Nervous System
What are the two main divisions of the nervous system?
The central nervous system (CNS) and the peripheral nervous system (PNS).
What are the three anatomical planes used to study the brain?
The coronal (frontal), sagittal, and horizontal (axial/transverse) planes (Hoit et al., 2020).
Which are the three exit points in the brainstem for the cranial nerves?
The three exit points are the midbrain, pons, and medulla (Hoit et al., 2020).
What are the two main arterial systems supplying the brain?
The internal carotid arteries and vertebral arteries (Hoit et al., 2020).
What are the three main structural parts of a neuron responsible for transmitting information?
The three main parts of a neuron are the dendrites, cell body (soma), and axon. Dendrites receive incoming signals, the soma integrates information, and the axon carries electrical impulses away from the neuron (Hoit et al., 2022).
What are the main differences between the CNS and the PNS?
The CNS includes the brain and spinal cord and serves as the control center, while the PNS consists of nerves and ganglia that connect the CNS to the rest of the body (Hoit et al., 2020).
What is a gyrus and what is a sulcus and where are they located?
A gyrus is a raised ridge or “hill” of cortical tissue, while a sulcus is a groove or dip between those ridges. These structures are found on the surface of the cerebral hemispheres (the cerebral cortex). Their folded arrangement increases the overall surface area of the brain, allowing more neurons to fit within the limited space of the skull (Hoit et al., 2020).
There are three main cranial nerves that control eye movement: They manage extraocular muscles to enable gaze tracking, focusing, and alignment, along with pupil size and eyelid function. What are these three nerves called?
The three cranial nerves that are involved in eye movements are the Oculomotor - CN III, Trochlear - CN IV, and Abducens - CN VI (Hoit et al., 2020).
This is especially relevant when certain drugs are administered to alleviate symptoms and signs of a CNS disease. What is this called?
This is called the blood-brain barrier (Hoit et al., 2020).
What is a synapse, and why is it essential for nervous system communication?
A synapse is the junction where one neuron communicates with another neuron or target cell. It allows electrical signals to be converted into chemical signals through neurotransmitter release, enabling neural communication throughout the nervous system (Hoit et al., 2022).
What is the difference between a nerve and a tract, and where is each found?
A tract is a bundle of axons located in the central nervous system (CNS), whereas a nerve is a bundle of axons located in the peripheral nervous system (PNS) (Hoit et al., 2020).
What is the significance of cortical sulci in the human brain?
Cortical sulci are significant because they increase the surface area of the cerebral cortex. Meaning they allow a greater number of neurons to be packed into the limited space of the skull. This increased surface area enhances the brain’s processing capacity and supports higher levels of cognitive function and performance (Hoit et al., 2020).
It is stated that there are two specific cranial nerves that are not associated with nuclei in the brainstem. Which two are these?
The two cranial nerves not associated with brainstem nuclei are the Olfactory nerve (CN I) and the Optic nerve (CN II). These nerves do not emerge from the brainstem, but rather as outgrowths of the forebrain and are considered extensions of the CNS tracts (Hoit et al., 2020).
This artery is of particular interest to speech-language pathologists and audiologists because it supplies blood to much of the lateral surfaces of the cerebral hemispheres. What is this artery called?
The artery that is the source for the perisylvian speech, language, and hearing areas of the dominant hemisphere is the Middle Cerebral Artery (Hoit et al., 2020).
What is the difference between depolarization and hyperpolarization during neural signaling?
Depolarization occurs when the neuron’s membrane becomes less negative due to sodium ions entering the cell, increasing the likelihood of an action potential. Hyperpolarization occurs when the membrane becomes more negative, usually due to potassium ions leaving the cell, temporarily inhibiting neural firing (Hoit et al., 2022).
What is the difference between nuclei and ganglia, and how does their location relate to CNS and PNS function?
Nuclei are clusters of neuron cell bodies located in the CNS, while ganglia are clusters located in the PNS. This difference reflects their roles, as nuclei are involved in central processing, whereas ganglia act as relay points for sensory information entering or leaving the CNS (Hoit et al., 2020).
Name the four lobes of the brain and explain one major function of each.
The four lobes of the brain are the frontal, parietal, temporal, and occipital lobes. The frontal lobe is responsible for motor control, the parietal lobe processes sensory information such as touch, the temporal lobe is involved in hearing, and the occipital lobe is responsible for vision (Hoit et al., 2020).
Cranial nerve VII controls the orbicularis oris muscles and the associated muscle complex in which are critical to the production of vowel contrasts that have to do with labial configurations and motions. For what consonants are these important to?
The consonants that these are important for are /p/, /b/, /f/, and /v/ (Hoit et al., 2020).
This artery provides blood to the posterior parts of the cerebral hemispheres, including the occipital lobes, and parts of the thalamus and corpus callosum. Which artery is this?
This artery is called the Posterior Cerebral Artery (Hoit et al., 2020).
How does sensory information from a touch on the arm travel to the primary somatosensory cortex?
Touch information travels through the posterior column–medial lemniscal pathway. Sensory signals enter through the dorsal root ganglion, ascend the spinal cord, synapse in the medulla, cross to the opposite side, pass through the thalamus, and terminate in the primary somatosensory cortex (Hoit et al., 2022).
How do afferent and efferent pathways differ, and how do they work together to produce a behavioral response?
Afferent pathways carry sensory information toward the CNS, while efferent pathways carry motor commands away from the CNS. Together, they allow the body to detect stimuli and produce appropriate responses, forming the basis of behaviors such as movement and reflexes (Hoit et al., 2020).
How do Broca’s area, Wernicke’s area, and the planum temporale differ in both location and function, and how do they work together to support language?
Broca’s area is located in the frontal lobe and is primarily involved in speech production and motor planning for language, while Wernicke’s area and the planum temporale are located in the temporal lobe and are involved in language comprehension and auditory processing. These regions work together by allowing the brain to both understand incoming language and produce meaningful speech, integrating auditory input with motor output for effective communication (Hoit et al., 2020).
There are seven cranial nerves that are important for speech and hearing. Which are they?
The seven cranial nerves that are essential for speech and hearing are the CN V - Trigemenal, CN VII - Facial, CN VIII - Auditory/Vestibular Nerve, CN IX - Glossopharyngeal, CN X - Vagus, CN XI - Accessory, and CN XII - Hypoglossal (Hoit et al., 2020).
The circular blood flow in the _______ has the capability of compensating for loss of blood flow from one of the main blood supplies to the brain. Where does this happen?
The circle of Willis (Hoit et al., 2020).
Describe the functional role of the cortico-cerebellar-cortical loop in speech and motor control.
The cortico-cerebellar-cortical loop connects the cerebral cortex to the cerebellum via the pons and returns information through the thalamus to the cortex. This circuit refines motor planning, timing, coordination, and error correction, all of which are essential for accurate speech production, swallowing, and skilled motor behaviors (Hoit et al., 2022).