Flashcards
Week 8
Flashcards do conjunto (33)
- 1Features of the autonomic nervous system (ANS)?-Maintains homeostasis
-Becomes active during organogenesis
-Functions non-stop during life
-Actions of the ANS reflects an imbalance between the para/sympathetic NS - 2General actions of the ANS?-Establishes/maintains homeostasis through regulation of various systems in the body
-Promotes excretory mechanisms when needed
-Effector organs are visceral organs: smooth muscle, secretory glands and cardiac muscle - 3What is the general layout of the ANS?-2 neurone chain
-1 neurone (cell body) is in the CNS (pre-ganglionic neurone)
-1 neurone in the PNS (post-ganglionic) - 4Describe the outflow of autonomic signals for para/sympathetic NSPara:
ACh acts via nicotinic receptors. The autonomic ganglia is in the walls of effector organs/near branches of CNV. The post-ganglionic neurone synthesises ACh which acts via muscarinic receptors
Sympathetic:
ACh acts on nicotinic receptors. The autonomic ganglia forms the paravertebral chain. The post-ganglionic neurone synthesises NA which acts via alpha/beta adrenoceptors - 5Most organ have dual innervation of the SNS/PNS. What gland is the exception?Sweat glands
Receive sympathetic innervation only by action of ACh at both synapses - 6What is the neurovascular bundle?-Blood vessels and nerves serving a common organ/site tend to travel together
-They are bound with the same connective tissue - 7Where do the parasympathetic autonomic fibres originate from?Cranial-sacral sources:
CN III, VII, IX, X
S2, 3, 4 - 8Where do the sympathetic autonomic fibres originate from?Thoraco-lumbar sources:
From T1 to L2 - 9What are the sources of para. autonomic outflow to viscera? Where are the pre-ganglionic neurones found?CN X (Vagus nerve)/ S2-4
Dorsal vagal motor nucleus/spinal segmental nerves of S2-4 - 10Which cranial nerves are used in distribution of autonomic fibres?CN III- Oculomotor
CN VII- Facial
CN IX- Glossopharyngeal
CN X- Vagus - 11Where do the pre-ganglionic axons of the para. autonomic terminate?Oculomotor nerve (CN III) terminates in the ciliary ganglion
Facial nerve (CN VII) terminates in either the pterygopalatine ganglion or the submandibular ganglion
Glossopharyngeal nerve terminates in the otic ganglion
Pre-ganglionic axons of the vagus nerve do not terminate in discrete ganglia - 12What part of the trigeminal nerve (CN V) is each ganglion associated with?Ciliary ganglion - Ophthalmic division
Pterygopalatine ganglion- Maxillary division
Submandibular- Mandibular division
Otic ganglion- Mandibular division - 13Pre-ganglionic nucleus for para. outflow? What nerves do they hijack?Edinger-Westphal -CN III
Superior salivatory -CN VII
Inferior salivatory -CN IX
Dorsal vagual motor nucleus -CN X - 14What is the lateral horn of a vertebral level?-cell bodies of pre-ganglionic autonomic fibres
-only seen where there is autonomic outflow (T1-L2 and S2-S4) - 153 possible modes of termination of sympathetic pre-ganglions?-White rami communicans
-Grey rami communicans
-Splanchnic nerves - 16What are the different ways sympathetic pre-ganglions can leave the vertebral column?-Synapse in chain at the same level of origin (paravertebral chain)
-Synapse at a different level to origin up/down the paravertebral chain
-Don't synapse in paravertebral chain (splanchnic nerves) - 17How can sympathetic ganglia be divided by?-Paravertebral chain
-Prevertebral chain (lie anterior to coeliac, superior/inferior mesenteric artery) - 18How to sympathetic post-ganglionic fibres reach the head and neck?-Hitch-hike on arterial system of the head and neck
-Lie outside the carotid sheath of common carotids, external/internal carotids - 19What are the receptors for autonomic sensory NS?-Viscera (not consciously perceived)
-Somatosensory/external environment - 20In what ways is the autonomic motor components different to somatic?-Effectors innervated
-Number of neurones between CNS/effector
-Neurotransmission (neurotransmitter release/compound) - 21What effector cells are innervated by somatic/autonomic motor neurones?Somatic:
-skeletal muscle
Autonomic:
-smooth muscle
-cardiac muscle
-glands
(viscera) - 22What is the difference between the number of neurones between the CNS/effector for somatic/autonomic NS?Somatic:
-Cell bodies of motor neurone in ventral horn
-Often is a single neurone so there is no change in information. There is precise control of the effector
Autonomic:
-there is a pre-post-ganglionic neurone
-The pre-ganglionic neurone can interact with many post-ganglionic neurones
-This results in synchronised widespread activity in the effector - 23What neurotransmitters are involved in the (para) sympathetic pathways? 2 exceptions to this rule?Sympathetic:
ACh in the ganglia and NA at the NMJ
Para: ACh at both the ganglia and NMJ
*Sweat glands are sympathetically innervated but use ACh at both the ganglia and NMJ
*Skeletal muscle only uses ACh (somatic NS) - 24What's special about the adrenal medulla?-It is sympathetically innervated
-Acts as a neuroendocrine organ
-Neurone releases ACh to receptors in adrenal medulla
-Adrenal medulla releases adrenaline/NA
-This interacts with non-innervated adrenergic receptors - 25Purpose of SNS/PNS?-Alert & active
-Emergency defence response
-Rest & digest
-Energy conservation
-Digestion + emptying
-More active at rest - 26How is the heart/GIT affected by the SNS and PNS?SNS:
Heart: increases HR
GIT: decreases motility
PNS:
Heart: decreases HR
GIT: increases motility - 27How is the smooth muscle in the eye affected by the SNS and PNS?SNS:
-Contraction of radial muscle resulting in pupil dilation
PNS:
-Contraction of circular muscle resulting in pupil constriction - 28What organs/glands are singly innervated?-Sweat glands- SNS only
-Most blood vessels - SNS only
(vasoconstriction-increased SNS)
(vasodilation- decreased SNS) - 29Name an example that is an exception to the singly innervated blood vessels What is its resting condition?Salivary glands
SNS: vasoconstriction of blood vessels leading to a small quantity of sticky saliva
PNS: vasodilation leading to a large volume of watery saliva
Resting: PNS>SNS - 30Why do we see vasodilation of some blood vessels when there is body-wide activation of the SNS?-Increased SNS activity releases NA which binds to alpha adrenergic receptors causing vasoconstriction of most blood vessels
-Since the SNS also innervates the adrenal medulla adrenaline (Ad) is also released
-Ad binds to beta adrenergic receptors causing vasodilation
-Skeletal muscle blood vessels have a high density to beta receptors, hence vasodilation is seen here - 31How does the autonomic NS work in the male reproductive system?PNS- erection
SNS- ejaculation - 32How does the autonomic/somatic NS interact together to: -focus eyes on a near object -respond to cold?ANS: pupil/lens adjustment
Somatic: eye movements
ANS: Vasoconstriction in skin
Somatic: shivering - 33How is the bladder affected by the ANS?SNS:
Contraction of internal urethral sphincter prevents emptying
PNS:
contraction on detrusor muscle leads to emptying of bladder
Informações
- Descrição
- Organisation of the autonomic nervous system
- Criado por
- Dolu Falowo · dez 2017
- Atualizado
- 3 fev 2018
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