Wednesday, November 13, 2019
As classified by Thibodeau and Patton (2007) the six major classifications of the brain from the bottom of the brain and going upwards in direction are: Ã¢â¬Å"the medulla oblongata, pons, midbrain (the first three can be classified simply as the brain stem), cerebellum, diencephalon, and cerebrum. For the purpose and focus of this class, more attention will be made on specific anatomy found within those major classifications. According to Hart and Ksir, (2013) the midbrain, pons and medulla as the whole brainstem are responsible for the coordination of motor reflexes and sensory reflexes and are also listed as the general location as to which the neurotransmitters serotonin, dopamine, and norepinephrine are released. Nearly the entire amount of these neurotransmitters is produced within this proportionately small area (Hart & Ksir, 2013). A further breakdown of the reflex centers controlled by the brain stem as stated by Thibodeau and Patton, (2007) are as follows: Nuclei in the medulla contain a number of reflex centers. Of first importance are the cardiac, vasomotor, and respiratory centers. Other centers present in the medulla are for various non-vital reflexes such as vomiting, coughing, sneezing, hiccupping, and swallowing. The pons contains centers for reflexes mediated by the fifth, sixth, seventh, and eight cranial nervesÃ¢â¬ ¦In addition, the pons contains the pneumotaxic centers that help regulate respiration. The midbrain, like the pons, contains reflex centers for certain centers for certain cranial nerve reflexes, for example, papillary reflexes and eye movements, mediated by the third and fourth cranial nerves, respectively. Having more neurons than all the other parts of the nervous system combined a... ...when a drug binds with a receptor in the brain, two effects can be had. The first effect is an agonist effect, in which the substance or drug is able to mimic the effect of the neurotransmitter it resembles and the second is an antagonist effect in where the substance or drug is able to fit the receptor but there is no resultant effect- in essence it blocks the receptor from accepting anything else, including the intended neurotransmitter (Hart & Ksir, 2013). As described by my previous Anatomy Professor Joseph Staley, Ã¢â¬Å"an agonist effect is like being able to start a Ferrari with the keys to a Honda and driving away while the antagonist effect is like getting the key to the Honda stuck in the FerrarisÃ¢â¬â¢ ignition and not being able to even put the real key in it and not drive it anywhere.Ã¢â¬ While it is very basic, it is also a very accurate description.