tailieunhanh - Applied Surgical Physiology Vivas - part 3

Làm thế nào để nguồn gốc của các PNS khác nhau từ các SNS? Preganglionic phó giao cảm: những neurones có nguồn gốc từ các hạt nhân thần kinh sọ não cụ thể và từ đoạn ở xương cùng 2-4 của tủy sống (cranio-xương cùng dòng chảy so với nguồn gốc thoraco-thắt lưng của các SNS) hạch phó giao cảm: không giống như chuỗi giao cảm, hạch PNS nằm tại các điểm rời rạc gần cơ quan | APPLIED SURGICAL PHYSIOLOGY VIVAS A AUTONOMIC NERVOUS SYSTEM 5. How does the origin of the PNS differ from the SNS Preganglionic parasympathetic these neurones take origin from specific cranial nerve nuclei and from sacral segments 2-4 of the spinal cord outflow vs. thoraco-lumbar origin of the SNS Parasympathetic ganglia unlike the sympathetic chain the PNS ganglia are located at discrete points close to their respective target organs 6. Which cranial nerves have a parasympathetic outflow Cranial nerves III VII IX and X. 7. Taking all of this into account summarise briefly the neurotransmitters of the ANS and which types of receptor they act on. Preganglionic cells the cells of both systems release ACh at the synapse with the postganglionic cells. It acts on nicotinic cholinoceptors Postganglionic cells PNS - ACh is released acting on muscarinic cholinoceptors. SNS - noradrenaline acting on a- or fi-adrenoceptors 8. Generally speaking how does the distribution of parasympathetic inner vation in the body differ from sympathetic distribution Parasympathetic fibres are visceral they do not supply the trunk or limbs Parasympathetic fibres do not supply the gonads or adrenal glands 9. Which second messengers are important for the function of the different types of receptors in the ANS The most important second messengers through which the cholinoceptors and adrenoceptors function are 26 APPLIED SURGICAL PHYSIOLOGY VIVAS cyclic adenosine monophosphate cAMP diacylglycerol DAG and inositol diphosphate IP2 . a1-adrenoceptors stimulation causes an increase of intracellular phospholipase C leading to an increase of the second messengers IP2 and DAG. This causes activation of a number of protein kinases and stimulates release of intracellular Ca2 stores. So in the cases of arterioles leads to vasoconstriction following stimulation of mural smooth muscle contraction a 2-adrenoceptors stimulation leads to inhibition of the enzyme adenylyl cyclase reducing the .