Functional Neuroanatomy Questions - p. 2

Correct answer: B

The primary motor cortex is found in the precentral gyrus. It is an important area in the brain for voluntary movement.

Correct answer: B

The soma (aka cell body) contains the nucleus of the cell.

Correct answer: B

The primary visual cortex, also known as V1, is a brain region that is critically important for the processing of visual information. It is found in the occipital lobe, surrounding and extending into a sulcus called the calcarine sulcus.

Correct answer: D

Ependymal cells are a type of glial cell found in the central nervous system (CNS). They line the ventricles of the brain and the central canal of the spinal cord. Their primary function is to produce cerebrospinal fluid (CSF) and to help circulate it.

Correct answer: B

The central sulcus is a fissure that runs down the side of the brain and separates the frontal and parietal lobes.

Correct answer: B

The spinal cord is divided into segments, each of which gives rise to a pair of spinal nerves. There are 31 segments, named for their location: there are 8 cervical segments, 12 thoracic segments, 5 lumbar segments, 5 sacral segments, and 1 coccygeal segment.

Correct answer: A

While the right cerebral hemisphere primarily controls voluntary movement in the left side of the body, the right cerebellar hemisphere is primarily responsible for the right side of the body. Jean might experience symptoms such as impaired coordination, unrefined movements, tremors, etc., and they would likely be more prominent on the right side of the body.

Correct answer: A

Postganglionic neurons of the parasympathetic nervous system primarily release acetylcholine, while the postganglionic neurons of the sympathetic nervous system primarily release norepinephrine. The preganglionic neurons of both the parasympathetic and sympathetic nervous systems primarily release acetylcholine.

Correct answer: C

The subarachnoid space is found between the arachnoid mater and the pia mater. The subarachnoid space is filled with cerebrospinal fluid (CSF).

Correct answer: B

The hypothalamus is involved in many processes that are critically important to maintaining homeostasis across various bodily systems. Some of the major functions generally attributed to the hypothalamus include the regulation of: thirst and drinking behavior, fluid and electrolyte balance, hunger and feeding, body temperature, stress responses, aggressive behaviors, reproductive behaviors, circadian rhythms, the sleep-wake cycle, and more.

Correct answer: D

When an action potential reaches the axon terminals/synaptic boutons, it causes an influx of calcium ions. These ions prompt vesicles to fuse with the presynaptic membrane, and cause the release of neurotransmitters into the synaptic cleft.

Correct answer: C

CSF is produced in the ventricles, but the ventricles only contain about 1/8 of the total CSF in the central nervous system. The rest of the CSF is primarily found in the subarachnoid space.

Correct answer: A

Myelin is an insulating material that covers the axons of most neurons in the nervous system. Oligodendrocytes are the cells responsible for myelinating central nervous system neurons, while Schwann cells myelinate neurons in the peripheral nervous system.

Correct answer: B

The idea that we use only a fraction of our brain is a myth that was long ago debunked by neuroscience research. Modern neuroimaging methods in particular have demonstrated that nearly every part of the brain is active at some point.

Correct answer: D

The red nucleus is found in the brainstem, and is thought to be involved in motor coordination (among other things). It is not, however, considered part of the basal ganglia. Major structures of the basal ganglia include the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nucleus.

Correct answer: C

The inferior colliculi form two bumps on the posterior surface of the brainstem just below the superior colliculi. The inferior colliculus is best known for its role in hearing. It is the largest nucleus of the auditory system in humans, and it is the point in the brainstem where all auditory pathways traveling through the brainstem converge.

Correct answer: A

When used for animals that move through the world horizontally (e.g., on all fours), dorsal refers to the back and ventral refers to the abdominal region. With humans, the same usage applies when we are looking at the spinal cord. At the junction between the top of the brainstem and the diencephalon, however, the axis shifts due to the fact that humans walk upright. Above this level dorsal refers to the superior portion of the brain and ventral refers to the inferior portion.

Correct answer: B

The midbrain contains the ventral tegmental area (VTA) and substantia nigra, which are the two largest concentrations of dopamine neurons in the brain.

Correct answer: C

The anterior horn contains the cell bodies of motor neurons that activate skeletal muscle. These neurons, called alpha motor neurons, leave the cord in the ventral roots and represent the way the nervous system enacts movements. Thus, damage to the anterior horn would result in a deficit of movement.

Correct answer: B

The dopamine neurons in the substantia nigra are primarily found in the substantia nigra pars compacta; the pars reticulata is more heavily populated with GABA neurons. The substantia nigra gets its dark coloring from the large number of dopamine neurons in the pars compacta, as they express high levels of a dark pigment called neuromelanin.

Correct answer: B

The auditory cortex is found in the temporal lobe. Most of it is hidden from view, buried deep within a fissure called the lateral sulcus. Some auditory cortex is visible on the external surface the brain, however, as it extends to a gyrus called the superior temporal gyrus.

Correct answer: B

Pain and temperature sensations are primarily carried in the spinothalamic tract. This pathway carries these sensations from receptors to the spinal cord and then crosses over (i.e., decussates) to the other side of the spinal cord before traveling up to the brain. Thus, the tract in the spinal cord is carrying info from the other side of the body. Damage to the spinothalamic tract then, results in a deficit in pain and temperature sense on the opposite side of the body---below the damage.

Correct answer: C

Earlier estimates suggested glia outnumbered neurons 10 to 1, but more recent research using better cell-counting techniques (e.g., isotropic fractionation) has shown the neuron-to-glia ratio is closer to 1:1 across the whole brain.

Correct answer: A

The Circle of Willis is made up of the anterior cerebral arteries, internal carotid arteries, posterior cerebral arteries, anterior communicating artery, and posterior communicating arteries. The interconnection of these vessels can allow blood flow to continue if a major vessel is blocked on one side of the brain.

Correct answer: C

Purkinje cells are a distinctive type of neuron found only in the cerebellum. They have extensive branching dendrites, which gives them a very unique appearance.

Correct answer: B

The mammillary bodies are small structures in the brain that have critical connections with other areas involved in processing and storing memories. When the mammillary bodies are damaged, such as in conditions like Wernicke-Korsakoff syndrome, individuals often experience severe amnesia, particularly the inability to create new long-term memories.

Correct answer: C

The longest axons in the human body are those of the sciatic nerve, which extends from the lower back down to the toes. This nerve is both the largest and longest in the body, with axons that can reach about 1 meter (~3.3 feet) in length (its actual length is dependent on the height of the individual). It plays a crucial role in controlling movement and sensation in the legs and feet.

Correct answer: C

Most of the cerebral cortex in humans is classified as neocortex, which is so named because it is thought to have appeared relatively recently in vertebrate evolution. Neurons in the neocortex are typically arranged in six layers, which are distinguished from one another by differences in cell type and cell density.

Correct answer: B

While various cerebellar regions are involved with posture, the vermis controls the trunk and axial muscles, making it the cerebellar region most directly responsible for maintaining posture and balance during standing and slow movement.

Correct answer: B

The medulla oblongata, or the medulla, is the lowest part of the brainstem, found below the pons and above the spinal cord. There is no clear separation between the medulla and the spinal cord; instead the spinal cord gradually transitions into the medulla.