Nervous Tissue, spinal cord and spinal nerve (Chp.13-14) Flashcards
nervous system:
* Maintains ________ coordination with electrical or chemical
messages containing ________ and PNS
* CNS contains _____ & _______ while PNS is all the system except CNS
* PNS contains sensory and motor divisions, further dividing into ________ and ________ divisions.
internal; CNS; brain; spinal cord; somatic; visceral (內臟）Both sensory and motor have both divisions.
Sensory VS Motor:
* Sensory: sends signal to ______; bring sensation
* Motor: sends signals from CNS to _______ or _________ & bring response
Somatic VS Visceral:
* Somatic （身體的）: connect to ______, ________ & ___________.
* Visceral（內臟的）: connect to _________ & ____________.
CNS; gland; muscles; bone joint; skin; muscle; internal organs; involuntary muscles
Properties of neutrons:
* Basic __________
* Excitability: responsive to ___________
* Conductivity: transduce __________
* Secretion: secret __________ to stimulate
another neuron
functional unit; stimuli; signals; neurotransmitters
Neuron mainly contains cell body, ________, ________ and axons.
neurites; dendrites
- Cell body: aka _______
Neurofibrils: network within _______, maintain
________ of neuron - Neurites: _________ or ________
- Dendrites: ________ signals from other cells
- Axons: Conduction of signals to other cells
- Usually enclosed in _________________
soma; soma; shape; axon; dendrites; receive; myelin sheath
- Multipolar:
- One _______ + >2 ________
- Bipolar:
- Two neurites from soma
- One _______ + one ________
- Unipolar:
- _______ neurite from soma
- Pseudounipolar: neurite branches to ______ neurites
axon; dendrites; axon; dendrite; one; two
Pseudo: 假性
I.2.2 Neuroglia
* A.k.a. Glia
* Protects neurons and aids their function
* Glia = Glue
* __________ neurons together via a framework
* Six types of glia in human
* CNS:
1. _________________
2. ___________ cells
3. ___________
4. ___________
* PNS:
1. __________ cells
2. __________ cells
Sticking; Oligodendrocyte; Ependymal; Microglia; Satellite; Schwann
- Oligodendrocyte:
* ___________ body, >10 processes
* The processes wrap axons in CNS, form the ____________ - Ependymal cells:
* Resemble (像） ________________
* Lining ________________ of brain and ______________ of the spinal cord
* Produce ________________ in spinal cord and
_____________
bullous; myelin sheath; cuboidal epithelium; internal cavities; central canal; cerebral spinal fluid; ventricles (腦的空位）
- Microglia
* ________ cells in CNS
* Phagocytic ____________
* Remove dead tissue and foreign materials
* Found in site with injury and infection - Astrocytes
* Most abundant glia
* Many-branched, ________ shape
* Functions: form _________________
* Form __________ barrier,
* restricting material transfer into ______, ________ neurons
* Other functions: chemical balances, promote neuronal/synapse growth, etc
（提供營養）
immune; macrophage; star-like; supportive framework; blood-brain; CNS; protect
血腦屏障=》選擇性地阻止某些物質進入大腦
- Schwann Cells
* Envelop nerve fibers of _______ neurons, forming myelin sheath
* Each Schwann cell wraps only on one myelin sheath
* Assist in _____________________ in PNS - Satellite cells
* Surrounds soma of neurons at regions called _______
* Ganglion: region at ________, where neuronal soma are located
together
PNS; nerve regeneration; ganglion; PNS
- Myelin sheath:
- Insulating layer around nerve fiber
- Formed by:
- _______________ in CNS (one cell,
__________ segments) - _________________ in PNS (one cell, _______
segment) - Composed of protein and ________
- Speed up nerve signal transduction
oligodendrocytes; several; Schwann cells; one; lipid
*Oligodendrocyte可以myelinate mulitiple axons in one cell，但係Schwann cells剩係可以myelinate一個segment in one cell。
ganglion=> a group of neurons
Synapse:
The meeting point between an neutron and another cells (e.g. neuron, muscule,
glandular cells)
* decide if a signal is passed to another cell
* Consists ___________ and postsynaptic neurons
* Forms of synapses:
* ___________: between axon and dendrites
* ___________: between axon and soma
* ____________: between axon and axon
presynaptic; axodendritic; axosomatic; axoaxonic
Two kinds of synapses:
* Chemical:
* With synaptic cleft
* release neurotransmitters
* Electrical:
* With _________________
* Allows __________ diffuse directly
gap junctions; ions
Chemical synapse:
* Cells separated by synaptic cleft
* ____________________(CAMs) connecting ____________________________________________________________
* Neurotransmitters are stored in synaptic vesicles
Common neurotransmitters:
* _________________ (stimulate muscles)
* __________________ (stimulate organs)
* _______________ (excite neurotransmission)
* _____________________(GABA, inhibit neurotransmission)
Cell adhesion molecules; pre and postsynaptic membranes; Acetylcholine; Norepinephrine; Glutamate; Gamma-aminobutyric acid
Brain tumors:
* Usually due to uncontrolled proliferation of ______ cells, not neuron
Diseases of myelin sheath
-Multiple __________（硬化症）:
* degeneration of myelin sheath
* Deterioration of ______________
* May eventually become bedridden (臥床不起）
glial cells; sclerosis; oligodendrocytes
I.4.1 Spinal cord
* ‘’Information highway’’ connects the brain with lower body
* Four principal functions:
1. _____________: conducts information from/to the brain and
other body parts
2. _______________ : integrate information from multiple
sources
3. ______________: controls simple, repetitive muscle contraction
(by __________________________) (中樞模式發生器）
4. ___________: involuntary, stereotyped responses to stimuli
Conduction; Neural integration; Locomotion; Central pattern generators; reflexes
CPGs 是一種不需要傳感器反饋就能產生節律模式輸出的神經網絡
I.4.2 Spinal cord: surface anatomy
* Cylinder of nervous tissue from brainstem
* Passes down the _____________
* In adult: 45cm long, 1.8 cm thick
* Gives rise to ___________ of spinal nerves
vertebral canal; 31 pairs
I.4.2 Spinal cord: surface anatomy
* Divided into 4 regions: _________, ________, ________ & ________ (由上至下）
-Enlargement areas:
* Cervical enlargement: give rise to nerves for _____________
* Lumbosacral enlargement: gives rise to nerves to ____________ and __________
Cauda equina: (Situated in ____________)
* Similar to horse’s tail
* Innervates ___________________
Cervical; Thoracic; Lumbar; Sacral; upper limbs; pelvic region; lower limbs; lumbar; pelvic and lower limbs
Spinal cord (and brain) are protected by membranes named meninges
1. Three layers of meninges:
* ___________ mater:
* Outermost layer
* _________ collagenous membrane
2. ____________ mater:
* _________ array of collagenous/elastic fibers
* _________________ filled with cerebrospinal fluid (CSF)
3. ____________ mater:
* _________, transparent membrane
* ___________ spinal cord to vertebral column at some regions
Dura; tough; arachnoid; looser; sub-arachnoid space; Pia; delicate; anchoring
I.4.3 Spinal cord: cross-sectional anatomy
* Spinal cord consists gray matter and white matters
* Gray matter:
* ____-shaped
* Consists ___________, __________ horns
* Lateral horns at ________ and __________ regions
* ________________ joins right and left sides
* Central canal (space) in middle
* Spinal nerve branches and connects to the spinal cord via _________ and _________ roots
H; posterior; anterior; thoracic; lumbar; Grey commissure; dorsal; ventral
-White matter:
* Surrounds gray matters
* Consists _________ of axons
* Divided into posterior, lateral and anterior _________
bundles; columns
- White matters in spinal cord form __________________
- Types: Ascending tract:
- __________________ up the cord to the brain
- Descending tract: _________________ down to muscle/effectors
- ____________ may be found in tracts
- E.g. left brain sends motor commands to right side of body
spinal tracts; carry sensory information; carry motor impulses; decussation
Ascending Tracts:
* Carry sensory signals up the spinal cord
-Typically has three neurons:
* First-order neuron: ______________, conduct signal to spinal cord
* Second-order neuron: continues to ______________;
* Third-order neuron: carries signal to ______________
* Spinothalamic tract :
* Carries signals for _________, ___________ & ___________
detect stimuli; thalamus; sensory cortex; pain; temperature; pressure
- Descending Tract:
- Carry motor signals down the spinal cord
- Typically involves two neurons:
- Upper motor neuron: from _________ to lower part of spinal cord
- Lower motor neuron: leads to muscle or organ
- Example on right: ________ tract
cortex; corticospinal
I.5.1 General anatomy of Nerves
* Nerve: A collection of numerous nerve fibres (axons) bound together
* ________ → Myelin→ _____neurium → _______neurium → _____neurium (Formation of nerve from inner to outer)
* _________: collection of axons
* _______: collection of fascicles
* Mixed nerve: with both _______ and _______ axons
Axon; Endo; Peri; Epi; Fascicles; Nerve; sensory; motor
- Spinal Nerves:
- Nerve in connection with spinal
cord - 31 pairs of spinal nerves:
- _ X cervical
- _ X thoracic
- _ X lumbar
- _ X sacral
- _ X coccygeal
8; 12; 5; 5; 1
- In each spinal cord segment, _________ rootlets emerge from anterior and posterior surface, converge to form ________ (anterior) root and
________ (posterior) roots respectively - The ventral and dorsal root then converge to form the ______________
- Posterior root ganglion: collection of _________ neuron somas
6-8; ventral; dorsal; spinal nerve; sensory
- Spinal nerve branches after leaving the vertebral column:
- Anterior ramus: innervate skin/muscles on
_________ and _______ side - Posterior root: innervates skin/muscles on the ____________________
- Meningeal branch: reenters ________________,
innervate ___________, __________, ___________
anterior; lateral; back of the body; vertebral canal; meninges; vertebrae; spinal ligaments
Nerve Plexuses: Anterior rami from spinal nerve
branch and merge repeatedly, forming a network of
nerve at particular regions:
* Cervical Plexus
* ________ Plexus
* Lumbar plexus
* Sacral plexus
* Coccygeal plexus
Brachial
- Cervical Plexus:
- From spinal nerves ____ to _____
- Innervate ________ and some ________ and __________
muscles - Brachial Plexus:
- From _____ to ______
- Innervates _________ and some ______ and _______________
C1; C5; diaphragm; neck; back; C5; T1; upper limb; neck; shoulder muscles
- Lumbar Plexus:
- From ______ to ______
- Transduce sensory information from ______ or ____________, skin of ____________ region, ___________ region, _____________
- Motor fibers innervate muscles of ______, ________ and _____________
- Sacral and coccygeal plexus
- From ____ to _____
- Give rise to ______ nerve
L1; L4; hip; knee joints; genital; abdominal; lower limb; hip; thigh; scrotum; L4; S4; Sciatic
- Each spinal nerve (except ________) receives sensory input from specific skin areas
called dermatome - ___________: indicates approximate
areas innervated by corresponding spinal
nerve - Same area may be innervated by ______
spinal nerve
C1; Dermatome (皮節) map; 2-3
Common clinical conditions
_________________________:
* Inflammation of the spinal meninges
________:
* Viral infection, usually from animal bites, spreads along the somatic
motor nerve to CNS and out via autonomic nerve fibers
* Seizures （癲癇）, coma （昏迷）, death
Spinal menigitis; Rabis
Common clinical conditions
_____________:
* Pressure on sacral and coccygeal plexuses（壓住L4-S4）, pain radiating from __________________ to lower limb
Sciatica (坐骨神經痛）; gluteal regions
Common clinical conditions
Shingles (帶狀疱疹):
* Viral infection (______________) with fluid-filled vesicles
* Virus travel down the sensory nerves by axonal transport
* May cause long-lasting intense pain
Varicella-zoster
