PNS

• Peripheral Nervous System


  links the CNS to the rest of the body
• Somatic System


  voluntary control, carries sensory receptors to skeletal muscle
• Autonomic System


  involuntary control, maintains homeostasis(heart rate, breathing)
• Sypathetic "Fight or Flight"


  activated during stressful situations, releases epinephrine and norepinephrine
• Parasympathetic "Rest and Digest"


  activated when calm and at rest, releases acetylcholine
• Sympathetic Heart


  increases heart rate
• Parasympathetic Heart


  decreases heart rate
• Sympathetic Liver


  glycogen to glucose
• Parasympathetic Liver


  glucose to glycogen
• Sympathetic Bladder


  inhibits urination
• Parasympathetic Bladder


  promotes urination
• Sympathetic Eyes


  dilates pupils
• Parasympathetic Eyes


  constricts pupils
• Sensory Adaption


  when the brain filters out redundant sensory information to prevent over-stimulation
• Photoreceptors


  stimulated by light
• Mechanoreceptors


  stimulated by pressure
• Sclera


  tough outer layer
• Cornea


  front of sclera. light enters through the eye and is bent through the cornea
• Choroid


  middle layer with blood vessels to nourish the eye
• Ciliary Body


  attached to the lens for focusing
• Iris


  pigmented muscle that controls the amount of light entering the eye
• Pupil


  opening the front of the eye
• Adaption


  pupil dilates or constricts
• Lens


  focuses light on retina
• Accommodation


  lens changes shape is objects are near or far
• Retina


  inner layer contains photoreceptors
• Ganglion Layer


  forms the optic nerve at the back of the eye
• Rods


  night vision
• Cones


  fovea, most accurate vision and color vision
• Aqueous Humour


  maintains cornea shape
• Vitreous Humour


  maintains eyeball shape
• Mechanoreception


  hearing associated sounds waves, the fluid-filled inner ear converts sound waves into electrochemical impulses which the brain perceives as sound
• Auditory Canal


  where the sound waves travel
• Tympanum (Ear Drum)


  sound waves push against this and the vibrations are passed on to the ossicles
• Ossicles


  vibrations are amplified and transferred to the liquid-filled organs
• Oval Window


  opening
• Cochlea


  pressure stimulates the hair cells and generates an action potential in the auditory nerve
• Which lobe is the auditory nerve passing signals to?

  temporal lobe
• Which lobe is the optic nerve passing signals to?

  occipital lobe
• Semicircular Canals


  maintain balance