Neuro - ANS Flashcards
A system that is totally involuntary and without conscious awareness. It came from the visceral motor division of the peripheral nervous system. It controls glands, cardiac muscles and smooth muscles but NOT skeletal muscles. It targets the organs of the thorax, abdominal cavity, blood vessels, sweat glands and muscles in the skin.
Autonomic Nervous System
ANS motor neurons that conduct impulses from the spinal cord or brain stem to the effectors. (3)
Cardiac muscle tissue, smooth muscle tissue of blood vessel and organs, and glandular epithelial tissue.
Two divisions of the ANS
Sympathetic and Parasympathetic division.
ANS effectors have ______- they are innervated by both the sympathetic and parasympathetic fibres.
Dual innervation
Division of the ANS that covers the thoracic and lumbar spine. It has dendrites and cell bodies in the grey matter of the thoracic and upper lumbar segments of the spinal cord. It is also known as the thoracolumbar division as the nerve fibres comprising this division arise off the cord between T1-L1. It has 2 kinds of neurons-preganglionic and postganglionic neurons. All in all, it functions as an emergency system. (fright, flight, fight system)
Sympathetic Nervous System or SNS or Thoracolumbar division.
SNS neurons that leave the spinal cord and terminate collateral ganglia.
Preganglionic Neuron
SNS neurons that leaves the collateral ganglia and terminates in smooth muscle, cardiac muscle or glands.
Postganglionic Neuron
Division of the ANS that promotes homeostasis when the body is at rest. It has dendrites and cell bodies located in the grey matter of the brain stem and the sacral segment of the spinal cord. It is also known as the craniosacral division as the nerve fibres comprising this division arise in the brain stem and off the cord. Preganglionic neurons travel long distances and terminate on postganglionic neurons near organs and glands. It functions mainly as a vegetative system.
Parasympathetic Nervous System or PaSNS or Craniosacral Division.
PaSNS cranial nerves. (4)
Oculomotor
Facial and Glossopharyngeal
Vagus (x nerve)
PaSNS cranial nerve that innervates smooth muscle within the eye itself and causes pupil constriction.
Oculomotor Nerves
PaSNS cranial nerves that innervate the salivary glands.
Facial and Glossopharygeal Nerves.
PaSNS cranial nerve that carries about 75% of PaSNS output. It innervates most thoracic and abdominal glands.
Vagus (X nerve)
PaSNS output in the sacral area (Pelvic splanchnic nerves) operates.. (3)
Bladder, reproductive organs, & large intestine/rectum.
PaSNS nerves in the sacral area.
Pelvic sphlanchnic nerves.
- ↑ HR and strength of contraction
- ↑ BP, release of epinephrine, & sweat secretions
- Dilate blood vessels in skeletal muscles, pupils, & respiratory passages
- ↓ peristalsis, digestive secretion, salivation
- Inhibit defecation and bladder function
Sympathetic Control
- ↓ HR, strength of contraction, & BP
- ↑ peristalsis, salivation, & digestive secretions
- Stimulate contraction of bladder
- Constricts the pupils & respiratory gases
Parasympathetic Control
To supply (an organ or other body part) with nerves.
Innervate
Bring to an end.
Terminate
Sympathetic ganglia which lie between the para-vertebral ganglia and the organ of supply. They are also called the prevertebral ganglia, receive input from the splanchnic nerves and innervate organs of the abdominal and pelvic region. These include the celiac ganglia, superior mesenteric ganglia, and inferior mesenteric ganglia.
Collateral ganglia
3 organs that only have sympathetic innervation.
Blood vessels, sweat glands, & adrenal medulla
Sympathetic stimulation causes ____ of smooth muscle in the vessel wall resulting in increased vascular changes.
Contraction
Vasodilation occurs in the CVS by SNS causes..
↑ blood flow to skeletal muscle and organs
Vasoconstriction occurs at the cutaneous membrane by SNS causes..
↓ blood flow, blood; renal blood flow is shunted to the heart and intestinal blood flow shunted to skeletal muscles.
Increases SNS stimulation increases stimulation to the sweat glands thus increases..
sweat production.
A high spinal cord transection (above T1) essential eliminates the sympathetic response and the patient has difficulty in ____ their body.
cooling
A condition in which the nerves inside the spinal column become damaged
Spinal cord transection
Organ in which increased SNS stimulates the release of the hormones E and NE.
Adrenal Medulla
Several varieties of molecules with axon terminals of neurons that are released into the synaptic cleft in response to a nerve impulse and affect the membrane potential of the postsynaptic neurons.
Neurotransmitters and receptors
3 possible effects of synapses
- Stimulated or inhibited by other NT, drugs, or toxins.
- Removed from synaptic cleft.
- Binding to the receptor site.
NT that is released by the PNS and CNS neurons.
Ach or Acetylcholine
NT that is released by post-ganglionic sympathetic nerves.
Epinephrine and Norepinephrine.
2 major types of neurons, receptors and NT present in the ANS.
Cholinergic and Adrenergic
Cholinergic NT
Ach or acetylcholine
3 Cholinergic neurons (that secretes Ach)
- All the sympathetic and parasympathetic preganglionic neurons.
- Sympathetic postganglionic neurons to sweat glands.
- All parasympathetic postganglionic neuron.
2 Cholinergic receptors.
- Nicotinic receptors
2. Muscarinic receptors
Cholinergic receptors that is present in the plasma membrane of dendrites and cell bodies and motor end plates at neuromuscular joints.
Nicotinic receptors
Cholinergic receptors that is present in the plasma membrane of smooth muscles, cardiac muscle and glands including sweat glands.
Muscularinic receptors
Ach binds to both nicotinic and muscarinic. True or False.
True.
What part of the neuron is Ach released
Synaptic cleft
What enzyme continuously inactivates Ach
Acetylcholinesterase (Ach-ase)
Adrenergic NT
NE, E (aka adrenaline and noradrenaline)
Adrenergic Neurons
all mostly postganglionic neurons
Adrenergic Receptors
- Binds NE and E
2. Two types of receptors a and b which are further divided in α1, α2, β1, β2, β3.