周圍神經系統結構

2024-01-03新聞

本文嘗試從英、漢對照的方式來學習有關神經方面知識，希望對大家的學習有幫助。

神經系統

構成

神經系統有兩個主要部份，中樞神經系統（CNS）和周圍神經系統（PNS）。中樞神經系統由大腦和脊髓組成。PNS 由 顱神經和脊神經及分布在顱神經和脊神經裏的神經節及分支組成 。它主要由在中樞神經系統和身體之間傳遞的感覺神經元和運動神經元的軸突組成。自主神經系統（ANS）由位於 CNS 和 PNS 內的神經元組成，它們控制分泌腺、平滑肌和心肌。它被細分為交感神經和副交感神經成分，主要由控制內部環境組成。胃腸道壁中的神經元形成腸神經系統（ENS），能夠維持與中樞神經系統無關的局部反射活動。

The nervous system神經系統 has two major divisions, the central nervous system中樞神經系統 (CNS) and the peripheral nervous system周圍神經系統 (PNS). The CNS consists of the brain大腦 and spinal cord脊髓. The PNS consists of the cranial and spinal nerves and their peripheral ganglia and ramifications分支. It is composed mainly of the axons of sensory and motor neurones that pass between the CNS and the body. The autonomic nervous system植物神經 (ANS) consists of neurones located within both the CNS and PNS which control secretory glands and smooth and cardiac muscle. It is subdivided into sympathetic交感 and parasympathetic副交感 components and is concerned primarily with control of the internal environment. Neurones in the wall of the gastrointestinal tract form the enteric 腸 nervous system (ENS) and are capable of sustaining local reflex activity that is independent of the CNS.

function

The nervous system is a network of neurons whose main feature is to generate, modulate and transmit information between all the different parts of the human body . This property enables many important functions of the nervous system, such as regulation of vital body functions ( heartbeat , breathing , digestion), sensation and body movements . Ultimately, the nervous system structures preside over everything that makes us human; our consciousness, cognition, behaviour and memories.

周圍神經

範圍

周圍神經系統是指神經從腦和脊髓離開開始到全身（如皮膚、肌肉、腺體）路程都是神經系統範圍。內容包括腦、脊神經神經和神經節細胞如脊神經感覺神經節、交感神經節。

內容

神經

nerves神經 are bundles of axons (or nerve fibers) found in the PNS. Within the CNS, the axons form entities are known as tracts傳導束.

Nerve Ganglia神經節

A nerve ganglion is a collection of neuronal bodies found in the somatic軀體 and autonomic植物 branches of the peripheral nervous system (PNS) .

Ganglia can be thought of as synaptic relay stations突觸中轉站 between neurons. The information enters the ganglia, excites the neuron in the ganglia and then exits. The ganglia can be broadly categorized into two groups, that is, sensory ganglia感覺神經節 (relating to the somatic nervous system (SNS)), and autonomic ganglia植物神經節 (relating to the autonomic nervous system (ANS) ).

腦神經

definition

A set of 12 peripheral nerves emerging from the brain that innervate the structures of the head, neck, thorax and abdomen.

function

The function of a cranial nerve is to carry sensory and/or motor information between the body and the brain.

脊神經

定義

Spinal nerves are composed of both motor and sensory fibres , as well as autonomic fibres , and exist as 31 pairs of nerves emerging intermittently from the spinal cord to exit the vertebral canal.

脊神經包括軀體神經、交感和副交感神經，腦神經包括感覺和運動，但只有副交感神經（存在在3、7、9、10腦神經），交感神經節，位於脊柱兩側和前面，副交感節一般在臟器附近或壁內。

功能

Spinal reflexes

A reflex is an involuntary response that occurs at a subconscious level in response to a sensory stimulus. Reflex pathways are composed of afferent neurons relaying sensory information from sensory receptors to the CNS, and efferent neurons conveying the motor stimulus back to the effector muscle or gland. Interneurons are also present between the afferent and efferent neurons, in all but the simplest reflexes.

Stretch reflex

When a muscle is stretched, it responds by contracting. The stretch reflex is one of the most simple reflexes and is known as a monosynaptic reflex arc since there is no interneuron between the efferent and afferent neurons. The afferent and efferent signals are relayed at the level of a single spinal nerve.

Flexor reflex

The flexor reflex is commonly referred to as the withdrawal reflex , and occurs in response to a harmful (noxious) sensory stimulus, such as pain.

機體有哪些神經節？

脊神經軀體感覺神經節在椎管脊髓外

dorsal root ganglion感覺神經節

脊神經節就是感覺神經節，一端透過後根進入脊髓，一端分布在軀體。

Sensory ganglia of the cranial nerves

Trigeminal ( Gasser’s ) ganglion

Geniculate ganglion

Spiral ganglion

Vestibular ganglion

Superior and inferior ganglia of the vagus nerve

Glossopharyngeal ganglia

Autonomic ganglia植物神經節（植物神經包括感覺和運動）

交感神經節分別在脊神經裏，腦神經沒有交感神經節

交感神經節在在脊柱兩側，由多個神經元構成，其軸突（神經）到達汗腺等，被稱為灰交通支。

腹腔神經節、腸系膜上、下神經節（脊神經）

副交感神經節，副交感節一般在臟器附近或壁內

Parasympathetic ganglia related to head and neck

3、7、9、10腦神經有副交感神經節

Parasympathetic ganglia related to the rest of the body

In this category we have two distinct groups:

The ganglia surrounding the bronchial passages 氣管(eliciting bronchoconstriction), pancreas 胰腺(stimulating the release of pancreatic enzymes and buffer), and in Meissner’s submucosal and Auerbach’s myenteric plexus along the gastrointestinal tract (stimulating digestion and releasing sphincter muscles). Those ganglia receive innervation from the vagus nerve.

The ganglia that provide parasympathetic innervation to the pelvic viscera 盆腔臟器(the prostate , urinary bladder , penis , seminal vesicles , uterus , vagina , and clitoris). Due to their position close to or within the organs they innervate, those parasympathetic ganglia are known as terminal or intramural ganglia.

挑戰一下

腦神經有交感神經和副交感神經嗎？

周圍神經系統有沒有神經細胞？