Animal Senses

• Sensory receptors respond to specific stimuli by transmitting signals that the central nervous system decodes, processes, and responds to in the form of motor output
• Mechanoreceptors respond to physical deformation changing the membrane potential
• Chemoreceptors respond to specific chemicals or change in solute concentration
• Thermoreceptors are proteins that respond to hot or cold
• Nociceptors may be temperature, pressure, or chemical sensitive but react to extremes and lead to a defensive pathway
• Electromagnetic receptors detect a form of electromagnetic energy such as light, electricity or magnetism
• Examples of mechanoreceptors are our senses of touch, hearing and balance
• An example of chemoreceptors is our sense of thirst
• Examples of thermoreceptors include those in our skin but also our hypothalamus
• Nociceptors include pain receptors
• Electromagnetic receptors are found in migrating animals including in eyespots and electrosensory fishes
• Invertebrates sense gravity using organs calls stratocysts containing ciliated receptor cells and sensory nerve fibres
• Invertebrates sense vibrations and sound using tympanic membranes found in a variety of locations on the body
• Vertebrates sense gravity using the vestibular system in the ear and sound using the cochlea in the ear to detect vibrations
• Vision in invertebrates exists as (a) a patch of pigmented cells, (b) an eyecup, (c) a pinhole camera-type eye, (d) an eye with primitive lens, or (e) a complex camera lens-type eye
• Hormone effectivity depends on the concentration of the hormone, the presence of receptors, and the response of the cell when the receptor binds the hormone
• Intercellular signalling includes synaptic signalling, neuroendocrine signalling, endocrine signalling, paracrine signalling, and autocrine signalling
• A neuron receives information, transmits it along an axon, and transmits the information to other cells via synapses
• The forebrain consists of the cerebrum, thalamus, and hypothalamus
• The hindbrain consists of the pons, the medulla oblongata, and the cerebellum