According to Human Physiology please answer the following questions with Detaile
ID: 3523356 • Letter: A
Question
According to Human Physiology please answer the following questions with Detailed Explanations, thank you
56) The mechanisms by which catecholamines activate postsynaptic cells
57) How a photoreceptor cell detects light and sends an action potential
58) The two-point touch threshold
59) How different tastes are detected by taste bud receptors
60) How the sense of smell is detected by the brain, in comparison with how other sensory modalities are detected by the brain
61) The role of the otolith organs (utricle/saccule) versus the semicircular canals
Explanation / Answer
Q 56. activation of postsynaptic cells by catecholamines is known as neurotranmission.
Q 57. this is done by photo transduction(a process which converts light in to electrical signals).this sensory information travells along afferent nerve fibres in sensory nerve.these signals are refined and controlled by the interactions with other types of neurons in the retina.
Q 58.the two point threshold is the minimum distance at which two points of touch can be perceived as separate i.e. a measure of distance between receptive fields.it is an indication of sharpness of touch percetion.
Q 59.the microvilli of the taste cells bear taste receptors.when taste cells are stimuulated by binding of chemicals(Na etc) to their receptors,they depolarize and this depolarization is transmitted to the taste nerve fibres resulting in action potential transmitted to the brain.
Q.60.the sense of smell is detected by a chemoreception called olfaction. in comparision with other sensory modalities olfactory neurons are continuosly replaced by mitotic division of the basal cells of the olfactory epithelium and also with out thalamic relay.
Q.61.utricle and saccule respond to changes in the position of the head with respect to grvity i.e. linear acceleration ,where as semicircular canals respond to rotational movements i.e.angular acceleration.these are the sensory aparatus of the inner ear that helps the body to maintain its potural equilibrium.