Lab 10 and Chapter 14: Brain and Cranial Nerves Flashcards

Question

What is Cerebrospinal Fluid and how does it work?

Answer 1

* clear, colorless liquid that fills ventricles and canals of CNS * Production begins with flitration of blood plasma through capillaries of brain * CSF continually flows around the CNS * 3rd and 4th ventricles add more CSF during cycle * small amount fills central canal of spinal cord * All CSF eventually escapes through three pores into subarachnoid space * CSF is reabsorbed by arachnoid villi (granulations)

Answer 2

* buoyancy * protection * prevents brain from striking the cranium * shaken child syndrome and concussions do still occur * chemical stability * rinses metabolic waste, regulates chemical environment * blood substitute

Answer 3

* Brain is only 2% of adult body weight but receives 15% of all blood * Neurons have high demand for ATP, and therefore oxygen and glucose, so blood supply is critical * 10 second interruption of blood flow may cause loss of consciousness * 4 minutes = irreversible brain damag

Answer 4

* System regulates what substances can get from bloodstream itno tissue fluid of the brain * blood is crucial but can contain harmful agents * Two points of entry must be guarded * blood capillaries through brain tissue * Consists of tight junctions between endothelial cells that form capillary walls * capillaries of choroid plexus * forms tight junctions between ependymal cells * Anything leaving blood must pass through cells (not between) so harmful substances don't get to brain tissue

Answer 5

* Highly permeable to water, glucose, and lipid soluble substances * coffee, alcohol, oxygen, carbon dioxide, nicotine, and anesthetics

Answer 6

* trauma and inflammation an damage BBS and allow pathogens to enter brain tissue * Circumventricular organs--in 3rd and 4th ventricles (no BBS) * blood has direct access to brain * enables brain to monitor and respond to fluctuations in blood glucose, pH, osmolarity, etc. * CVOs afford a route for invasion by HIV

Answer 7

* Begin at foramen magnum * Slightly wider than spinal cord * all ascending and descending fibers connecting to brain/spinal cord pass through here * Contains pyramids (and their decussations): large motor tracts from cerebrum to spinal cord * most neurons decuss here!!! * Autonomic functions * cardiac and vasomotor (blood pressure) center * respiratory center * reflex centers for swallowing, sneezing, couching, and vomiting

Answer 8

Thick stalks on posterior pons that connect it (and the midbrain) to the cerebellum.

Answer 9

* regulates auditory and visual reflexes * startle reflex * Contains cerebral aqueduct

Answer 10

* Loose web of gray matter that runs vertically through all levels of the brain stem * Has connections with many areas of cerebrum * Functions: * somatic motor control * ^{adjust muscle tension for tone, balance, posture} * ^{central pattern generators for breathing and swallowing} * ^{Cardiovsacular centers of medulla oblongata} * Pain modulation * some pains signals ascend through here * some descending analgesic pathways begin here * sleep and consciousness * alerts cerebral cortex to awaken from sleep; maintains alertness * Habituation * filters out reptitive and weak stimuli (99%)

Answer 11

* highly important in motor coordination * Aids in learning motor skills * Maintains muscle tone and posture * LEsions can cause ataxia * clumsy, awkward gait

Answer 12

* controls and integrates activities of the Autonomic NS and the Endocrine System * Controls the pituitary gland * Produces hormones * REgulates rage, aggression, pain, pleasure, and arousal * Hunger, thirst, and satiety centers * Thermoregulation * Regulates daily patterns of sleep

Answer 13

* secretes melatonin during darkness * promotes sleepiness and sets biological clock

Answer 14

* Seat of sensory perception, memory, thought, judgement, and voluntary motor actions

Answer 15

* Emotional or affective brain * Cingulate gyrus * aids in expressing emotions * Hippocampus * memory functions * Amygdala * emotion functions * Compnents are connected through loop of fiber tracts * somewhat circular pattersn of feedback * Structures have centers for both gratification (pleasure/reward) and aversion (fear/sorrow) * There is a limbic system in each cerebral hemisphere

Answer 16

* Masses of cerebral gray matter buried deep in the white matter, lateral to the thalamus * Control large automatic movements of skeletal muscles * unconscious body movements and facial expressions) * Uses dopamine

Answer 17

* Higher brain functions: sleep, memory, cognition, emotion, sensation, motor control, and language * Involve interactions between cerebral cortex, basal nuclei, brainstem, and cerebellum * Do not have easily defined anatomical boundaries * Focus on the cerebrum, but involve action of multiple brain levels

Answer 18

* monitors surface electrical activity of the brain waves * used for studying normal brain functions such as sleep and consciousness * diagnoses degenerative brain diseases, metabolic abnormalities, brain tumors, etc. * ^{lack of brain waves is common criteria of brain death}

Answer 19

* Motor areas: control voluntary movement * Sensory areas: conscious awareness of sensation * Association areas: integrate diverse information * ^{Conscious behavior involves the entire cortex working together}

Answer 20

* The range of mental processes by which we acquire and use knowledge * sensory perception, thought, reasoning, judgement, memory, imagination, and intuition * Accomplished by distributed association areas of the cerebral cortex * about 75% of all brain tissue

Answer 21

* Emotional feelings and memories are interactions between prefrontal cortex and diencephalon * Prefrontal cortex: seat of judgement, intent, and control over expression of emotions * fully matures at about age 25 * Feelings: (fear, etc.) arises from the hypothalamus and the amygdala

Answer 22

* primary sensory cortex: sites where sensory input is first received and one becomes conscious of the stimulus * Association areas: near primary sensory areas process and interpret that sensory information * Multimodal association areas: receive input from multiple senses and integrate this into an overall perception of our surroundings

Answer 23

* senses that require their own special organ * Vision * primary cortex * association area: makes cognitive sense of visual stimuli * Hearing * Primary auditory cortex * association area: recognizes spoken words, familiar piece of music, or voice on the phonw * Equilibrium * signals for balance and sense of motion: to cerebellum * Association cortex * ^{lateral sulcus near the lower end of the central sulcus} * ^{consciousness of our body movements and orientation (balance) in space}

Answer 24

* aka somesthetic, somatosensory, or somatic * distibuted over entire body and employ simple receptors * Touch, pressure, stretch, movement, heat, cold, and pain * Primary somatosensory cortex: provides awareness of stimulus * Somatosensory association area: makes cognitive sense of stimulus * Brought in by cranial nerve (ascending tracts)\> thalamus processes input from contralateral side \> parietal lobe

Answer 25

* Motor association area of frontal lobes * where we plan our behavior (e.g. intention to contract a muscle) * Where neurons compile a program for muscle contraction * Program sent to the **precentral gyrus** (primary motor area) * neurons send signals to the brainstem\>descending tracts in spinal cord\> skeletal muscles * Basal nuclei and cerebellum also help

Answer 26

* Wernicke's area * usually in left hemisphere * permits recognition of spoken and written language * when we intend to speak, formulates phrases and transmits plan of speech to Broca's * Broca's area * usually in left hemisphere (frontal area--goes to muscle movement) * generates motor program for the muscles of the larynx, tongue, cheeks, and lips for speaking and hands when signing * transmits program to primary motor cortex for movement * Affective language area * usually in right hemisphere * lesions produce aprosody: flat, emotionless speech

Answer 27

* Left hemisphere * specialized for spoken and written language * sequential and analytical reasoning * math and science * breaks info into fragments and analyzes it * Right hemisphere * seat of imagination and insight * musical and artistic skill * perception and patterns and spatial relationships * comparison of sights, sounds, smells, and taste

Answer 28

* allows two hemispheres to communicate and coordinate their functions * transfers/integrates motor, sensory, and even cognitive information between the two hemispheres * If damaged, info processed in one hemisphere cannot reach the other * ^{Symptoms: poor coordination, trouble with complex problem solving skills, seizures, developmental delays, trouble swallowing or feeding, social immaturity}

Answer 29

* motor fibers of cranial nerves begin in nuclei of brainstem and lead to glands and muscles * Sensory fibers begin in receptors located mainly in the head and neck and lead mainly to the brainstem * most cranial nerves carry fibers between brainstem and ipsilateral receptors and effectors * exceptions: optic nerve and trochlear nerve

Answer 30

* Sensory (I, II, and VIII) * Motor (III, IV, VI, XI, and XII) * Mixed (V, VII, IX, X)