BSC 2086 1st EditionExam 1 Study GuideChapter 15 1.What is the difference between the afferent division and the efferent division of the nervous system? Which involves the sensory pathway? Which involves the motor pathway? What are their components?a. Afferent Division: information approaching CNSi. Involves sensory pathwayii. Receptors detect stimuli from external and internal environmentiii. Sensory neurons relay info. down axonsiv. Sensory pathways send info. to CNS 1. Tracts (CNS)2. Nerves (PNS)3. Nuclei (CNS)b. Efferent Division: information leaving CNS i. Involves motor pathwayii. Motor neurons in cell bodies iii. Motor tracts and nerves send signals to muscles/glands 2.What are the 6 general senses? What are the 5 special senses? Why is receptor specificity important to the detection of a specific stimulus? What does that have to do with labeled lines in the nervous system?a. General Senses:i. Pain ii. Temperatureiii. Pressureiv. Touchv. Vibrationvi. Proprioception (body position)b. Special Senses: i. Smell = olfactionii. Sight = visioniii. Taste = gustationiv. Balance = equilibriumv. Hearing c. Receptors are very specific to the stimuli that they sense. Stimulus travels down labeled lines, which are always relayed by the same axon. How a person perceives the stimulus depends on the labeled line it takes to the CNS, therefore allowing only certain stimulus to reach certain parts of the brain. 3.What is the difference between sensation and perception? If a receptor has a large receptive field, is it easier or harder to localize the stimulus? What if the receptor has a small receptive field?a. Sensation is the information arriving from each of these general senses, while perception is our awareness of these sensations.b. If a receptor has a large receptive field it is harder to localize the stimulus, while if it has a small receptive field it is much easier to localize the stimulus. 4.What is adaptation and how are tonic and phasic receptors involved? What is the difference between central adaptation and peripheral adaptation?a. Adaptation: reduced sensitivity to stimuli that is constant and does not cause painb. Tonic receptors: slow to adapti. Ex. Pain receptorsc. Phasic receptors: fast to adapt i. Frequency of action potentials due to the stimulus gives body an idea of intensity and rate of change caused by the stimulus d. Peripheral adaptation occurs when level of receptor activity changes and gradually declines.e. Central adaptation: inhibition of nuclei along a sensory pathwayi. Happens inside CNSii. Conscious awareness of the stimuli disappears even though neurons are still active5.What are the four types of general sensory receptors? What is the difference between the pain information sent by type A fibers and type C fibers?a. Nociceptors: pain detectorsi. Type A fibers: fast pain (prickling pain) ii. Type B fibers: slow pain sensations (burning or aching pain)b. Thermoreceptors: temperature change detectorsc. Mechanoreceptors: detects changes in plasma membraned. Chemoreceptors: detect chemical effects on the body6.How many different classes of mechanoreceptors are there? Of the tactile receptors, how many types are there? Can you name the different types of stimuli that each type detects?a. There are 3 different types of mechanoreceptors i. Tactile receptors ii. Baroreceptorsiii. Proprioceptors b. There are six types of tactile receptors found on the skin:i. Free nerve endings: tonic receptors with small receptive fieldii. Root hair plexus: rapid adapters that detects movements and distortionsiii. Tactile discs (Merkel discs): detect fine touch and pressure receptorsiv. Tactile corpuscles (Meissners corpuscles): detect fine touch, pressure, andlow frequency vibrations v. Lamellated corpuscles (Pacinian corpuscles): detect deep pressure vi. Ruffini corpuscles: tonic receptors sensitive to pressure and skin distortion 7.Where can you find baroreceptors, proprioceptors, and chemoreceptors?a. Baroreceptors found in: i. Blood vesselsii. Digestive tractiii. Urinary tractiv. Reproductive tractb. Proprioceptors found in:i. Muscle spindlesii. Golgi tendon organs (between skeletal muscles and their corresponding tendons)iii. Joint capsules c. Chemoreceptors found in:i. Carotid arteriesii. Aortic arch 8.What are the three major somatic sensory pathways that carry sensory information to upper CNS centers? What kind of information does each pathway carry? How are these sensory pathways involved in referred pain?a. Spinothalamic pathway: carries conscious sensation of crude touch, pressure, temperature and paini. Referred pain: felt when pain begins in an uninjured body part when the real source of pain is in another locationii. Ex. When heart attack pain is felt in the left armb. Spinocerebellar pathway: proprioceptive information sent to cerebellumc. Posterior column pathway: Sensation of fine touch pressure, vibration and proprioception 9.What is the difference between spastic and flaccid paralysis? What causes these types of paralysis?a. Spastic paralysis: upper motor neuron damagei. Muscles not in a relaxed state b. Flaccid paralysis: lower motor neuron damagei. Cant move limbs at all, wheelchair bound 10. What is amyotrophic lateral sclerosis? How does it affect the nervous and muscular systems?a. A progressive degenerative disorder that affects motor neurons found in the brains stem, spinal cord and cerebral hemisphere. 1. Once these neurons die, skeletal muscles stop being used which causes atrophy 2. Deterioration of skeletal muscles occursChapter 171.What are the cells involved in olfaction and gustation? How do olfactory receptor cells detect different odors? How do gustatory cells detect foods of different taste? How are salty and sour foods detected differently than bitter, sweet, and umami tastes? a. Olfaction: i. Olfactory receptor cells: detect dissolved chemicals interacting with odor binding proteins ii. Supporting cellsiii. Basal stem cells that replenish the receptor cells b. Gustation: i. Taste receptors: clustered in taste buds ii. Basal stem cells that replenish the receptor cellsiii. Gustatory cells: taste hairs extend through the taste pore c. Gustatory discrimination: detect 4 primary sensations (sweet, salty, bitter and sour)i. Salty and sour foods have chemically gated receptors which depolarize membrane which causes neurotransmitter releaseii. Sweet, bitter and umami tastes bind to receptor proteins and activate G proteins which will cause
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