DSM CH 12 Module 3: Sections 12.03-12.05

Artificial stimulation of which area has been shown to be a clinical method to elicit pain suppression?

"A" Running through the midbrain is the hollow cerebral aqueduct, which connects the third and fourth ventricles. It delineates the cerebral peduncles ventrally from the tectum, the midbrain's roof. Surrounding the aqueduct is the periaqueductal gray matter, which is involved in pain suppression and links the fear-perceiving amygdaloid body and ANS pathways that control the "fight-or-flight" response. The periaqueductal gray matter also includes nuclei that control two cranial nerves, the oculomotor and the trochlear nuclei (trok'le-ar).

Which area of the brain would be responsible for sleep-wake cycle?

"B" Epithalamus - The most dorsal portion of the diencephalon, the epithalamus forms the roof of the third ventricle. Extending from its posterior border and visible externally is the pineal gland or body (pin'e-al; "pine cone shaped") (see Figure 12.11). The pineal gland secretes the hormone melatonin (a sleep-inducing signal and antioxidant) and, along with hypothalamic nuclei, helps regulate the sleep-wake cycle. The posterior commissure forms the caudal border of the epithalamus.

Which of the indicated areas are relay nuclei in some descending motor pathways that cause limb flexion?

"B" The oval red nucleus lies deep to the substantia nigra (Figure 12.15a). Its reddish hue is due to its rich blood supply and to the presence of iron pigment in its neurons. The red nuclei are relay nuclei in some descending motor pathways that cause limb flexion, and they are embedded in the reticular formation, a system of small nuclei scattered through the core of the brain stem.

Which of the indicated areas have been implicated in Parkinson's disease?

"C" Embedded in each side of the midbrain white matter are two pigmented nuclei, the substantia nigra and red nucleus. The bandlike substantia nigra (sub-stan'she-ah ni'grah) is located deep to the cerebral peduncle (Figure 12.15a). Its dark (nigr = black) color reflects a high content of melanin pigment, a precursor of the neurotransmitter (dopamine) released by these neurons. The substantia nigra is functionally linked to the basal nuclei (its axons project to the putamen), and many scientists consider it part of the basal nuclear complex. Degeneration of the dopamine-releasing neurons of the substantia nigra is the ultimate cause of Parkinson's disease.

Which of the indicated areas are important for relaying information from motor cortex to skeletal muscles?

"D" Pyramids - Flanking the midline on the medulla's ventral aspect are two longitudinal ridges called pyramids, formed by the large pyramidal (corticospinal) tracts descending from the motor cortex (Figure 12.15c). Just above the medulla-spinal cord junction, most of these fibers cross over to the opposite side before continuing into the spinal cord. This crossover point is called the decussation of the pyramids (de"kus-sa'shun; "a crossing"). As a result of this crossover, each cerebral hemisphere chiefly controls the voluntary movements of muscles on the opposite side of the body.

Match the area with the appropriate function: Medulla oblongata

An autonomic reflex center involved in maintaining body homeostasis (cardiovascular center; respiratory centers; centers for sneezing, vomiting, hiccupping, swallowing, and coughing)

Match the area with the appropriate function: Epithalamus

Associated with the pineal gland; secretes melatonin to induce sleep

Which center is not located in the hypothalamus?

Center for central balance

Match the area with the appropriate function: Pons

Contains nuclei that are part of the reticular formation and some that help the medulla oblongata maintain the normal rhythm of breathing

Which area of the brain is most involved in maintaining the body's homeostasis?

Hypothalamus

Which of the following is incorrect with regards to inputs to the thalamus?

Inputs from the anterior association areas that regulate working memory for object-recall tasks

Which of these is not a function of the pons? - Is the site where 10 of 12 cranial nerves exit the brain - Is a major pathway between the higher brain centers and spinal cord - Is a major pathway between the cerebellum and the motor cortex - Nuclei are part of the reticular formation - Plays a role in regulating the normal pattern of breathing

Is the site where 10 of 12 cranial nerves exit the brain

Match the area of the brain with the appropriate function: Reticular formation

Keeps the cerebral cortex alert and conscious and enhances its excitability

Match the area of the brain with the appropriate function: Cerebellum

Provides precise timing and appropriate patterns of skeletal muscle contraction, allowing smooth, coordinated movements and agility

Which of the following functions is not associated with the midbrain?

Sleep induction via melatonin

Which of the following is not a function of the hypothalamus?

Sort incoming information

Match the area with the appropriate function: Thalamus

Sorts and "edits" information from sensory areas ascending to the cerebral cortex

Which of the following is false with regard to the brain stem? - Unlike the cortex, gray matter is on the inside of the brain stem and white matter is on the outside. - Brain stem nuclei are associated with 10 of the 12 pairs of cranial nerves. - The brain stem has nuclei of gray matter embedded in the white matter. - The brain stem produces rigidly programmed automatic behaviors for survival. - The brain stem is another name for the medulla oblongata.

The brain stem is another name for the medulla oblongata.

A mysterious lesion occurred in a boy from Cedar Falls, Iowa, where he lost his sense of thirst. From what we know about the functional areas of the brain, what area must be affected?

The hypothalamus

If deafness is caused by a lesion in the auditory cortex, rather than in the eardrum or the nerve carrying sensory information to the auditory cortex, the person may be startled by loud noises due to the action of what structure?

The inferior colliculi

Which of the following areas regulates body temperature, food intake, and endocrine functions?

hypothalamus

Which of the following regions acts as an autonomic reflex center of the brain?

medulla oblongata

The major role of the thalamus is to __________.

sort out and edit incoming information

In cases where CSF fluid is depleted, the brain will lose its flotation and the underside of the brain will rest on the base of the skull. What structures may be damaged and what would be the behavioral effect?

the pituitary may be damaged and this would affect water balance as well as many other functions controlled by the pituitary.

Those with damage to vision due to lesions of visual cortex may still be able to reflexively follow a laser shined on a wall. This ability would be due to what area of the brain?

the superior colliculi