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APHY 101 Exam 5b
Ch. 12 Central Nervous System
| Question | Answer |
|---|---|
| what comprises the central nervous system? | composed of brain and spinal cord |
| what comprises the brain? (surface anatomy) | composed of wrinkled, pinkish gray tissue; anatomy includes cerebral hemispheres, cerebellum, and brain stem |
| where do the ventricles of the brain originate? | arise from expansion of the lumen of the neural tube |
| what are the ventricles? (which are which) | there are the paired C-shaped lateral ventricles ("ram's horns"), the third ventricle found in the diencephalon, and the fourth ventricle found in the hindbrain dorsal to the pons |
| notes on Fig. 12.5 | the lateral ventricles and third and fourth ventricles kind of look like the shape of the female reproductive system, with the lateral ventricles coming out to the side and the fourth ventricle continuing to the central canal |
| what do the cerebral hemispheres form at the brain? | they form the superior part of the brain and make up 83% of its mass (quite big proportionally for our body size) |
| what are the 3 basic regions of the cerebral hemispheres? | cortex, white matter (oligodendrocytes on axons in CNS), and basal nuclei (gray - cell bodies - remember chart) |
| what anatomy do the cerebral hemispheres have? (google image) | ridges called gyri (gyrus) and shallow grooves called sulci (sulcus); the deep grooves = fissures; hemispheres are separated by the longitudinal fissure |
| what are the 5 lobes of the hemispheres divided by deep sulci? | frontal, parietal, temporal, occipital, and insula (seen if you peel away temporal lobe - has to do with taste) |
| what are the sulci of the brain? | central, parieto-occipital, lateral |
| what does the central sulcus separate? | the central sulcus separates the frontal and parietal lobes |
| what does the parieto-occipital sulcus separate? | the parieto-occipital sulcus separates the partietal and occipital lobes |
| what does the lateral sulcus separate? | the lateral sulcus separates the parietal and temporal lobes |
| (starred) what are the gyri of the brain named as, and where are they? | precentral and postcentral gyri, they border the central sulcus (recommend referring to Fig. 12.6a-b) |
| what is the cerebral cortex of the brain? | it is the superficial layer of gray matter of the brain that accounts for 40% of the brain's mass |
| what does the cerebral cortex do? | it enables sensation, communication, memory, understanding, and voluntary movements |
| (starred) factoid about each cortex's hemisphere | each hemisphere acts contralaterally (controls the opposite side of the body) |
| true or false, the two hemispheres are equal in function | false, but still, no functional area acts alone; conscious behavior involves the entire cortex |
| what are the 3 types of functional areas of the cerebral cortex? | motor areas (ex. precentral gyrus), sensory areas (ex. postcentral gyrus), and association areas (ex. visual and sensory association areas) |
| what do the motor areas of the cerebral cortex do? | control voluntary movement |
| what do the sensory areas of the cerebral cortex do? | promote conscious awareness of sensation |
| what do the association areas of the cereral cortex do? | integrate diverse information |
| refer to Fig. 12.8a-b | if he mentions needing to recognize by sight where the different cerebral cortex areas are :) |
| what are the motor areas of the cerebral cortex? | primary (somatic) motor cortex aka precentral gyrus 🎉, premotor cortex, Broca's area (motor speech area), frontal eye field |
| which lobe is the precentral gyrus in? | frontal lobe |
| where is the primary motor cortex, and what is it made of? | located in the precentral gyrus 🎉 (its other name) in the (frontal lobe), and it has pyramidal cells whose axons make up the corticospinal tracts |
| what does the primary motor cortex do? | allows conscious control of precise, skilled, voluntary movements |
| what is the homunculus, e.g. of the primary motor cortex or primary somatosensory cortex? | a map (e.g. Fig. 12.9.1, 12.9.2) along the cerebral cortex of where each part of the body is processed. in the homunculus, the size of the part is proportional to the amount of cortex devoted to it |
| where is the premotor cortex? | located anterior to the precentral gyrus 🎉 (aka primary motor cortex) |
| what does the premotor cortex do? | controls learned, repetitious, or patterned motor skills; coordinates simultaneous or sequential actions (like for a game), involved in the planning of movements |
| what is Broca's area? | for speech preparation and production. is a motor speech area that directs muscles of the tongue; is active as one prepares to speak |
| where is Broca's area? | Broca's (speech) area is located anterior to the inferior region of the premotor area, usually present in the left hemisphere regardless of handedness but not both |
| where is the frontal eye field? | located anterior to the premotor cortex and superior to Broca's area |
| what does the frontal eye field do? | controls voluntary eye movement - motor CN 3, 4, 6 |
| what are the 5+ *sensory* areas of the brain? | primary somatosensory cortex; somatosensory association cortex; visual areas; auditory areas; olfactory, gustatory, and vestibular cortices (look these up) |
| (starred) where and what is the primary somatosensory cortex? | located in the postcentral gyrus (parietal lobe), this area receives information from the skin and skeletal muscles to exhibit spatial discrimination |
| where is the somatosensory association cortex? | located posterior to the primary somatosensory cortex |
| what does the somatosensory association cortex do? | integrates raw sensory information; forms comprehensive understanding of the stimulus; determines size, texture, and relationship of parts |
| where is the primary visual (striate) cortex? | seen on the extreme posterior tip of the occipital lobe; most of it is buried in the calcarine sulcus |
| what does the primary visual cortex do? | receives visual information from the retinas |
| where is the visual association area and what does it do? | surrounds the primary visual cortex and interprets visual stimuli (e.g. color, form, movement) ("it's a bird, a plane, it's Superman!") |
| where it the primary auditory cortex and what does it do? | at the superior margin of the temporal lobe and receives raw information related to pitch, rhythm, and loudness |
| where is the auditory association and what does it do? | located posterior to the primary auditory cortex; stores memories of sounds and permits perception of them ("oh, that sounds like __"). INCLUDES Wernicke's area |
| what are the 4 association areas? | prefrontal cortex, language areas, general (common) interpretation area, visceral association area |
| where is the prefrontal cortex? (starred) | located in the anterior portion of the frontal lobe, and closely linked to the limbic system (emotional part of the brain) |
| what does the prefrontal cortex do? | involved with intellect, cognition, recall, and personality; necessary for judgment, reasoning, persistence, and conscience |
| (starred) what should I know about the accidental lobotomy of Phineas Gage? | it was the accidental destruction of both ventromedial region of both frontal lobes, and personality changed to an irreverent, profane and fitful person |
| what functions do neuroscientists believe are associated with the prefrontal cortex? | planning, moral judgment, and emotional control (things Phineas Gage lost) |
| where are the language areas? | located in a large area surrounding the left (or language-dominant) lateral sulcus (google it) |
| what are the 4 major parts of the language areas of the brain? | 1. Wernicke's area 2. Broca's area 3. lateral prefrontal cortex 4. lateral and ventral temporal lobe |
| what does Wernicke's area do? | sounds out unfamiliar words |
| what does Broca's area do? | speech preparation and production |
| what does the lateral prefrontal cortex do? | language comprehension and word analysis |
| what does the lateral and ventral temporal lobe do? | coordinate auditory and visual aspects of language (close to Wernicke's) |
| what is lateralization of cortical function? | the tendency for certain cognitive processes and behaviors to be more specialized in one hemisphere of the brain than the other - each hemisphere has abilities not shared with its partner |
| what is cerebral dominance? | the normal tendency for one side of the brain to control particular functions, such as handedness and speech. designates the hemisphere dominant for language |
| what does the left hemisphere usually control? | language, math, and logic |
| what does the right hemisphere usually control? | visual-spatial skills, emotion, and artistic skills |
| what by definition is consisting of deep myelinated fibers and their tracts? | cerebral white matter |
| what is cerebral white matter responsible for? | communication between the cerebral cortex and the lower CNS centers, and areas of the cerebrum |
| what are the 3 types of cerebral white matter? | commissures, association fibers, projection fibers |
| what are commissures? | they are tracts connecting corresponding gray areas of the two hemispheres (most famously the corpus callosum) |
| what are association fibers? | they are pathways connecting different parts of the SAME hemisphere |
| what are projection fibers? | white matter tracts in the brain that act as communication pathways, entering the cerebral hemispheres from lower brain and going up or cord centers |
| (starred) note Fig. 12.10a of fiber tracts in white matter | association fibers are the red U's up top, projection fibers are the radiant purple fibers, and commissural fibers are the green dots running between |
| what are basal nuclei? | masses of gray matter found deep within the cortical white matter |
| what is the corpus striatum? | the largest subcortical structure of the basal ganglia located in the forebrain, is a nucleus responsible for motor control, planning, habit formation, and reward processing |
| (starred) what 3 parts comprise the corpus striatum? | caudate nucleus, and, lentiform nucleus composed of the putamen and globus pallidus (see Fig. 12.11a & b) |
| what type of fibers compose the corona radiata (Fig. 12.11a)? | projection fibers |
| notes on Fig. 12.11b | corpus callosum is green palm branches at the top of the view, lateral ventricle with third ventricle is the blue tuning fork, the caudate nucleus is the pink lobster claw base and the claws are the putamen, the thalamus is the large purple blob... |
| (starred) what is the diencephalon? | a critical, central region of the forebrain situated between the cerebrum and brainstem, enclosing the third ventricle (term used for adults) |
| what are the 3 paired structures of the diencephalon? | thalamus, hypothalamus, and epithalamus (google it to look, but hypo is under thalamus and epi is above it. Fig. 12.12) |
| what is the anatomy of the thalamus? | paired, egg-shaped masses that form the superolateral walls of the third ventricle, connected at midline by the intermediate mass, its 4 nuclei groups project and receive fibers from the cerebral cortex |
| what are the 4 groups of the thalamus' nuclei? | anterior, ventral, dorsal, and posterior (Fig. 12.13a) |
| what is the thalamus' function? | thalamic function includes sensual afferent impulses converging and synapsying in the thalamus, like a sensory switchboard of the brain |
| true or false: all inputs ascending to the cerebral cortex pass through the thalamus | false - smell doesn't |
| what is the anatomy of the hypothalamus? | located below the thalamus, it caps the brainstem and forms the inferolateral walls of the third ventricle, has mammillary bodies and infundibulum |
| what are mammillary bodies? | small, paired nuclei (*collection of cell bodies in the CNS) that bulge anteriorly from the hypothalamus; serve as a relay station for olfactory pathways |
| (starred) what is the infundibulum? | stalk of the hypothalamus; connects to the pituitary gland(!), and is the main visceral control center of the body! |
| (starred) note on Fig. 12.13b, the preoptic nucleus | it is a key nucleus in the hypothalamic nuclei (*collection of cell bodies in CNS) *will edit later |
| what are some of the hypothalamic functions? | mainly medulla oblongata does these, but hypothalamus helps it: regulates BP/rate and force of heartbeat, digestive tract motility, rate and depth of breathing, and many other visceral activities; perception of pleasure, fear, and rage |
| what are the main homeostatic functions of the hypothalamus? | maintains normal body temperature, regulates feelings of hunger and satiety, regulates sleep and sleep cycle (though the pineal gland produces melatonin at the epithalamus) |
| what is an endocrine function of the hypothalamus? | its releasing hormones control secretion of hormones by the anterior pituitary (ant pit also known as master gland) |
| (starred) which two nuclei produce antidiuretic hormone and oxytocin? | the supraoptic and paraventricular nuclei produce ADH and oxytocin which are released by the posterior pituitary |
| what is the anatomy of the epithalamus? | it's the most dorsal portion of the diencephalon; forms roof of the third ventricle; has also got the pineal gland and choroid plexus |
| (starred) where/what is the pineal gland? | extends from the posterior border of the epithalamus and secretes melatonin, which is a hormone involved with sleep regulation, sleep-wake cycles, and mood |
| what is a choroid plexus? | a structure that secretes CSF - cerebrospinal fluid - (made by ependymal cells!) |
| prominent features of Fig. 12.14 | the human brain from the ventral aspect: you can see the frontal lobe, olfactory bulb, optic chiasma, optic nerve II, optic tract, mammillary body, pons, temporal lobe, medulla, cerebellum, and spinal cord |
| (highly testable) what are the 3 regions of the brain stem? | midbrain, pons, and medulla oblongata |
| what does the brain stem do? | control automatic behaviors necessary for survival |
| (starred) Fig. 12.15c of brain stem | the pineal gland of the epithalamus sits right on top of the brain stem... not sure what's most important here, but you see the midbrain, pons and medulla |
| (starred) what is the anatomy of the midbrain? | located between the diencephalon and the pons, and include structures such as the cerebral peduncles and cerebral aqueduct, and various nuclei |
| what are the cerebral peduncles? | two bulging structures that contain descending pyramidal motor tracts |
| (starred) what is the cerebral aqueduct? | a hollow tube that connects the third and fourth ventricles (study google images) |
| (starred) midbrain nuclei to know | corpora quadrigemina = four domelike protrusions of the dorsal midbrain; superior colliculi = VISUAL reflex centers (2) and inferior colliculi = AUDITORY relay centers (2) |
| (starred) another midbrain nucleus to know | substantia nigra - functionally linked to basal nuclei (*masses of gray matter found deep within the cortical white matter) - degeneration of this leads to Parkinson's(!) |
| what does Parkinson's disease feature? | tremoring, pill-rolling tremor in hand, shuffling gait |
| midbrain nuclei - what are red nuclei? | largest nucleus of reticular formation; red nuclei are relay nuclei for some descending motor pathways (Fig. 12.16a) |
| what is the anatomy of the pons? | bulging brainstem region between the midbrain and medulla oblongata, forms part of the anterior wall of the fourth ventricle, also contains nuclei of the reticular formation (google it & see Fig. 12.16b) |
| what do fibers of the pons do? | connect higher brain centers and the spinal cord, and, relay impulses between the motor cortex and the cerebellum |
| what is the anatomy of the medulla oblongata? | most inferior part of the brain stem; along with the pons, forms the ventral wall of the fourth ventricle; contains a choroid plexus of the fourth ventricle |
| what unique anatomical features does the medulla oblongata have? | pyramids - two longitudinal ridges formed by corticospinal tracts; decussation of the pyramids = crossover points of the corticospinal tracts |
| (starred) Fig. 12.16c of the medulla oblongata | notice the choroid plexus enclosing the fourth ventricle, nuclei near the ventricle, reticular formation of nuclei groups, pyramids... |
| (starred) what is the physiology of medulla nuclei? | cardiovascular control center - adjusts force and rate of heart contration; respiratory centers - control rate and depth of breathing; additional centers regulate vomiting, hiccuping, swallowing, coughing, and sneezing |
| medulla nuclei also include inferior olivary nuclei, what is that? | gray matter that relays sensory information |
| what is the anatomy of the cerebellum? | located dorsal to the pons and medulla, protrudes under the occipital lobes of the cerebrum, makes up 11% of the brain's mass |
| (starred) what does the cerebellum do? | provides precise timing and appropriate patterns of skeletal muscle contraction |
| true or false, cerebellar activity occurs consciously | false, activity of the cereBELLUM occurs subconsciously |
| Fig. 12.17b | has homunculi of the anterior and posterior lobes |
| what is the anatomy of the cerebellum? | two bilaterally symmetrical hemispheres connected medially by the vermis (Lat. "worm") (google it! it does look like a worm lol); folia, 3 lobes, arbor vitae |
| what are folia of the cerebellum? | transversely oriented mini-gyri (*ridges) |
| what are the 3 lobes of each cerebellar hemisphere? | anterior, posterior, and flocculonodular (recognize for multiple choice) |
| what are the arbor vitae of the cerebellum? | arbor vitae are the distinctive "tree of life" pattern of the cerebellar white matter (myelinated!) |
| what are the cerebellar peduncles? | three paired fiber tracts that connect the cerebellum to the brain stem: superior peduncles, middle peduncles, and inferior peduncles |
| true or false, all fibers in the cerebellum are ipsilateral | true |
| what do superior peduncles connect? | the cerebellum to the midbrain (highest) |
| what do middle peduncles connect? | the pons to the cerebellum (middle) |
| what do inferior peduncles connect? | the medulla to the cerebellum (lowest structure of the three) |
| which area of the brain receives impulses of the intent to initiate voluntary muscle contraction? | cerebellum |
| how does the cerebellum process the intent to move? | proprioceptors and visual signals "inform" the cerebellum of the body's condition; cerebellar cortex calculates the best way to perform a movement, then a "blueprint" of coordinated movement is sent to the cerebral motor cortex |
| what role does the cerebellum play in cognitive function? | plays a role in language and problem solving, recognizes and predicts sequences of events |
| what are the 2 functional systems of the brain system? these are networks of neurons working together and spanning wide areas of the brain | limbic system and reticular formation system |
| what is the anatomy of the limbic system? | structures located on the medial aspects of cerebral hemispheres and diencephalon, includes the rhinencephalon, amygdala, hypothalamus, and anterior nucleus of the thalamus, cingulate gyrus |
| what parts of the limbic system are especially important in emotions? | amygdala - deals with anger, danger, fear responses; cingulate gyrus (superior to corpus callosum) - role in expressing emotions via gestures & resolves mental conflict; these parts put emotional responses to odors like skunks smelling bad |
| what does the limbic system enable one to do emotively, cognitively? | due to the interaction with the prefrontal lobes, the limbic system allows one to react emotionally to conscious understandings, and one is consciously aware of emotion in one's life |
| what do the hippocampal structures do in regards to the limbic system? | convert new information into long-term memories |
| what is the anatomy of the reticular formation (system)? | composed of 3 broad columns along the length of the brain stem: raphe nuclei, medial (large cell) group, lateral (small cell) group; has far-flung connections with the hypothalamus, thalamus, cerebellum, and spinal cord |
| (starred) Fig. 12.19 | the reticular formation is a diffuse, net-like network of neurons and nuclei spanning the brainstem's core (medulla, pons, and midbrain) that integrates essential functions for survival |
| what is the RAS? | reticular activating system sends impulses to the cerebral cortex to keep it conscious and alert, and filters out repetitive and weak stimuli |
| (starred) what does the RAS do? | helps control coarse motor movements, and autonomic centers regulate visceral motor functions (e.g. vasomotor, cardiac and respiratory centers) |
| (starred) what is the blood-brain barrier and what does it do? | a highly selective, semi-permeable protective mechanism, made of a border of cells (endothelial cells, pericytes, and astrocyte end-feet) that separates circulating blood from the brain's extracellular fluid; controls the composition of CSF*! |
| what protects the brain? | bone, meninges, and cerebrospinal fluid, and the blood-brain barrier |
| what are the meninges? | the meninges are three layers of protective membranes—the dura mater (tough), arachnoid mater (spider webbish), and pia mater (tender)—that surround and protect the brain and spinal cord |
| (starred) what are the 4 functions of the meninges | cover and protect the CNS, protect blood vessels and enclose venous sinuses, contain cerebrospinal fluid (CSF), form partitions within the skull |
| Fig. 12.24a notes | from superficial to deep: skin of scalp, periosteum, bone of skull, dura mater (2 layers - periosteal, meningeal), arachnoid mater, pia mater... |
| (starred) which meninx layer is outermost, aka most superficial? | dura mater |
| what is the dura mater? | leathery, strong meninx composed of two fibrous connective tissue layers, which separate in certain areas and form dural venous sinuses |
| what are dural septa? | dural septa (or dural reflections) are rigid, sheet-like inward extensions of the meningeal dura mater that partition the cranial cavity |
| what 3 dural septa extend inward and limit excessive movement of the brain? | falx cerebri, falx cerebelli, tentorium cerebelli (Fig. 12.25) |
| what is the falx cerebri? | a septa/fold of the dura mater that dips into the longitudinal fissure of the brain, separating the two cerebral hemispheres |
| what is the falx cerebelli? | a septa/fold of the dura mater that runs along the vermis of the cerebellum, separating the two cerebellar hemispheres |
| what is the tentorium cerebelli? | a septa/fold of the dura mater that is horizontal and extends into the transverse fissure, separating the cerebellum from the cerebrum |
| what is the arachnoid mater? | the middle meninx, which forms a loose brain covering; it is separated from the dura mater by the subdural space; beneath the arachnoid is a wide subarachnoid space filled with CSF and large blood vessels |
| what part of the arachnoid mater permit the CSF to be absorbed into venous blood? | the arachnoid villi which protrude superiorly |
| what is the pia mater? | deep meninx composed of delicate conective tissue that clings tightly to the brain |
| what is CSF? | cerebrospinal fluid is a watery solution similar in composition to blood plasma, but contains less protein and different ion concentrations. forms a liquid cushion that gives buoyancy to the CNS organs |
| what are the 4 functions of cerebrospinal fluid/ CSF? | prevents brain from crushing under its own weight, protects CNS from blows and other trauma that might cause concussion, nourishes the brain and carries chemical signals throughout it, maintains chemical homeostasis around the brain |
| (starred) Fig. 12.26b circulation of CSF | CSF moves in a specific, generally outward, direction (come back and add notes) |
| what are choroid plexuses? | clusters of capillaries that hang from the roof of EACH ventricle, that deliver blood to the ependymal cells so CSF can be formed through their tissue fluid filters |
| true or false, choroid plexuses are neurological (nerve) plexuses | false |
| what are some additional characteristics of choroid plexuses? | they have ion pumps that allow them to alter ion concentrations of the CSF and help cleanse CSF by removing wastes (Fig. 12.26a) |
| what 3 structures separate bloodborne substances from neurons? | 1. continuous endothelium of capillary walls 2. relatively thick basal lamina 3. bulbous perivascular feet of astrocytes |
| true or false, the blood brain barrier allows nutrients to pass freely | true, but many large molecules are prevented including therapeutic drugs for neurons (unfortunately) |
| true or false, the blood brain barrier is effective against substances that can diffuse through plasma membranes | false, those can get through |
| where is the blood brain barrier absent? | vomiting center and the hypothalamus (so that these areas can monitor the chemical composition of the blood directly) |
| what is a circumventricular organ? | CVOs are highly vascularized, specialized midline brain structures bordering the third and fourth ventricles that lack a functional blood-brain barrier (BBB) |
| the choroid plexus is a circumventricular organ that allows HIV, true or false? | true, it can invade brain tissue through this "breach" in the BBB |
| true or false, stress increases the ability of chemicals to pass through the blood-brain barrier | true |
| CVAs are short for what? | cerebrovascular accidents (strokes) |
| how are cerebrovascular accidents caused? | when blood circulation to the brain is blocked and brain tissue dies (infarction), most commonly caused by blockage of a cerebral artery |
| what are other causes of strokes? | compression of the brain by hemorrhage or edema, and atherosclerosis (*a disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls) |
| what are TIAs (transient ischemic attacks)? | temporary episodes of reversible cerebral ischemia (*a critical condition involving restricted blood flow to tissues); often a warning sign of impending stroke |
| what are TPAs (tissue plasminogen activator)? | the only approved treatment for stroke |
| what are some degenerative brain disorders? | Alzheimer's, Parkinson's, Huntington's |
| what is Alzheimer's? | progressive degenerative disease of brain that results in dementia |
| what is Parkinson's? | degeneration of the dopamine-releasing neurons of the substantia nigra (*a midbrain nucleus) |
| what is Huntington's disease? | a fatal hereditary disorder caused by accumulation of the protein huntingtin that leads to degeneration of the basal nuclei, leads to chorea and hemiballismus |
| why is Huntington's also called Huntington's chorea? | the afflicted person does a wild, flapping, involuntary "dance" |
| what is hemiballismus? | windmilling of the upper extremities characterized by violent, high-amplitude, flinging movements, usually on one side of the body, involving proximal muscles |
| how is the spinal cord anatomically related to the CNS? | CNS tissue is enclosed within the vertebral column from the foramen magnum to L1 (cord ends before it gets to the loin and hips) |
| what is the conus medullaris? | terminal portion of the spinal cord |
| how many spinal nerves are there? | 31 pairs attach to the cord by paired roots |
| what is the collection of nerve roots at the inferior end of the vertebral canal? | cauda equina (Fig. 12.29a) |
| cross-sectional anatomy of the spinal cord includes what structures? | anterior median fissure that separates anterior funiculi, and posterior median sulcus that divides posterior funiculi |
| reminder, what does gray matter consist of? | soma, unmyelinated processes, and neuroglia |
| what is the gray commissure? | connection between masses of gray matter; encloses central canal of the spinal cord |
| what are the posterior (dorsal) horns of the spinal cord? | interneurons, sensory |
| what are the anterior (ventral) horns of the spinal cord? | interneurons and somatic motor neurons |
| what are the lateral horns of the spinal cord? | contain sympathetic neuron somas and nerve fibers (Fig. 12.31b) |
| what kind of neurons are gray matter, structurally? | multipolar |
| white matter in the spinal cord has fibers that run in what 3 directions? | ascending, descending, and tranversely |
| white matter in the spinal cord is divided into what 3 funiculi (columns)? | posterior, lateral, and anterior |
| what does each funiculus in the spinal cord contain? | several fiber tracts whose names reveal their origin and destination; fiber tracts are composed of axons with similar functions |
| true or false: white matter pathways decussate | true |
| how many neurons do most white matter pathways consist of? | two or three, and pathways are paired (one on each side of the spinal cord or brain) |
| main ascending (sensory) pathways have how many neurons? | usually 3 |
| where are the perikaryons of the first-order neurons located? | primarily located in the peripheral nervous system, within the dorsal root ganglia (associated with spinal nerves) and cranial nerve ganglia |
| where are the perikaryons of the third-order neurons lcoated? | the ventral posterolateral (VPL) nucleus of the thalamus |
| (starred) 3 neurons are in the sensory, afferent, ascending, or sensual pathway! | Fig. 12.34a |
| how many neurons are involved in descending (motor) pathways? | 2 |
| (starred) the direct (pyramidal) system | corticospinal tracts - the direct pathway regulates fast and fine (skilled) movements (Fig. 12.35a) |
| what is the other name for the primary somatosensory cortex (the anatomical name)? | postcentral gyrus |
| what does gustatory mean? | having to do with taste (remember, CN 7 9 and 10 - facial, glossopharyngeal, and vagus) |
| what does vestibular mean? | having to do with balance |
| which cranial nerves have to do with taste? | 7, 9 and 10 |
| which cranial nerves have to do with parasympathetic functions? | 3, 7, 9, and 10 |
| which lobe of the brain is hearing associated with? | temporal lobe |
| what does Wernicke's area have to do with? | language and comprehension - sounding out unfamiliar words, interpreting language whether spoken or visual |
| what do Broca's area and Wernicke's area have in common? | they have to do with communication |
| where would the body's signals for voluntary skeletal contractions begin in the brain? | the precentral gyrus 🎉 |
| what are 1st, 2nd, and 3rd order neurons? | 1st - Detects stimuli at sensory receptors; travels to spinal cord/brainstem. 2nd - Located in the spinal cord/brainstem; decussates (crosses over) and ascends to the thalamus. 3rd - Located in the thalamus; transmits signals to the somatosensory cortex |
| what are collections of cell bodies in the CNS? | nucleus (nuclei) |
| what are collections of cell bodies in the PNS? | ganglion (ganglia) |
| what are collections of axons in the CNS? | tract or fasciculus |
| what are collections of axons in the PNS? | nerve |
| what exactly do the nuclei of the thalamus receive from the cerebral cortex? | any sensory stimuli except smell |
| what is the visual pathway to the lateral geniculate body (LGB/LGN)? | 1. light hits retina where bipolar cells are 2. ganglion cell axons form optic nerve 3. nerves travel to optic chiasm, where nasal fibers cross (decussate) to opposite side 4. temporal fibers remain on same side, forming optic tract that terminates in LGB |
| which hypothalamic nuclei acts as our alarm clock? | suprachiasmatic nucleus |
| is the thalamus part of the brainstem? | no |
| what are our reflex centers for vision? | the superior colliculus |
| what are our reflex centers for hearing? | inferior colliculus |
| what are the fasciculi cuneatus and gracilis? | axons of the CNS in the brain stem |
| why is the substantia nigra important clinically? | it dampens precentral gyrus impulses or we'd be tremoring all the time like Parkinson's patients |
| if Dr. Simerlein sneezes a lot what would he say? | "overactive medulla oblongata" |
| what is similar and different about the cerebellum in its role for movement compared to the precentral gyrus? | precentral gyrus (primary motor cortex) and cerebellum both play roles in motor control: precentral gyrus initiates, plans, executes voluntary, conscious movements. cerebellum provides coordination, precision, timing, and unconscious corrections |
| what is the difference between cerebellar peduncles and cerebral peduncles? | cerebral: massive bundles of motor nerve fibers on the ventral midbrain connecting the cerebrum to the brainstem; cerebellar: 3 pairs of tracts (superior, middle, inferior) connecting the cerebellum to the brainstem |
| if the reticular activating system fails, what happens? | we go into a coma |
| what cell makes up the BBB blood brain barrier? | astrocytes |
| what separates the two hemispheres? | falx cerebri |
| (starred) what is the pattern of the circulation of CSF? | lateral ventricles - 3rd ventricle - 4th ventricle - subarachnoid space -arachnoid granulations/venous blood |
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