

Which lobe is responsible for goal-oriented behavior?

Occipital lobe. ANS: C. The prefrontal area is responsible for goal-oriented behavior (i.e., ability to concentrate), short-term or recall memory, and the elaboration of thought and inhibition on the limbic (emotional) areas of the CNS.

Which nerves carry sensory impulses toward the CNS?

Peripheral nerve pathways can be afferent (ascending) pathways that carry sensory impulses toward the CNS. The remaining options do not carry sensory information to the CNS.

What are the two major areas of hypothalamic function?

Hypothalamic function falls into two major areas: (1) maintenance of a constant internal environment, and (2) implementation of behavioral patterns. The remaining options do not address these functions.

What happens when a neurotransmitter is bind to a receptor?

The binding of the neurotransmitter at the receptor site changes the permeability of the postsynaptic neuron and , consequently, its membrane potential. The remaining options do not accurately describe the occurrence.

Where are the nuclei of the cranial nerves located?

The nuclei of cranial nerves IX through XII (see Table 15-6 for discussion) are located only in the medulla oblongata.

Which postganglionic fibers release norepinephrine?

Most postganglionic sympathetic fibers release norepinephrine (adrenaline). The remaining options do not reflect the correct site of norepinephrine secretion.

Where does nerve regeneration occur?

Nerve regeneration is limited to only myelinated fibers and generally occurs only in the peripheral nervous system.

How are B. Upper Motor Neurons classified?

B.Upper motor neurons are classified according to the pathways they travel in

Where are the lower motor neurons located?

This statement is true. The cell bodies of the lower motor neurons are located in the brainstem and the grey mater of the spinal cord and their axons leave and synapse with the muscles in the body

Which type of LMN regulates movement?

This is true. LMNs carry information passed to them from the upper motor neurons and then synapse with the muscles of the body. There are two types of LMNs: the alpha LMNs regulate contraction of skeletal muscle to produce movement; and the gamma LMNs regulate the sensitivity of the muscle spindles for modulation of alpha LMN excitability.

Which synapse is associated with skeletal muscle fibers?

A.Alpha LMNs synapse with skeletal muscle fibers

How many pathways are there for UMNs?

This statement is true. There are 6 pathways or tracts for UMNs: corticospinal, corticobulbar, tectospinal, rubrospinal, vestibulospinal, and reticulospinal tract.

Which tract of the brain is responsible for synapse?

A. CORTICOSPINAL TRACT. This is true. Axons from the corticospinal tract (CST)or pyramidal tract carry information from the precentral gyrus (brodmann area 4 of the motor cortex), the supplemental, and premotor cortices (area 6) to Lower motor neurons (LMNs) which will synapse with muscle cells in the body effecting voluntary movement.

Where do axons originate from?

This is true. Like the CST, axons from this descending tract originate in the motor cortex and enter the brainstem synapsing on the LMNs of cranial nerves. This tract runs alongside the CST passing through the internal capsule and into the medulla oblongata (also called bulbar) before synapsing with the LMNs of cranial nerves (CN).