Chapter 13 review questions 18. Polysynaptic reflexes can produce far more complicated responses than can monosynaptic reflexes because the response time is quicker the response is initiated by highly sensitive receptors motor neurons carry impulses at a faster rate than so sensory neurons the interneurons involved can control several muscle groups 30. Bowel and urinary bladder control involve spinal reflex arcs that are located in the sacral region of the spinal cord. In both instances, two sphincter muscles – an inner sphincter muscle of smooth muscle and an outer sphincter of skeletal muscle – control the passage of wastes (feces and urine) out of the body. How would a transection of the spinal cord at the L1 segment level affect an individual’s bowel and bladder control?
The Brain (material from and inspired by Chapter 14) How have brain structures’ functions been discovered? Summary of brain parts and cranial nerves Processing sensory info: examples Responding to bright light Localizing sounds in space Negative feedback and the brain: examples Medulla/pons Hypothalamus
Understanding a region of the brain: the example of Phineas Gage H.J. Bigelow, via Wikipedia
Broca’s area and Wernicke’s area Example of Broca’s aphasia: person says, "Book book two table," meaning, "There are two books on the table." Example of Wernicke’s aphasia: person says, "You know that smoodle pinkered and that I want to get him round and take care of him like you want before.“ Meaning: ???? Source: http://www.nidcd.nih.gov/health/voice/pages/aphasia.aspx
Corpus callosum (clinical note, p. 488) The corpus callosum was sometimes cut as a treatment for severe epilepsy. Consequences? David Wolman, “Split brain: a tale of two halves,” Nature 2012
Cortical maps of body (motor & sensory) Image: merckmanuals.com
BRIEF summary of brain structures/functions Major functions (partial list) Frontal lobe Parietal lobe Temporal lobe Occipital lobe Cerebellum Pons Medulla Superior colliculus Inferior colliculus Corpus callosum Thalamus Hypothalamus (from lab quiz study guide)
BRIEF summary of the 12 cranial nerves Number (Roman numeral) Name of nerve Sensory, Motor, or Both? Type of information 1 (I) 2 (II) 3 (III) 4 (IV) 5 (V) 6 (VI) 7 (VII) 8 (VIII) 9 (IX) 10 (X) 11 (XI) 12 (XII)
Cranial nerve mnemonic #1: nerve names Number Saying Nerve Name 1 Oh 2 3 Oh -- 4 To 5 Touch 6 And 7 Feel 8 Very 9 Good 10 Velvet -- 11 Ah, 12 Heaven!
Cranial nerve mnemonic #2: sensory, motor, or both? Number Saying Sensory, Motor, Both? 1 Some 2 Say 3 “Money 4 Matters” 5 But 6 My 7 Brother 8 Says 9 “Big 10 Brains 11 Matter 12 More!”
Cranial Nerve Mnemonic #3: functions http://www.noteflight.com/scores/view/7dc90d51c8730d5c36f51d18aa774fbf5b844ac9 Nerves correspond to notes 1 (lowest) to 12 (highest). Nerves 7 & 9 are grouped together; so are nerves 3, 4, & 6.
Processing sensory info Recall earlier slides about synapses between neurons, tracts connecting parts of the brain with each other, cranial nerves coming into and out of the brain…. Examples of the brain processing sensory info: Responding to bright light Localizing sounds in space
Processing sensory info: responding to bright light Background info on the eye (10th Martini, Figures 17-5 & 17-6)
Processing of sensory info: responding to bright light http://www.tedmontgomery.com/the_eye/reflex.html
Processing sensory info: responding to bright light
Processing sensory info: localizing sounds in space Background info on the ear (10th Martini, Figure 17-21)
Processing sensory info: localizing sounds in space image: www.d.umn.edu/~jfitzake/
Processing sensory info: localizing sounds in space
Negative feedback and the brain Review: what is negative feedback? Today’s examples Pons/medulla: control of breathing rate Hypothalamus: control of hydration & temperature
Pons/medulla: control of breathing rate
Hypothalamus: control of hydration
Hypothalamus: control of temperature 10th Martini, Figure 1-3!