Anatomy - Chapters 9-10

Chapter 9: Nervous System Functions to monitor the external and internal environment to process and integrate information to decide what to do to tell effectors in the body what to do Neuroglial Cells MICROGLIAL CELLS eat bacteria and cellular debrisOLIGODENDROCYTES provide the myelin sheath in the Central Nervous SystemSCHWANN CELLS provide the myelin sheath in the Peripheral Nervous System Neurons SENSORY are stimulated by changes in the environment and they are usually bipolar and sometimes unipolarINTERNEURONS transfer and direct messages within the CNS, and are usually multipolarMOTOR carries messages from CNS to the effectors, and are usually multipolar

Neurotransmitters EXCITATORY - closer to action potential, or causes actionINHIBITORY - moves neuron further from action potentialSome examples of neurotransmitters are acetylcholine, monoamines, amino acids, and neuropeptides.Depression is caused by an imbalance of neurotransmitters, and many drugs are created to imitate the effects of them (ie. Prozac, Zoloft)THE RELEASE OF A NEUROTRANSMITTERWhen action potentials reach the end of an axon, calcium channels open and allow a swell of calcium in. After the neurotransmitter binds to the calcium, it will either be destroyed in the synaptic cleft or be taken back to surrounding neurons. Parasympathetic vs. Sympathetic Parasympathetic is UNDER NORMAL CONDITIONSSympathetic is UNDER STRESS OR EMERGENCY (fight or flight response) The Peripheral Nervous System The nervous system active in everywhere else of the body besides the brain and spinal cord. The part that exercises the motor functions.It is divided into the SOMATIC (conscious activities) and AUTONOMIC (unconscious activities) systems. The Central Nervous System Consists of the brain and spinal cord. It uses both gray and white matter to protect the nerves, which are also covered in meninges. Chapter 10: The Senses Touch FREE NERVE ENDINGS respond to warm and cold temperatureMEISSNER'S CORPUSCLES respond to light touch usually picked up by hairsPACINIAN CORPUSCLES respond to heavy pressure, and are usually located in deeper tissues Sound The Outer Earsound waves are directed into it, and travels to the eardrum (or tympanic membrane) to make it vibrateThe Middle Ear uses 3 auditory bones that feel the eardrum vibrate to mimic the vibrations and amplify them the Eustachian tube connects the middle ear to the throat in order to equalize pressure The Inner Ear made of 2 labyrinths made of the OSSEOUS LABYRINTH of canals and the MEMBRANOUS LABYRINTH tube inside the osseous the labyrinths end with the semicircular canals leading to the COCHLEA, which is the organ that "hears" Sight The accessory organs of the eye are the eyelids, the eye muscles, and the lacrimal apparatus (produces tears to take to ducts)SCLERA is a tough coveringCHOROID COAT contains the pigment for the eyeRETINA is the inner layers that continues to the optic nerve and contains receptorsVITREOUS HUMOR is jelly-likeCORNEA is the transparent coveringAQUEOUS HUMOR is the fluid between the iris and lensIRIS is a pigmented layer that contains muscle that controls the size of the pupilLENS is the layer that focuses the image on the retinaThe retina uses two receptors:RODS for black and white vision, indistinct imagesCONES for color vision, for a more refined image