1. Ch. 27: Nervous, Sensory, & Motor Systems..animations..NeuroSci..For Kids..
Biology and Society: Battling Depression
  1. Depression is either mood, or clinical.
  2. Fig 1: depressed brain has less activity, text: neurotransmitter imbalance - too little serotonin. 
  3. Treatments include exercise, support groups, & antidepressants(scroll for SSRI)
A. An Overview of Animal Nervous Systems

1 Oganization of Nervous Systems:
     simplest: hydra nerve net: enables a reflex, but fig 2 (show it) implies more:
     receptor, sensory neuron, CNS integration, motor neuron, effector (muscle or gland)
     All of the nervous systems here integrate: from peripheral NS scroll up
2 Neurons:
     motor neuron fig 3, neurons have three regions: 1) input, 2) transmit impulse, 3) output
     Myelin often covers the part that transmits impulses: faster conduction
     Myelin is one kind of cell that supports neruns = glia
3 Sending a signal through a neuron = region 2: transmit impulse
     1) resting potential, I:\Wilkin\neurophys\NEUROLAB\neurolab.exe OR for Kids
     2) action potential, fig 4, Na+ channel briefly opens > depolarize,
         then K+ channel opens to repolarize back to resting, note threshold potential
         the sodium-potassium pump carries the Na+ back out of the cell, & the K+ back in
     3) propagation, fig 5, or zoom out from: complete animation but too much   
     4) Puffer fish has neurotoxin - blocks Na+ channels,  recipes,  Columbo,  episode
4 Passing a signal from one neuron to another or other receiving cell (muscle/gland)
     The output region of one neuron + the input region of the next = a synapse
     1) synapse: chemical (usual) or electrical > connections so cells work together.
     It is at chemical synapses that integration is done
     2) chemical synapse: fig 6 & 7: pre-synaptic cell, synaptic cleft, neurotransmitter, for kids
        Fig 7: neurons integrate their numerous inputs: some excite, others inhibit
        complete animation
    3) Neurotransmitters: (acetylcholine is at nerve > skeletal muscle, & in CNS, & in ANS)
        biogenic amines:
        epinephrine & norepinephrine are also hormones, part of sympathetic nervous system
        serotonin & dopamine affect sleep, mood, attention & learning
        endorphins = endogenous opiod peptide, decrease pain
        there are many other kinds of neurotransmitters
    4) Drugs & the Brain (plants make many chemicals to stop being eaten)
        Caffine inhibits inhibitory neurotransmitters
        Nicotine stimulant at acetylcholine synapses       
        Alcohol strong CNS depressant
        Skip abused drugs

CHECKPOINT p 592
1. Put in order for reflex: interneuron, muscle or gland, motor neuron, sensory neuron, receptor
    Which is entirely within the central NS?
2. What is the function of the myelin sheath?
3. How does an action potential show positive feedback? once at threshold this happens
4. How does a synapse ensure the signal goes only one way?
5. What determines that a synapse is affected by only one specific neurotransmitter?
6. Why are endorphins "natural opiates"? some athletes claim addiction to their sport
7. electricity in wires is due to the flow of electrons, in the body it is due to the flow of?

B. The Human Nervous System, fig 8, (others < click peripheral NS & scroll up)
 The central nervous system: spinal cord is larger in plexus regions of upper & lower limbs
     brain: fig 9, cerebrospinal fluid made in lateral ventricles flows to venous sinuses (dark blue):
     cushions & protects entire CNS, as do meninges   
     spinal cord, fig 9: central grey matter: synapses & interneurons, peipheral white matter = myelin,
     dorsal root is sensory & has ganglon for cells' somas, ventral root is motor
 The peripheral nervous system: fig 10 divisions,
     Somatic has both sensory & motor parts
     Autonomic NS, for kids fig 11, sympathetic: fight & flight, & parasympathetic: resting & digesting
       Note: fig 11 lists the major organs & the effects of both sympathetic & parasympathetic  
       Opposite effects as sympathetic releases norepinephrine, but parasympathetic releases acetylcholine
 The human brain (click 2005 neuro teacher animations) show figs first, then discuss table 1:
     Brainstem: hindbrain & midbrain
         Medulla oblongata: controls breathing, circulation, swallowing & digestion   
         Pons: relay center, also involved in breathing
         Midbrain: click it, integrates auditory & visual reflexes, visual center in lower vertebrates
     Cerebellum: coordinates movement, learns motor skills
     Thalamus, or use textbook fig 12: relay center both up & down transmission, data sorting
     Hypothalamus, or same: homeostatic control center for many organ systems: controls pituitary gland
     Cerebrum: sophisticated integration, memory, learning, speech, emotions, formulates complex behavioral responses
          Corpus callosum (fiber tract) bridges the hemispheres, fig also shows ventricles
          Cerebral cortex is only surface layers of cerebrum
What can a broken brain teach us? Phineas Gage is in lab ex
Limbic system (part of cerebrum) is also in lab ex

CHECKPOINT
1. Name the two structures making up the central nervous system
2. The CNS is protected by a liquid: name? that cushions it & supplies nutrients
     (but most nutrients come in the blood), & by layers of tissue called ?
3. How would a drug that interferes with the parasympathetic NS affect a persons pulse? digestion? salivation?
4. Largest & most sophisticated part of the brain?
    It is divided into halves, connected by big white matter bundle called?
    It's surface region is the __  __? 
5. In which lobe do you see? hear? smell? think?

C. THE SENSES .wiki: senses.
Knowing what is going on requires three components
1) sensory receptors:
     General/somatic (body shell) senses: in skin (fig 18), muscles, joints, ligaments, tendons.
     5 Special Senses on head: sight, hearing, balance, taste & smell.
     Visceral Receptors e.g. blood pressure & blood pH (not perceived), also referred pain
2) impulses transmit information to brain
3) brain: perception & understanding

1.  Sensory input
Sensory transduction: all (sensory) receptors convert stimulus energy to nerve impulses
The membrane of the receptor cell has a device which responds to specific stimulus energy
Fig 17: sweet taste: sugar binds to receptor protein > cell releases neurotransmitter onto dendrite of sensory nerve > impulses
vibration receptor potential: smell, &
sensory adaptation: some receptors stop firing: touch yes, pain no.
  1. Classify as Five types by nature of stimulus:
  2. 1) mechano- (touch, pressure, blood presure), fig 18 has skin receptors
  3. 2) chemo- (taste, smell, blood pH)
  4. 3) thermo- temperature, in skin, hot & cold, also in hypothalamus < monitors body temp
  5. 4) pain (a type of chemoreceptor: responds to chemicals released in inflammation, like prostaglandins)
    6. 5) electromagnetic (spectrum): photo- (vision), UV, weakly electric fish: electroreceptor,
2.  Vision
  1. Textbook: human eye, optical parts & ray diagram: fig 19, conjunctiva, lacrimal gland
  2. focus is by lens thickening, bends light rays more, fig 20
  3. Rods: most of retina, b & w, sensitive, night vision, fig 21
  4. Cones: fovea only, 3 types (yellow, green, violet) = color, less sensitive: fig 21,
  5. rhodopsin, visual pigment, contains vitamin A (black in fig), which light hits to excite
  6. Retina, fig 22, photoreceptors are on dark side!, neuron layers are infront,
  7. Causes & symptoms of, fig 23 
  8. nearsighted: cannot see distance: reduce lens curvature
  9. farsighted: cannot see close: increase lens curvature
  10. astigmatism lens curves more in one plane than another
  11. hyperopia, myopia, presbyopia, and astigmatism,
3.  Hearing
  1. Ear structures, show it > fig 24:
  2. 1) outer ear: pinna, auditory canal, eardrum,
  3.     sound (= pressure waves) vibrates ear drum
    4.  2) middle ear: bones: hammer, anvil & stirrup (= malleus, incus, stapes)
  4.    bones convert large air vibrations to small fluid vibrations, at oval window
  5.    eustachian tube equalizes pressure across ear drum.
    6. 3) Inner ear: has two funtions: hearing & balance

    1) hearing    : spiral cochlea, fig 24, contains organ of corti fig 25, & clear diag.
    basilar membrane bounces, bends hair cells against tectoral membrane > nerve impulses   
  6. Place theory of pitch discrimination: fig 26, basilar membrane thickness changes along cochlea

  8. Balance is NOT in Chapter?
  9. 2) balance: a) static: utricle & saccule & b) dynamic: semicircular canals

    10. IN Chapter: Hearing loss     may be due to either or both:
  10. 1) conduction deafness: loss of sound conduction through middle ear, &/or
  11. 2) neural deafness: damage to inner ear/nerve impulse production.
CHECKPOINT
1. What is sensory transduction?
2. For each sense, ID the receptor: seeing, tasting, hearing, smelling, balance, touch, pain
3. Correct light path? pupil, retina, cornea, lens, vitreous humor, aqueous humor
4. Reading a book: is your lens thick or thin?
5. Night vision is black-grey-white, why?  Can you see any color at night?
6. How does the ear convert sound waves in air to nerve impulses?

D. MOTOR SYSTEMS: skeletons, joints, & muscles: Farabee also combines systems

1. The Skeletal System

     NOT in CH earthworms/annelids have a hydraulic skeleton
     NOT in CH arthropods have an exoskeleton made of chitin, receptors project through it
     Vertebrates have endoskeleton: cartilage in early fish like sharks, rest have bones

     Human Skeleton: fig 27 = test to know bones' names
  1. Axial (trunk), fig 27, skull, vertebrae, sacrum, ribs & sternum
  2. Appendicular (girdles & limbs): fig 27: dark blue is cartilage = light blue here 
  3. ligaments bind bones together 
    4. Joints are either 1) fibrous e.g. suture, 2) cartilage e.g. vertebral discs, or ) synovial = most
Synovial joints < surfaces fit together!!, contain fluid, freely moveable:
fig 28: has 3 types: ball & socket, hinge, & pivot, more.  Joint surfaces are cartilage
  1. A bone, fig 29, is both compact/solid bone (shaft & surface) & "spongy bone" (inside, heads & flat bones)
  2. Bone tissue: cells + matrix = collagen fibers + calcium salt crystals - like reinforced concrete
  3. Fibrous connective tissue covers bones, except at joint surfaces.
  4. Red marrow lies in spaces in spongy bone, & makes all your blood cells
  5. Yellow marrow is fat tissue & lies in shaft of long bones 
  6. SKIP DISORDERS: arthritis, osteoporosis
  7. Bones break, but they heal well: electricity promotes healing
  8. Exercise strengthens bones
2. The Muscular System
  1. Kimball & Farabee (simpler), fig 31-34
  2. Fig 31: muscles have antagonstic actions at joints: flexors/extensors etc

  4. The Cellular Basis of Muscle Contraction: fig 32, 33, 34
  5. A muscle = cells wrapped into bundles by connective tissue which forms tendons at ends
    6. Muscle cell = muscle fiber (click fig): cell is shaped like a pencil & has many nuclei
  6. it contains myofibrils, each wraped by sarcoplasmic reticulum (stores calcium ions).
  7. myofibrils are divided lengthwise by Z lines into sarcomeres
  8. myofibrils contain two kinds of protein filaments:
  9. thick (myosin tails, with heads sticking out) & thin (many G-actins form double stranded beads)
    10.   good animation of fig 32, 33 & 34
     The cell contracts using the cross bridge cycle: fig 34,
    Myosin head grabs actin > pulls > releases > repeat
    ATP is needed to energize release of the bridge, so no ATP > rigor/rigid
  10. animation adds role of calcium = to switch cycle on & off

  12. A whole muscle is divided into motor units =
    13. 1 motor neuron & the muscle cells it controls: fig 35, animation
  13. the neuromuscular junction is a big synapse
  14. the neuron makes the muscle cell produce an impulse/action potential
  15. which causes the endoplasmic reticulum to release calcium ions > bind to thin filament: Kimball,
3.  Stimulus & Response: Putting It All Together
  1. Activity requires sensory receptors, PNS, CNS, muscles, joints & skeleton: fig 36.
CHECKPOINT p 613
1. Axial or appendicular skeleton: skull, ribs, sacrum, pelvis, shoulder?
2. Things to do to help prevent osteoporosis?
3. Two steps to heal a broken bone?
4. When exercising why provide resistance both when flexing and extending?
5. Thin filament protein?  Thick filament protein?
6. Role of endoplasmic reticulum in regulating muscle contraction?

E. Evolution Connection: Evolution of the Eye
  1. Our eye developed over millions of years:
  2. Planarian photoreceptors, eyespot: fig 37,  eye evolution
  3. Two types of eyes: either 1) cilia or 2) rhabdomere,  source,