Chapter 12: The Central Nervous System

A number of brain structures are listed below. If an area is primarily gray matter, write (a); if mostly white matter, respond with (b) 1. cerebral cortex 2. corpus callosum and corona radiata 3. red nucleus 4. medial and lateral nuclear groups 5. medial lemniscus 6. cranial nerve nuclei 7. spinothalamic tract 8. fornix 9. cingulate and precentral gyri

1. a 2. b 3. a 4. a 5. b 6. a 7. b 8. b 9. a

The average weight of the adult brain is _____. a. 1 - 1.5 lbs b. 2 - 2.5 lbs c. 3 - 3.5 lbs d. over 5 lbs

3 - 3.5 lbs

What is a transient ischemic attack (TIA) and how is it different from a stroke?

A TIA is a temporary loss of blood supply to brain tissue, and it differs from a stroke in that the resultant impairment is fully reversible.

Roy was tackled while playing football. After hitting the ground, he was unable to move his lower limbs. What is a loss of motor function called? What level of his spinal cord do you think was injured (cervical, thoracic, lumbar, or sacral)?? Is this a permanent injury??? What diagnostic procedure might be helpful????

A loss of motor function is called paralysis. Lower limb paralysis could be caused by a spinal cord injury in the thoracic region (T1 and L1). If the spinal cord is transected, the result is paraplegia. If the cord is only bruised, he may regain function in the limbs. An MRI scan (or CT scan) of the spinal cord would be helpful.

What functional type of neuron is derived from the alar plate? From the basal plate??

Alar plate neuroblasts become interneurons, whereas basal plate neuroblasts become motor (efferent) neurons.

List the major spinal cord tracts, and classify each as a motor or sensory tract.

Ascending (sensory) tracts include the fasciculi gracilis and cuneatus, spinothalamic tracts, and spinocerebellar tracts. The dorsal column -- medial lemniscal pathway consists of the dorsal white column (fasciculus cuneatus, fasciculus gracilis) and the medial lemniscus, which are concerned with straight-through, precise transmission of one or a few related types pf sensory input. The spinothalamic pathways transmit pain, temperature, and course touch, and permits brain stem processing of ascending impulses. The spinocerebellar tracts, which terminate in the cerebellum, serve muscle sense, not conscious sensory perception. Descending tracts include the pyramidal tracts (ventral and lateral corticospinal tracts) and a number of motor tracts originating from subcortical motor nuclei. These descending fibers issue from the brain stem motor areas (indirect system) and cortical motor areas (direct pyramidal system).

Explain the effects of aging on the brain.

Brain growth ends in young adulthood. neurons die throughout life and most are not replaced; brain weight and volume decline with age. Healthy elders maintain nearly optimal intellectual functions. Disease -- particularly cardiovascular disease -- is the major cause of declining mental function with age.

What is CSF? Where is it produced?? What are its functions???

CSF, formed by the choroid plexuses as a filtrate of blood plasma, is a watery "broth" similar in composition to plasma. It protects the brain and spinal cord from blows and other trauma, helps nourish the brain, and carries chemical signals from one part of the brain to another.

Explain how cerebrospinal fluid is formed and describe its circulatory pathway.

Cerebrospinal fluid (CSF), formed by the choroid plexuses from blood plasma, circulates through the ventricles and into the subarachnoid space. It returns to the dural venous sinuses via the arachnoid villi.

Describe the cause (if known) and major signs and symptoms of cerebrovascular accidents, Alzheimer's disease, Parkinson's disease, and Huntington's disease.

Cerebrovascular accidents (also known as a stroke) result when blood circulation to brain neurons is impaired and brain tissue dies. The result may be hemiplegia, sensory deficits, or speech impairment. The most common cause of CVA is a blood clot that blocks a cerebral artery. General symptoms of CVA include: - sudden numbness, tingling, weakness, or loss of movement in the face, arm, or leg, especially on only one side of the body - sudden vision changes - difficulty speaking - sudden confusion or difficulty understanding simple statements - sudden difficulties with balance or walking - a sudden, severe headache that is different from past headaches CVA Symptoms can vary depending on whether the stroke is caused by a blood clot (ischemic stroke) or bleeding (hemorrhagic stroke), where the stroke occurs in the brain, and how bad it is. Alzheimer's disease is a degenerative brain disorder in which beta-amyloid peptide deposits and neurofibrillary tangles appear. Its victims exhibit memory loss (particularly for recent events) shortened attention span, disorientation, and eventual language loss. Over a period of several years, formerly good-natured people may become irritable, moody, and confused. Hallucinations may ultimately occur. Alzheimer's disease also causes changes in thinking, behavior, and personality. Close family members and friends may first notice these symptoms, although the person may also realize that something is wrong. Mild symptoms of Alzheimer's include: - person may avoid new and unfamiliar situations - person may have delayed reactions and slowed learning ability - person may begin speaking more slowly than in the past - person may start using poor judgment and making inappropriate decisions - person may have mood swings and become depressed, irritable, or restless Moderate symptoms of Alzheimer's include: - has problems recognizing close friends and family - becomes more restless, especially in late afternoon and at night, this is called sundowning - has problems reading, writing, and dealing with numbers - has trouble dressing - cannot work simple appliances such as a microwave Severe symptoms pf Alzheimer's includes: - can no longer remember how to bathe, eat, dress, or go to the bathroom independently - no longer knows when to chew and swallow - has trouble with balance or walking and may fall frequently - becomes more confused in the evening (sundowning) and has trouble sleeping - cannot communicate using words - loses bowel or bladder control (incontinence) Parkinson's disease and Huntington's disease are neurodegenerative disorders of the basal nuclei. Both involve abnormalities of the neurotransmitter dopamine (too little or too much secreted) and are characterized by abnormal movements. Symptoms of Parkinson's disease differ from person to person. They also change as the disease progresses. Symptoms that one person gets in the early stages of the disease, another person may not get until later - or not at all. Symptoms typically begin appearing between the ages of 50 and 60. They develop slowly and often go unnoticed by family, friends, and even the person who has them. The disease causes motor symptoms and non-motor symptoms. Motor symptoms are those that have to do with how you move. The most common one is tremor. Other common symptoms of Parkinson's disease include: - stiff muscles (rigidity) and aching muscles - slow, limited movement - weakness of face and throat muscles - difficulty with walking and balance - freezing, a sudden, brief inability to move, it most often affects walking Huntington's disease is a genetic, progressive, neurodegenerative disorder characterized by the gradual development of involuntary muscle movements affecting the hands, feet, face, and trunk and progressive deterioration of cognitive processes and memory (dementia). Neurologic movement abnormalities may include uncontrolled, irregular, rapid, jerky movements (chorea) and athetosis, a condition characterized by relatively slow, writhing involuntary movements. Dementia is typically associated with progressive disorientation and confusion, personality disintegration, impairment of memory control, restlessness, agitation, and other symptoms and findings. In individuals with the disorder, disease duration may range from approximately 10 years up to 25 years or more. Life-threatening complications may result from pneumonia or other infections, injuries related to falls, or other associated developments. Some common early symptoms of Huntington's disease include: - slight changes in coordination, affecting balance or making you more clumsy - fidgety movements that you can't control - slowing or stiffness - trouble thinking through problems - depression or irritability Some common middle stage symptoms of Huntington's disease include: With time, symptoms begin to interfere more with your day-to-day life. For example, you might start to drop things or to fall. Or you may have trouble speaking or swallowing. Staying organized may be difficult and emotional changes may put pressure on relationships. Some common late stage symptoms of Huntington's disease include: In this stage, people with Huntington's must depend on others for their care. Walking and speaking are not possible, Most likely you will still be aware of loved ones around you. Fidgety movements may become severe, or may subside. In children or teens, Huntington's may progress more quickly and cause symptoms like: - stiff or awkward walking - increased clumsiness - changes in speech - trouble learning new information, or loss of previously learned skills

Which type of fiber allows the two cerebral hemispheres to "talk to each other"?

Commissural fibers (which form commissures) allow the cerebral hemispheres to "talk to each other".

Describe consciousness clinically.

Consciousness is described clinically on a continuum from alertness to drowsiness to stupor and finally to coma. Human consciousness is thought to involve holistic information processing, which is (1) not localizable, (2) superimposed on other types of neural activity, and (3) totally interconnected. Fainting (syncope) is a temporary loss of consciousness that usually reflects inadequate blood delivery to the brain. Coma is loss of consciousness in which the victim is unresponsive to stimuli.

What is the function of convolutions of the brain?

Convolutions increase surface area of the cortex, which allows more neurons to occupy the limited space within the skull.

Describe the roles of the major brain structures believed to be involved in declarative and procedural memories.

Declarative memory is the ability to learn and consciously remember information. Procedural memory id the learning of motor skills, which are then performed without conscious thought. Declarative memory appears to involve the medial temporal lobe (hippocampus and surrounding temporal cortical areas), thalamus, basal forebrain, and prefrontal cortex. Procedural memory ( a type of non-declarative memory) relies on the basal nuclei. The nature of memory formation at the molecular level is not fully known, but NMDA receptors (essentially calcium channels), activated by depolarization and glutamate binding, play a major role in long-term potentiation (LTP). The calcium influx that follows NMDA receptor activation mobilizes enzymes that mediate events necessary for memory formation.

When would you see delta waves in an EEG?

Delta waves are typically seen in deep sleep in normal adults.

List and explain several techniques used to diagnose brain disorders.

Diagnostic procedures used to assess neurological condition and function range from routine reflex testing to sophisticated techniques such as cerebral angiography, CT scans, MRI scans, and PET scans.

Which two states of consciousness are between alertness and coma?

Drowsiness (or lethargy) and stupor are stages of consciousness between alertness and coma.

Name the major regions of the adult brain.

In a widely used system, the adult brain is divided into the cerebral hemispheres, diencephelon, brain stem, and cerebellum. The cerebral hemispheres and cerebellum have gray matter nuclei surrounded by white matter and an outer cortex of gray matter. The diencephalon and brain stem lack a cortex.

Explain language function in the brain.

In most people, the left hemisphere controls language. The language implementation system, which include Broca's and Wernicke's areas and basal nuclei, analyzes incoming and produces outgoing language. The opposite hemisphere deals with the emotional content of language.

Where are the cell bodies of the first-, second-, and third-order sensory neurons in the spinothalamic pathway located?

In the spinothalamic pathway, the cell bodies of the first-order sensory neurons are outside the spinal cord in a ganglion, cell bodies of the second-order sensory neurons are in the dorsal horn of the spinal cord, and cell bodies of third-order sensory neurons are in the thalamus.

Distinguish between flaccid and spastic paralysis, and between paralysis and paresthesia.

Injury to the ventral horn neurons or the ventral roots result in flaccid paralysis. (Injury to the upper motor neurons in the brain result in spastic paralysis.) If the dorsal roots or sensory tracts are damaged, paresthesia occurs. Poliomyelitis results from inflammation and destruction of the ventral horn neurons by the Polio virus. Paralysis and muscle atrophy ensue. Amyotrophic lateral sclerosis (ALS) results from the destruction of ventral horn neurons and the pyramidal tracts. The victim eventually loses the ability to swallow, speak, and bathe. Death generally occurs within five years.

Which of the following statements concerning epilepsy is INCORRECT? a. It can have a genetic factor. b. It involves abnormal discharges from a group of brain neurons. c. Most cases are caused by brain injuries, such as blows to the head, stroke, or infections. d. It is associated with intellectual impairment. e. It affects < 5% of the population.

It is associated with intellectual impairment.

Indicate several maternal factors that can impair development of the nervous system in an embryo.

Maternal and environmental factors may impair embryonic brain development, and oxygen deprivation destroys brain cells. Severe congenital brain disorders include cerebral palsy, anencephaly, hydrocephalus, and spina bifida. Premature babies have trouble regulating body temperature because the hypothalamus is one of the last brain areas to mature prenatally. Development of motor control indicate progressive myelination and maturation of a child's nervous system.

Compare and contrast the stages and categories of memory.

Memory is the storage and retrieval of information. It is essential for learning and is part of consciousness. Memory storage has two stages: short-term memory (STM) and long-term memory (LTM). transfer of information from STM to LTM takes minutes to hours, but more time is required for LTM consolidation.

During which sleep stage are most skeletal muscles actively inhibited?

Most skeletal muscles are actively inhibited during REM sleep.

Mike, who is left-handed, decided to wear his favorite t-shirt to his anatomy class. On his t-shirt were the words "Only left-handed people are in their right minds." What does this statement mean?

Motor functions on the left side of the body are controlled by the right hemisphere of the brain because motor tracts from the right hemisphere cross over (in the medulla oblongata) to the left side of the spinal cord to go to the left side of the body.

Mrs. Lee, a neurology patient, seldom smiles, has a shuffling, stooped gait, and often spills her coffee. What degenerative brain disorder might she have?

Mrs. Lee might have Parkinson's disease.

Name some of the most common sleep disorders.

Narcolepsy is involuntary lapses into REM sleep that occur without warning during waking periods. Insomnia is a chronic inability to obtain the amount or quality of sleep needed to function adequately. A person with sleep apnea stops breathing temporarily during sleep, causing hypoxia.

Define EEG and distinguish between alpha, beta, theta, and delta brain waves.

Patterns of electrical activity of the brain are called brain waves; a record of this activity is and electroencephalogram (EEG). Brain wave patterns, identified by their frequencies, include alpha, beta, theta, and delta waves. Alpha waves (8 - 13 Hz) are relatively regular and rhythmic, low-amplitude, synchronous waves. In most cases, they indicate a brain that is "idling" -- a calm, relaxed state of wakefulness. Beta waves (14 - 30 Hz) are also rhythmic, but less regular than alpha waves and with a high frequency. Beta waves occur when we are mentally alert , as when concentrating on some problem or visual stimulus. Theta waves (4 - 7 Hz) are still more irregular. Though common in children, theta waves are uncommon in awake adults but may appear when concentrating. Delta waves (4 Hz or less) are high-amplitude waves seen during deep sleep and when the reticular activating system is damped, such as during anesthesia. In awake adults, they indicate brain damage. Epilepsy results from abnormal electrical activity of brain neurons. Involuntary muscle contractions and sensory auras are typical during some epileptic seizures.

Premature babies have problems controlling their body temperature. Why?

Premature babies have trouble regulating body temperature because the hypothalamus is immature.

Identify the stage of sleep best described by "indicated by movement of the eyes under the lids; dreaming occurs". a. stage 1 b. stage 2 c. stage 3 d. stage 4 e. REM

REM

List several causes of reversible dementia in the elderly.

Reversible cause of dementia includes prescription drug effects, low blood pressure, poor nutrition, hormone imbalances, depression, and dehydration.

Compare and contrast the events and importance of slow-wave and REM sleep, and indicate how their patterns change through life.

Sleep is a state of partial consciousness from which a person can be aroused by stimulation. The two major types of sleep are non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. During stages 1 - 4 of NREM sleep, brain wave frequency decreases and amplitude increases until delta wave sleep (stage 4) is achieved. REM sleep is indicated by a return to alpha waves on the EEG. During REM, they eye moves rapidly under the lids. NREM and REM sleep alternate throughout the night. Slow-wave sleep (stages 3 and 4 of NREM) appears to be restorative. REM sleep is important for emotional stability. REM occurs half of an infant's sleep time and then declines to about 25% of sleep time by age 10. Time spent in slow-wave sleep declines steadily throughout life.

What is the importance of sleep, why do we sleep?

Slow-wave and REM sleep seem to be important in different ways. Slow-wave sleep is presumed to be restorative, the time when most neural activity can wind down to basal levels. When deprived of sleep, we spend more time than usual in slow-wave sleep during the next sleep episode. People who are persistently deprived of REM sleep become moody and depressed, and exhibits various personality disorders. REM sleep may give the brain an opportunity to analyze the day's events and work through emotional problems in dream imagery. Another idea is that REM sleep is reverse learning. According to this hypothesis, accidental, repetitious, and meaningless communications continually occur. Dreaming eliminates them from our neural networks so the cortex remains a well-behaved and efficient thinking system. In other words, we dream to forget.

In what ways are the cerebellum and the cerebrum similar? In what ways are they different??

Structurally, the cerebellum and cerebrum are similar in that they both have a thin outer cortex of gray matter, internal white matter, and deep gray matter nuclei. Also, both have body maps (homunculi) and large fiber tracts connecting them to the brain stem. Both receive sensory input and influence motor output. A major difference is that the cerebellum is almost entirely concerned with motor output, whereas the cerebrum has much broader responsibilities. Also, while a cerebral hemisphere controls the opposite side of the body, the cerebellar hemisphere controls the same side of the body.

When Taylor begins to feel drowsy while driving, she opens her window, turns up the volume of the car stereo, and sips ice-cold water. How do these actions keep her awake?

Taylor is increasing the amount of sensory stimuli she receives, which will relay to the reticular activating system, which, in turn, will increase activation in the cerebral cortex.

Describe the development of the brain and spinal cord.

The CNS develops from the embryonic neural tube -- the brain from the rostral part and the spinal cord from the caudal part. The gray matter of the spinal cord forms from the alar and basal plates. Fiber tracts from the outer white matter. The neural crest forms the sensory (dorsal root) ganglia.

Which functional areas of the cerebrum are involved in the formation of procedural (skill) memory, but not involved in declarative memory?

The basal nuclei and premotor cortex are involved in procedural (skill) memory, but not in declarative memory.

Name and locate the ventricles of the brain.

The brain contains four ventricles filled with cerebrospinal fluid. The lateral ventricles are in the cerebral hemispheres; the third ventricle is in the diencephalon; the fouth ventricle is between the brain stem and the cerebellum and connects with the central canal of the spinal cord.

Describe how space constraints affect brain development.

The brain provides for voluntary movements, interpretation and integration of sensation, consciousness, and cognitive function. Early brain development yields the primary brain vesicles: the prosencephalon (cerebral hemispheres and diencephalon), mesencephalon (midbrain), and rhombencephelon (pons, medulla oblongata, and cerebellum). As a result of cephalization, the diencephelon and superior brain stem are developed by the cerebral hemispheres. Because the brain grows more rapidly than the membranous skull that contains it, it folds up to occupy the available space.

Identify the three major regions of the brain stem, and not the functions of each area.

The brain stem includes the midbrain, pons, and medulla oblongata. The midbrain contains the corpora quadrigemina (visual and auditory reflex centers), the red nucleus (subcortical motor centers), and the substantia nigra. The periaqueductal gray matter is involved in pain suppression and contains the motor nuclei of cranial nerves III and IV. The cerebral peduncles on its ventral face house the pyramidal fiber tracts. The midbrain surrounds the cerebral aqueduct. The pons is mainly a conduction area. Its nuclei contribute to regulating respiration and cranial nerves V - VII. The pyramids (descending corticospinal tracts) form the ventral face of the medulla oblongata. These fibers cross over (decussation of the pyramids) before entering the spinal cord. Important nuclei in the medulla regulate respiratory rhythm, heart rate, and blood pressure and serve cranial nerves VIII - XII. The olivary nuclei and cough, sneezing, swallowing, and vomiting centers are also in the medulla.

Name the components of the basal nuclei.

The caudate nucleus, putamen, and globus pallidus together form the basal neclei.

What anatomical landmark of the cerebral cortex separates primary motor areas from somatosensory areas?

The central sulcus separates primary motor areas from somatosensory areas.

Describe the structure and function of the cerebellum.

The cerebellum consists of two hemispheres, marked by convolutions and separated by the vermis. It is connected to the brain stem by superior, middle, and inferior peduncles. The cerebellum processes and interprets impulses from the motor cortex and sensory pathways and coordinates motor activity so that smooth, well-timed movements occur. It also plays a poorly understood role in cognition.

List the major lobes, fissures, and functional areas of the cerebral cortex.

The two cerebral hemispheres exhibit gyri, sulci, and fissures. The longitudinal fissure partially separates the hemispheres; other fissures or sulci subdivide each hemisphere into lobes. Each cerebral hemisphere consists of the cerebral cortex, the cerebral white matter, and basal nuclei (ganglia). Each cerebral hemisphere receives sensory impulses from, and dispatches motor impulses to, the opposite side of the body. The body is represented in an upside-down fashion in the sensory and motor cortices. Functional areas of the cerebral cortex include: (1) motor areas: primary motor and premotor cortices of the frontal lobe, the frontal eye field, and Broca's area in the frontal lobe of one hemisphere (usually the left); (2) sensory areas: primary somatosensory cortex and somatosensory association cortex in the parietal lobe; visual areas of the occipital lobe; olfactory and auditory areas in the temporal lobe; gustatory, visceral, and vestibular areas in the insula; and (3) association areas: anterior association area in the frontal lobe, and posterior and limbic association areas spanning several lobes.

Name the three factors that can enhance transfer of information from STM to LTM.

Transfer of memory from STM to LTM is enhanced by (1) rehearsal, (2) association (trying "new" information to "old" information), and (3) a heightened emotional state (for example, alert, motivated, surprised, or aroused).

Why is the thalamus called the "gateway to the cerebral cortex"?

Virtually all inputs ascending to the cerebral cortex synapse in the thalamus en route.

Which of the following is the central layer of the meninges? a. pia mater b. dural sinuses c. dura mater d. arachnoid mater

arachnoid mater

Fiber tracts that allow neurons within the same cerebral hemisphere to communicate are a. association fibers b. commissures c. projection fibers

association fibers

Which type of brain waves are seen when a person is concentrating on solving a problem? a. beta waves b. delta waves c. theta waves d. alpha waves e. gamma waves

beta waves

Which of the following centers is NOT located in the hypothalamus? a. autonomic control center b. food intake regulation center c. body temperature regulation center d. center for central balance e. a center for regulation of sleep-wake cycles

center for central balance

Which term is best stated by "brain area most concerned with equilibrium, body posture, and coordination of motor activity"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

cerebellum

Cerebrospinal fluid is formed by a. arachnoid villi b. dura mater c. choroid plexuses d. all of these

choroid plexuses

Which of the following is a function of the pons? a. acts to regulate body temperature b. nucleus for the abducens nerve c. provides motor signals to the red nucleus d. controls vomiting and coughing e. contains nuclei that relay information from the cerebrum to cerebellum

contains nuclei that relay information from the cerebrum to cerebellum

Which term is best stated by "relay stations for visual and auditory stimuli input; found in midbrain"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

corpora quadrigemina

Which of the following is NOT one of the basal nuclei? a. corpus callosum b. globus pallidum c. caudate nucleus d. putamen

corpus callosum

The CNS starts differentiating from the neural tube in the developing embryo after week _____. a. two b. three c. four d. six

four

The primary motor cortex, Broca's area, and the premotor cortex are located in which lobe? a. frontal b. parietal c. temporal d. occipital

frontal

A patient has suffered a cerebral hemorrhage that has caused dysfunction of the precentral gyrus of his right cerebral cortex. As a result, a. he cannot voluntarily move his left arm or leg b. he feels no sensation on the left side of his body c. he feels no sensation on the right side of his body

he cannot voluntarily move his left arm or leg

Which of the following areas of the brain is most involved in maintaining the body's homeostasis? a. cerebral cortex b. hypothalamus c. medulla oblongata d. pons e. cerebellum

hypothalamus

Which of the following is the autonomic control center? a. diencephalon b. pons c. medulla oblongata d. midbrain e. hypothalamus

hypothalamus

Which part of the brain is involved in thirst sensations? a. temporal lobe b. hypothalamus c. cerebral cortex d. cerebellum e. pons

hypothalamus

Which term is best stated by "control of temperature, autonomic nervous system reflexes, hunger, and water balance"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

hypothalamus

Which of the following is NOT a feature of the cerebral cortex? a. it is composed of white matter b. it accounts for 40% of the brain mass c. it is arranged in six layers d. its convoluted surface triples its surface

it is composed of white matter

Which of the following tracts convey vibration and other specific sensations that can be precisely localized? a. pyramidal tract b. medial lemniscus c. lateral spinothalamic tract d. reticulospinal tract

medial lemniscus

Which term is best stated by "houses vital centers for control of the heart, respiration, and blood pressure"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

medulla

Which term is best stated by "region where there is a gross crossover of fibers of descending pyramidal tracts"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

medulla

Which term is best stated by "houses the substantia nigra and cerebral aqueduct"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

midbrain

The innermost layer of the meninges, delicate and closely apposed to the brain tissue, is the a. dura mater b. corpus callosum c. arachnoid mater d. pia mater

pia mater

Identify the stage of sleep best described by "when the sleeper is very easily awakened; EEG shows alpha waves". a. stage 1 b. stage 2 c. stage 3 d. stage 4 e. REM

stage 1

Identify the stage of sleep best described by "when nightmares are likely to occur". a. stage 1 b. stage 2 c. stage 3 d. stage 4 e. REM

stage 3 and stage 4

Identify the stage of sleep best described by "the stage when blood pressure and heart rate reach their lowest levels". a. stage 1 b. stage 2 c. stage 3 d. stage 4 e. REM

stage 4

Which of the following is a function of the basal ganglia? a. starting, stopping, and monitoring arm swinging and gait b. regulation of body temperature c. processing of sensory information d. determining whether a person is left- or right-handed e. connecting corresponding areas of the cerebral cortex to enable them to function as a coordinated whole

starting, stopping, and monitoring arm swinging and gait

Which term is best stated by "basal nuclei involved in fine control of motor activities"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

striatum

Which part of the brain produces dopamine? a. pontine nuclei b. reticular formation c. substantia nigra d. pineal gland e. red nucleus

substantia nigra

A professor unexpectedly blew a loud horn in his anatomy and physiology class. The students looked up, startled. The reflexive movement of their eyes were mediated by the a. cerebral cortex b. inferior olives c. raphe nuclei d. superior colliculi e. nucleus gracilis

superior colliculi

Which of the following areas is NOT involved in speech processing? a. Wernicke's area b. superior colliculi c. lateral prefrontal cortex d. Broca's area

superior colliculi

Which of the following coordinate head and eye movements when we visually follow a moving object? a. substantia nigra b. pneumotaxic center c. superior colliculi d. red nucleus e. inferior colliculi

superior colliculi

In which of the following areas does sorting and editing of sensory impulses take place? a. hypothalamus b. basal nuclei c. postcentral cortex d. prefrontal cortex e. thalamic nuclei

thalamic nuclei

Which term is best stated by "brain area through which all the sensory input is relayed to get to the cerebral cortex"? a. cerebellum b. corpora quadrigemina c. corpus callosum d. striatum e. hypothalamus f. medulla g. midbrain h. pons i. thalamus

thalamus

Which of the following landmarks separates the cerebral hemispheres? a. the central sulcus b. the longitudinal fissure c. the transverse cerebral fissure d. septum pelllucidum

the longitudinal fissure

All of the following descriptions refer to dorsal column-medial lemniscal ascending pathways except one: a. they include the fasciculus gracilis and fasciculus cuntaeus b. they include a chain of three neurons c. their connections are diffuse and poorly localized d. they are concerned with precise transmission of one or a few related types of sensory input.

their connections are diffuse and poorly localized

Destruction of the ventral horn cells of the spinal cord results in loss of a. integrating impulses b. sensory impulses c. voluntary motor impulses d. all of these

voluntary motor impulses

Differentiate between commissures, association fibers, and projection fibers.

Fiber tracts of the cerebral white matter include commissures, association fibers, and projection fibers. Commissural fibers connect corresponding gray areas of the two hemispheres. Association fibers connect different parts of the same hemisphere. Projection fibers either enter the cerebral cortex from lower brain or cord centers or descending from the cortex to lower areas.

Explain what head trauma is.

Head trauma may cause brain injuries called concussions or, in severe cases, contusions (bruising). When the brain stem is affected, unconsciousness (temporary or permanent) occurs. Trauma-induced brain injuries may be aggravated by intracranial hemorrhage or cerebral edema, both of which compress brain tissue.

Which two areas of the adult brain have an outside layer of gray matter in addition to central gray matter and surrounding white matter?

The cerebral hemispheres and the cerebellum have an outside layer of gray matter in addition to central gray matter and its surrounding white matter.

Explain lateralization of hemisphere function.

The cerebral hemispheres show lateralization of cortical function. In most people, the left hemisphere is dominant (i.e., specialized language and mathematical skills); the right hemisphere is is more concerned with visual-spatial skills and creative endeavors.

Which region of the brain stem is associated with the cerebral peduncles and the superior and inferior colliculi?

The cerebral peduncles and the colliculi are associated with the midbrain.

Describe how meninges, cerebrospinal fluid, and the blood brain barrier protect the CNS.

The delicate brain is protected by bone, meninges, cerebrospinal fluid, and the blood brain barrier. The meninges from superficial to deep are the dura mater, arachnoid mater, and pia mater. They enclose the brain and spinal cord and their blood vessels. Inward folds of the inner layer of the dura mater secure the brain to the skull. The cerebrospinal fluid supports and cushions the brain and cord and helps to nourish them. The blood brain barrier reflects the relative impermeability of the epithelium of capillaries of the brain. It allows watery, respiratory gasses, essential nutrients, and fat-soluble molecules to enter the neural tissue, but blocks other, water-soluble, potentially harmful substances.

Describe the location of the diencephalon, and name its subdivisions and functions.

The diencephelon includes the thalamus, hypothalamus, and epithalamus ans encloses the third ventricle. The thalamus is the major relay station for (1) sensory impulses ascending to the sensory cortex, (2) inputs from subcortical motor nuclei and the cerebellum traveling to the cerebral motor cortex, and (3) impulses traveling to association cortices from lower centers. The hypothalamus is an important control center of the autonomic nervous system and a pivotal part of the limbic system. It maintains water balance and regulates thirst, eating behavior, gastrointestinal activity, body temperature, and the activity of the anterior pituitary gland. The epithalamus includes the pineal gland, which secretes the hormone melatonin.

Describe the gross and microscopic structure of the spinal cord.

The spinal cord, a two-way impulse conduction pathway and a reflex center, resides within the vertebral column and is protected by meninges and cerebrospinal fluid. It extends from the foramen magnum to the end of the first lumbar vertebra. Thirty-one pairs of spinal nerves issue from the cord. The cord is enlarged in the cervical and lumbar regions, where spinal nerves serving the limbs arise. The central gray matter of the cord is H-shaped. Ventral horns mainly contain somatic motor neurons. Lateral horns contain visceral (autonomic) motor neurons. Dorsal horns contain internuerons. Axons of neurons of the lateral and ventral horns emerge in common from the cord via the ventral roots. Axons of sensory neurons (with cell bodies located in the dorsal root ganglion) from the dorsal roots and enter the dorsal aspect of the cord. The ventral and dorsal roots combine to form the spinal nerves. Each side of the white matter of the cord has dorsal, lateral, and ventral columns (funiculi), and each funiculus contains a number of ascending and descending tracts. All tracts are paired and most decussate.

Which ventricle is surrounded by the diencephalon?

The third ventricle is surrounded by the diencephalon.

The limbic system is sometimes called the emotional-visceral brain. Which part of the limbic system is responsible for the visceral connection?

The hypothalamus is part of the limbic system and also an autonomic (visceral) control center.

The hypothalamus oversees a branch of the peripheral nervous system. Which branch?

The hypothalamus oversees the autonomic nervous system.

Locate the limbic system and the reticular formation, and explain the role of each functional system.

The limbic system consists of numerous structures that encircle the brain stem. It is the "emotional-visceral brain." It also plays a role in memory. The reticular formation is a diffuse network of neurons and nuclei spanning the length of the brain stem. It maintains the alert state of the cerebral cortex (RAS), and its motor nuclei serve both somatic and visceral motor activities.

What is the explanation for the cervical and lumbar enlargements of the spinal cord?

The nerves serving the limbs arise in the cervical and lumbar enlargements of the spinal cord.

Describe the general function of the basal nuclei (basal ganglia).

The paired basal nuclei (also called basal ganglia) include the globus pallidus, putamen, and caudate nucleus. Functionally, they are closely associated with the substantia nigra of the midbrain. The basal nuclei recieve input from the entire cerebral cortex as well as other subcortical nuclei and each other. The basal neclei are subcortical nuclei that help control movements.

What are the pyramids of the medulla? What is the result of decussation of the pyramids??

The pyramids of the medulla are the corticospinal (pyramidal) tracts, the large voluntary motor tracts descending from the motor cortex. The result of decussation (crossing over) is that each side of the motor cortex controls the opposite side of the body.