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S2 Bio 109 A&P 2 > CNS brain > Flashcards

Flashcards in CNS brain Deck (93)
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1
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Intro

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Brain and spinal cord - evaluating incoming information and formulating responses to changes that threaten our homeostatic balanace

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Protective coverings

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  1. Bone: cranial bones encase the brain and vertebrae encase the spinal cord 2. Membranes: coverings of nervous tissue known as meninges
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Meninges

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Dura mater > arachnoid mater > pia mater

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Dura mater

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Made of strong, white, fibrous tissue - connected to periosteum of cranium

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Arachnoid mater

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  • delicate, cobweb-like layer that lies between the dura mater and the pia mater - pia mater adheres to the outer surface of the brain and spinal cord
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Meningeal spaces

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Between and around the meninges - epidural - subdural - subarachnoid space

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Epidural space

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  • located immediately outside the dura mater, but inside the bony coverings - contains a supporting cushion of fat and other connective tissues - because it is continuous with periosteum on the interior surface of the cranial bones, no epidural space is normally present in the brain
13
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Epidural injections

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Targeted injection to anesthetize a region of the spine - nerve roots around this region will be anesthetize as well

14
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Meningitis

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Inflammation of the meninges caused by either a virus or bacterial infection - symptoms are the same for either viral or bacterial meningitis - differential diagnosis is through culturing CSF via a spinal tap

15
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Subdural space

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Located between dura mater and arachnoid mater - contains a small amount of lubricating serous fluid

16
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Subarachnoid space

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Located between arachnoid mater and pia mater - contains a significant amount of cerebral fluid

17
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Meninges of the spinal cord

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Continue down the spinal column

18
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Film termínale

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Formed from pia mater - around S3, the film termínale blends with the dura mater to form a fibrous cord that is continuous with the periosteum of the coccyx

19
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cerebrospinal fluid

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Provides a supportive and protective cushion around and within the brain and spinal cord - reservoir of circulating fluid that, alon with blood, the brain monitors for changes in the internal environment - found within the subarachnoid space, around the brain and spinal cord, and within the cavities and canals of the brain and spinal cord - fills up the ventricles

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21
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Formation of CSF

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Occurs mainly by separation of fluid from blood in the choroid plexuses - network of capillaries that project from the pia mater into the lateral ventricles and into the 3 and 4 ventricles

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Circulation of CSF

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Blood is filtered by the choroid pexuses and CSF is produced - after circulating through the ventricles of the brain, the central canal, and the subarachnoid spaces, it is then absorbed back into the blood

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27
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Medulla oblongata

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  • just above the foramen magnum and extends to inferior border of the pons - composed of all ascending and descending tracts (white matter) and gray matter called the regular foramen - pyramids: 2 bulges of white matter on the central surface - olive: oval projection appearing one on each side of the ventral surface lateral to the pyramids
28
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Reticular foramen

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Contains nuclei (clusters of cell bodies) - some are called control centers for cardiac, respiratory, and vasomotor control - contains vital reflex centers (cardiac, respiratory, vasomotor) and non vital reflexes (vomiting, coughing, sneezing, hiccuping, and swallowing)

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30
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Pons

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Bridge: fibers run transversely across the pons into the cerebellum - lies superior to the medulla and inferior to the midbrain - composed of white matter and reticular formation - contains centers for reflexes mediated by cranial nerves V, VI, VII, VIII - contains the pneumotaxic centers that help regulate respiration

31
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Midbrain

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Located superior to the pons and inferior to the cerebellum - composed of both white matter and reticular formation - cerebral peduncles (anterior): extend through the midbrain and conduct impulses esteem the midbrain and cerebrum - tectum (posterior): corpora quadrigemina (2 inferior and 2 superior) - red nucleus - substantial negra

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33
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Cerebellum

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Little brain - second largest part of the brain (after cerebrum) but contains more neurons that all other parts of the nervous system combined

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35
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Functions of cerebellum

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  • acts with the cerebral corte to produce skilled movements by coordinating the activities of groups of muscles - helps control posture; operates at a subconscious level to make movements efficient and coordinated - controls skeletal muscles to maintain balanace - coordinates incoming sensory information from skeletal muscles
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37
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Diencephalanon

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Between brain - thalamus and hypothalamus - pineal gland: part of the epithalamus (various small nuclei just outside the thalamus and hypothalamus) - optic chiasma

38
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Thalamus

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Dumbbell shaped mass of gray matter made up of many nuclei - each lateral mass forms one lateral wall of the 3rd ventricle - major center for relaying sensory input to cerebral cortex from the spinal cord, brain stem, cerebellum, basal nuclei, and various parts of the cerebrum

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Functions of thalamus

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  • impulses from receptors produce conscious recognition of crude (non critical) sensations of pain, temperature, and touch - cell bodies in nuclei of the thalamus relay various sensory impulses (except possibly olfactory) to the cerebrum - associates sensory impulses with feelings of pleasantness/un - relays info from cerebellum and basal nuclei to motor area of cerebral cortex - plays a part in arousal or alerting mechanism - plays a part in production of complex reflex movements
40
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Hypothalamus

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Major regulator of the ANS (HR, respiration’s, GI tract, urinary bladder) - major regulator of homeostasis; it receives input that is interpreted to correct for changes in osmotic pressure, hormone concentrations, and blood temperature - it affects emotions of afforestation, pain, and pleasure - regulates thirst and hunger responses - controls body temp via vasoconstriction, dilation, and sweating

41
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Pineal gland

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  • pine nut - important part of the body’s biological clock mechanism - sets/regulates the body’s biological clock - secretes hormones, the most noteable is melatonin (sleep inducer)
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45
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Cerebrum

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Largest and uppermost division of the brain - contains bulk of brain’s mass - right and left hemisphere

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47
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Info about cerebrum

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Cerebral cortex is outer rim and composed of gray matter. Contains more than 1 billion neurons - surface of the cerebral cortex is irregular, each ridge is called a gyrus - between adjeacent Geri lie either shallow grooves called Sullivan, or deeper grooves called fissures (divide hemispheres into lobes)

48
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Lobes of cerebrum

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  1. Frontal lobe: control of emotion 2. Parietal lobe: processes senses other than hearing and vision 3. Temporal lobe: processes hearing 4. Occipital lobe: processes vision 5. Ínsula: riel island, hidden from view buried in lateral fissure
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51
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Longitudinal fissure

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The deepest groove; division of cerebrum into right and left hemis

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Central sulcus

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Groove between the frontal and parietal lobes

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Lateral fissure

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Deep groove between the temporal lobe and the frontal and parietal lobes

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Parietooccipital fissure

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Groove that separates the parietal lobe from the occipital lobe

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Cerebral tracts and basal nuclei

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Cerebral tracts are under the cerebral cortex - white matter - 3 types: projection, association, commissural

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Projection tracts

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Extensions of ascending (sensory) spinothalamic tracts and descending (motor) corticospinal tracts

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Association tracts

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Most numerous - extend from one convolution to another in the same hemisphere

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Commissural tracts

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Extend from a point in one hemisphere to a point in the other hemisphere ( compose the corpus callosum)

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Corpus callosum

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Nerve tissue connecting the right and left cerebral hemispheres - much of the inter-hemispheric communication in the brain is conducted across this

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61
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Basal nuclei

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Islands of gray matter that lie deep in white matter in each hemisphere - play a role in regulating initiation and termination of movement - helps regulate muscle tone required for body movement - control subconscious contraction of skeletal muscles (arm swing) - help initiate and terminate attention, memory, planning - help regulate emotional behaviors

62
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Inter capsule

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White matter connecting nuclei (v close to basal nuclei)

63
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Functions of cerebral cortex

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Certain areas of the cerebral cortex engage predominantly in one particular funciton - function of each region depends on structures with which it communicates

64
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Cerebral localization

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Many cerebral cortex functions have a typical location

65
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Cerebral plasticity

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Localization of funciton varies from person to person and even at different times in an individual’s life when the brain has sustained damage

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67
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Postcentral gyrus

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Primary somatic sensory area - receives impulses from receptors activated by hear, cold, and touch stimuli - cortex contains a somatic sensory may of the body (sensory homunculus)

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69
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Precentral gyrus

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Primary somatic motor area - impulses from neurons in this area descend over motor tracts and stimulate skeletal muscles

70
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Transverse gyrus

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Primary auditory area (sensory)

71
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Occipital lobe

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Primary visual area (sensory)

72
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Broca’s area

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Motor speech area, executive (motor)

73
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Wernicke’s area

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Sensory speech area (receptive)

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75
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Integrative functions of cerebral cortex

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Consist of all events that take place in the cerebrum between its reception of sensory impulses and its sending out of motor impulses - conscious - language - emotions -memory

76
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Consciousness

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Sácate of awareness fo one’s self, one’s environment, and other humans - very little is known about the neural mechanisms that produce consciousness - depends on excitation of cortical neurons by impulses conducted by the reticular activating system

77
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Reticular activating system

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Centers in the brainstem’s reticulat formation that receive impulses from the spinal cord anda relay to the thalamus. From the thalamus to all parts of cerebral cortex - sensory or ascending - functions: arousal or alerting system, crucial for maintaining consciousness, alertness and attentiveness

78
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Language

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The ability to speak and write workds, the ability to understand spoken and written words - speech centers are located in the frontal, parietal, and temporal lobes - the left cerebral hemisphere contains language areas in about 97% of the population - lesions in the speech centers give rise to language defects: aphasia or dysphasia

79
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Emotions

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Both the subjective experiencing and objective expression of emotions, involve the cerebrum’s limbic system (emotional brain)

80
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Limbic system

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To bring about normal expression of emotions parts of the cerebral cortex other than the limbic system must also function - cingulate gyrus - hippocampus - and primary connections with thalamus, amígdala and more

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82
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Stress

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Hippocampus, amígdala, and limbic system are affected by prolonged stress

83
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Hippocampus

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Primary role in converting short-term to long-term memory - regulates activity of the hypothalamus-pituitary-adrenal axis (HPA) by shutting down the stress response when it is no longer needed - prolonged stress interferes with memory, spatial navigation, and the ability to regulate the HPA axis - prolonged stress can cause atrophy of the hippocampus

84
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Amygdala

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Associated with emotions, survival instincts, and memory - plays a significant role in fear response - prolonged stress seems to cause hypersensitivity in the amygdala (increases anxiety and reaction to fear) - prolonged stress results in enlargement of the amygdala

85
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Prefrontal cortex (stress)

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Responsible for planning, logic, self-regulation, and higher mental functioning - stress results in shrinkage and loss of dendrites in this area - results in impaired decision making, self regulation, and higher mental function, and decreases the ability to cognitively adapt - allows the amygdala to go un key and creates a viscous loop!

86
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Memory

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  • the cortex is capabel of stoking and retrieving both short-term memory and long-term memory - the temporal, parietal, and occipital lobes are amount the areas responsible for short and long term memory - research findings indicate that the cerebrum’s limbic system pays a key role in memory - the hippocampus pays a primary role in converting short-term to long-term memory
87
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Left hemisphere

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  • Language functions - analytic and local thought - pattern sequencing
88
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Right hemisphere

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  • perception of auditory material - perceiving and visualizing spatial relationships - creativity
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