Hondros Bio 253 Layers of the skin - ✔✔epidermis, dermis, hypodermis Stratum Corneum - ✔✔Protective durable overcoat, waterproof, t ough, relatively insensitive to biological, chemical and physical assault. Stratum Lucidum - ✔✔visible only in thick skin, few layers thick, dead clear cells Stratum Granulosum - ✔✔3-5 layers of thick keratinocytes flastten out Stratum Spinosum - ✔✔overlies the stratum basale, cells come from the basale, filaments u the cells that resist tension, keratinocytes have a spiny appearance, contain langerhen cells Stratum Basale - ✔✔Deepest layer, single row if renewing keratinocytes that are getting ready to push up, melaninocytes, small portion of merkel cells Parts of a neuron - ✔✔Cell body, Dendrites, Axon Cell body - ✔✔Provide protein for maintaining and rege nerating nerves Dendrites - ✔✔Each neuron had one or more dendrites, branch from the cell body, bring impulses in, distal ends of dendrites of sensory neurons are receptors Axon - ✔✔Each neurons has one axon, axon hillock integrates incoming signals. axo ns carry impulses away and communicates Afferent neurons - ✔✔Brings signal to CNS, *sensory Efferent neurons - ✔✔Carry signals away, *motor Reflex Arc - ✔✔Receptor, afferent, interneuron, efferent, effector, response Membrane potential - ✔✔Slight defic iency of positively charged ions on the inside of the membrane Saltatory conduction - ✔✔In myelinated fibers, action potentials in the membrane occor only at the nodes of Raniver Continuous conduction - ✔✔In unmyelinated fibers Acetylcholine - ✔✔chemica l structure, found in junctions with motor effectors (skeletal muscles, glands, many parts of the brain Brain stem - ✔✔Medulla oblongata, pons, midbrain Diencephalon - ✔✔Hypothalamus, Thalamus Cerebellum - ✔✔Compares motor commands of cerebrum with proprioceptor information, acts with cerebral cortex to produce skilled movements, controls balance and posture Frontal lobe - ✔✔Reasoning, planning, parts of speech, movements, emotions, and problem solving Parietal lobe - ✔✔movement, orientation, recognition, perception of stimuli, lanuagae Temporal lobe - ✔✔perception and recognition of auditory stimuli, memory, and speech Occipital lobe - ✔✔visual processing