L11 Systems Neurobiology ✅

What are the two major divisions of the vertebrate nervous system?

Differentiate between "nuclei" and "ganglia" in terms of neuronal cell bodies.

Explain the difference between "tracts" and "nerves" in relation to bundles of axons.

What are the three main branches of the autonomic nervous system?

The two major divisions of the vertebrate nervous system are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

Nuclei are groups of neuronal cell bodies within the CNS, whereas ganglia are groups of neuronal cell bodies outside of the CNS.

Tracts are bundles of many axons within the CNS, while nerves are bundles of many axons outside of the CNS.

The three main branches of the autonomic nervous system are the sympathetic nervous system, the parasympathetic nervous system, and the enteric nervous system

Describe the primary roles of the sympathetic and parasympathetic nervous systems, including their common "nicknames."

How do the sympathetic and parasympathetic nervous systems generally interact in controlling effector organs? Provide an example.

For the pupil of the eye, what is the effect of parasympathetic stimulation versus sympathetic stimulation? What adrenergic receptor is involved in sympathetic stimulation?

The sympathetic nervous system is most active during stress or physical activity, known as "fight or flight," increasing heart rate and breathing and directing blood to working muscles. The parasympathetic nervous system is most active during periods of rest, known as "resting and digesting," redirecting energy toward maintenance activities like digestion.

The sympathetic and parasympathetic nervous systems are typically antagonistic. For example, sympathetic stimulation increases heart rate and force, while parasympathetic stimulation slows heart rate.

For the pupil of the eye, parasympathetic stimulation constricts the pupil, while sympathetic stimulation dilates it. The alpha (\alpha) adrenergic receptor is involved in sympathetic stimulation.

Which branch of the autonomic nervous system is responsible for increasing heart rate and force? What adrenergic receptor mediates this effect?

Explain how a single branch of the autonomic nervous system, like the sympathetic system, can control both dilation and constriction of an effector organ.

Which specific gland is innervated only by the sympathetic nervous system?

The sympathetic nervous system is responsible for increasing heart rate and force. The beta1 (\beta_1) adrenergic receptor mediates this effect.

A single branch of the autonomic nervous system, such as the sympathetic system, can control both dilation and constriction through a mechanism called basal tone. Changes in the frequency of action potentials in sympathetic fibers can increase or decrease sympathetic input, leading to constriction or dilation, respectively.

The adrenal medulla is innervated by the sympathetic nervous system only.

What are the two main components of the vertebrate central nervous system?

What are the primary functions of the spinal cord?

Describe the composition of nerves in the peripheral nervous system.

How do ascending and descending tracts in the spinal cord differ in the types of signals they carry?

The two main components of the vertebrate central nervous system are the brain and the spinal cord.

The spinal cord mediates spinal reflexes and serves as a pathway for impulses to and from the brain.

Nerves in the peripheral nervous system consist of myelinated and unmyelinated axons enclosed in connective tissue, and they may contain either sensory or motor fibers, or both.

Ascending tracts of the spinal cord carry afferent (sensory) signals, while descending tracts carry efferent (motor) signals.

Ispilateral

Contralateral

What are the three main components of the hindbrain and what basic functions do they support?

What is the role of the cerebrum, and how are its two hemispheres connected?

Damage to the primary motor cortex would result in what kind of impairment? Would reflexes be affected?

Same side

Opposite side

The hindbrain includes the medulla oblongata, pons, and cerebellum. The medulla oblongata regulates breathing, heart rate, and blood pressure. The pons communicates between the medulla, cerebellum, and forebrain. The cerebellum coordinates motor behaviors.

The cerebrum controls "higher" processes and is divided into two hemispheres connected by the corpus callosum.

Damage to the primary motor cortex would result in paralysis of voluntary movements. However, reflexes would remain intact.

What is the function of the premotor cortex, and what happens if it is damaged?

What is the primary input to the primary somatosensory cortex? What is the consequence of damage to this area?

What is the role of the somatosensory association area, and what deficit would occur if it were damaged?

The premotor cortex coordinates movements of groups of muscles. Damage to this area can lead to a loss of skill, although the skill can often be relearned.

The primary somatosensory cortex receives primary input from sensory receptors in the skin and muscle. Damage to this area results in a loss of sensation.

The somatosensory association area is responsible for the interpretation of sensation and its integration with memory. Damage to this area can lead to a loss of identification.