Chapter 13 - The Central Nervous System

*Thalamus*

+measures about 3 cm in length and makes up 80 percent of the diencephalon. +It consists of paired oval masses of gray matter organized into nuclei, with interspersed tracts of white matter.

*Cerebral aqueduct*

passes through the midbrain into the fourth ventricle.

The brain is continuous with the spinal cord and together they comprise the ____.

central nervous system (CNS)

*Brain stem*

consists of the midbrain, pons, and medulla oblongata.

*Cerebral white matter*

consists primarily of tracts.

*Association tracts*

contain axons that conduct impulses between gyri in the same hemisphere.

*Commissural tracts*

contain axons that conduct impulses from gyri in one cerebral hemisphere to corresponding gyri in the other cerebral hemisphere.

*Projection tracts*

contain axons that conduct impulses from the cerebrum to lower parts of the CNS (thalamus, brain stem, or spinal cord) or from lower parts of the CNS to the cerebrum. +An example is the internal capsule.

*Superior cerebellar peduncles*

contain axons that extend from the cerebellum to the midbrain and thalamus.

*Anterior root*

contains axons of motor neurons which conduct impulses from the CNS to effectors (muscles and glands).

+Posterior root*

contains only sensory axons, which conduct impulses from sensory receptors in the skin, muscles, and internal organs into the central nervous system.

*Spinothalamic tract*

conveys impulses for sensing pain, warmth, coolness, itching, tickling, deep pressure, and crude touch.

*Perception*

+The conscious awareness of a sensation.

*Spinal cord*

extends inferiorly from the medulla oblongata to the level of the first or second lumbar vertebra.

The surrounding ____ and ____ provide a strong, protective shelter against damaging blows or bumps.

skull vertebral column

The *cerebellum*, second only to the cerebrum in size,

occupies the inferior and posterior aspects of the cranial cavity.

*Spinal reflex*

+When integration takes place in the spinal cord gray matter, the reflex is called this.

*Hypothalamus*

is a small part of the diencephalon located inferior to the thalamus. +Composed of a dozen or so nuclei. +

*Pineal gland*

is about the size of a small pea and protrudes from the posterior midline of the third venctricle. +Secretes the hormone melatonin.

The *cerebrum*

is the "seat of intelligence." +Provides us with the ability to read, write, and speak; to make calculations and compose music; and to remember the past, plan for the future, and imagine things that have never existed before.

*Vermis*

is the central constricted area of the cerebellum.

*Cerebrum*

is the largest part of the brain.

The first layer of protection for the central nervous system is the hard bony ____ and ____.

skull vertebral column

*Internal capsule*

+A thick band of white matter that contains both ascending and descending axons.

*Septum pellucidum*

+Anteriorly, the lateral ventricles are separated by this thin membrane.

*Basal nuclei*

+Are deep within each cerebral hemisphere are three (masses of gray matter).

*Tracts*

+Bundles of myelinated axons that propagate impulses throughout the CNS to allow communication between its regions. +Tracts are the CNS equivalent of nerves (bundles of axons in the PNS).

*Superior sagittal sinus*

+Drains blood from the brain and delivers it to the internal jugular veins of the neck. +A sinus is similar to a vein but has thinner walls.

Circulation of CSF

+Ependymal cells line the ventricles of the brain and central canal of the spinal cord. +Movement of their cilia assists in the flow of CSF.

Three extensions of the dura mater separate portions of the brain:

+Falx cerebri +Falx cerebelli +Tentorium cerebelli

*Premotor area*

+It generates impulses that cause specific groups of muscles to contract in a specific sequence. +Through repitition, the *premotor area* serves as a memory bank to store specific patterns of movements.

*Common integrative area*

+It integrates sensory interpretation from all sensory association areas, allowing the formation of thoughts based on a variety of sensory inputs.

*Visual association area*

+It relates present and past visual experiences and is essential for recognizing and evaluating what is seen. +Example: this area allows you to recognize an object such as a spoon simply by looking at it.

*Longitudinal fissure*

+The most prominent fissure. +Separates the cerebrum into right and left halves.

*Coma*

+This may result in damage to the *RAS*. +A state of unconsciousness from which an individual cannot be aroused.

*Cerebellar peduncles*

+Three paired, attache the cerebellum to the brain stem. +Bundles of white matter consist of axons that conduct impulses between the cerebellum and other parts of the brain.

*Regulation of emotional and behavioral patterns*

+Together with the limbic system, the *hypothalamus* participates in expression of rage, aggression, pain, and pleasure, and the behavioral patterns related to sexual arousal.

*Impulse propagation*

+Tracts within the white matter of the spinal cord serve as highways for *impulse propagation*. +Sensory input travels along these tracts toward the brain, and motor output travels from the brain along these tracts toward skeletal muscles and other effector tissues.

*Denticulate ligaments*

+Triangular-shaped membranous extensions of the pia mater. +Project laterally from the spinal cord and fuse with the arachnoid mater and inner surface of the dura mater.

*Roots*

+Two bundles of axons. +Connect each spinal nerve to a segment of the cord.

*Spinal meninges*

+Surround the spinal cord.

*Circulation*

+CSF is a medium for exchange of nutrients and waste products between the blood and adjacent nervous tissue.

*Reticular formation*

+The broad region where white matter and gray matter exhibit a netlike arrangement.

The brain consists of four major parts:

+cerebrum +diencephalon +brain stem +cerebellum

*Primary somatosensory area*

+Located in each parietal lobe in the postcentral gyrus directly posterior to the central sulcus. +Receives impulses for touch, pressure, vibration, itch, tickle, and temperature (coldness and warmth), pain, and proprioception (joint and muscle position). +A "map" of the entire body is present in this area: Each point within the area receives impulses from a specific part of the body.

*Dura mater*

+Means "tough mother". +The most superficial and strongest of the three meninges. +Composed of dense, irregular connective tissue. +The *dura mater* of the brain adheres directly to the periosteum of the interior surface of cranial bones.

The CSF has three basic functions:

+Mechanical protection +Chemical protection +Circulation

The *brain stem* consists of three structurally and functionally connected regions:

+Midbrain +Pons +Medulla oblongata

*Third ventricle*

is a narrow cavity along the midline superior to the hypothalamus and between the right and left halves of the thalamus.

The *reticular activating system (RAS)*

is also active during *arousal* (aweakening from sleep) and helps maintain *attention* and alertness. +The *RAS* also *prevents sensory overload* by filtering out insignificant snesory information so that it does not reach consciousness. +Familiar or repeated impulses are ignored, while new or unusual impulses are passed on to the cerebral cortex.

*Postcentral gyrus*

is located immediately posterior to the central sulcus.

*Primary motor area*

is located in each frontal lobe in the precentral gyrus directly anterior to the central sulcus. +A "map" of the entire body is present iin the primary motor area: Each region within the area controls voluntary contractions of specific muscles or groups of muscles.

*Broca's area*

is located in the frontal lobe close to the lateral cerebral sulcus. +The planning and production of speech occurs in the Broca's area, located in one frontal lobe--the left frontal lobe in 97 percent of the population.

*Primary auditory area*

is located in the superior part of the temporal lobe near the lateral cerebral sulcus. +It receives information for sound and is involved in auditory perception.

*Flocculonodular lobe*

is on the inferior surface and contributes to equilibrium and balance.

*Limbic system*

is sometimes called the "emotional brain" because it plays a primary role in a range of emotions, including pain, pleasure, docility, affection, and anger. +It also is involved in olfaction (smell) and memory.

*Infundibulum*

is stalk-like and connects the pituitary gland to the *hypothalamus*.

*Brain stem*

is the part of the brain between the spinal cord and the diencephalon.

*Fourth ventricle*

lies between the brain stem and the cerebellum.

*Pons*

lies directly inferior to the midbrain and anterior to the cerebellum, and is about 2.5 cm (1 inch) long. +As its name implies, the *pons* is a bridge that connects parts of the brain with one another. +These connections are provided by bundles of axons.

*Central sulcus*

separates the *frontal lobe* from the *parietal lobe*.

*Lateral cerebral sulcus*

separates the *frontal lobe* from the *temporal lobe*.

*Parieto-occipital sulcus*

separates the *parietal lobe* from the *occipital lobe*.

*Tentorium cerebelli*

separates the cerebrum from the cerebellum.

*Falx cerebelli*

separates the two hemispheres (sides) of the cerebellum.

*Falx cerebri*

separates the two hemispheres (sides) of the cerebrum.

The *medulla* also contains

several nuclei that control vital body functions. +The *cardiovascular center* regulates the rate and force of the heartbeat and the diameter of blood vessels. +The *medullary rhythmicity area* adjusts the basic rhythm of breathing. +Other nuclei in the *medulla* control reflexes for vomiting, coughing, sneezing, and hiccupping.

Lobes of the cerebrum:

+Frontal +Parietal +Temporal +Occipital

Three basal nuclei:

+Globus pallidus +Putamen +Caudate nucleus

*Caudate nucleus*

+Has a large "head" connected to a small "tail" by a long, comma-shaped "body."

The *spinal cord* has two principal functions in maintaining homeostasis:

+Impulse propagation +Information integration

*Conus medullaris*

+Inferior to the lumbar enlargement, the spinal cord tapers to a conical portion referred to as this.

*Inferior cerebellar peduncles*

carry sensory information into the cerebellum from the medulla, pons, and spinal cord.

*Satiety center*

causes a sensation of fullness and cessation of eating.

*Subarachnoid space*

+A space between the arachnoid mater and the pia mater. +Contains cerebrospinal fluid.

____ fluid is a buoyant liquid that suspends the delicate nervous tissue of the brain and spinal cord in a weightless environment while surrounding them with a shock-absorbing, hydraulic cushion.

Cerebrospinal

*Fissures*

are the deepest grooves between the gyri.

*Gyri*

are the folds of the cerebrum part of the brain that we see.

*Cerebellar hemispheres*

are the lateral "wings" or loves of the cerebellum.

*Spinal nerves*

are the paths of communication between the spinal cord and specific regions of the body. +The spinal cord appears to be segmented because the 31 pairs of spinal nerves emerge at regular intervals through intervertebral foramina of the vertebral column.

*Reflexes*

are fast, involuntary responses to stimuli.

The *pneumotaxic area* and the *apneustic area*

are nuclei in the *pons* that work with the medullary rhythmicity area of the *medulla* to help control breathing.

*Sulci*

are the shallower grooves between the gyri.

*Choroid plexuses*

are the sites of CSF production. +Networks of capillaries in the walls of the ventricles. +The capillaries are covered by ependymal cells (a type of neuroglia) joined by tight junctions. +Selected substances (mostly water) filtered from the blood plasma are secreted by the ependymal cells to produce the cerebrospinal fluid.

*Meninges*

are three protective, connective tissue coverings that lie between the bony encasement of teh skull and vertebral column and the brain and spinal cord. The three are: +Cranial meninges +Spinal meninges +Dura mater

*Association areas*

deal with more complex integrative functions such as memory, emotions, reasoning, will, judgement, personality traits, and intelligence.

*Medulla oblongata* or *medulla*

forms the inferior part of the brain stem and is a continuation of the spinal cord.

The *anterior lobe* and *posterior lobe*

govern subconscious aspects of skeletal muscle movements.

*Motor areas*

initiate voluntary movements.

*Cerebrospinal fluid (CSF)*

is a clear, colorless liquid that protects the brain and spinal cord against chemical and physical injuries. +It also carries oxygen, glucose, and other needed chemicals from the blood to neurons and neuroglia.

*Cerebral cortex*

is a region of gray matter that forms the outer rim of the cerebrum.

*Prefrontal cortex*

is concerned with the makeup of a person's personality, intellect, complex learning abilities, recall of information, initiative, judgement, foresight, reasoning, conscience intuition, mood, planning for the future, and development of abstract ideas.

*Diencephalon*

is immediately below the cerebrum and contains the thalamus and hypothalamus. +Provides a structural connection between the cerebrum and the brain stem.

*Primary gustatory area*

is located at the base of the postcentral gyrus superior to the lateral cerebral sulcus in the parietal cortex. +It receives impulses for taste and is involved in taste perception and discrimination.

*Primary visual area*

is located at the posterior tip of the occipital lobe, mainly on the medial surface (next to the longitudinal fissure). +It receives visual information and is involved in visual perception.

*Primary olfactory area*

is located iin the temporal lobe on the medial aspect (and thus is not visible). +It receives impulses for smell and is involved in the perception and discrimination of the various odors.

*Precentral gyrus*

is located immediately anterior to the central sulcus.

Inactivation of the *reticular activating system (RAS)*

produces *sleep*, a state of partial consciousness from which an individual can be aroused.

*Feeding center*

promotes eating.

*Blood-brain barrier (BBB)*

protects the CNS from harmful substances and pathogens by preventing passage of these substances from blood into the interstitial fluid of brain tissue.

*Sensory areas*

receive sensory information and are involved in *perception*.

The ____ controls some of your most rapid reactions to environmental changes. If you pick up something hot, you may drop the object even before you are consciously aware of the extreme heat or pain. This is an example of a ____ reflex--a quick, automatic response to certain kinds of stimuli that involves neurons only in the ____.

spinal cord

The ____ is also the pathway for sensory impulses traveling to the brain and motor impulses traveling from the brain to skeletal muscles and other effectors.

spinal cord

Even though the *RAS* receives input from the eyes, ears, and other sensory receptors,

there is no input from receptors for the sense of smell; even strong odors may fail to cause arousal.

Association areas

usually receive input both from the primary sensory areas and from other brain regions. +Association areas integrate sensory experiences to generate meaningful patterns of recognition and awareness.

*Chemical protection*

+CSF provides an optimal chemical environment for accurate neuronal signaling. +Even slight changes in the ionic composition of CSF within the brain can seriously disrupt production of action potentials and postsynaptic potentials.

*Mechanical protection*

+CSF serves as a shock-absorbing medium that protects the delicate tissues of the brain and spinal cord from jolts that would otherwise cause them to hit the bony walls of the cranial cavity and vertebral canal. +The fluid also buoys the brain so that is "floats" in the cranial cavity.

*Cerebellar nuclei*

+Even deeper, within the white matter. +Regions of gray matter that give rise to axons carrying impulses from the cerebellum to other brain centers and to the spinal cord.

*Arachnoid villi*

+Fingerlike extensions of the arachnoid mater that project into the dural sinuses, especially the superior sagittal sinus.

*Filum terminale*

+Arises from the conus medullaris. +An extension of the pia mater that extends inferiorly and anchors the spinal cord to the coccyx.

The three types of *tracts* are:

+Association tracts +Commissural tracts +Projection tracts

*Putamen*

+Beside the globus pallidus. is closer to the cerebral cortex.

*Globus pallidus*

+Beside the putamen. is closer to the thalamus.

*Subdural space*

+Between the dura mater and the arachnoid mater. +Is a thin space that contains interstitial fluid.

*Reticular activating system (RAS)*

+A part of the reticular formation. +Consists of sensory axons that project to the cerebral cortex. +The *RAS* helps maintain consciousness, a state of wakefulness in which an individual is fully alert, aware, and oriented.

+Posterior root ganglion*

+A swelling on the root which contains the cell bodies of snesory neurons.

In an adult, the ____ represents only 2 percent of total body weight, but it consumes 20 percent of the oxygen and glucose used by the body even when you are resting.

brain

The ____ is the control center for registering sensations, correlating them with one another and with stored information, making decisions, and taking actions.

brain

*Middle cerebellar peduncles*

carry commands for voluntary movements from the pons (which receive input from motor areas of the cerebral cortex) into the cerebellum.

*Sensory (ascending) tracts*

consist of axons that conduct sensory impulses toward higher brain areas.

*Cauda equina*

+Meaning "horse's tail."

*Regulation of eating and drinking*

+The *hypothalamus* regulates food intake. +Contains a feeding center, a satiety center, and a thirst center.

*Regulation of circadian rhythms and states of consciousness*

+The *hypothalamus* serves as the body's internal biological clock because it establishes circadian rhythms.

*Interventricular foramina*

+The CSF formed in the choroid plexuses of each lateral ventricle flows into the third ventricle through these two narrow, oval openings.

*Somatosensory association area*

+Integrates and interprets sensations. +This area permits you to determine the exact shape and texture of an object by feeling it, to determine the orientation of one object with respect to another as they are felt, and to sense the relationship of one body part to another. +Example: this area allows you to recognize objects such as a pencil and a paper clip simply by touching them.

*Corpus callosum*

+Internally connects the cerebral hemispheres. +A broad band of white matter containing axons that extend between the hemispheres.

*Auditory association area*

+It allows you to recognize a particular sound as speech, music, or noise.

*Decussation of pyramids*

+Just superior to the junction of the *medulla* with the spinal cord, 90 percent of the axons in the left pyramid cross to the right side, and 90 percent of the axons in the right pyramid cross to the left side. +Hence, the name of this crossing and explains why each side of the brain controls voluntary movements on the opposite side of the body.

*Information integration*

+The gray matter of the spinal cord receives and integrates incoming and outgoing information.

*Lumbar enlargement*

+The inferior enlargement of the spinal cord. +Provides nerves to and from the lower limbs.

*Pia mater*

+The innermost meningeal membrane. +Is a thin, transparent connective tissue layer that adheres tightly to the surface of the brain and spinal cord. +It contains interlacing bundles of collagen fibers and some fine elastic fibers. +Within the *pia mater* are many blood vessels that supply oxygen and nutrients to the brain and spinal cord.

*Corpus callosum*

+The largest fiber bundle iin the brain, containing about 300 million axons.

*Hemispheric lateralization*

+The left hemisphere receives somatic sensory signals from and controls muscles on the right side of the body, and the right hemisphere receives sensory signals from and controls muscles on the left side of the body.

*Corpora quadrigemina*

+The posterior part of the *midbrain* contains four hundred elevations known as this. +The two superior elevations are known as superior colliculi.

*Cerebellar cortex*

+The superficial layer of the cerebellum. +Consists of gray matter in a series of slender, parallel folds.

*Cervical enlargement*

+The superior enlargement of the spinal cord. +Supplies nerves to and from the upper limbs.

*Inferior colliculi*

+The two inferior elevations. +Part of the auditory pathway, relaying impulses from the receptors for hearing in the ear to the brain. +They also are reflex centers for the startle reflex, sudden movements of the head, eyes, and trunk that occur when you are surprised by a loud noise such as a gunshot.

*Superior colliculi*

+The two superior elevations. +Serves as reflex centers for certain visual activities. +Visual stimuli elicit eye movements for tracking moving images (such as a moving car) and for scanning stationary images (as you are doing to read this sentence). +Also responsible for reflexes that govern the movements of the head, eyes, and trunk in response to visual stimuli.

*Wernicke's area*

+This area interprets the meaning of speech by recognizing spoken words. +It is active as you translate words into thoughts.

*Motor *descending) tracts*

+Tracts consisting of axons that carry motor impulses from higher brain areas.

*Thirst center*

+When certain cells in the *hypothalamus* are stimulated by rising osmotic pressure of the extracellular fluid, they cause the sensation of thirst. +The intake of water by drinking restores the osmotic pressure to normal, removing the stimulation and relieving the thirst.

*Epidural space*

+Within the vertebral canal, this space exists between the dura mater and the wall of the vertebral canal. +The spinal cord is protected not only by the strong dura mater, but also by a cushion of fat and connective tissue located within the epidural space.

The *hypothalamus*

controls many body activities and is on of the major regulators of homeostasis. +Sensory impulses related to both somatic and visceral senses arrive at the *hypothalamus*, as do impulses from receptors for vision, taste, and smell. +Has several very important connections with the pituitary gland and produces a variety of hormones.

*Blood-cerebrospinal fluid barrier*

controls passage of substances from *blood* into CSF.

*Blood-brain barrier*

controls passage of substances from blood into *interstitial fluid* of neural tissue.

*Indirect pathways*

convey impulses from the brain stem to cause *automatic movements* that maintain skeletal muscle tone, sustain contraction of postural muscles, and play a major role in equilibrium by regulating muscle tone in response to movements of the head.

*Direct pathways*

convey impulses that originate in the cerebral cortex and are destined to cause *voluntary* movements of skeletal muscles.

*Arachnoid mater*

+Deep to the dura mater and is an avascular covering so named because of its spider's web arrangement of delicate collagen fibers and some elastic fibers.

*Ventricles*

+CSF-filled cavities within the brain.

Important functions of the *hypothalamus* include the following:

+Control of the ANS +Production of hormones +Regulation of emotional and behavioral patterns +Regulation of eating and drinking +Control of body temperature +Regulation of circadian rhythms and states of consciousness

Three important commissural tracts are:

+Corpus callosum +Anterior commissure +Posterior commissure

*Arbor vitae*

+Deep to the gray matter. +Are tracts of white matter called this that resemble branches of a tree.

*Lateral ventricle*

+There is one "lateral ventricle* in each hemisphere of the cerebrum.

*Amygdala*

+One of the basal nuclei of the cerebrum, produces fear and a behavioral pattern called rage. +A person whose *amygdala* is damaged fails to recognize fearful expressions in others or fails to express fear in situations where this emotion would normally be appropriate, for example, while being attacked by an animal.

*Circadian rhythms*

+Patterns of biological activity (such as the sleep-wake cycle) that occur on a daily schedule (cycle of about 24 hours).

*Cerebellum*

+Posterior to the brain stem.

Right hemisphere functions:

+Receives somatic sensory signals from and controls muscles on left side of body. +Musical and artistic awareness. +Space and pattern perception. +Recognition of faces and emotional content of facial expression. +Generating emotional content of language. +Generating mental images to compare spatial relationships. +Identifying and discriminating among odors.

Left hemisphere functions:

+Receives somatic sensory signals from and controls muscles on right side of body. +Reasoning. +Numerical and scientific skills. +Ability to use and understand sign language. +Spoken and written language.

*Cranial reflex*

+Reflex is called this if the integration occurs in the brain rather than the spinal cord.

*Cerebral hemispheres*

+Right and left halves of the cerebrum.

*Melatonin*

+Secreted by the *pineal gland*. +Is thought to promote sleepiness as more *melatonin* is liberated during darkness than in light.

*Mammillary bodies*

+Small, rounded nuclei projecting from the *hypothalamus* that serve as relay stations for reflexes related to the sense of smell.

*Pyramids*

+Some of the white matter of the *medulla* forms bulges on the anterior aspect of the medulla. +These protrustions (*pyramids*) are formed by the large motor tracts that pass from the cerebrum to the spinal cord. +These motor tracts control voluntary movements of the limbs and trunk.

*Cranial meninges*

+Surround the brain and are continuous with the spinal meninges.

The *diencephalon* includes the

+Thalamus +Hypothalamus +Pineal gland

*Control of body temperature*

+The *hypothalamus* also functions as the body's thermostat.

*Control of the ANS*

+The *hypothalamus* controls and integrates activities of the autonomic nervous system (ANS), which regulates contraction of smooth muscles and cardiac muscle and the secretion of many glands. +Through the ANS, the *hypothalamus* is a major regulator of visceral activities, including regulation of heart rate, movement of food through the gastrointestinal tract, and contraction of the urinary bladder.

*Production of hormones*

+The *hypothalamus* produces several hormones and has two types of important connections with the pituitary gland, an endocrine gland located inferior to the *hypothalamus*.

*Cerebral peduncles*

+The anterior part of the *midbrain* contains paired bundles of axons known as this. +They consist of axons of motor (descending) tracts that conduct impulses from motor areas in the cerebral cortex to the medulla, pons, and spinal cord.

*Dural sinuses*

+The dura mater of the brain contains these. +Spaces within the dura mater itself such as the superior sagittal sinus.

*Frontal eye field area*

in the frontal cortex controls voluntary scanning movements of the eyes--like those you just used in reading this sentence.

*Posterior column*

consists of tracts that convey impulses for discriminative touch, light pressure, vibration, and conscious proprioception (the awareness of the positions and movements of muscles, tendons, and joints).

The primary function of the *cerebellum* is to

evaluate how well movements initiated by motor areas in the cerebrum are actually being carried out. +Besides coordinating skilled movements, the cerebellum is the main brain region that regulates posture and balance. +These aspects of cerebellar function make possible all skilled muscular activities, from catching a baseball to dancing to speaking.

*Midbrain*

extends from the pons to the diencephalon and is about 2.5 cm (1 inch) long. +The cerebral aqueduct passes through the *midbrain*, connecting the third ventricle above with the fourth ventricle below.

In adults, the *spinal cord* extends from the

medulla oblongata, the inferior part of the brain, to the level of the second lumbar vertebra.

*Blood-cerebrospinal fluid barrier*

permits certain substances to enter the CSF but excludes others, protecting the brain and spinal cord from potentially harmful blood-borne substances.

The *basil nuclei*

receive input from the cerebral cortex and provide output to motor portions of the cerebral cortex via nuclei of the thalamus. +The *basil nuclei* also control subconscious contractions of skeletal muscles - like automatic arm swings while walking and laughing in response to a funny joke. +The *basil nuclei* also help initiate and terminate some cognitive processes, such as attention, memory, and planning.

The *thalamus*

relays impulses between different areas of the cerebrum. +In addition to serving as a relay station, thalamic nuclei function along with other parts of the brain in movement control, emotions, maintenance of consciousness, pain perception, learning, memory, and cognition (thinking and knowing).