1. Chapters 48 & 49 Campbell Biology – 9 th ed.

2.  Central nervous system (CNS) = brain + spinal cord  Peripheral nervous system (PNS) = nerves throughout body  Sensory receptors: collect info  Sensory neurons: body  CNS  Motor neurons: CNS  body (muscles, glands)  Interneurons: connect sensory & motor neurons  Nerves = bundles of neurons  Contains motor neurons +/or sensory neurons

5. Peripheral nervous system Somatic nervous system Autonomic nervous system Sympathetic division Parasympathetic division Enteric division

8.  cell body: contains nucleus & organelles  dendrites: receive incoming messages  axons: transmit messages away to other cells  myelin sheath: fatty insulation covering axon, speeds up nerve impulses  synapse: junction between 2 neurons  neurotransmitter: chemical messengers sent across synapse  Glia: cells that support neurons  Eg. Schwann cells (forms myelin sheath)

12. Microelectrode Reference electrode Voltage recorder –70 mV

13. The Na + /K + pump (using ATP) maintains a negative potential inside the neuron.

14.  Resting potential: membrane potential at rest; polarized   Na + outside,  K + inside cell  Voltage-gated Na + channel = CLOSED stimulus  Nerve impulse: stimulus causes a change in membrane potential  Action potential: neuron membrane depolarizes  All-or-nothing response Na + channels open Na + enters cell K + channels open K + leaves cell

15.  Action Potential Action Potential  Nerve Impulse - McGraw-Hill Nerve Impulse - McGraw-Hill

17. Conduction of an action potential

19. Saltatory conduction speed: 120 m/sec

23.  Chemicals released from vesicles by exocytosis into synaptic cleft  Diffuse across synapse  Bind to receptors on neurons, muscle cells, or gland cells  Broken down by enzymes or taken back up into surrounding cells  Types of neurotransmitters:  Excitatory: speed up impulses by causing depolarization of postsynaptic membrane  Inhibitory: slow impulses by causing hyperpolarization of postsynaptic membrane

24.  Acetylcholine (ACh): stimulates muscles, memory formation, learning  Epinephrine: (adrenaline) fight-or-flight  Norepinephrine: fight-or-flight  Dopamine: reward, pleasure (“high”)  Loss of dopamine  Parkinson’s Disease  Serotonin: well-being, happiness  Low levels  Depression  GABA: inhibitory NT  Affected by alcohol

25.  Simple, automatic response to a stimulus  Conscious thought not required  Reflex arc: 1. Stimulus detected by receptor 2. Sensory neuron 3. Interneuron (spinal cord or brain stem) 4. Motor neuron 5. Response by effector organ (muscles, glands)

28. Major Regions: forebrain, midbrain, hindbrain

29. Forebrain  cerebrum Midbrain  brainstem Hindbrain  cerebellum

30. StructureFunction Cerebrum Information processing (learning, emotion, memory, perception, voluntary movement) Right & Left cerebral hemispheres Corpus callosum: connect hemispheres Brainstem *Oldest evolutionary part* Basic, autonomic survival behaviors Medulla oblongata –breathing, heart & blood vessel activity, digestion, swallowing, vomiting Transfer info between PNS & CNS Cerebellum Coordinate movement & balance Motor skill learning Human Brain

31. StructureFunction Cerebrum Information processing (learning, emotion, memory, perception, voluntary movement) Right & Left cerebral hemispheres Corpus callosum: connect hemispheres Brainstem *Oldest evolutionary part* Basic, autonomic survival behaviors Medulla oblongata –breathing, heart & blood vessel activity, digestion, swallowing, vomiting Transfer info between PNS & CNS Cerebellum Coordinate movement & balance Motor skill learning Human Brain

32. StructureFunction Cerebrum Information processing (learning, emotion, memory, perception, voluntary movement) Right & Left cerebral hemispheres Corpus callosum: connect hemispheres Brainstem *Oldest evolutionary part* Basic, autonomic survival behaviors Medulla oblongata –breathing, heart & blood vessel activity, digestion, swallowing, vomiting Transfer info between PNS & CNS Cerebellum Coordinate movement & balance Motor skill learning Human Brain

35. Chapter 50 Campbell Biology – 9 th Edition

36.  Mechanoreceptors: physical stimuli – pressure, touch, stretch, motion, sound  Thermoreceptors: detect heat/cold  Chemoreceptors: transmit solute conc. info – taste (gustatory), smell (olfactory)  Electromagnetic receptors: detect EM energy – light (photoreceptors), electricity, magnetism  Pain receptors: respond to excess heat, pressure, chemicals

37. This rattlesnake and other pit vipers have a pair of infrared receptors, one between each eye and nostril. The organs are sensitive enough to detect the infrared radiation emitted by a warm mouse a meter away. Eye Infrared receptor Some migrating animals, such as these beluga whales, apparently sense Earth’s magnetic field and use the information, along with other cues, for orientation.

38.  Reception  Reception: receptor detects a stimulus  Sensation  Sensation = action potentials reach brain via sensory neurons  Perception  Perception: information processed in brain

39. Outer ear Middle ear Inner ear Pinna Auditory canal Tympanic membrane Eustachian tube Middle ear Stapes Incus Malleus Skull bones Semicircular canals Auditory nerve, to brain Tympanic membrane Oval window Round window Cochlea Eustachian tube Auditory nerve Tympanic canal Cochlea duct Organ of Corti Vestibular canal Bone To auditory nerve Axons of sensory neurons Basilar membrane Hair cells Tectorial membrane

40. Semicircular canals Flow of endolymph Vestibular nerve Nerve fibers Vestibule Utricle Saccule Ampulla Flow of endolymph Cupula Body movement Hairs Hair cell

41. Cornea Ciliary body Suspensory ligament Iris Pupil Aqueous humor Lens Vitreous humor Central artery and vein of the retina Optic disk (blind spot) Fovea (center of visual field) Optic nerve Retina Choroid Sclera

42. Compound eyes: several thousand ommatidia (light detectors) with its own lens; insects & crustaceans Vertebrates:  Rods: sense light  Cones: color vision  Rhodopsin: light-absorbing pigment that triggers signal transduction pathway that leads to sight Retina Optic nerve To brain Cone Photoreceptors Retina Rod Neurons Pigmented epithelium Bipolar cell Amacrine cell Horizontal cell Optic nerve fibers Ganglion cell

43.  Hydrostatic: fluid held under pressure in closed body compartment  Hydra, nematodes, annelids  Exoskeletons: hard encasements on surface of animal  Insects, mollusks, crustaceans  Endoskeleton: hard supporting elements buried within soft tissues  Human bony skeleton

44. Shoulder girdle Scapula Clavicle Sternum Skull Appendicular skeleton Axial skeleton Key Rib Humerus Vertebra Radius Examples of joints Fibula Ulna Tibia Pelvic girdle Carpals Phalanges Metacarpals Femur Patella Tarsals Metatarsals Phalanges Ulna Pivot joints allow us to rotate our forearm at the elbow and to move our head from side to side. Ulna Hinge joints, such as between the humerus and the head of the ulna, restrict movement to a single plane. Humerus Ball-and-socket joints, where the humerus contacts the shoulder girdle and where the femur contacts the pelvic girdle, enable us to rotate our arms and legs and move them in several planes. Head of humerus Scapula Radius

45. Bundle of muscle fibers Single muscle fiber (cell) Plasma membrane Nuclei Muscle Myofibril Dark band Sarcomere Z line Light band I band TEM A bandI band 0.5 µm M line Thick filaments (myosin) Sarcomere H zoneZ line Thin filaments (actin) Z line  Attached to bones by tendons  Types of muscle:  smooth (internal organs)  cardiac (heart)  Skeletal (striated)  1 long fiber = single muscle cell  Each muscle fiber = bundle of myofibrils, composed of: ▪ Actin: thin filaments ▪ Myosin: thick filaments

46. Sarcomere 0.5 µm Z H A Relaxed muscle fiber I Contracting muscle fiber Fully contracted muscle fiber  Z lines – border  I band – thin actin filaments  A band – thick myosin filaments Sarcomere: basic contractile unit of the muscle

47. Sarcomere 0.5 µm Z H A Relaxed muscle fiber I Contracting muscle fiber Fully contracted muscle fiber 1. Sarcomere relaxed: actin & myosin overlap 2. Contracting: motor neuron  Muscle fiber stimulated by motor neuron  Length of sarcomere is reduced  Actin slides over myosin 3. Fully contracted: actin & myosin completely overlap Sliding-filament model: thick & thin filaments slide past each other to increase overlap (Note: Filaments do NOT shorten!) Muscle Contraction:

48. Ca 2+ released from sarcoplasmic reticulum Mitochondrion Motor neuron axon Synaptic terminal T tubule Sarcoplasmic reticulum Myofibril Plasma membrane of muscle fiber Sarcomere

49. Ca 2+ CYTOSOL Ca 2+ SR PLASMA MEMBRANE T TUBULE Synaptic cleft Synaptic terminal of motor neuron ACh Synaptic terminal of motor neuron releases acetylcholine Muscle fiber depolarizes Ca 2+ released Initiate sliding of filaments

50. Myosin-binding sites blocked. Myosin-binding sites exposed. Tropomyosin Ca 2+ -binding sites Actin Troponin complex Myosin- binding site Ca 2+

51. Thin filaments Thick filament Thin filament Thick filament Myosin head (low-energy configuration) Cross-bridge binding site Myosin head (high- energy configuration) Actin Cross-bridge Myosin head (low- energy configuration) Thin filament moves toward center of sacomere. Hydrolysis of ATP by myosin  cross-bridge formed  thin filament pulled toward center of sarcomere