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160 Cards in this Set

  • Front
  • Back
How do the brain and spinal cord originate?
From the folding of ectoderm (neural plate), resulting in the formation of the embryonic neural tube.
What happens to the brain during the 4th week of embryonic development?
Anterior segment of the neural tube undergoes the formation of three primary swellings: prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain). The remaining portion of the neural tube does not undergo any significant change and becomes the spinal cord.
What happens to the brain during the 5th week of embryonic development?
Secondary swellings develop within the prosencephalon and rhombencephalon giving rise to future adult structures.
Telencephalon - cerebrum
Diencephalon - thalamus, hypothalamus, and epithalamus
Mesencephalon - midbrain
Metencephalon - cerebellum and pons
Myelencephalon - medulla oblongata
When the neural tube is formed, what does the lumen become?
The portion of the lumen associated with the anterior swellings become the ventricles.
How are the ventricles interconnected?
Through a series of foramen (intervertebral foramen, and cerebral aqueduct)
Where is Cerebrospinal fluid (CSF) manufactured?
In the choroid plexus within each ventricle.
How is the Cerebrospinal fluid (CSF) circulated?
The ventricles are lined with ependymal cells (ciliated glial cells) which assist in circulating the CSF
What is the lumen within the spinal cord called?
The central canal
What are the three openings associated with the Cerebrospinal fluid (CSF)?
The median aperture and the paired lateral apertures, which allow the CSF to exit internally and circulate around the brain and spinal cord within the subarachnoid space.
What are the three parts of the brain stem?
The medulla oblongata, the pons, and the midbrain.
What are the five areas contained within the medulla oblongata?
The cardiovascular center, the respiratory center, the reflex centers (for coughing, sneezing, swallowing, and vomiting), the corticocpinal tracts (descending motor, located within the pyrimids, where they decussate or crossover, controlling voluntary movement on opposing sides of the body), and the nuclei of cranial nerves VIII-XII.
What are the functions of the pons?
The pons is primarily composed of ascending sensory and descending motor tractways connecting the cerebrum with the spinal cord. Also forms a connection between the cerebrum and cerebellum (the middle cerebellar peduncles). Also contains the pneumotaxic center, which regulates respiration (inspiration).
What are the functions of the midbrain?
The cerebral peduncles which contain descending motor tracts connect the cerebrum to the brainstem. The substantia nigra works with the basal nuclei, and is responsible for the inhibition of antagonistic muscle groups throught he release of the neurotransmitter dopamine. The coropora quadrigemina (located dorally) is represented by the:
Inferior colliculi, reflex center for the head and shoulders, responses to auditory stimuli, turn head towards the stimulus.
Superior colliculi, reflex center for the eyes, head and neck. Responses to visual stimuli allows for visual tracking.
What separates the cerebellum from the cerebral hemispheres?
The transverse cerebral fissure.
What connects the two cerebellar hemispheres?
The vermis
What are the numerous convolutions covering the cerebellum called?
Folia
Describe the composition of the cerebellum
A thin outer cortex of gray matter and internal white matter
What are the functions of the cerebellum?
Regulates posture and balance. Coordinates skeletal muscle movement producing a smooth action (throwing a baseball or ballroom dancing). Constantly receives sensory input from proprioceptors in muscles, joints, and tendons (inferior cerebellar peduncles). Relays this information (superior cerebellar peduncles) to higher brain centers where adjustments can be made ot modify, inhibit, or generate new motor responses (catching a ball).
Where is the diencephalon located, and what are the three structures composing it?
It is an area deep between the brainstem and cerebrum, consisting of three paired structures; the thalamus, hypothalamus, and epithalamus.
What is the function of the thalamus?
Composed of an oval mass of gray matter, functions as a relay station for all sensory information coming into the brain, except olfaction.
What are the functions of the hypothalamus?
Positioned below the thalamus, controls the basic functions that regulate autonomic activities of the visceral organs; Cardiovascular regulation, body temperature regulation, regulation of food and water intake, regulation of sleep/wake cycles, regulation of sex drive, center of primitive sensations (anger, fear, pain and pleasure), Endocrine function
What area represents the largest part of the brain? (80%)
The cerebrum, which is responsible for higher mental functions.
List the divisions and features composing the cerebrum
Right and left cerebral hemisphere, longitudinal cerebral fissure, corpus callosum, central sulcus, lateral sulcus, precentral gyrus, postcentral gyrus, sulci (invaginations), gyri (convolutions), and the 5 distinct lobes (frontal, parietal, temporal, occipital, and the insula)
Describe the cerebral cortex
Located externally on the brain, approximately 2-4 mm thick. Composed of gray matter unmyelinated axons, specifically interneurons which are only found in the CNS. The deeper and predominate white matter is composed of myelinated axons, budled into large nerve tracts.
What are the three types of nerve tracts found within cerebral cortex?
Commissural fibers - connecting corresponding areas between right and left hemisphere (corpus callosum)
Association fibers - connect different regions of gray matter within the same hemisphere
Projection fibers - represent ascending and descending (sensory and motor neurons)
What are the functions represented by the frontal lobe?
Personality, memory, judgment, emotions, reasoning, and planning. Primary motor cortex governs all voluntary skeletal muscle movement, located within the precentral gyrus.
What are the specific regions of the precentral gyrus governing muscle movement called?
Homunculus
What controls learned muscle skills of a repetitious nature?
The premotor cortex
What does the motor speech area control?
Directs the muscles of the tongue, lips, and the shape of the oral cavity, and larynx for the articulation of word formation (the pronunciation of speech). Only present in the left cerebral hemisphere, also known as Broca's area.
Where is the postcentral gyrus (primary somatosensory cortex) located? What does it do?
Within the parietal lobe. Responds to all stimuli from cutaneous and muscular receptors throughout the body, including taste, but excludes both hearing and vision.
When the parietal lobe is described as contralateral, what does this mean?
Right cerebral hemisphere receives its sensory input from the left side of the body (spinothalamic tract)
How does the size of portions of the postcentral gyrus relate to sensory neurons leading to the area? (homunculus)
The size of the portions of the postcentral gyrus corresponds to the number of sensory neurons leading to the area.
What are the three areas associated with the temporal lobe, and what do they do?
Primary auditory cortex - receives sensory neurons from the cochlea of the ear (hearing)
Auditory association area - evaluation of sound and memory of sound (speech comprehension and word recognition)
Wernickes area - generally left hemisphere, overlapping temporal and parietal lobes. Responsibe for the recogniiton of the spoken and written word. Verbal articulation - formulates phrases (word choice) according to the learned rules of grammer, transmits this information to Broca's area.
What are the two areas associated with the occipital lobe, and what are their functions?
Primary visual cortex - posterior aspect of the occipital lobe, receives visual information that originates on the retina of the eye.
Visual association area - accounts for the recognition of objects, words, and faces.
What are the functions of the basal nuclei?
Influences the activities of the premotor and primary motor cortex; the start, stop such as sitting up and walking and regulates the intensity of voluntary movements. Inhibits the relevant antagonistic muscles through the assistance of the substantia nigra of the midbrain, which secretes the inhibitory neurotransmitter dopamine.
Describe the function and circulation of cerebrospinal fluid
Cushions the brain and spinal cord. Similar chemical composition as blood plasma. Manufactured by the choroid plexuses located within each ventricle. Exits the 4th ventricle through the two lateral and median apertures. Circulates in the subarachnoid space around brain and spinal cord. Reabsorbed into venous drainage by the arachnoid villi (granulations).
What are the three meningeal layers?
The outer dura mater, the arachnoid mater, and the pia mater.
The cerebrospinal fluid circulates between two meningeal layers - what are they?
Between the pia and arachnoid mater is the subarachnoid space; the cerebrospinal fluid circulates within this compartment.
How is excess cerebrospinal fluid dealt with?
Excess fluid is drained by the arachnoid villi and returned to systemic circulation
The spinal cord is described as beginning at the ______ ______ and extending to the ______ ______ ______
Foramen magnum, second lumbar vertebra
What are the primary functions of the brain?
The brain provides for voluntary movements, interpretation and integration of sensation, consciousness, and cognitive function.
What embryonic tissue does the brain develop from?
The brain develops from the rostral portion of the embryonic neural tube
What are the three primary brain vessicles formed during early brain development?
Early brain development yeilds the three primary brain vesicles: the prosencephalon (cerebral hemispheres and diencephalon), mesencephalon (midbrain) and rhombencephalon (pons, medulla, and cerebellum)
Cephalization results in what during brain development?
Cephalization results in the envelopment of the diencephalon and superior brain stem by the cerebral hemispheres
What are the primary divisions of the brain?
In a widely used system, the adult brain is divided into the cerebral hemispheres, diencephalon, brain stem, and cerebellum.
Describe the physical structure of the cerebral hemispheres and cerebellum, diencephalon, and brain stem.
The cerebral hemispheres and cerebellum have gray matter nuclei surrounded by white matter an outer cortex of gray matter. The diencephalon and brian stem lack a cortex.
How many ventricles are there? Where are they located?
The brain contians four ventricles filled with cerebrospinal fluid. The lateral ventricles are in the cerebral hemispheres; the third ventricle is in the diencephalon, the fourth ventricle is in the brain stem and connects with the central canal of the spinal cord.
Describe the physical features found on the two cerebral hemispheres
The two cerebral hemispheres exhibit gyri, sulci, and fissures. The longitudinal fissure partially separates the hemispheres; other fissures or sulci subdivide each hemisphere into loves.
What structures make up the cerebral hemispheres?
Each cerebral hemisphere consists of the cerebral cortex, the cerebral white matter, and basal nuclei (ganglia)
How are sensory and motor impulses routed within the cerebral hemispheres?
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.
What are the motor areas of the cerebral cortex?
Motor areas: primary motor and premotor areas of the frontal lobe, the frontal eye field, and Broca's area in the frontal lobe of the one hemisphere (usually the left) (2) sensory areas: primary somator
What are the sensory areas of the cerebral cortex?
Sensory areas: primary somatosensory cortex and somatosensory association cortex in the parietal lobe; visual areas in the occipital lobe, olfactory and auditory areas in the temporal lobe, gustatory, visceral, and vestibular areas in the insula
What are the association areas of the cerebral cortex?
Anterior association area in the frontal lobe, and posterior and limbic association areas spanning several lobes.
What are the normal divisions of cortical function between right and left cerebral hemispheres?
The cerebral hemispheres show lateralization of cortical function. In most people, the left hemisphere is dominant (i.e. specialized for language and mathematical skills), the right hemisphere is more concerned with visual-spatial skills and creative endeavors.
What are the three types of fiber tracts found in the cerebral white matter?
Fiber tracts of the cerebral white matter include commissures, association fibers, and projection fibers.
What are the two structures making up each basal nuclei?
The paired basal nuclei (also called basal ganglia) include the lentiform nucleus (globus pallidus and putamen) and caudate nucleus. The basal nuclei are subcortical nuclei that help control muscular movements. Functionally they are closely associated with eh substantia nigra of the midbrain.
What structures comprise the diencephalon?
The diencephalon includes the thalamus, hypothalamus, and epithalamus and encloses the third ventricle.
The thalamus acts as a relay station - what structures does it serve in this capacity?
The thalamus is the major relay station for sensory impulses ascending to the sensory cortex, inputs from subcortical motor nuclei and the cerebellum traveling to the cerebral motor cortex, and impulses traveling to association cortices from lower centers.
What are the functions of the hypothalamus?
The hypothalamus is an important autonomic nervous system control center 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.
What is the function of the epithalamus?
The epithalamus includes the pineal glad, which secretes the hormone melatonin
What structures are part of the brain stem?
The brain stem includes the midbrain, pons, and medulla oblongata.
What structures comprise the midbrain?
The midbrain contains the corpora quadrigemina (visual and auditory reflex 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.
What is the function of the pons?
The pons is mainly a conduction area. It's nuclei contribute to regulation of respiration and cranial nerves V-VII.
What functions are served by the pyramids?
The pyramids (descending corticospinal tracts) form the ventral face of the medulla oblongata; these fibers cross over (decussatoin 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.
Describe the physical structure 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.
What are the functions of the cerebellum?
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 an poorly understood role in cognition.
What is another name for the limbic 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.
What is the reticular formation?
The reticular formation is a diffuse network of neurons and nuclei spanning the length of the brian stem. It maintains the alert state of the cerebral cortex (RAS), and its motor nuclei serve both somatic and visceral motor activities.
What is a record of brain wave activity called? What types of brain waves are there?
Patterns of electrical activity of the brain are called brain waves; a record of this activity is an electroencephalogram (EEG). Brain wave patterns, identified by their frequencies, include alpha, beta, theta, and delta waves.
What causes epilepsy? What are the results of an epileptic seizure?
Epilepsy results from abnormal electrical activity of brain neurons. Involuntary muscle contractions and sensory auras are typical during such seizures.
There are four clinical descriptions of varying states of consciousness. What are they?
Consciousness is described clinically on a continuum from alertness to drowsiness to stupor and finally to coma.
What is the current description of human consciousness?
Human consciousness is through to involve holistic information processing, which is not localizable, superimposed on other types of neural activity, and totally interconnected.
What causes fainting? How does the definition of coma differ?
Fainting (syncope) is a temporary loss of consciousness that usually reflects inadequate blood delivery to the brain. Coma is loss of consciousness in which a victim is responsive to stimuli.
What are the two major types of sleep?
Sleep is a state of partial consciouness from which one can be aroused by stimulation. Two major types of sleep are non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
What happens to a patient's EEG at the onset of REM sleep?
During stages 1-4 of NREM sleep, brain wave frequency decreases and amplitude increases until delta wave sleep (stage 4) is acheived. REM sleep is indicated by a return to a stage 1 EEG. During REM, the eyes move rapidly under the lids. NREM and REM sleep alternate throughout the night.
What are thought to be the respective functions of NREM and REM sleep?
Slow-wave sleep (stage 4 of NREM) appears to be restorative. REM sleep is important for emotional stability.
How do the respective proportions of NREM and REM sleep change with aging?
REM sleep occupies half of an infant's sleep time and then declines to about 25% of sleep time by the age of 10 years. Time spent in slow-wave sleep declines steadily throughout life.
Describe 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. Sleep apnea is a temporary cessation of breathing during sleep, causing hypoxia.
What structures and areas of the brain are involved in language processing?
In most people language is controlled by the left hemisphere. The language implementation system, which includes Broca's and Wernicke's areas and the basal nuclei, analyzes incoming and produces outgoing language. The opposite hemisphere deals with the motional content of language.
What is the definition of memory?
Memory is the ability ot recall one's thoughts. It is essential for learning and is part of consciousness.
How long does it take for information to migrate from short term to long term memory?
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.
How do declarative and procedural memory differ?
Declarative memory is the ability to learn and consciously remember information. Procedural memory is the learning of motor skills, which are then performed without conscious thought
What structures serve declarative and procedural memory, respectively?
Declarative memory appears to involve the medial temporal lobe (hippocampus and surrounding temporal cortical areas), thalamus, basal forebrain, and prefrontal cortex. Skill memory (a type of procedural memory) relies on the basal nuclei.
What type of receptors are associated with memory traces?
The nature of memory traces in the human brain is not fully known, but NMDA receptors (essentially calcium channels), activated by depolarization and glutamate bind calcium influx that follows NMDA receptor activation mobilizes enzymes that mediate events necessary for memory consolidation.
What forms of physical protection protect the brain?
The brain is protected by bone, meninges, cerebrospinal fluid, and the blood-brain barrier.
What are the 3 meningeal layers?
The meninges from superficial to deep are the dura mater, the arachnoid mater, and the pia mater. They enclose the brian and spinal cord and their blood vessels. Inward folds of the inner layer of the dura mater secure the brain to the skull.
How is CSF manufactured? What is it's purpose?
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. CSF supports and cushions the brain and cord, and helps to nourish them.
What substances can get through the blood-brain barrier? What substances cannot?
The blood-brain barrier reflects the relative impermeability of the epithelium of capillaries of the brain. It allows water, respiratory gases, essential nutrients, and fat-soluable molecules to enter the neural tissue, but prevents entry of other, water-soluble, potentially harmful substances.
What are some potential results of head trauma?
Head trauma may cause brain injuries called concussions or, in severe cases, contusions (Bruising). When the brain stem is affected, unconsciousness (Temporary or permanaent) occurs. Trauma-induced brain injuries may be aggravated by intracranial hemorrhage or cerebral edema, both of which compress brain tissue.
What are some likely results of stroke?
Cerebrovascular accidents (strokes) result when blood circulation to brian neurons is imparied and brain tissue dies. The result may be hemiplegia, sensory deficits, or speech impairments.
How does Alzheimer's disease affect patients?
Alzheimer's disease is a degenerative brain disease in which beta amyloid peptide deposits and neurofibrillary tangles appear. Marked by a deficit of ACh, it results in slow, progressive loss of memory and motor control and increasing dementia.
What neurotransmitter is affected in both Parkinson's and Huntington's disease?
Parkinson's 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.
What does the spinal cord develop from?
The spinal cord develops from the neural tube. It's gray matter forms from the alar and basal plates. Fiber tracts form the outer white matter. The neural crest forms the sensory (dorsal root) ganglia.
Where is the spinal cord located? What protects it?
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.
How many nerve roots are there in the spinal cord?
Thirty-one pairs of spinal nerve roots issue from the cord. The cord is enlarged in the cervical and lumbar regions, where spinal nerves serving the limbs arise.
Describe the physical arrangement of the gray matter and horns of the spinal cord.
The central gray matter of the cord is H shaped. Ventral horns mainly contain somatic motor neurons. Lateral horns contian visceral (autonomic) motor neurons. Dorsal horns contain interneurons.
How do the ventral and dorsal roots of the spinal cord connect with other structures?
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) enter the posterior aspect of the cord and form the dorsal roots. The ventral and dorsal roots combine to form the spinal nerves.
What are funiculi? How do they relate to the spinal cord?
Each side of the white matter of the cord has posterior, lateral, and anterior columns (funiculi), and each funiculus contains a number of ascending and descending tracts. All tracts are paired and most decussate.
What are some examples of ascending tracts?
Ascending (sensory) tracts include the fasciculi gracilis and cuneatus, spinothalamic tracts, and spinocerebellar tracts.
What are the specific and non-specific sensory pathways?
The specific sensory pathway consists of the dornal white column(fasciculus cuneatus, fasciculus gracilis) and the medial lemniscal tracts, which are concerned with straight-through, precise transmission of one or a few related sensory modalities. The non-specific pathway (The spinothalmic tracts) is a multimodal pathway that permits brain stem processing of ascending impulses. The spinocerebellar tracts, which terminate in the cerebellum, serve muscle sense, not conscious sensory perception.
What are some examples of descending tracts?
Descending tracts include the pyramidal tracts (anterior and lateral corticospinal tracts) and a number of motor tracts originating from the brian stem motor areas (indirect [extrapyramidal] system) and cortical motor areas (direct [pyramidal] system).
What might result from damage to the ventral horns or roots? From the dorsal roots or sensory tracts?
Injury to the ventral horn neurons or the ventral roots results in flaccid paralysis. (Injury to the upper motor neurons in the brain results in spastic paralysis). If the dorsal roots or sensory tracts are damaged, paresthesias occur.
What causes polio? What are the results?
Poliomyelitis results from inflammation and destruction of the ventral horn neurons by the polio virus. Paralysis and muscle atrophy ensue.
What causes amyotrophic lateral sclerosis?
Amyotrophic lateral sclerosis results form destruction of the ventral horn neurons and the pyramidal tract. The victim eventually loses the ability to swallow, speak, and breathe. Death generally occurs within five years.
What are some examples of diagnostic procedures pertaining to the central nervous system?
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.
What are some examples of congenital brain diseases?
Maternal and environmental factors may impair embryonic brain development, and oxygen deprivation destroys brain cells. Severe congenital brain diseases include cerebral palsy, anencephaly, hydrocephalus, and spina bifida.
Why is hypothermia a common problem with premature babies?
Premature babies have trouble regulating body temperature because the hypothalamus is one of the last brain areas to mature prenatally.
What does the development of motor control indicate, with respect to brain development in a growing child?
Development of motor control indicates progressive myelination and maturation of a child's nervous system.
When does brain growth end? What happens to brain weight and volume over time?
Brain growth ends in young adulthood. Neurons die throughout life and are not replaced, thus, brain weight and volume decline with age.
What is the major cause of declining mental function with age?
Healthy elders maintain nearly optimal intellectual function. Disease - particularly cardiovascular disease - is the major cause of declining mental function with age.
The primary motor cortex, Broca's area, and the premotor area are located in which lobe?
A) frontal
B) parietal
C) temporal
D) occipital
A) frontal
The innermost layer of the meninges, delicate and closely apposed to the brain tissue, is the:
A) dura mater
B) corpus callosum
C) arachnoid
D) pia mater
D) pia mater
Cerebrospinal fluid is formed by:
A) arachnoid villi
B) the dura mater
C) choroid plexuses
D) all of these
C) choroid plexuses
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 his right side
A) he cannot voluntarily move his left arm or leg
Which of the following tracts convey vibration and other specific sensations that can be precisely localized?
A) pyramidal tract
B) medial lemniscal tract
C) lateral spinothalamic tract
D) reticulospinal tract
B) medial lemniscal tract
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
C) voluntary motor impulses
Fiber tracts that allow neurons within the same cerebral hemisphere to communicate are:
A) association tracts
B) commissures
C) projection tracts
A) association tracts
A professor unexpectedly blew a loud horn in his anatomy and physiology class. The students looked up, startled. The reflexive movements of their eyes were mediated by the:
A) cerebral cortex
B) inferior olives
C) raphe nuclei
D) superior colliculi
E) nucleus gracilis
D) superior colliculi
Why are the lateral ventricles horn-shaped rather than vertically erect like the third and fourth ventricles?
Because their growth is restricted by the forming embryonic skull, the cerebral hemispheres are forced to grow posteriorly and inferiorly. Hence their cavities (ventricles) become horn-shaped.
What anatomic landmark separates motor areas of the cerebral cortex from sensory areas?
Central sulcus
Why are the motor and sensory homunculi anatomically "deformed"?
Because the relative size of each body area in the drawing represents the relative amount of the cerebral cortex dedicated to that body area.
Why are the lentiform nucleus and caudate nucleus collectively referred to as the corpus striatum?
Because the fibers of the corona radiata running through them make them appear striated.
What part of the brain lies between the optic chiasma and the mammilary bodes?
The hypothalamus
Just what are the pyramids of the medulla?
The corticospinal (pyramidal) tracts. The large voluntary motor tracts descending from the motor cortex.
The cerebellum is primarily involved in motor control. What type of sensory information do you think is relayed to the sensory areas of the cerebellum?
Position sense (proprioception), for example from muscle and tendon stretch receptors.
What structures return CSF to the bloodsteam?
Arachnoid villi
What information would you get by performing a lumbar tap?
Obtaining a sample of CSF allows you to check for CNS infection, inflammation, or the presence of abnormal cells.
What is a tract?
A collection of axons in the CNS, having the same origin and termination.
The rhombencephalon gives rise to:
The metencephalon, which in turn develops into the brain stem: pons, and cerebellum, and the myelencephalon, which develops into the brain stem: medulla oblongata (p432)
The adult cerebrum originates from the:
Telencephalon, which in turn originates from the proscencephalon (forebrain) (p432)
Cerebrospinal fluid (CSF) enters the subarachnoid space through the:
Lateral and median apertures of the fourth ventricle. (p465)
What are the functions of the medulla oblongata?
Cardiovascular center (adjusts rate and force of hear contractions), vasomotor center (changes blood vessel diameter to regulate blood pressure), respiratory centers (control the rate and depth of breathing, work with pons to maintain respiratory rhythm), also regulates vomiting, hiccuping, swallowing, coughing and sneezing through other centers. (p451)
The prevention of over-inflating the lung is a function of the:
The pneumotaxic center of the pons controls inspiration depth. (P3, brain notes handout.)
The thalamus and hypothalamus are associated with the:
Endocrine function (neurosecretory cells e.g., ADH and Oxytocin secreted from
the posterior pituitary gland, which is influenced by the actions of the
hypothalamus. Diencephalon
An area deep between the brainstem and the cerebrum and consists of three paired
structures: the thalamus, hypothalamus, and epithalamus.
Thalamus – oval mass of gray matter, functions as a relay station for all sensory
information coming into the brain, except olfaction.
Hypothalamus – positioned below the thalamus, control the basic functions that
regulate autonomic activities of the visceral organs.
Cardiovascular regulation – heart rate and blood pressure.
Body temperature regulation.
Regulation of food and water intake.
Regulation of sleep/wake cycles.
Regulation of sex drive.
Center of primitive sensations; anger, fear, pain, and pleasure. (P4, brain notes)
What are the functions of the cerebellum?
The Cerebellum
The cerebellum is located inferior to the occipital lobe and dorsal to the pons and
medulla.
It is separated from the cerebral hemispheres by the transverse cerebral fissure.
Represented by two cerebellar hemispheres connected by the vermis. The surface
contains numerous convolutions (folia), and has a thin outer cortex of gray matter and
internal white matter.
Regulates posture and balance.
Coordinates skeletal muscle movement producing a smooth action (throwing a baseball
or ballroom dancing).
Constantly receives sensory input from proprioceptors in muscles, joints, and tendons
(inferior cerebellar peduncles).
Relays this information (superior cerebellar peduncles) to higher brain centers where
adjustments can be made to modify, inhibit, or generate new motor responses
(catching a ball). (P3, cerebellum)
Describe the cerebral cortex:
Gross Anatomy:
Right and left cerebral hemisphere
Longitudinal cerebral fissure
Corpus callosum
Central sulcus
Lateral sulcus
Precentral gryus
Postcentral gryus
Sulci (invaginations)
Gyri (convolutions)
5 distinct lobes – frontal, parietal, temporal, occipital, and the insula

In cross-section the cerebral cortex is located externally on the brain, approximately 2-4 mm
thick. The cerebral cortex is composed of gray matter unmyelinated axons, specifically
interneurons which are only found in the CNS. The cortex represents the site of integration
(the decision making).
Recall that the nervous system carries out three basic functions: sensory, integration, and
motor response.
The deeper and predominate white matter is composed of myelinated axons; these axons are
bundled into large nerve tracts:
Commissural fibers – connecting corresponding areas between right and left
hemisphere (corpus callosum).
Association fibers – connect different regions of gray matter within same hemisphere.
Projection fibers – represent ascending and descending (sensory & motor) neurons.
Trauma to the frontal lobe may result in
Frontal lobe:
Personality, memory, judgment, emotions,
reasoning, and planning.
Primary motor cortex governs all voluntary
skeletal muscle movement is located within the
precentral gyrus of the frontal lobe.
Specific regions of the precentral gyrus govern
muscle movement (homunculus).
Premotor cortex controls learned muscle skills of a
repetitious nature.
The motor speech area directs the muscles of the
tongue, lips, and the shape of the oral cavity, and
larynx for the articulation of word formation (the
pronunciation of speech).
Only present in the left cerebral hemisphere, also
known as Broca’s area.
Word choice and the application of grammar is a function of the:
Temporal Lobe:
Primary auditory cortex - receives sensory neurons from the cochlea of the ear
(hearing).
Auditory association area – evaluation of sound and memory of sound (speech
comprehension and word recognition).
Wernickes Area
o Generally left hemisphere, overlapping temporal and parietal lobes.
o Responsible for the recognition of the spoken and written word.
o Verbal articulation – Formulates phrases (word choice) according to the learned
rules of grammar, transmits this information to Broca’s Area.
The inhibition of antagonistic muscle groups is accomplished by the:
Basal Nuclei:
Clusters of paired gray matter located deep
within the cerebrum.
Caudate nucleus and the lentiform nucleus
(putamen & globus pallidus).
Influences the activities of the premotor and
primary motor cortex; the start, stop such as
sitting up or walking and regulates the intensity of voluntary movements.
Inhibits the relevant antagonistic muscles
through the assistance of the substantia nigra of the midbrain which secretes the inhibitory neurotransmitter dopamine.
Developmentally, the cerebral hemispheres originate from which secondary neural swelling?
A) Mesencephalon
B) Telencephalon
C) Myelencephalon
D) Rhombencephalon
B) Telencephalon
The reflex center for coughing, swallowing, and vomiting are located within the:
A) Superior colliculi
B) Medulla oblongata
C) Lentiform nucleus
D) Cerebellum
B) Medulla oblongata
The cerebral peduncles which contain ascending and descending nerve tracts are part of the:
A) Diencephalon
B) Basal nuclei
C) Midbrain
D) Medulla oblongata
C) Midbrain
The coordination of skilled motor function is accomplished by the:
A) Postcentral gyrus
B) Corpora quadregemina
C) Cerebellum
D) Cerebral pedundcles
C) Cerebellum
The control of numerous visceral functions is controlled by the:
A) Hypothalamus
B) Medulla oblongata
C) Pineal gland
D) Premotor area
A) Hypothalamus
Communication between right and left cerebral hemisphere is accomplished by:
A) Gray commissure
B) Corpus callosum
C) Basal nucleu
D) Middle cerebellar peduncles
B) Corpus callosum
A person's personality, and ability to reason or plan is located within the:
A) Parietal lobe
B) Frontal lobe
C) Temporal lobe
D) Hypothalamus
B) Frontal lobe
Stimulating the cerebral cortex of the precentral gyrus will result in:
A) The acceleration of heart rate
B) An increased glandular secretion
C) The initiation of voluntary skeletal muscle contraction
D) The sensation of external temperature (hot or cold)
C) The initiation of voluntary skeletal muscle contraction
Verbal articulation and the recognition of the written and spoken word are functions of:
A) Broca's area
B) Temporal lobe
C) Precentral gyrus
D) Substantia nigra
B) Temporal lobe
The thalamus is part of the:
A) Diencephalon
B) Midbrain
C) Cerebral cortex
D) Rhombencephalon
A) Diencephalon
The islands of gray matter which assist in voluntary muscle movement are:
A) Pineal gland
B) Corpora quadrigemina
C) Basal nuclei
D) Thalamus
C) Basal nuclei
The hormones oxytocin and ADH are synthesized by:
A) Epithalamus
B) Posterior pituitary gland
C) Neurosecretory cells of the hypothalamus
D) Substantia nigra
C) Neurosecretory cells of the hypothalamus
Which statement best describes the function of the thalamus?
A) Relay center for all incoming sensory information except olfaction
B) Responsible for smooth and graceful muscle movements
C) Initiation for motor speech
D) Termination site for all incoming motor neurons
A) Relay center for all incoming sensory information except olfaction
The separation between frontal and parietal lobe is the:
A) Longitudinal fissure
B) Lateral sulcus
C) Transverse cerebral fissure
D) Central sulcus
D) Central sulcus
The cerebrospinal fluid is manufactured by the:
A) Arachnoid villi
B) Choroid plexus
C) Ependymal cells
D) Septum pellucidum
B) Choroid plexus
The cerebral peduncles are associated with this part of the brain:
A) Corpora quadrigemina
B) Medulla oblongata
C) Midbrain
D) Pons
D) Pons
In addition to the cerebellum, this structre also assists in making muscle movement smooth by inhibiting antagonistic muscle groups (Stimulate biceps, inhibit triceps)
A) Vermis
B) Thalamus
C) Basal nuclei
D) Precentral gyrus
C) Basal nuclei
The stimulating of the cerebral cortex of the precentral gyrus results in:
A) Accelerated heart rate
B) An increase in glandular secretion
C) The sensation of pain
D) The initiation of voluntary skeletal muscle contraction
D) The initiation of voluntary skeletal muscle contraction
This region of the diencephalon is responsible for a variety of autonomic functions
A) Epithalamus
B) Thalamus
C) Hypothalamus
D) Subthalamus
C) Hypothalamus
Damage to a person's frontal lobe could result in:
A) Changes in personality, problem solving, or judgement
B) Complete loss of somatosensory function
C) The inability to recognize faces or objects
D) The loss of memory related to sounds
A) Changes in personality, problem solving, or judgement
This meningeal layer adheres to the neural tissue of brain and spinal cord
A) Dura mater
B) Arachnoid mater
C) Pia mater
D) Ependymal layer
C) Pia mater