the autonomic nervous system · 2020. 11. 12. · autonomic nervous system •sympathetic nervous...
TRANSCRIPT
自主神經系統及下視丘
Autonomic Nervous System
Hypothalamus
Principle of Neuroscience (第五版Ch 47)
楊靜修 老師
Sympathetic NS:
energy-consuming
1. Decrease GI
2. Increase HR, BP
3. Bronchi relax
4. Blood glucose increase
5. NE, Epi release increase
Sympathetic nervous system
Parasympathetic NS:
gain and conserve energy for
the body
1. increase secretion & motility
(salivary gland, GI)
2. decrease HR
ANS (屬PNS但可反應CNS)
-大腦的天線 (接收訊習)
-將大腦訊習傳給全身臟器(ANS可以反應大腦許多功能及問題,所以有機會為biomaker) Parasympathetic nervous system
Reflex arch of autonomic nervous system
CNS: central nervous system
CNS
Visceral
receptors
Afferent autonomic
pathway
Efferent autonomic
pathway
Visceral
effector
integrated
stimulation
Figure 49-1 Anatomical organization of the somatic and autonomic motor pathways.
+
+ or -
Anatomy
IML: intermediolateral horn
Figure 49-2 Anatomical organization of the sympathetic preganglionic and postganglionic axons.
C fiber
交感神經: IML: intermediolateral hornIML--para v.c. 換cell--回spinal nerve (8%) 分泌ACh
--分支出去分泌NEIML--pre v. 換cell--分泌NEIML--adrenal medulla--分泌NE
S2-S4
T1
L3
22對
75%
8% ACh
其他為NEACh
1.分布較少2.反應較不連續且為局部作用
Summary
Autonomic Nervous System• Sympathetic nervous system:
– Spinal nerves T1-L3
• Parasympathetic nervous system:
– Cranial nerves III, VII, IX, X
– Spinal nerves S2-S4
• Enteric nervous system:
– Myenteric (Auerbach’s) plexus
– Submucous (Meissner’s) plexus
Physiology
Transmission Process
Biosynthesis of Neurotransmitters (NE)
Biosynthesis of Neurotransmitters (ACh)
Mechanisms of signal transduction
ACh receptorsNicotinic receptor: N receptor
Muscarinic receptor: M receptor
NE receptor: Adrenergic receptor
ANS(Autonomic nervous system)
Sympathetic
nervous system
Parasympathetic
nervous system
a1-receptor:
contraction BP
b1-receptor:
HR
contractility
b2-receptor:
relaxation
M2 receptor
短
短長
長
Involuntary command: Emergency!
M o t o r n e u r o n
Involuntary command: Rest & digest.
Voluntary command: Move!
以作用到的receptor種類決定何種反應
CNS
Prejunctional autoreceptors
Biosynthesis of Neurotransmitters (NE)
In terminal
Rate limiting step
In vesicle
Tissue, blood, urine可檢測濃度
MAO: monoamine oxidase
COMT: Catechol-O-methyl transferase
Biosynthesis of Neurotransmitters (ACh)
In terminal
合成之酵素choline-O-acetyltransferase
degradation
Mechanisms of signal transduction
Neurotransmitter receptors in the peripheral ANS (adrenoceptors)
Neurotransmitter receptors in the peripheral ANS (cholinoceptors)
Prejunctional autoreceptors
S2-S4
T1
L3
1. 不完全什麼臟器都有兩者控制2. 興奮及抑制都有
HR 以副交感影響為主
副交感系統過度興奮並不好但是維持生存所必需
Autonomic neurons use a variety
of chemical transmitters
• Ganglionic transmission involves both fast and
slow synaptic potentials
• Norepinephrine and acetylcholine are the
predominant transmitters in the ANS
• ATP and adenosine have potent extracellular
actions
• Many different neuropeptides are present in
autonomic neurons
Figure 49-6 Both acetylcholine (ACh) and a luteinizing hormone-releasing hormone (LHRH)-like
peptide are released by presynaptic cells at synapses in the sympathetic chain ganglia in
the bullfrog. The two transmitters produce different types of postsynaptic potentials in
different postganglionic neurons because of their actions on different receptors. .
A central autonomic network
coordinates autonomic function
Central autonomic network
ANS
sympathetic NS parasympathetic NS
Baroreceptor reflex
Brain stem and spinal circuits
Neuronal Regulation of Cardiovascular SystemBaroreceptor Reflex Response (BRR)
vasomotor
center
tonic excitation
交感神經系統 副交感神經系統
Figure 49-9 Pathways that distribute visceral sensory information in the brain.
Figure 49-10 Pathways that control autonomic responses.
Autonomic pharmacology• Ganglionic blockers (transmission and receptor)
-block sympatheric and parasympathetic nerve activity (other factor)
• Drugs that inhibit synthesis of neruotransmitter
• Drugs that inhibit release of neruotransmitter
• Drugs that promote release of neruotransmitter
• Drugs that interfere with storage of neurotransmitter
• Drugs that affect neuronal uptake
• Drugs that inhibit metabolism of neurotransmitter
• Drugs that block autonomic receptors
• Drugs that stimulate autonomic receptors
Adrenoceptor-activating drugsAdrenoceptor-antagonist drugsChlinoceptor-activating & chlinesterse-inhibiting drugsCholinoceptor-blocking drugs
Drugs that inhibit synthesis of neruotransmitter
Drugs that inhibit release
of neruotransmitter
Drugs that promote release of neruotransmitter
Drugs that stimulate autonomic receptors
Drugs that interfere with storage of neurotransmitter
Drugs that affect neuronal uptake
Drugs that block autonomic receptors
Drugs that inhibit metabolism
of neurotransmitter
• Adrenergic transmission:
Uptake
Drugs that inhibit release
of neruotransmitterDrugs that promote release
of neruotransmitterDrugs that stimulate autonomic receptors
Drugs that interfere with storage
of neurotransmitter
Drugs that affect neuronal
uptake and inhibit synthesis
of neruotransmitter
Drugs that inhibit metabolism
of neurotransmitter
Drugs that block autonomic receptors
• Cholinergic transmission:
Effects of drugs:
mechanism
The Hypothalamus Integrates
Autonomic and Endocrine
Functions With Behavior
‘head ganglion’ of ANS
Hypothalamus:
內分泌系統之控制中樞飽食中樞, 飲水中樞, 體溫調節中樞, sexual behavior & 血壓調控,
sleep/wake, circadian rhythms
Neuroendocrinology
Hypothalamus
Anterior pituitary
Posterior pituitary
Homeostasis
HypothalamusNervous system
Pituitary gland
Internal condition
External environment
• It controls blood pressure and electrolyte composition by a set of
regulatory mechanisms that range from control of drinking and salt
appetite to the maintenance of blood osmolality and vasomotor tone.
• It regulates body temperature by means of activities ranging from
control of metabolic thermogenesis to behaviors such as seeking a
warmer or cooler environment.
• It controls energy metabolism by regulating feeding, digestion, and
metabolic rate.
• It regulates reproduction through hormonal control of mating,
pregnancy, and lactation.
• It controls emergency responses to stress, including physical and
immunological responses to stress by regulating blood flow to
muscle and other tissues and the secretion of adrenal stress
hormones.
The hypothalamus serves this integrative function by
regulation of five basic physiological needs:
The Hypothalamus Contains Specialized
Groups of Neurons Clustered in Nuclei
4 g/1400 g adult human brain weight
重點:下視丘各核區參與之生理功能
SON
SCN
AH
PVN
AN
VMH
MPO
LHA
PHA
DMH
重點:下視丘各核區參與之生理功能
Figure 49-11 The structure of the
hypothalamus.
SON
AN VMH
LHADMH
前葉
下視丘
甲狀腺素
The Hypothalamus Controls
the Endocrine System
Guillemin and Schally, 1977 Nobel Prize
內分泌系統簡介
腦下垂體
下視丘
腎上腺
甲狀腺
性腺
Figure 49-12 The hypothalamus controls the pituitary gland both directly
and indirectly through hormone-releasing neurons.
Figure 49-13 The paraventricular nucleus of
the hypothalamus is a microcosm of the
autonomic and endocrine control systems.
PVN
Table 49-2 Hormones of the Posterior Pituitary Gland
Name Structure Function
Vasopressin H-Cys-Tyr-Phe-Gln-Asn-
Cys-Pro-Arg-Gly-NH2 S-S
Vasoconstriction, water
resorption by the kidney
Oxytocin H-Cys-Tyr-Ile-Glu-Asn-
Cys-Pro-Leu-Gly-NH2 S-S
Magnocellular Neurons Secrete
Oxytocin and Vasopressin Directly
From the Posterior Pituitary
後葉
PVN (paraventricular nucleus)
SON (supraoptic nucleus)
Parvocellular Neurons Secrete
Peptides That Regulate Release
of Anterior Pituitary Hormones
Table 49-3 Hypothalamic Substances That Release or Inhibit the Release of Anterior
Pituitary Hormones
Hypothalamic substance Anterior pituitary hormone
Releasing
Thyrotropin-releasing hormone (TRH) Thyrotropin, prolactin
Corticotropin-releasing hormone (CRH) Adrenocorticotropin, β -lipotropin
Gonadotropin-releasing hormone (GnRH) Luteinizing hormone (LH), follicle-stimulating
hormone (FSH)
Growth hormone-releasing hormone
(GHRH or GRH)
Growth hormone (GH)
Prolactin-releasing factor (PRF) Prolactin
Melanocyte-stimulating hormone-
releasing factor (MRF)Melanocyte-stimulating hormone (MSH), β -
endorphin
Inhibiting
Prolactin release-inhibiting hormone
(PIH), dopamine
Growth hormone release-inhibiting
hormone (GIH or GHRIH; somatostatin)
Growth hormone, thyrotropin
Melanocyte-stimulating hormone release-
inhibiting factor (MIF)
Melanocyte-stimulating hormone (MSH)
前葉
前葉
TRH, CRH, GnRH, GRH GIH, PRF PIH, MRF
甲狀腺
前葉
下視丘
前葉
下視丘
性腺
前葉
下視丘
腎上腺皮質素
前葉
Short-term & long-term
nervous system & endocrine system
壓力
內分泌系統
內分泌系統
神經系統
內分泌系統
全自動控溫系統
Homeostasis
set point, receptor, effector
全自動控溫系統
Homeostasis
set point, receptor, effector
Temperature Regulation
Receptor (hypothalamus)
AH/POA
heat sens. cell 2/3
cold sens. cell 1/3
PH
AH
Heat conservation
(shivering)
Heat dissipation
(sweat)
Glucostatic Hypothesis of Appetite
Regulation
• Satiety Center (飽食中樞)-VMH
• Feeding Center (餵食中樞)-LHA
• glucostats: 位於VMH 內,其glucose 利用可控制 VMH 細胞活性
VMH LHA- eat
Relation to Cyclic Phenomena
Infradian (longer than one day)menstral cycle
Circadian (approx. one day)sleeping, body temperature, various hormones, drinking, locomotor activity…
Ultradian (shorter than one day)feeding, respiration, heart rate, nerve impulse discharge
Circadian rhythm: light signal from retina SCN
Circadian Rhythms
Witte et al. 1998, Physiology & Behavior
Sleep-Awake Circuit
1.
2.
Awake Pathway Sleep Pathway
LDT: laterodorsal tegmental nuclei, PPT: pedunculopontine
TMN: tuberomammillary nucleus, Raphe: raphé nuclei, LC: locus coeruleus
VLPO: ventrolateral preoptic nucleus
Sleep center: GABA
S2-S4
T1
L3ACh
75%
8% ACh1.分布較少2.反應較不連續且為局部作用
Hypothalamus:內分泌系統之控制中樞 (PVN, SON, AN, ME...)飽食中樞 (VMH, LHA), 飲水中樞 (CVO, SFO, MPO), 體溫調節中樞 (PH, AH, POA),
sexual behavior, 血壓調控(PVN...), sleep (VLPO)/wake (TMN, LH), circadian rhythms (SCN)
NeuroendocrinologyExternal environment Hypothalamus pituitary gland (Hormones)
Internal condition nervous system (head ganglion of ANS)
Hypothalamus
Anterior pituitary
Posterior pituitary
Homeostasis