Science Olympiad Cheat Sheet

• Neurons: dendrites (input), soma (integration), axon (output), myelin (insulation). • Synapse: neurotransmitters cross cleft to receptors. • Glial Cells: astrocytes (support/BBB), oligodendrocytes & Schwann cells (myelin), microglia (immune), ependymal (CSF). • Action Potentials: depolarization (Na+ in), repolarization (K+ out), refractory period prevents backflow. • Electrophysiology: Goldman–Hodgkin–Katz equation. 2. Central Nervous System • Cerebrum (frontal: motor/planning, parietal: sensory, temporal: hearing/memory, occipital: vision). • Cerebellum (coordination, balance). Brainstem: midbrain (reflexes), pons (relay/breathing), medulla (autonomic). • Spinal Cord: dorsal root = sensory, ventral = motor. 3. Peripheral Nervous System • Somatic (voluntary). Autonomic: sympathetic (?HR, pupils dilate, ?digestion), parasympathetic (?HR, ?digestion). 4. Disorders & Toxins • Epilepsy, Alzheimer’s, Parkinson’s, MS, Stroke, ALS. • Tetrodotoxin (blocks Na+), Curare (blocks AChR), Botulinum toxin (?ACh). • Drugs: caffeine (adenosine block), alcohol (depressant), nicotine (stimulates AChR), marijuana (cannabinoid). 5. Advanced • EEG: alpha, beta, delta, theta. Hodgkin-Huxley AP model. Spinal disorders (Brown-Séquard, syringomyelia). ? Endocrine System 1. Hormones • Steroids (lipid-soluble, slow, long-lasting). Peptides/amines (water-soluble, fast). Negative vs positive feedback. 2. Glands • Hypothalamus ? pituitary. Anterior (GH, TSH, ACTH, FSH, LH, Prolactin). Posterior (Oxytocin, ADH). • Thyroid: T3/T4 ?metabolism, calcitonin ?Ca2+. • Parathyroid: PTH ?Ca2+. • Adrenals: cortex (cortisol, aldosterone, androgens), medulla (Epi/NE). • Pancreas: insulin ?glucose, glucagon ?glucose. • Pineal (melatonin), Gonads (sex hormones). • Others: kidney (EPO, renin), heart (ANP), adipose (leptin). 3. Disorders • Hypo vs hyperthyroidism, diabetes insipidus, Addison’s, Cushing’s, acromegaly, dwarfism, adrenal hyperplasia, myxedema. 4. Endocrine Disruptors • DDT, BPA, PFAS ? mimic/block hormones. ? Special Senses 1. Vision • Pathway: cornea ? pupil ? lens ? retina ? optic nerve ? occipital lobe. • Rods (dim), Cones (RGB). • Disorders: myopia, hyperopia, presbyopia, astigmatism, glaucoma, cataracts, color blindness. 2. Hearing & Balance • Outer: pinna, canal. Middle: eardrum, ossicles. Inner: cochlea (hearing), semicircular canals/vestibule (balance). • Pathway: sound ? hair cells ? auditory nerve ? brain. • Disorders: conductive/sensorineural loss, tinnitus, otitis media, Ménière’s. 3. Smell (Olfaction) • Odor ? receptors ? bulb ? brain. Disorders: anosmia, hyposmia, dysosmia. 4. Taste (Gustation) • 5 tastes: sweet, sour, salty, bitter, umami. Nerves: VII, IX, X. Disorders: ageusia, dysgeusia.