ANS Flashcards
the maintenance of an optimal internal environment, including body temp and chemical composition of tissues and fluids
Homeostasis
What plays a big role in controlling homeostasis?
controlling blood flow
What receptor types are included in autonomic sensation?
- Mechanoreceptors -Stretch/ Pressure (bladder full, GI tract, BP)
- Nociceptors - Pain
- Thermoreceptors - Temperature (measures external and internal temp, to adjust accordingly)
- Chemoreceptors - Oxygen, pH
Where are chemoreceptors of the ANS located and what do they measure?
- Carotid and aortic bodies for O2
- Medulla for pH levels
- Hypothalamus for glucose and electrolyte levels
What do the nociceptors in the ANS respond to? where are they located?
- Stretch
- Ischemia
- walls of arteries and internal viscera
What do the mechanoreceptors of the ANS respond to? where are they located?
- Pressure - aortic artery, carotid sinus (blood pressure)
2. stretch - bladder, veins
Where are the thermoreceptors of the ANS located? what do they respond to?
- hypothalamus - internal temperature
2. skin - outside temperature
How does ANS information get into the CNS?
- Dorsal roots - travel with the normal nerves
2. Cranial nerve - Taste information (7, 9 and 10) and visceral sensation (9 and 10)
Where are visceral control areas? what do they control?
- Medulla- HR, respiration, blood vessels (vasodilation)
2. Pons - respiratin
Where are visceral modulatory areas? what do they control?
- Hypothalamus - overal control of homeostaces (cardiorespiratory, metabolic, water reabsorption, and digestion)
- Thalamus - relay station that gives the info to the limbic cortex (connection btwn visceral fxns and emotions/ psychological state)
- Limbic system - can produce autonomic responses (anxiety, blushing with embarrassment, crying)
How many neurons are included in the efferent motor system of the PNS?
two;
- CNS (preganglionic)
- PNS (postganglionic)
What is the preganglionic neurotransmitter in the ANS? what is the receptor it binds to?
Acytlcholine; nicotinic receptors
What neurotransmitter do sympathetic postgangliongic neurons that go to sweat glands and some blood vessels produce? what do the receptors bind to?
Acytlcholine; muscarinic receptors
What neurotransmitter do most sympathetic postganglionic neurons produce? what are its target receptors?
NE; Alpha and Beta receptors
What does the adrenal medulla release? What receptors?
primarily Epinephrine
secondarily NE
- alpha and beta receptors
What neurotransmitter parasympathetic postganglionic neurons produce? what are its target receptors?
ACh; Muscarinic receptors
What neurotransmitter somatic neurons produce? what are its target receptors?
ACh; nicotinic receptors
-no pre/post ganglionic neurons in somatic NS
What spinal levels are pregagnlionic neurons located?
T1-L2
What are the targets of the ANS?
- GI tract
- Skin of extremities and face (sweat glands, hair sticking up, oil glands) - Only supplied by sympathetic fxn, no parasympathetic fxn
What does the adrenergic (sympathetic) do to blood vessels? cholinergic?
- vasoconstriction
- cholinergic
What are the functions of the sympathetic NS at the heart, lungs, and GI tract?
- increase HR and contractility (Beta 1)
- Bronchodilation (beta 2)
- Slows down GI tract
What are the ganglia above T1 (in the neck region)?
- Superior cervical ganglion
- Middle cervical ganglion
- Stellate ganglion (inferior cervical ganglion)
- Sympathetic fxns: control heart (BV), lungs, skin in the face (BV, sweating), pupil dilation, 1 muscle that opens the eye, thick saliva
What regulates body temp in the sympathetic nervous system?
- Increase metabolic rate (warms)
- Decreased blood flow to the skin (warms)
- Sweating (cools)
- Erection of hair (warms)
What is another name for Parasympathetic NS? sympathetic?
Cranialsacral (brainstem, S2,S4); thoracolumbar
What is the parasympathetic function for CN III?
(oculomotor)
- Constrict pupil
- Increases convexity of lens – near vision
What is the parasympathetic function for CN VII?
(facial)
- Salivary glands
What is the parasympathetic function for CN IX?
(glossopharyngeal)
- Salivary glands
- Lacrimal glands
What is the parasympathetic function for CN IX?
(vagus; 75% of brainstem autonomic efferents)
- Heart
- Lungs
- Upper GI tract
- Liver
What is the parasympathetic function for S2-S4 nerves?
- bowel and bladder
2. sexual organs
What are the unique functions in the sympathetic system that do not have an opposition by the parasympathetic NS?
- Effectors in limbs, face and body wall
2. Assist in elevation of upper eyelid (other part is skeletal muscle and somatic motor system)
What are the unique functions in the parasympathetic system that do not have an opposition by the sympathetic NS?
Increasing convexity of lens
What happens if the sympathetic innervation is lost to the skin through a peripheral nerve?
- lose ability to vasoconstrict in the skin; skin will be flushed
- inability to sweat
- seen horner’s syndrome
Damage to cervical ganglia (either to or from); loss of pupil constriction on involved side; eye droop on involved side; flushing and loss of sweating on involved side
one cause is a pancoast tumor (lung cancer in top part of the lung) grows medially and damages ganglia
Horner’s Syndrome
What problems are seen in SCIs?
- Bowel and bladder control problems
- BP regulation
- Body temperature
What problems are seen in brain stem injuries?
- visceral control area so:
1. Interfere with control of heart rate, blood pressure, respiration
2. May affect cranial nerve nuclei (many go through this area, damage to vagus nerve and other parasympathetic nerves)
What problems are seen in hypothalamus injuries?
Disrupts homeostasis (metabolic and behavioral dysfunctions)
- Weight
- Temperature regulation
- Emotional displays
