解剖学_神经系统

神经系统

基础
- 分类
  - CNS
    - brain
    - spinal cord
  - PNS
    - consists of all nervous tissue outside the CNS
    - 12 pairs of cranial N
    - 31 pairs of spinal N
- Neuron
  - Neuron: an individual nerve cell
  - Dendrites: receiving or input portions of a neuron 树突
  - Cell body: contains the cell nucleus 胞体
  - Axon: carries the impulse away from the cell body 轴突-传导冲动
  - Myelin sheath: multilayered lipid and protein covering around some axons that insulates them and increases the speed of nerve impulse conduction 髓鞘
  - Nodes of Ranvier: gaps in the myelin sheath
- Collections of Nervous Tissue
  - Clusters of Neuronal Cell Bodies神经元胞体聚集
    - A ganglion (plural ganglia): a cluster of neuronal cell bodies in the PNS. 神经节
    - A nucleus (plural nuclei): a cluster of neuronal cell bodies in the CNS. 神经核
  - Bundles of Axons
    - A nerve: a bundle of axons in the PNS
      - Cranial nerves connect the brain to the periphery
      - Spinal nerves connect the spinal cord to the periphery
    - A tract: a bundle of axons in the CNS 纤维束
      - Tracts interconnect neurons in the spinal cord and brain
  - White matter
    - composes of myelinated axons
    - whitish color of myelin
    - 脑-髓质
    - 脊髓-白质
  - Gray matter
    - contains neuronal cell bodies, dendrites
    - Nissl bodies impart a gray color and there is little or no myelin
    - 脑-皮质
    - 脊髓-灰质
  - 图
Brain
- 结构
  - Encephalon/telencephalon 端脑(Cerebrum 大脑)
  - Diencephalon 间脑
    - Epithalamus
    - Thalamus
    - Hypothalamus
  - Cerebellum 小脑
  - Brainstem 脑干
    - Midbrain 中脑
    - Pons 脑桥
    - Medulla oblongata 延髓
  - 图
- Cerebrum
  - Largest part of the brain
  - Associated with
    - thought and consciousness
    - Perception
    - Communication
    - Understanding
    - Memory
  - Cerebral hemispheres
    - Left cerebral hemisphere
    - Right cerebral hemisphere
    - Divided by longitudinal cerebral fissure 大脑纵裂
    - Cerebral hemispheres are connected by corpus callosum 胼胝体
  - 沟/回
    - Hills - Gyrus (singular), Gyri (pleural) 回
    - Valleys - Sulcus (singular), Sulci (pleural) 沟
    - Deepest valleys between hills - fissures 裂
  - Lobes of the Cerebrum
    - Frontal lobe
    - — central sulcus —
      - 中央沟
      - separates the frontal lobe from the parietal lobe
      - Pre-central gyrus 中央前回
        
        locates immediately anterior to central sulcus, and contains primary motor area
      - Post-central gyrus 中央后回
        
        locates immediately posterior to the central sulcus, and contains primary somatosensory area 初级躯体感觉区
      - 图
    - Parietal lobe
    - Temporal lobe
      - Auditory processing, language and memories
    - Occipital lobe
      - Primary visual cortex 初级视皮质
    - Insula 岛叶
    - 图
- Diencephalon 间脑
  - 左右对称,有两个
  - Thalamus 丘脑
  - Hypothalamus 下丘脑
  - Epithalamus 上丘脑
  - 图
- Brainstem
  - Midbrain
  - Pons
    - Anterior to the cerebellum
    - 2.5 cm long
  - Medulla oblongata
    - 3 cm long
    - Starts at the inferior border of the pons
    - ends at the foramen magnum
    - continuous with the superior part of the spinal cord
    - Decussation of pyramids 锥体交叉
    - Pyramids 锥体束
      - formed by corticospinal tracts that control voluntary movements of the limbs and trunk
      - Superior to the junction of the medulla with the spinal cord
      - 90% of the axons in the left pyramid cross to the right side
      - 90% of the axons in the right pyramid cross to the left side
      - Each side of the brain controls voluntary movements on the opposite side of the body.
  - 图
- Cerebellum
  - Central area is the vermis (= worm) 小脑蚓
  - lateral lobes are cerebellar hemispheres
  - 小脑前面正好是 fourth ventricle
Ventricular system of the brain
- ventricles
  - Lateral ventricles/Ventricles 1 and 2
    - Paired C-shaped chamber in each cerebral hemisphere
    - Largest of the ventricles
    - Below the corpus callosum
  - Ventricle 3
    - Midline, narrow space b/t L and R diencephalon
    - 在间脑中间
  - Ventricle 4
    - Between the brainstem and the cerebellum
  - 1,2是在周围的,所以正中间的截面看到的很小
- Cerebrospinal fluid
  - CSF
  - a clear, colorless liquid
- CSF circulates
  - Through ventricles
  - Around the brain and spinal cord in the subarachnoid space蛛网膜下腔 (the space between the arachnoid mater and pia mater)
  - 侧脑室脉络丛产生的脑脊液经室间孔流至第三脑室，与第三脑室产生的脑脊液汇合，经中脑水管流至第四脑室，再与第四脑室脉络丛产生的脑脊液一起，经第四脑室正中孔和第四脑室外侧孔流入小脑延髓池，并迅速扩散至整个蛛网膜下隙，流向大脑背面，经Arachnoid villus蛛网膜粒渗入到上矢状窦，会流入血液循环中
  - Choroid plexus 脉络膜
    - 产生Cerebrospinal fluid
  - Interventricular foramen
    - lateral ventricles →3rd ventricle
  - Cerebral aqueduct
    - Locates in the midbrain
    - 3rd → 4th ventricles
  - 图
Protective Coverings of the Brain
- Cranium
- Cranial meninge
  - dura mater 硬脑膜
    - 1. Periosteal layer 骨膜层
      - Lines internal surface of skull
      - ends at the foramen magnum枕骨大孔
    - 1. Meningeal layer 脑膜层
      - Continuous with spinal meninge 脊膜
    - 图
    - Restrict displacement of the brain (much like a seat belt) falx cerebri - 大脑镰
  - arachnoid mater 蛛网膜
  - pia mater 软脑膜
  - 图，淡蓝色的是静脉窦
Spinal Cord
- 基础
  - 45 cm in adults
  - locates within the vertebral canal 椎管 (All vertebral foramina form the vertebral canal 椎孔)
    - Cervical Vertebra
  - slightly flat anteriorly and posteriorly
  - 结构
    - 长度
      - in adults
        
        medulla oblongata - L1
      - in newborn infants
        
        medulla oblongata - L3
    - 特殊区域
      - Cervical enlargement C4-T1
      - Lumbar enlargement T9-12
    - Conus medullaris 脊髓圆锥
    - Cauda equina 马尾神经
    - 图
- Meninges
  - surround the spinal cord
  - continuous with the cranial meninges
  - ① dura mater
  - ② arachnoid mater
  - ③ pia mater
  - 图
- 病-A Lumbar Puncture and Epidural Anesthesia
  - A lumbar puncture 腰椎穿刺
    - Undertake a sample of cerebrospinal fluid
    - Insert into the subarachnoid space 蛛网膜下腔
    - In the midline between the L3 and L4 or the L4 and L5 vertebral spinal processes
  - Epidural Anesthesia 硬膜外麻醉
    - Inject anesthetic agents into the epidural space (above the dura mater)
    - Anesthetize the nerve fibers of the cauda equina
    - Commonly used during childbirth
  - 图
- Relationship of Spinal Nerves to Vertebrae
  - All of the nerves pass via the intervertebral foramen 椎间孔
  - Naming
    - C1-C7 name as the vertebra below
    - C8 b/t C7 and T1
    - T1-Co name as the vertebra above
  - 图
- Internal anatomy of the spinal cord
  - Gray matter of the spinal cord
    - butterfly-shaped
    - Clusters of dendrites and cell bodies of neurons
    - 结构
      - anterior horn
        
        contain somatic motor nuclei
      - posterior horn
        
        contain axons of incoming sensory neurons
        
        contain cell bodies of interneurons // 紫色的
      - lateral horn
        
        contain autonomic motor nuclei
        
        only in thoracic and upper lumbar segments of the spinal cord
      - Intermediate column 中间柱
      - Central zone 中心带
      - 图
  - White matter of the spinal cord
    - Bundles of myelinated axons of neurons
    - Rich in lipids
    - Two grooves
      - anterior median fissure 前正中裂
      - posterior median sulcus 后正中沟
  - 图
- Central Canal 中央管
  - extends the entire length of the spinal cord
  - continuous with the fourth ventricle
  - fills with cerebrospinal fluid
Cranial nerves分类
- Cranial nerves I, II, and VIII
  - Special sensory (afferent) nerves 特殊感觉神经
  - Associated with smelling, seeing, and hearing
- Cranial nerves III, IV, VI, XI, and XII
  - Motor (efferent) nerves
  - Contain only axons of motor neurons
- Cranial nerves V, VII, IX, and X
  - Mixed nerves
  - Contain axons both of sensory neurons and motor neurons
- 图
Cranial nerves
- I. Olfactory 嗅神经 (olfact- = to smell)
  - arises from olfactory receptors in nasal cavity which includes superior nasal concha and part of nasal septum
  - Pass through the foramina of the ethmoid bone
  - Olfactory bulb 嗅球
  - Olfactory track
  - Connects to cerebrum 连端脑
  - Function - special sense of smell
  - 病-Anosmia - Loss of the sense of smell
    - Infection
    - Swelling of nasal mucosa
    - Head injury
  - 图
- II. Optic 视神经
  - Retina → Optical nerve through optic canal视神经管 in the orbit
  - Visual sensory information courses to the ipsilateral同侧的 and contralateral对侧的 side of the brain at the optic chiasm (an X)
  - Connects to diencephalon 连间脑
  - Optic tract - pathway to occipital lobe,连接视交叉(间脑)到大脑皮层
- III. Oculomotor 动眼神经
  - Arises from the midbrain
  - Function
    - Somatic motor to extraocular muscle眼外肌
    - Visceral motor to pupillary constrictorand ciliary muscle
      - Pupillary constrictor瞳孔括约肌 adjusts the size of the pupil
      - Ciliary muscle睫状肌 adjusts the lens
  - 通过Superior orbital fissure
- IV. Trochlear 滑车神经
  - Motor to superior oblique muscle 上斜肌
  - Control eyeball movement
  - 上卖弄这个绿色的是滑车
- V. Trigeminal 三叉神经
  - Largest cranial nerve
  - A swelling一个膨大 - trigeminal ganglion
  - Gives rise to 3 branches
    - Ophthalmic N 眼神经
    - Maxillary N 上颌神经
    - Mandibular N 下颌神经
    - 图
  - Mixed nerve
    - Sensory
      - to face, orbit, nose, teeth and anterior 2/3 tongue
    - Motor
      - to muscles of mastication 咀嚼肌
      - Control chewing movements
      - Motor fibers hitchhike伴随 along mandibular branch下颌神经分支
- VI. Abducens 外展神经
  - Motor to lateral rectus muscle of the eyeball 眼球外直肌
  - cause abduction (lateral rotation) of the eyeball
- VII. Facial 面神经
  - Arises from the pons
  - Mixed nerve
  - Gives rise to 3 branches
    - Facial nerve proper 面神经主干
      - Goes through parotid gland腮腺, but doesn’t innervate it
      - Motor to muscles of facial expression
    - 1. Chorda tympani nerve 鼓索神经
      - Motor to submandibular颌下腺 and sublingual glands舌下腺
      - SS特殊感觉 taste from anterior 2/3 of tongue
    - 1. Greater petrosal nerve 岩大神经
      - Motor to lacrimal, nasal and palatine glands
  - 功能小口诀
    - Closes your eye
    - Tastes pie
    - Makes you cry
    - Innervates all glands in head except the one it goes through
  - 图
- VIII.Vestibulocochlear 位听神经/前庭蜗神经
  - Function - SS. hearing and balance
  - vestibular branch for equilibrium
  - cochlear branch for hearing
- IX. Glossopharyngeal 舌咽神经
  - mixed nerve
    - sensory
      - Sensory to posterior 1/3 tongue, oropharynx , carotid sinus , carotid body , and auditory tube
      - gag reflex 咽反射
      - baroreceptors in the carotid sinus
      - chemoreceptors in the carotid bodies
      - SS. taste - posterior 1/3 tongue
    - motor
      - Motor to parotid gland to secrete saliva
      - Motor to stylopharyngeus muscle 茎突咽肌assists in swallowing
  - 图
- X. Vagus迷走神经
  - Wide distribution - head, neck, thorax and abdomen
  - It goes along internal jugular V and common carotid A in the neck region
  - Mixed nerve
    - sensory
      - Sensory to laryngopharynx, larynx
      - Sensory to thoracic and abdominal viscera
      - e.g. such as hunger, fullness, and discomfort
    - motor
      - Motor to thoracic and abdominal viscera
      - Motor to muscles of soft palate, pharynx and larynx that are used in swallowing, vocalization, and coughing
      - Loss of motor function to pharynx, larynx and palate via loss of gag reflex
  - 图
- XI. Accessory 副神经
  - origin in upper cervical spinal cord and medulla
  - corss foramen magnum and jugular foramen颈静脉孔
  - Function
    - Motor sternocleidomastoid and trapezius mm
- XII. Hypoglossal 舌下神经
  - Origin in medulla oblongata
  - Function
    - motor to muscles of the tongue
    - e.g. genioglossus m.颏ke舌肌